THE BIG QUESTIONS

Mind

Richard M. Restak

SERIES EDITOR

Simon Blackburn

Quercus

55 Baker Street

7th Floor, South Block

London,

W1U 8EW

First published in 2012

Copyright © 2012 Richard M. Restak

The moral right of Richard M. Restak to be identified as the author of this work has been asserted in accordance with the Copyright, Design and Patents Act, 1988.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior permission in writing of the copyright owner and publisher.

The picture credits constitute an extension to this copyright notice.

Every effort has been made to contact copyright holders. However, the publishers will be glad to rectify in future editions any inadvertent omissions brought to their attention.

Quercus Editions Ltd hereby exclude all liability to the extent permitted by law for any errors or omissions in this book and for any loss, damage or expense (whether direct or indirect) suffered by a third party relying on any information contained in this book.

A catalogue record of this book is available from the British Library

eBook ISBN 978 1 78087 567 5

UK and associated territories:

Print ISBN 978 1 78087 035 9

Canada: Print ISBN 978 1 84866 206 3

Design and illustrations in How do Brains Come to Exist? by Patrick Nugent

You can find this and many other great books at:

www.quercusbooks.co.uk

THE BIG QUESTIONS

Mind

Richard M. Restak is a practising neurologist and former president of the American Neuropsychiatric Association.

Author of nearly 20 books, including several New York Times bestsellers, he has received widespread acclaim for his incisive and accessible treatment of this complex topic. He is currently Clinical Professor of Neurology at George Washington Hospital University, and maintains a private practice in in neurology and neuropsychiatry in Washington, DC.

The Big Questions confronts the fundamental problems of science and philosophy that have perplexed enquiring minds throughout history, and provides and explains the answers of our greatest thinkers. This ambitious series is a unique, accessible and concise distillation of humanity’s best ideas.

Series editor Simon Blackburn is Professor of Philosophy at the University of Cambridge, Research Professor of Philosophy at the University of North Carolina and one of the most distinguished philosophers of our day.

Titles in The Big Questions series include:

PHILOSOPHY

PHYSICS

THE UNIVERSE

MATHEMATICS

GOD

EVOLUTION

MIND

ETHICS

Contents

Introduction

CAN WE HAVE A MIND WITHOUT A BODY?

Are we creatures of pure thought?

HOW DO BRAINS COME TO EXIST?

The development of the human brain

CAN WE BUILD A SUPER-BRAIN?

Achieving the highest levels of brain performance

HOW DO WE MAKE SENSE OF SENSATION?

Seeing things as we are

WHAT DOES IT MEAN TO BE CONSCIOUS?

Problems of identity and awareness

WHAT MAKES THE HUMAN BRAIN SPECIAL?

Looking under the hood

CAN BRAINS COMMUNICATE WITHOUT WORDS?

The secrets of body language

WHAT IS THE ‘I’ IN OUR BRAIN?

The quintessential identity problem

IS FREE WILL AN ILLUSION?

Does our brain already know what we’re going to do?

WHAT IS THINKING?

Putting our minds to work

WHAT DOES A BRAIN DO WHEN IT IS DOING NOTHING?

The pleasures and perils of mind wandering

IS IT POSSIBLE TO THINK OF TWO THINGS AT ONCE?

The dangers of multitasking and thought suppression

WHAT IS KNOWLEDGE?

What do we know and how do we know that we know it?

HOW DO WE STEP OUT OF THE HERE AND NOW?

Processing the past and the future

WHERE DO EMPATHY AND ALTRUISM COME FROM?

Seeing ourselves in others

WHAT IS THIS THING CALLED LOVE?

Addiction, pure sex, evolutionary necessity or a beautiful relationship?

WHAT HAPPENS WHEN WE GET ANGRY?

Fury and the frontal lobes

DO DREAMS HAVE MEANING?

Random noise or vital insight into the unconscious?

DOES THE MIND PLAY TRICKS?

Illusion, reality and the mind

ARE MACHINES SCRAMBLING OUR BRAINS?

Thinking in new and different ways

Glossary

INTRODUCTION

The mind – what it is, how it works – has long exerted a fascination, and dedicated thinkers since the early philosophers have wracked their brains over it. In fact, therein lies an enduring Big Question. Is the brain the same as the mind? And following on from that, if we cannot look at our mind or our brain without employing them as instruments of our exploration – do we risk invalidating our investigation? The paradox of ‘self-reference’ hovers over attempts to understand the mind.

There are other ways of formulating this paradox, but at the core of it is a question about identity, a sense of an ‘I’. In the history of thought, the mind has, along with the brain and the soul, formed a triad of ways to understand the essence of a person. Once of vital importance to philosophers, the soul is now largely the province of theology and religion; the brain, by contrast, has entered common parlance comparatively recently, while ‘mind’ endures in both everyday language (‘keep it in mind’, ‘mind your manners’, ‘he’s losing his mind’) and remains suggestive of higher purposes – reflection, intellect, imagination. Philosophers and anatomists – witness Descartes or Leonardo da Vinci – could, if not always accurately, attempt to delineate connections between motor functions, the senses and the brain. On the other hand, there is not much poetry associated with the brain – and a very great deal with the mind.

Today, with the advance of science, the brain edges into the limelight, its status enhanced as new discoveries about its structures and operations emerge. Computer science suggests a metaphor, whereby the brain may be the hardware and the mind its software. Reducing the metaphor to its simplest form produces an equation: mind = all the things a brain does.

While I too have made such claims in several of my earlier books, I’m now less certain of that equivalence. For one thing, the word ‘mind’ can be a collective attitude or Zeitgeist, as in ‘the mind of a nation’. Further insights into this mind-writ-large view have been achieved thanks to technology. The Internet now makes it possible to gather real-time data on the activity patterns and verbal and written expressions of millions of people, confirming that a person may have a different mind to say or do something when part of a group than when in isolation. This is one of the reasons behavioural predictions, about individuals or groups, are so difficult to make. Sometimes collective actions – both positive and negative – may be unimaginable to the individual minds comprising the group. It is difficult to account for this solely in terms of brain activity and neuroscience in its present form.

In addressing Big Questions about the mind, the sense of self-referentiality is never far from the surface. We cannot ask ‘What is thinking?’ without thinking about it. We cannot ponder ‘What is knowledge’ without reflecting on the thought processes that we use in order to acquire much of our knowledge. However, in tackling such questions there is a choice: whether to regard it as primarily a philosophical enquiry, or whether it is a scientific enquiry. My approach is to tend towards the latter. In the 21st century few would argue that memories and emotions, words and ideas, dreams and imagination, perceptions and thoughts, and a sense of self and of the outside world are not activities of the brain. We often recognise this most clearly in their absence, by what we see when there are interferences with the normal workings of the brain. And today we are not simply relying on our own self-referring minds to consider these issues – brain imaging, cognitive studies, precise anatomical studies, chemistry and many other investigative modes are playing a role. To put it another way, while, philosophically, the ‘self-referential’ paradox remains, there are practical ways in which we can step outside of ourselves to help tackle the Big Questions.

In approaching the questions posed in the chapters that follow, I have not aimed at definitive answers; in many instances there are no single answers. I have sometimes taken an author’s privilege of emphasizing answers that I personally favour, but in doing so I don’t expect that my responses will meet with universal agreement. My purpose is to entice the reader to assume an active role in exploring and thinking – to use my responses as a spur to coming up with their own responses to the 20 Big Questions. If I’ve achieved my purpose, readers will be persuaded to assume the role of good jurors who, after examining the evidence, reach their own conclusions, while retaining full awareness that other people might come to different conclusions.

Richard Restak

Washington, DC, USA

Morell, Prince Edward Island, Canada

CAN WE HAVE A MIND WITHOUT A BODY?

Are we creatures of pure thought?

Think back to the last time you had a bad case of flu. Alongside the fever and aching body, you weren’t able to think very clearly, were you? If you tried to read a book or do any work you couldn’t concentrate on it. In such a state, you would be unlikely to believe that the mind can be considered separate from the body – the flu was affecting both your mind and your body.

Neuroscientists speak of ‘embodied cognition’ as a shorthand for the linkage of all aspects of our mental lives to our bodily experiences. The ancients had an inkling of this mind–body dependence. They postulated different personality types based on the prevailing influence of the four physical elements of air, fire, earth and water and their respective qualities of dryness, warmth, cold and moisture. Later theories associated air, fire, earth and water with yellow bile, blood, phlegm and black bile. Diseases were believed to be due to an imbalance of one or more of these four bodily ‘humours’, with humoral theory inspiring one of the earliest methods for personality assessment. We still employ humoral terms in describing people’s personalities. Short-tempered people are ‘choleric’, pessimistic types ‘bilious’, confident individuals ‘sanguine’ and apathetic folk ‘phlegmatic’.

Although personality assessment has come a long way since the Greeks, the path has not been smooth. From the 17th century onwards, Cartesianism (more about that in a moment) held out for the belief that the mind existed apart from the body. (Apparently Descartes never suffered a case of the flu.) However, by the 19th and early 20th centuries psychologists such as William James linked personality and emotions with bodily states. James suggested that emotions arose from a person’s perception of physical changes in the various internal organs: stomach contractions, heart and breathing rates, the dilation and contraction of blood vessels – in other words, those bodily changes mediated by the autonomic nervous system. James went even further and maintained that our mental states were the consequences of these bodily changes: ‘We feel sorry because we cry … not that we cry … because we are sorry.’

Bodily illusions

Recently neuroscientists have elaborated on James’s emphasis on how our bodily states can influence our mind, especially our thoughts and behaviour. They’ve found that people differ from each other a good deal when it comes to their awareness of their bodily states.

Here’s a quick test you can use that will give you some insight into your own bodily awareness. Have a friend take your pulse over the course of one minute. While they’re doing that silently estimate your heart rate. Compare your estimation with the actual measured heart rate. About a quarter of people engaging in this exercise will achieve an accuracy of at least 80 per cent. Another quarter, in contrast, will be off by 50 per cent or more. Intriguingly, those who do well on the test are less susceptible to what neuroscientists refer to as ‘embodiment illusions’.

One such illusion is the face-swap illusion, where a person is stroked on the face while he is looking at a screen showing a face other than his own being stroked in at the same time. The synchronous tactile stimulation of his own face and the face on the monitor increases the likelihood that the person will believe that the image on the screen is his own. This simple experiment of neuroscientist Manos Tsakiris provides evidence that sensory inputs can alter our mental representations of ourselves, such as face recognition, as well as our sense of ownership of our body’s components.

This fluidity in body perception actually influences how we see the world around us. In another experiment from the Karolinska Institute in Stockholm volunteers were tricked into full-body illusions in which they experienced ownership of a small doll’s body or a giant’s body. This change in the size of the experienced body from a small one to a large one resulted in consistent changes in the perception of the world: it appeared larger in the case of the doll illusion, and smaller in the case of the giant illusion.

Body-swap illusions emphasize the significant influence that our bodily sensations exert on what our brains perceive. (See How Do We Make Sense of Sensation?)

Body movement and the mind

In all of the examples described so far, mind, sensation and bodily movement are intertwined. Bodily movement is especially important as a direct expression of the mind. Movement can be immediate and subconsciously generated, such as the automatic movements of my legs as I walked across the room a few moments ago with no specific intention in mind. Or it can be based on will and conscious intention, such as when I decide (as I did a moment later) to contact my travel agent to book a flight.

Automatic bodily movements such as walking across a room are largely under the control of areas beneath the cerebral cortex (the subcortical nuclei and circuits, as neuroscientists refer to them). The cerebral cortex plays little part and this makes sense since we don’t consciously plan or concentrate on the movements of our legs except under special circumstances, for instance, learning to dance.

In contrast, deliberate actions such as calling a travel agent to book a flight require some degree of conscious intention associated with activation of the prefrontal and frontal areas of the cerebral cortex where the intention originates. Once an intention is formulated, it is conveyed to the premotor area of the cerebral cortex, which formulates the motor programme for motion. Finally, the motor programme is conveyed to the motor areas, which communicate with the muscles carrying out the movement.

However, the presence of movement doesn’t necessarily imply a mind. Mechanical devices routinely carry out movements that if done by a person would require acts of mind. Take, for example, sliding automatic doors, which have been around since 1954. Minds aren’t involved beyond the design, construction, installation and maintenance of the door.

More recent and more mind-like since they involve more than just movement are some of the currently available mobile phone apps that can identify such things as landmarks, barcodes, wine labels, textbooks and DVD covers. One app identifies works of art based on a database of more than a million paintings.

The body isn’t completely eliminated, of course. Somebody has to activate, read and interpret the information provided by these apps. Rather than representing a mind operating without a body we have in these examples a weakening of the links between mind and body: a technologically created disembodiment.

Disembodied minds

We encounter the mind existing in the absence of body movement in locked-in syndrome. In this unfortunate state the patient is aware, awake and cognitively intact but cannot move or verbally communicate because of paralysis of all of the voluntary muscles of the body with the exception of the eyes. In the extreme version of this horrifying condition, total locked-in syndrome, the eyes are paralysed too. The condition was vividly described by French journalist Jean-Dominique Bauby, who suffered a stroke in 1995. When he came out of a coma three weeks later he was paralysed, with the exception of his left eyelid, the movement of which he retained the ability to control. Over time he developed a system of communication by blinking this eye and he succeeded in ‘dictating’ a memoir of his experiences, The Diving Bell and the Butterfly, later made into a 2007 film.

Another fictional example of locked-in syndrome is the character Monsieur Noirtier de Villefort in Alexandre Dumas’s novel The Count of Monte Cristo. Dumas describes him as a ‘corpse with living eyes’ who communicates his thoughts via eye movements and facial expressions. Monsieur de Villefort forms sentences by indicating with his eye movements the letters and words that he wants as his grand-daughter recites the alphabet and scans dictionary pages with her finger.

While locked-in syndrome allows for some minimal linkage between mind and body, in other neurologic conditions, such as minimally conscious state (MCS) and coma vigil, the retention of mental powers was, until recently, more controversial since the patient can’t communicate with others. But recent fMRI (functional magnetic resonance imaging) studies and electrical recordings reveal that the brains of such patients can respond appropriately to requests even though no outward movement occurs. For instance, one patient was asked to mentally envision a room in her house. Within seconds the patient’s brain became active in the same areas that would have become active if the request had been made to a person with a perfectly normal brain. But this activation was not accompanied by any bodily movement.

We routinely encounter mind embedded in disembodied forms in computer programs. One of the most intriguing of such programs, DOCTOR, was devised in the mid-1960s by Joseph Weizenbaum of Massachusetts Institute of Technology (MIT). Dubbed ‘Eliza’ after the character in George Bernard Shaw’s Pygmalion, Weizenbaum’s computer program analysed language and responded according to a script. Although these were the early days of computer programming and far more sophisticated programs have since been developed, Eliza remains relevant to any discussion today of whether the mind can exist without a body.

Eliza modelled the role of a psychotherapist practising nondirective therapy. The patient would make a statement and the program would respond in the manner of the then popular therapy guru Carl Rogers.

Patient: ‘My boyfriend made me come here.’

Computer: ‘Your boyfriend made you come here?’

Patient: ‘He says I’m depressed much of the time.’

Computer: ‘I’m sorry to hear that you’re depressed.’

Etc.

Soon after the introduction of Eliza, Weizenbaum began noticing peculiar behaviour on the part of some of the people who interacted with it. Even though they knew the ‘therapist’ was only a computer program, they nevertheless began to develop what Weizenbaum described to me during a discussion as ‘powerful delusionary thinking’. ‘Some people were conversing with computers as if they were a person who could be appropriately addressed in intimate terms,’ Weizenbaum commented.

More than a decade before Eliza, the Bletchley Park code-breaker and computer pioneer Alan Turing had suggested a test for determining whether a machine is capable of intelligent behaviour. To pass the Turing test a machine had to fool those interacting with it into believing they were interacting with another human being. Eliza passed the Turing test in those therapy seekers who earnestly believed in the existence of a real-life Dr Eliza capable of helping them to solve their personal problems.

But as critics have pointed out, the Turing test is not a valid test of whether a machine can think intelligently but assesses instead whether the program responds like a human being. The two processes are quite different. We have only to look around us to see that human behaviour and intelligent behaviour are not always synonymous.

Eliza and other computer programs developed over the past 50 years suggest, with varying degrees of credibility, that mind can exist without a body.

Not always a top-down process

In any discussion of whether a mind can exist separate from a body it’s important to avoid certain assumptions that may not always be correct. For instance, we usually think of the formation of mind as a top-down process: when the nervous system reaches a certain degree of complexity, mind emerges. But in some instances the process can work in the opposite direction: mind emerges from the body’s interaction with its environment. Take the lowly octopus, for example. Although the octopus seems at first sight to be a very simple creature, its behaviour is actually surprisingly rich. An octopus can selectively reach out and grasp food and other objects, clean its body by brushing its skin with its tentacles, hide from predators and construct homes built from collected shells and stones. An octopus even displays sometimes unsettling examples of apparent intelligence. If you stare into a tank containing an octopus the creature is likely to stare back out at you. If you can muster up the nerve to put your arm into the tank, one of the tentacles may reach towards it and ‘shake’ your hand. Such performances would seem worthy of being dubbed ‘intelligent’, except for one powerful objection. An octopus is essentially a mollusc and close cousin to the snail, one of the dumbest creatures on Earth. How then can an octopus exhibit such impressive indications of intelligence?

For one thing, the body of the octopus differs greatly from that of a snail. It possesses eight powerful legs and seemingly all-seeing eyes. The result is an ability to engage in a complex interaction with its environment. While the snail’s reaction to the world around it is passive and unvarying, the octopus explores the world through the senses of touch and sight. In other words – and this is my point – the mind of an octopus emerges not from a central brain but from the action of its tentacles, eyes and body shape. Thus the mind of an octopus is embodied and can be properly understood only by taking its body configuration into account.

Does the mind amount to more than the brain?

A major variant of ‘Can we have a mind without a body?’ is the equally tantalizing question ‘Is the mind more than the brain?’ In our scientific age we take for granted that the brain is the physical basis for the mind. But that wasn’t always so. The New Kingdom Egyptians favoured the heart and treated the brain with indifference. Aristotle also perpetuated this belief in the preeminence of the heart, and yet he did not completely ignore the brain: he suggested that ‘the region of the brain’ played a role in tempering ‘the heat and seething’ of the heart. His teacher, Plato, conferred some recognition of the importance of the brain in his theory of the Triune Soul. He suggested that the soul was divided into three parts: the first located in the head and associated with the intellect; the second in the heart and responsible for pride and courage; and the third in the liver, which played a part in lust, greed and other so-called ‘lower passions’.

But despite our unhesitating espousal of the importance of the brain over the heart in modern times, we still retain in our language some ambivalence about our choice. We speak of experiencing ‘heartbreak’ when our romances sour; ‘It’s raining in my heart’ lamented the rock ‘n’ roll pioneer Buddy Holly in one of his songs; our Valentine’s Day cards continue to depict Cupid with his arrow piercing a heart and not a brain.

On the brain side of things, we speak of trying to come up with a novel solution to a problem by gathering diverse people together for a ‘brainstorming’ session; we describe a brilliant student as a ‘real brain’ who, if he overworks himself, may suffer a ‘nervous breakdown’.

Thus concepts concerning the origin and location of the mind don’t so much replace each other as learn to coexist. This is true of the most basic question of all, the so-called mind–body dilemma: does the mind exist apart from the brain? And where does the soul stand in all of this?

Much of the mind–soul–body confusion can be traced to the 17th-century French philosopher René Descartes. At the basis of Descartes’ philosophical position was the proposition that the mind was qualitatively different from the body. According to Descartes: ‘The body is regarded as a machine, which, having been made by the hand of God is incomparably better arranged and possesses in itself movements which are more admirable than any of those which can be invented by man.’

The body’s responses, however, are not entirely typical of a machine, he added, since they involve communication with a soul. ‘But the movements which are thus excited in the brain by the nerves affect in different ways the soul or mind, which is intimately connected with the brain.’ That passage is notable for two reasons. First, Descartes had already achieved the pivotal insight that the proper conundrum to be solved was not mind–body but more specifically mind–brain. Second, in that passage Descartes conflates soul (a theological concept) and mind. This confusing mixture of theology, philosophy and science continues to this day.

Since Descartes invoked two interacting but distinct processes – mind and brain – he had to come up with some explanation of how these two very different entities interacted. In an early explanatory attempt to do this Descartes wrote of the ‘little gland which exists in the middle of the brain’ (the pineal). The pineal gland functioned as an intermediary, making possible the ‘Incorporeal Soul in the Bodily Machine’.

But the use of the pineal as an intermediary between mind and brain creates a huge explanatory problem, as pointed out in a letter written to Descartes by Princess Elisabeth of Bohemia, one of Descartes’ most highly placed and keenly perceptive students. ‘I beg of you to explain to me how the human soul can determine the movement of the body,’ she asked Descartes. With this question the princess touched upon a flaw in Descartes’ proposal: if the brain can be influenced only in material ways, then how does the immaterial mind interact with it? How does one envision the process whereby something immaterial moves something material?

Descartes’ distinction between mind and brain became known as dualism. Those who espouse dualism are referred to – sometimes sneeringly – as dualists. Sneering aside, I think it’s safe to say that those who believe in a completely incorporeal mind form a distinct minority today. But on occasion this minority includes people with impressive credentials. Sir John Eccles, who won the Nobel Prize in Medicine in 1963 for his neuroscientific research, believed firmly in the separation of mind from brain. I still treasure a letter he wrote to me after the publication of my first book on the brain. In it he referred to me as a ‘promissory materialist’. By that term he meant to imply that I was in agreement with scientists who try to explain the mind in brain terms and, as a result, always promise more than they can deliver. Eccles had a point: neuroscientists are still making claims about the brain that they can’t prove. It is not at all self-evident – as some neuroscientists claim – that we can do away with the concept of a mind altogether and simply speak of the brain. Nonetheless, most thinkers today on the relationship of mind and brain favour the view that much of what we refer to when we speak of the mind results from as yet incompletely understood operations of the brain.

Oxford philosopher Gilbert Ryle’s category mistake offers some assistance here. As Ryle suggested, we should take care not to confuse ourselves by mixing things that can be spoken about together only in a metaphorical sense. Can the chair that I’m now sitting on be related to the theory of evolution? I suppose a novelist or a poet could compose something playful and original linking those two topics, but that creation wouldn’t provide a causal connection. Evolution is one thing, chairs are another. Thinking of mind strictly in terms of brain function seems to involve a similar category mistake.

Mind is not a physical structure like the brain; it is not a ‘thing’. Mind has no visible form, no aroma, no taste; it can’t be held in the hand like the brain. Thoughts, the products of the mind, do not require physicality to exist. Thoughts, however, are meaningless without minds that can think and interpret them.

No final answer

Unfortunately our question ‘Can we have a mind without a body?’ resists our attempts at a summary answer. We know that the brain contains both large and small structures; it is functionally connected through circuits; it is electrical and chemical in function. But where is mind in all of this? And is the brain the exclusive repository of the mind? Or is the mind a more distributed entity encompassing other bodily communication channels such as our endocrine and immunological systems? A sizeable number of experts are espousing the monist position, where the mind is a catch-all term for all of the things the brain does. But at this point we remain far from capable of explaining how it does these things. Will we ever? Certainly we can expect a deepening understanding of mind and brain and whether we can have a mind without a body. But so far we have no overarching, completely satisfactory theory that explains how the brain ‘works’ or the exact relationship of mind to brain. But we shouldn’t be too critical of our explanatory failure: such a correlation won’t be easy to come up with. Philosopher Arthur Schopenhauer referred to this dilemma of explaining the mind–body problem as the ‘world knot’. Perhaps that knot will continue to resist our best attempts at unravelling it.

HOW DO BRAINS COME TO EXIST?

The development of the human brain

Before discussing how brains came to exist, it’s useful to ask a more fundamental question: what is a brain? Like many profound questions, this one seems, at first blush, easy to answer. Actually, it isn’t easy at all.

The first evolutionary step towards a brain occurs in the flatworm where nerve cell bodies are clustered towards the head end. Neuron fibre processes or nerves carry signals from sensory receptors to this primitive brain where integration with muscle movements takes place.

Although it’s a long and complex journey from flatworms to humans, the key element in defining a brain is centralization of the nervous system into the head region. The more complex this arrangement, the greater an animal’s responsiveness to its external and internal environments. In order to stay alive, ancient mammals and birds during the Mesozoic period (250 million to 65 million years ago) evolved brains ten times larger, relative to body weight, than their ancestors. Among the benefits of such large brains were the ability to stay warm by controlling body temperature, the formation of early social networks and the development of parental care, learning and tool use.

Among mammals, not all of the brain structures increased in equal proportion; the same goes for functional use: the brain of each creature is functionally organized to cope best with the world in which it finds itself. The need for increased integration of sensation and movement led to increases in the size of the cerebellum in mammals, the structure at the rear of the brain specializing in balance and coordination. An increase in the number of cells devoted to smell led to the high-resolution olfactory ability that is unique to many animals.

Brain development

All that can be observed at the moment of conception is a single cell resulting from the penetration of the father’s sperm into the mother’s egg. But within that cell, invisible to the naked eye, resides the DNA blueprint that will direct the construction of the entire human body.

The future brain first becomes apparent about four weeks later with the formation of a spoon-shaped structure only one cell thick known as the neural plate. A groove (the neural groove) runs the length of the neural plate, dividing it into right and left halves.

Even at this early stage of development the future brain possesses three defining characteristics. It is polarized (the head is wider and bigger than the remainder of the neural plate); it is bilaterally symmetrical (divided into right and left halves on either side of the neural groove); and it is regionalized (the wide end of the spoon will become the brain while the handle will develop into the spinal cord).

Next, the two sides of the neural plate fuse to form a tube from which emerge three swellings: the forebrain, midbrain and hindbrain. During the next few months in the womb these swellings enlarge, bend and expand to form the major divisions of the adult brain and nervous system: the cerebrum, the thalamus and hypothalamus, the cerebellum and the spinal cord.

When looked at from the side, only three of the brain’s major structures are visible: the cerebral hemispheres, the brain stem immediately below and the cerebellum towards the back of the brain. All other structures are hidden by the hugely expanded cerebral hemispheres, which represent more than 85 per cent of the brain’s weight.

With further development, dramatic changes occur in the cerebral hemispheres. Starting with a smooth billiard-ball appearance at five months’ gestation, the hemispheres eventually look like the matching halves of a gnarled walnut four months later. This transformation occurs in order to cram as many nerve cells as possible into the confined space of the skull. The same principle is involved as when you fold clothes before placing them into a suitcase: folding enables you to contain the large surface area of the clothes within the restricted confines of the suitcase. If the cerebral cortex – the thin outer layer of brain cells of the cerebral hemispheres – remained smoothed out instead of wrinkled, it would be about the size of a newspaper front page and we would have to possess a skull the size of an elephant’s in order to accommodate its surface area.

Such a large surface area is important, as the cerebral cortex contains almost all of the brain’s neurons. However, this rind (cortex means ‘rind’ in Latin) – the consistency of yoghurt – is astoundingly only 2 millimetres thick. It’s thinner than an orange peel, yet the cerebral cortex contains two-thirds of all of the 100 billion neurons in the human brain and almost three-quarters of its 100 trillion neuronal connections.

Because it contains so many of the brain’s neurons and most of its connections, the cerebral cortex is by far the largest component of the human brain. Comprising a single sheet of neurons and their supporting cells, the cerebral cortex is ten times larger in surface area than the cortex of a macaque monkey and 1,000 times larger than that of a rat. Even more important are the differences in the size of the prefrontal cortex of different animals as a percentage of total brain volume. Less than 4 per cent in cats, 7 per cent in dogs, 10 per cent in monkeys, 20–30 per cent in great apes (e.g. chimpanzees) and 30 per cent in humans.

As a result of its size and organizational complexity the cerebral cortex is a much better measurement of intelligence or other cognitive abilities than gross brain size alone. That’s because, in general, overall brain size parallels general body size: bigger animals have bigger brains but are not necessarily more intelligent. Compare elephants to humans, for example. Despite the huge intellectual gap between the two species, an adult human’s brain is actually about a quarter of the size of an adult elephant’s brain. Such observations led early neuroscientists to place less emphasis on measurements of total brain size and concentrate instead on the brain-to-body ratio. Our brains are the largest of all species relative to our body size.

Brain geography

Traditionally, neuroscientists have divided the brain into separate divisions and provided a kind of guidebook for each of the functions performed by each division. While such partitioning is helpful and indeed forms the basis for the medical specialties of neurology and neurosurgery, it’s important to remember that these compartmentalized areas aren’t absolute divisions based on distinctive differences from one lobe to another but are artificial divisions like property lines or national boundaries. In addition, the various lobes don’t exist in isolation but communicate with each other via association fibres. Indeed, almost 90 per cent of communication within the brain is carried out through tracts composed of these association fibres whereby the brain ‘talks’ to itself.

Viewed from the side, each of the overarching cerebral hemispheres resembles an old, wrinkled boxing glove. The front, middle and back of the gloves correspond to the brain’s frontal, parietal (from the Latin for ‘wall’) and occipital (‘back of the head’) lobes, while the thumb of the boxing glove corresponds to the temporal lobe.

The frontal lobes (one on each side) initiate all actions, including speech. The most anterior portions of each frontal lobe, the prefrontal lobes and supplementary motor cortex, integrate personality with emotion and transform thought into action. Picking up a cup of tea involves the prefrontal lobes deciding on the action, the premotor area programming the sequence of muscle movements necessary and the motor areas activating the muscles of the arms and hands required to carry it out.

A view of the human brain as seen from the side. Beneath the cerebral hemispheres are the basal ganglia, the centres crucial to involuntary automatic activity.

Each parietal lobe acts as a receiving station for sensations from the opposite side of the body and is responsible for integrating that information via the brain’s vast networks of association fibres. The temporal lobes are devoted to hearing and merge with the parts of the limbic system (amygdala, hippocampus) that are involved in learning, memory and the experience and expression of emotion.

Finally, the occipital lobe, located farthest back in the brain, processes vision.

Behind the occipital lobe is the cerebellum, a centre involved in movement, balance and coordination. When you watch a ballerina you’re witnessing the cerebellum performing at its highest level. But the cerebellum isn’t just for balance and coordination, it is also involved with the frontal lobes in the preparatory activities that precede movement.

Viewed from the top, the brain resembles a shard of sea coral, split down the middle by an easily discernable division called the longitudinal fissure. This ‘Grand Canyon’ divides the cerebrum into the right and left hemispheres, each with different specializations. At the risk of some oversimplification, the left hemisphere is best at reading, writing and other primarily language-based functions. The right hemisphere, among other things, processes visual and spatial matters, as well as analysing the emotional components of speech (tones of voice, revealing hesitations etc.).

A view of one half of the brain after transecting the brain down the middle into two identical halves. This view reveals deep-lying structures that are hidden in the previous diagram.

Connecting the two cerebral hemispheres is a rope-like structure called the corpus callosum, which carries messages from one side of the brain to the other. Since it isn’t fully functioning until ten years of age, information transfer in a young child’s brain is greatly limited. This first decade of immaturity of the corpus callosum is one of the reasons why few people can recall events that occurred during their infancy and early childhood.

Now let’s animate the above summary of cerebral geography. Suppose while reading this sentence you decide to go to the fridge for a Coke. That intention is formulated in your prefrontal and frontal lobes and then organized by the premotor cortex into an action plan that is then whisked to the cerebellum. The cerebellum then enlists the aid of structures lying deep below the cerebral hemispheres (known collectively as the basal ganglia) to translate the get-a-Coke decision into action. All of these brain areas, working in concert, enable you to get up from your chair and walk to the refrigerator. Note that all of this processing – with the exception of you deciding that you wanted a drink – occurs outside of your awareness. If asked about the process you would be comfortable asserting that you ‘freely’ decided about the soda while everything else was automatic. (In the chapter Is Free Will an Illusion? we’ll explore whether or not your decision to get a Coke was as freely chosen as it seems.)

A chicken-and-egg question

When we talk about how brains came to exist we encounter a chicken-and-egg question. Is our brain organized as a result of thousands of years of talking and adroit hand manipulation, as is often suggested? Or are these abilities the result of our brain’s organization? We know that the brain can be modified by activity: the brain of the concert pianist can be confidently distinguished by imaging and electrical recordings from the brain of the musical ingénue. So it seems to make sense that our brain’s organization both reflects our species’ experience on this planet while it also determines for us the nature of the ‘reality’ that we experience.

Part of our reality is logical and reasonable; another part is emotional, capricious and unpredictable. We feel, as well as cogitate. The limbic system, the mediator of all things emotional, consists of interconnected regions forming an emotional circuit deep within the brain. The first hint of an emotional circuit in the brain was provided in 1715 when a Dutch physician and chemist noticed that patients who had been bitten by a rabid animal began ‘gnashing their teeth and snarling like a dog’. At autopsy the brains of such unfortunate individuals (as well as the rabid animals that had bitten them) showed inflammation of the limbic system caused, it was later learned, by the rabies virus.

Perhaps it strikes you as appropriate that our mental functioning and our brain’s organization should mirror each other: the areas responsible for feeling reside in the deepest, darkest, most central areas, while our rational thoughts and mental processing emanate from our overlying cerebral hemispheres. Thus we ‘ascend’ from the influence of our ‘lower’ more emotional centres located in the limbic system towards the ‘higher’ brain centres in the cerebrum, especially the cerebral cortex. This analogy is consistent with the suggestion first made by the 19th-century neurologist-philosopher John Hughlings Jackson that the cerebral cortex holds in check the more ‘primitive’ impulses, such as sex and aggression, that arise within the limbic system. Sigmund Freud – a neurologist before he was a psychoanalyst – later incorporated this ‘hierarchical’ framework (without any reference to neuroanatomy) into his psychoanalytic theory. The ego and superego corresponded to the cerebral cortex while the impulses originating in the id smoulder in the depths of the limbic system from where they periodically erupt.

While a strict separation of higher-rational from lower-emotional processing appeals to our tendency to dichotomize (good–bad, high–low, liberal–conservative etc.), a moment of self-reflection reveals that our brain doesn’t work that way. Think of the last time you were casually sorting through your post and came upon an envelope from the Inland Revenue or other equivalent government entity devoted to collecting taxes or levying fines. You didn’t treat this letter as just another piece of mail. Instead it’s likely you experienced some form of somatic discomfort somewhere in your body. Perhaps you felt momentarily dizzy or short of breath or vaguely aware of a mild sense of constriction in your chest or abdomen. Those sensations resulted from your cerebral cortex and limbic system working together to identify this particular item of mail as a potential threat (‘Do I owe some tax I have forgotten about?’). In this example, intellectually knowing and emotionally responding are occurring simultaneously not sequentially, at least from the subjective point of view.

The microscopic and molecular brain

So far we’ve described the brain on the level of what can be seen with the naked eye. But the real action takes place on the microscopic and molecular level. When looked at through a microscope, all brain cells (neurons) show a similar structure. If you allow your imagination free rein you might liken their appearance to a tree. Information is carried to the nerve cell by thin, sensitive-looking dendrites arranged like twigs or branches. Information going from the nerve cell travels along a long taproot-like structure called the axon. Thanks to careful observation under powerful microscopes, neuroscientists know that neurons aren’t physically tethered to one another but are separated by a junction, the synapse (a Greek term meaning ‘contact’).

Far exceeding the neurons by a factor of at least 50 to 1 are the glial cells that help to maintain the brain’s structure, speed up the flow of information between neurons and also, as recently discovered, assist neurons in transferring information.

The transfer of information within the brain is both electrical and chemical. First the electrical nerve impulse travels along an axon until it reaches a synapse. It then stimulates the release of chemicals (neurotransmitters) that cross the synapse and upon reaching the other side stimulate electrical activation in an adjoining neuron. Mood and thinking are influenced by the action of these neurotransmitters, as suggested by the beneficial effects on depression exerted by drugs such as Prozac and its successors. Such psychopharmacological effects provide a sobering view of our mental processes. What does it say about our thinking and emotional experiences when they can be affected, perhaps even determined, by manipulations in the concentration and identity of our neurotransmitters and their receptors?

In any consideration of the brain at its cellular level two things are certain. First, the brain’s complexity and uniqueness have little to do with its physical composition alone. The brain consists of the common elements carbon, hydrogen, nitrogen and phosphorus, along with a few trace elements thrown in for good measure. Nothing in this simple blend, which exists in all of nature, provides an explanation for the brain’s power and uniqueness.

Secondly, many of the chemical messengers used by the brain as agents of communication can be found in single-celled organisms that can be traced back more than 850 million years. So it’s safe to say that the earliest living creatures, like ourselves, communicated with each other by a combination of electrical impulses combined with chemical signalling.

Although the exact number of neurotransmitters isn’t known for certain, each neurotransmitter has multiple receptors, which helps to explain the marvellous variety and subtlety of the brain’s responsiveness. Such receptor multiplicity is one of the reasons why a total ‘explanation’ of the brain may prove impossible to achieve. Indeed, it’s unfeasible to make either large-or small-scale predictions about what will happen in the brain beyond very short timeframes. Still more challenging to fathom is the relationship of events occurring in the brain to the subjective world of our inner thoughts and emotions.

Our situation today can be compared to the world contemplated by cartographers in Columbus’s time. That world included territories that were already known about (we know a lot about the macro and molecular functioning of the brain); vast expanses undergoing active exploration (we are learning about the brain at an exponential rate); and, finally, some territories that remained beyond the limits of even the most creative imaginations.

CAN WE BUILD A SUPER-BRAIN?

Achieving the highest levels of brain performance

Developing a super-brain is a real possibility because brains have plasticity: the capacity to change in response to experience. Without plasticity, the brain would be similar to a computer or machine – a comparison sometimes simplistically drawn – and would lack the power of adaptability.

Plasticity is most obvious in infancy. As the brain grows in size and complexity during the first few months of life, its cells interact with the environment and with one another to form networks of connections. Additional experience unites these connections into circuits.

Deprive the infant brain of light, sound and human contact and it will remain stunted. And the importance of plasticity doesn’t stop at infancy and childhood but extends into adulthood and old age. Think of the brain as a lifelong work-in-progress with plasticity as the underlying dynamic. The brain’s transformation in response to life experience can take place over timeframes varying from decades to days, hours and even seconds. Your brain today is different from your brain yesterday because of the effect on your brain of yesterday’s and today’s experiences.

Thanks to its plasticity, the brain’s performance can always be improved through environmental enrichment. We know this as a result of experiments on animals. If you provide laboratory animals such as mice with toys and other intellectual challenges and with treats, the animals perform better on tests of animal intelligence (negotiating mazes, for instance). The same principle holds for us. If we work at the goal of making our world more interesting and novel our brain functions more effectively: we become smarter, more successful at meeting mental challenges and – as a bonus for other people – more fun to be around.

We create new patterns of brain cell organization according to what we see, what we do, what we imagine and – most important of all – what we learn. Whenever we take in new information we establish new circuits and link with established circuits within the brain’s millions of nerve cells. The brains of laboratory animals provided with more novel and challenging cage environments contain 25 per cent more synaptic connections per neuron than isolated animals. Environmental enrichment leads, in turn, to enhanced brain development and performance. ‘Change the experience and you change the brain’ is the mantra.

The brain-enhancing effects of language

Building a super-brain should start early in life. Thanks to innovations in brain-imaging techniques, researchers can observe blood flow patterns in the brain of a baby as it sits comfortably on its mother’s lap. Using these techniques, researchers have discovered answers to important questions: what brain areas and systems help babies perceive the tiny phonetic units that make up the words and sentences in their native language? Does anything different happen in the brains of infants and young children who are exposed to two languages from their earliest years?

As background, it’s important to note that at birth infants from anywhere in the world learn to speak at roughly the same pace, regardless of the language spoken around them. This isn’t unexpected since in all spoken languages meaning is conveyed by means of phonemes that correspond to the letters in most written languages. Phonemes are few in number with no more than about 200 different distinct sounds across all of the world’s languages. Only about 38 of these phonemes are used in English.

Infants are born with an innate capacity for discerning phonetic contrast differences among languages the infant has never heard before and may never hear again. In fact, this capacity extends to all of the sounds used in all of the world’s languages. This amazing innate capacity disappears by 10–12 months. At that point the infant’s sensitivity to phonetic distinctions applies only to the language or languages it hears.

Adults, in contrast to infants less than a year old, experience difficulty in perceiving differences between sounds in a foreign language. This is true even among adults who become quite proficient after learning a second language. For instance, a native English speaker when learning Spanish as an adult often finds it hard to distinguish between b and p when hearing spoken Spanish. Adult native speakers of Japanese find it hard to discriminate between r and l in spoken English, requiring contextual clues to decide between word pairs such as rake and lake.

But such difficulty doesn’t arise in infants exposed from birth to two languages. Bilingual babies when compared to monolingual babies show unique patterns of brain activation coupled with a greater sensitivity to the phonetic units of speech in both languages. Two brain sites are especially important. The first, the superior temporal gyrus (STG), is associated with processing the phonemic distinctions between words (‘ba’ versus ‘pa’). The second, the left inferior frontal gyrus (LIFG), is associated with word meaning and syntax. While the brains of babies speaking only one language showed decreases in activity in the STG when the infant heard a non-native language, this didn’t occur in the brains of bilingual babies, suggesting that these bilingual babies have a linguistic processing advantage. The researcher suggests that early exposure to more than one language extends the 10- to 12-month window where the infant has the ability to process the phonetic range of the world’s languages.

Learning new languages enhances brain function not just in infants and young children but over the entire lifespan. But for those not drawn to learning new languages, there is no need for despair. Learning new words in one’s own language strengthens several brain functions: the language centres located principally in the left hemisphere, and the prefrontal lobes that work on the words and maintain them in working memory (more about that critical function in a moment).

Working components of a super-brain

Components comprising what psychologists refer to as cognition are important in forming a super-brain.

Cognition refers to the higher order processing that the brain carries out in order to attend, identify and act. More informally cognition refers to our thoughts, decisions and behaviours along with their accompanying moods. Included here are alertness, concentration, perceptual speed, learning, memory, problem-solving, creativity and mental endurance. By working on the following cognitive processes we can inch closer to the achievement of a super-brain.

Attention: Think of attention in the mental sphere as the equivalent of endurance or stamina in the physical sphere. Just as an athlete cannot prevail in a sport without stamina, anyone seeking to develop an optimally functioning brain cannot prevail without attention. This can be improved by exercises such as the following:

Make up a series of 3x5 index cards, each with either the word ‘red’ or the word ‘green’ written on it. On some of the cards make the ink and the word the same colour (the word ‘green’ written in green ink) while on others mismatch the word and ink colour (‘green’ written in red ink or ‘red’ written in green ink). After shuffling the cards, go through them one at a time and respond to each card in the following ways: if the word ‘red’ or ‘green’ is written in green ink, read the word aloud and tap the table twice. Remain silent and do not tap in response to any word written in red ink. This exercise shouldn’t prove too difficult since you’ve been doing something similar all your adult life: proceeding at traffic lights in response to a green light and stopping in response to a red light. Now redo the attention experiment with this change in the rules: tap and read the word aloud when you encounter red ink but make no tap and say nothing in response to green ink. Proceed as quickly as you can.

As you will discover, this simple exercise is difficult to perform without committing errors. You must remain fully attentive since the required inhibition of your responsiveness changes and is both verbal (speaking in response to only one colour) and motor (acting in response to only one colour). You must overcome the powerful tendency to respond to the written word, when the colour of the ink in which the word is written demands that you make no verbal or tapping response. This difficulty stems, of course, from our lifetime experience of attending to words while largely ignoring the colours the words are printed in.

With this as a preliminary exercise hone your power of attention further by forcing yourself to attend to what is happening around you. Everyday activities, such as shopping, enjoying sport or culture, present readily available opportunities to strengthen attention. What clothes and jewellery are the people around you wearing? What conversational topics do they introduce and in what order? Think of attention as a conduit for sharpening other cognitive skills, especially memory.

Memory: This is a natural extension of attention. If you pay attention to something you increase your chances of remembering it. We can learn from past experiences, but only those experiences that we can remember. Memory is also the repository of who we are – forgetting constitutes a kind of identity disorder. Conversely, the more things we can remember – up to a point – the richer our personality becomes. On the physical side, each time we learn something new, that new knowledge increases the number and complexity of the brain’s neuronal circuits. Unfortunately, contemporary cultural forces aren’t helpful in building a super power memory. Why bother to remember something when you can instantly retrieve the information by a Google search, or quickly bring it up on the screen of a mobile phone? As a result, all of us are threatened with a form of memory atrophy. Fortunately, this can be reversed. The exercise of our memory, just like physical exercise, depends on our personal efforts.

Begin with something simple such as memorizing a string of digits, starting with a list of four digits and working up to lists of nine or ten digits. Write down the lists of digits composed at random and then put the lists away. Later, read each string of digits, look away and then recite the sequence aloud. Despite the seeming simplicity of this exercise, memorizing strings of numbers increases the efficiency of the earliest stages of information processing. This is important because the quality of learning depends on how efficiently you process information during the first stages. In addition, digit span has been found to be correlated to reading proficiency, attention, concentration, sequencing, number facility and auditory and visual memory.

Techniques for developing a super power memory

Entire books have been devoted to methods for developing a super power memory. They all emphasize five rules:

Pay attention to what you’re trying to memorize. Without paying attention you can’t encode. Think of the last time that you forgot someone’s name seconds after an introduction. That happened because you were thinking of something else; your attention was elsewhere.

Employ multiple sensory faculties Silently recite the information, write it down, read it aloud and, if it’s short enough, use your forefinger to form the words on your palm. That sequence funnels the information to the brain through multiple sensory channels.

Encode the information into pictures The brain works primarily with pictures. Quickly think of a friend. Hold that thought in mind. Now, you’re seeing a mental picture of your friend, not your friend’s name spelled out on a kind of mental screen, right? Even highly abstract information such as mathematical equations is envisioned in pictures.

Create your own memory system based on the details of your life experiences This is the basis for establishing a super power general memory according to experts in mnemonics (the art of memory). I’ve memorized 12 locations near my home and can see them clearly in my mind. When I want to remember up to 12 items of information I mentally place them one at a time in front of the memorized locations. I then take a mental stroll and observe the 12 items sitting in front of each of the 12 locations.

Review the information you want to remember The older we are the more information we’ve accumulated over our lifetime. This is responsible for what psychologists refer to as ‘proactive interference’: past memories inhibit our ability to retain new memories. The longer we live, the more items there are in our memory that interfere with the establishment of new memories. The old saying ‘You can’t teach an old dog new tricks’ refers to this phenomenon. The best way to overcome proactive interference is by repetitively reviewing the new information you want to remember. After many repetitions the new information will replace the old in the same way that a new telephone number will eventually replace a number that you’ve used for many years.

Working memory: the key to increased intelligence

The most important type of memory to enhance is working memory. Briefly, this frontal lobe-based memory involves maintaining information ‘online’ for later retrieval while turning your attention to something else. You were using working memory when you engaged in the 3x5 card exercise described above. While turning over the cards you had to keep ‘in mind’ the rules for when to speak and tap on the table. Deficiencies in working memory underlie the easy distractibility and poor academic performance of children (and adults!) with attention deficit hyperactivity disorder (ADHD). Understanding a complex argument also challenges working memory: you can’t decide on the validity of the conclusion if you can’t keep in mind the assumptions allegedly supporting the conclusion. As working memory improves, brain activation in the frontal lobes decreases – an indication that with practice your brain doesn’t have to work as hard. Most importantly, working memory is considered an essential component of general intelligence and reasoning. The greater the working memory capacity, the higher the IQ. People who can hold the greatest number of items in mind are best equipped to consider multiple aspects of a problem simultaneously.

Here is an exercise for enhancing working memory. Shuffle a deck of cards and place it face down on the table. Decide on two cards – say ace and queen – to be the trigger cards. Now turn the cards over one at a time, look at each one and place it face down again on a discard pile. Whenever you turn over an ace or a queen, name the card you turned over two turns previously. To do that, you have to maintain a running account of the cards in your mind as you turn them over. As each new card is turned over the identity of the card two turns ago changes. After you become skilled at this, try holding in working memory the card you turned over three turns ago. Exercises like this improve working memory along with attention and concentration. Since these are the principal functions that deteriorate with ageing, these kinds of exercises provide as an added benefit a means of retaining high-level brain functionality in the later years.

The importance of memory testing

Another way of supercharging the brain is to test and retest yourself on how well you remember new information. Traditionally teachers have emphasized the importance of study in order for a student to learn and remember new information. The more the student studied the greater the grasp of the information – or so it was believed. Learning and testing were considered separate processes that had little to do with each other. Testing was thought to contribute nothing to the learning process itself. As a result, most teachers assumed nothing was to be gained by retesting students on the same material at a later time. But when this assumption was put to a test of its own, the results turned up a surprise: repetitive testing leads to greater learning than repetitive studying.

Here is an example used by the researchers to prove that enhanced learning is produced by retesting. Imagine yourself having to learn the Swahili equivalent of 40 English words (e.g. mashua for ‘boat’). Assuming you don’t speak or read Swahili, it’s likely you will have to study the words repetitively. But after a certain point, according to the experiment, additional studying of the words will prove less effective in improving your long-term recall than repeatedly testing yourself. The testing forces you to reconstruct the information actively – a process that itself enhances learning. Each time we are tested or, more commonly during adulthood, test ourselves, we strengthen our memory for the information. So you can increase your memory for newly learned material by repeatedly challenging yourself to summarize it. Each time you do this you further solidify your grasp of the material you’ve learned.

Retrieval is not a neutral process but a dynamically effective one. It leads to what Canadian neuroscientist Donald Hebb referred to as ‘cell assemblies’: networks of neurons working together. Each time you activate one cell in a cell assembly, you make it easier and more likely for more cells in the assembly to fire up. Each time a memory is retrieved the networks are strengthened.

A second principle is also at work when you activate the cell assemblies responsible for what you have learned. Your newly learned information doesn’t exist in your brain like a read-only file on a computer. Instead, your memory for the new material is dynamic. Biochemical research shows that each time we remember something our brain synthesizes additional proteins. In other words, our brain creates a newly reconsolidated version of what we’ve recalled. Repeated review of memorized material leads to multiple memory traces that aid in subsequent recall – hence the value of repeatedly testing oneself by bringing information to mind on repeated occasions rather than just once. Innovative teachers are now assimilating this principle into their teaching methods: material from earlier tests is tested again on the final exam.

A final way of building a super-brain is to harness it to electronic aids. Although, if taken too far, this approach can lead to forms of cognitive atrophy (see Are Machines Scrambling Our Brains?), technology can provide ways of augmenting important aspects of brain performance. We can learn to play better chess by engaging with any of several commercially available chess instruction programs; we can improve our athletic prowess by running videos of our performance through smartphone applications; we can use voice recorders as practice aids in testing and retesting our memory.

Achieving a super-brain is not that hard

Building a super-brain depends for the most part on our willingness to invest the time and effort in exercises such as those mentioned above to improve brain performance. Surprisingly, the amount of effort required is modest. According to a study by America’s National Institutes of Health, brain power can be increased by mental exercises aimed at boosting three functions: reasoning skills, memory and rapid mental processing. Ten exercise sessions each lasting 60–75 minutes were all that were needed to attain remarkable improvements: memory improved by 75 per cent, reasoning improved by 40 per cent and speed of response was 300 per cent faster.

All of the above suggestions for building a super-brain assume the effectiveness of effort and practice. Until recently this was an article of faith rather than a provable hypothesis. But thanks to the work of research psychologist K. Anders Ericsson, we now know that deliberate practice enhances brain performance. By deliberate practice Ericsson means practising with full awareness (concentrating intently) with the aim of avoiding automated habitual performances. Ericsson’s studies of musicians, chess players and memory virtuosos showed that super performance was correlated with the number of practice hours per day. In practical terms, Ericsson’s research confirms that plasticity, when combined with deliberate practice, can lead to the development of a super-brain.

So, if you want to develop a super-brain, work on enhancing your powers of attention, observation, general memory and working memory. Practise and retest yourself frequently. Finally, as Ericsson points out, deliberate practice when continued long enough and intensely enough leads to the achievement of the highest levels of brain performance.

HOW DO WE MAKE SENSE OF SENSATION?

Seeing things as we are

Although sensation is usually considered a lesser form of mental processing than thinking and feeling or experiencing emotion, it actually comes first. Indeed, sensation provides the raw material from which emerges all of our thoughts and feelings.

The actress Ellen Burstyn described the relationship between sensation and emotion in a conversation with the journalist Jonathan Kott. She spoke of preparing for a scene where she had to express grief: ‘If I approach it directly, trying to remember some time when I felt grief, the emotion usually retreats.’ However, if Burstyn approaches the earlier episode of grief through the senses, she finds that the emotions emerge. ‘I picture the clothes I was wearing then and see if I can feel the clothes on my body with my fingertips.’ She then tries to remember the room she was in, the locations of the windows, the direction from which light was striking her face, even the smells in the room. ‘I go through all of the senses – everything I saw, everything I heard.’ In this way, memory and emotions emerge from sensations. ‘As I create all of those sense memories the emotional memory will follow. It’s a question of creating all of the memories of the senses first, and then the emotional memory comes out of that.’

Although Burstyn speaks here of using the senses to re-establish contact with an earlier self-experience, it’s just a simple additional step to using one’s senses to feel the experience of another person. ‘Compassion is your ability to put yourself in another person’s position, and to feel what they feel.’ Although Burstyn speaks of ‘compassion’ in this conversation, her remarks apply equally and more precisely to empathy: putting yourself ‘in the shoes’ of the other person and thereby experiencing their sensations. As she points out, it’s the experience of one’s sensations that lends piquancy to empathetic experience.

Sensation and perception

Although seemingly quite similar, sensation and perception differ in subtle ways. Sensation is concerned with the detection of information by the sense organs. Perception deals with our interpretation of that sensory information. As we look up on a clear evening and stare at the stars, our eyes are sensing light waves from constellations originating in the distant past. But we interpret and describe that sensory experience in the form of a perception: ‘looking at the stars’. While our sensation is current, our perception of the physical objects allows us to understand that they are many light years away.

In addition, sensations provide unique perceptions that are determined by our interests and experiences: the oenophile (wine lover) and the professional musician perceive ‘notes’ and complexities in taste and sound sensations that escape the teetotaller and the musically naïve.

Admittedly, sensation and perception aren’t always easily distinguishable but can be blended in ways that render strict demarcation sometimes impossible. If you see a simple patch of red light your sensation of red will coexist with the perception of red based on all of the other reds you have ever encountered. And sensations can lead to different perceptions based on personal expectations and needs. When we hear the blast of a car horn outside the window of our study, that sensation cannot be disentangled from the annoyance it arouses in us. We’re not just sensing the sound of a car horn but perceiving that sound sensation as a violation of our desire for quiet and tranquillity within the confines of our private space.

When our senses fool us

Since we learn about the world on the basis of our sensations, it should come as no surprise that when our senses are manipulated we experience things that don’t exist, reach conclusions that are factually untrue and experience feelings that aren’t warranted. (See Does the Mind Play Tricks?) The same sensations that tell us about the world are also capable of deceiving us.

Essentially, all sensory illusions are based on our inherent need to find an explanation for the information delivered to us by our senses. When we are wrong about a perception, it’s usually not the sensory information that is at fault but the interpretation we put upon our perception. A mirage, for instance, involves correct sensory information (sunlight reflecting on sand far off in the distance) subjected to incorrect perceptions (the shimmering of the light on the sand evokes the false perception of a distant lake) leading to false conclusions (if I make it to the lake I’ll be able to drink).

Descartes had an interesting take on this point. When our senses appear to have deceived us the fault often lies with false inferences based on our misinterpretation of the information provided by our senses:

If a man suffering from jaundice persuades himself that the things he sees are yellow, this thought of his will be composite, consisting partly of what his imagination presents to him, and partly of what he assumes on his own account, namely, that the colour looks yellow, not owing to the defect in his eyes but because the things he sees really are yellow … We can go wrong only when the things we believe are in some ways compounded by ourselves.

In other words, the traditional aphorism that ‘seeing is believing’ must be countered by its opposite ‘believing is seeing’.

William James went a step further and held that our sensations form the bedrock of our conceptual systems. In Principles of Psychology he likens a blind man’s conception of the blueness of the sky with a person trying to conceive of a toothache when he has never personally experienced one.

A blind man may know all about the sky’s blueness, and I may know all about your toothache, conceptually … But so long as he has not felt the blueness, nor I the toothache, our knowledge, wide as it is of these realities, will be hollow and inadequate. Somebody must feel the blueness, somebody must have toothaches, to make human knowledge of these matters real. Conceptual systems which neither began nor left off in sensations would be like bridges without piers. Systems about fact must plunge themselves into sensation as bridges plunge their piers into the rock. Sensations are … the stable rock of thought.

At another point James rules out the possibility that imagination can provide a simulacrum of sensation: ‘No mental copy can arise in the mind, of any kind of sensation, which has never been directly excited from without.’ Although in these passages James did not use the word ‘qualia’ (it was not introduced until 1929 by Clarence Irving Lewis in Mind and the World Order), he was referring to what philosophers call qualia: the ‘raw feel’ of subjective conscious experiences.

Since descriptions of sensation can go only so far in communicating the ‘what it is like’ character of sensory experiences, sensations are inherently alienating. You can never know what it’s like to be me (or vice versa), not so much because of the differences in how each of us thinks (that comes later) but, rather, because of the differences in our sensations. These differences often originate at the primary sensory organ: one person is near-sighted while another has perfect vision; one is endowed with perfect pitch (a future professional musician) while another is tone deaf (fated to mature into an infrequent, frustrated and dissatisfied concert attendee).

Senses and well-being

Our senses are also influenced by physical health – perhaps even our digestion, as suggested by Scrooge in Charles Dickens’s A Christmas Carol. When Scrooge encounters the ghost of his former partner Jacob Marley he has this to say:

‘You don’t believe in me,’ observed the ghost.

‘I don’t,’ said Scrooge.

‘What evidence would you have of my reality beyond that of your senses?’

‘I don’t know,’ said Scrooge.

‘Why do you doubt your senses?’

‘Because,’ said Scrooge, ‘a little thing affects them. A slight disorder of the stomach makes them cheats. You may be an undigested bit of beef, a blot of mustard, a crumb of cheese, a fragment of an underdone potato. There’s more of gravy than of the grave about you, whatever you are!’

Scrooge’s refusal to accept the evidence provided by his own senses was based on a belief, common at the time, that the health of the body was a prime determiner of a person’s mental life. Thus indigestion or the malfunctioning of some other inward bodily process could exert a strong influence on what one saw or heard (even to the extent of seeing a ghost). We still believe today, in an attenuated form, that our senses play a role in determining our observations and beliefs. If we’re on a diet our hunger causes us to notice what everyone else is eating, especially those highly caloric food items we’d love to be consuming ourselves. If we engage in too much of this kind of observation we become grumpy and irritable – all because we realize we can’t have that tempting morsel. At any given time, our physical state influences our mental attitude, which, in turn, helps to determine what our senses take in. This is expressed in the Talmudic saying: ‘We don’t see things as they are, we see things as we are.’

Sensation helps mould personality

Sensation also plays a role in fashioning our personality – both for good and bad. Heightened visual acuity makes possible a deepened attentiveness to the level of detail required for the creation or appreciation of works of art; hypersensitivity to sound breeds crankiness when exposed to noisy environments. Sensation also influences career choices. A medical student endowed with enhanced manual sensitivity and dexterity is more inclined than his more klutzy classmates to select a surgical rather than a medical speciality. Sensory failures also mould personality – usually to its detriment. Elderly people with late-onset hearing loss often turn slightly paranoid in response to their hearing failure and interpret nearby conversations that they can’t hear as being critical of them.

Whatever a person’s age or auditory acuity, the brain incorporates sensations into networks of meaning. When hearing acuity decreases below a critical threshold, the consequences involve more than simple acoustic impairment. Meaning too is affected – witness the mild paranoia mentioned a moment ago. Our senses don’t simply function as conduits conveying information to the brain but form part of a family of networks. Thus meaning is expressed at multiple levels of function. If somebody shouts ‘Fire’ in a theatre, you don’t simply hear an acoustic signal or an isolated word. You immediately become engaged in the totality of the situation: the fear and panic that engulfs you as you rush to the exit. Our senses don’t just provide information to our brain; they help fashion its responses.

For instance, when we look at a scene the process is very different from what happens with a camera. A camera looks through one lens while most of us most of the time look through two eyes and two lenses. As British artist David Hockney describes it, we are not simply looking at a scene from outside: we are always in it. We are biological sensing devices engaging with a stunningly complex four-dimensional world (where time is the fourth dimension). But, as mentioned earlier, the processing of sensory channels differs greatly from one person to another thanks to variations in acuity of vision, hearing and other primary sensory receptors. As a result we have no way of guaranteeing that the colour red as we see it looks exactly the same to anyone else. This partially explains why colour arrangements that are perfectly acceptable for one person are judged too ‘loud’ or otherwise discordant to somebody else. In addition to innate differences in sensory acuity, the sensory information that we gather also depends heavily on our interests, especially in regard to vision. As Hockney pointed out ‘The eye is attached to the mind.’ An artist such as Hockney sees a world that remains invisible to the majority of us who are not artists. A similar distinction can be found in experts in other realms.

The unity of the senses

Our language contains phrases in which the contributions of the separate senses are conflated. ‘I see what you are saying’; ‘He wore a loud tie’; ‘She was tone deaf to her husband’s pleading looks.’ This substitution of one sensation for another is most pronounced in synaesthesia: a condition where one sensation involuntarily conjures up another. The autistic savant Daniel Tammet envisions numbers as shapes, colours, textures and motions. ‘The number one is a brilliant and bright white, like someone shining a flashlight into my eyes. Five is a clap of thunder or the sound of waves crashing against the rocks. Thirty-seven is lumpy like porridge, while eighty-nine reminds me of falling snow.’ Thanks to his synaesthesia, Tammet became famous for memorizing and reciting the number pi to 22,514 digits. He accomplished this world-record-setting feat (at that time) after only three months of practice. But synaesthesia may be more than a rare and inexplicable phenomenon. It’s speculated that infants are natural synaesthetics who lose this remarkable power as they grow older and acquire language.

In recent years neuroscientists such as Alvaro Pascual-Leone have taken the observations of synaesthetics further and demonstrated that the senses in all of us are not as strictly demarcated from each other as was traditionally believed. In one of his experiments, normally sighted individuals were blindfolded for up to five days. This was sufficient to induce the primary visual cortex of his subjects to begin processing sound and touch. The speed of these changes has persuaded Pascual-Leone ‘that it is highly improbable that new cortical connections are established. Therefore these somatosensory [touch] and auditory connections to the occipital cortex must already be present and are presumably “unmasked” under these experimental conditions.’ He goes on to suggest that any given cortical brain region ‘inherently possesses the computational machinery necessary for the processing of information from multiple senses’. Contrast this view with the traditional belief of the separation of the senses.

Traditionally sensation has been thought to involve different sense organs specialized for different sensations (sight, sound, touch etc.). But according to these new findings of Pascual-Leone, one sense organ can substitute for another. Furthermore, the absence of one sensory channel can stimulate the function of another beyond its usual capability. First hints of this emerged from studies of blind people. Children with early-onset or congenital blindness outperform sighted children in labelling odours, identifying syllables and discriminating pitch. Their enhanced auditory capabilities make them more skilled at discriminating the emotions underlying spoken communications. I personally experienced this highly attuned auditory sensitivity to emotions several years ago when I was treating a blind woman with multiple sclerosis. She was able to detect with uncanny accuracy any inadvertent (and, I thought, reasonably well-concealed) expressions on my part of inattention, impatience or fatigue. When I complimented her on the acuity of her responses, she told me she could intuit my emotions both by the sound of my voice and by my breathing pattern. ‘Ever so slightly you tend to take an in-breath whenever you want to interrupt me or hurry me on with my narrative,’ she said. Even though I tried harder after that to control my responses, she inevitably picked up on subtle auditory clues.

Blind people are also better at making fine tactile distinctions, not only at the tips of their fingers and at the tip of their tongues. Most striking is their superior ability to learn music from their earliest years. Piano-tuning was at one time a common profession among blind people, a career choice based on their heightened musical sensitivity. Absolute pitch is another example of their musical enhancement. (Absolute pitch is defined as a person’s ability to identify or produce the pitch of an isolated note on the Western musical scale without the benefit of an external reference sound.) While absolute pitch is extraordinarily rare among the musically inexperienced, and identified in only a small number of trained musicians, it is not at all uncommon among blind musicians. In one study 57 per cent of blind musicians were found to have absolute pitch compared to only 18 per cent of sighted musicians. Moreover, blind musicians showed a distinctive variability in the structure of the planum temporal, a portion of the temporal lobe involved in the processing of music.

Enhancements of one sensation at the expense of another can also be found in deaf people. When compared to a person with normal hearing, a deaf person is better at lip-reading, detecting emotional facial expressions and distinguishing one face from another on the basis of subtle clues.

Taken together, these findings suggest that the loss of the sensation of sight or sound influences the development of one or more of the other senses.

The unity provided by our senses depends upon a vast number of connections and interconnections within our brain. These, in turn, are influenced throughout our lives by our experiences. So, when we use phrases such as ‘the lowly senses’ or ‘a mere sensation’ we underestimate the importance of sensation and our dependence on it to make ‘sense’ of our lives.

WHAT DOES IT MEAN TO BE CONSCIOUS?

Problems of identity and awareness

At this moment, while writing this sentence, I’m fully conscious of my purpose. Indeed, each of the sentences in this essay would be impossible if I didn’t remain conscious of my intention while writing them. Yet I’m not aware what precise form the sentences will take – that comes when I see them displayed on the screen. Thus my writing of this essay is a mix of the conscious and the unconscious.

I’m referring here to the cognitive unconscious (thinking, remembering and other mental activities) rather than the unconscious of sex and aggression much written about by Freud. Rather than a rarity, the vast majority of our actions are grounded within this cognitive unconscious.

The movement of my fingers on the keyboard as I write these words is accompanied by activity in the prefrontal, motor and premotor areas of my brain – as can be revealed by imaging devices that measure chemical and electrical changes occurring within the brain during the act of writing. But such a correlation leaves unresolved several important issues.

Somewhere between the scanned images of my brain and my conscious typing of these specific words we encounter what’s been called ‘an explanatory gap’. While it’s true that the intact functioning of certain areas of the brain is a necessary prerequisite for consciousness, none of this provides a sufficient explanation for how consciousness arises. Our best estimation holds that consciousness involves many brain areas formed into anatomical or functional circuits (perhaps waves of brain activity travelling in rhythmic patterns over vast stretches of the brain). But so far, the number and precise identity of the components of these circuits remains unknown. In practical terms, this means we cannot bridge the gap between what appears on an imaging device and my conscious intention as I compose each sentence. The contents of my consciousness remain accessible to me alone.

A black cat in a dark room

After almost 300 years of tinkering with the brain we still haven’t come up with a satisfactory explanation for consciousness. Nor can we satisfactorily define consciousness. It isn’t divisible into component parts and must be experienced rather than analysed. And since we can experience consciousness in ourselves, we readily accept on faith that others are conscious as well. But it’s impossible to confirm that belief because we can’t enter directly into other people’s consciousnesses. We encounter what the Austrian philosopher Ludwig Wittgenstein referred to as ‘the beetle in the box’ that only we can see. A philosopher once compared the difficulty of defining consciousness to the challenge faced by a blind man stumbling around in a dark room looking for a black cat that may not be there.

In any discussion of consciousness it’s important to distinguish consciousness from simple awareness. If I sit in a darkening cinema I’ll gradually become aware of the dimming of the house lights several seconds before I’m fully conscious of the fact that the movie is about to start. Such awareness will vary from one person to another depending on his or her activities at the time: engaging in an animated conversation with a movie companion (delayed awareness) or sitting alone (early awareness).

If we get too careless in our use of the words ‘conscious’ and ‘aware’ we may end up talking nonsense, for example, attributing awareness or even consciousness to automated doors and supermarket scanners. The 19th-century biologist C. Lloyd Morgan had something like this error in mind when he suggested that we should always look for simple mechanical explanations before attributing awareness – and certainly consciousness – to describe seemingly complex behaviours.

In the cinema example awareness merged seamlessly into consciousness. As a more immediate example of this continuum, how conscious are you of the tactile experience of your back pressing against the chair you’re sitting on right now? How conscious are you of your hands holding this book (or its e-book counterpart)? You’re conscious of your back and your hands now that I’ve called your attention to them, aren’t you? But were you conscious of them a moment earlier? Most likely you had absolutely no consciousness of your back or your hands until I directed your attention to them. In a very real sense I played a role in creating your conscious experience.

A limited-capacity system

Consciousness at any age is intimately linked with language. We cannot talk of our earliest experiences of consciousness because they occurred prior to our learning a language, sufficiently complex to describe these experiences. That is the reason we don’t remember our preverbal years. Lacking a descriptive vocabulary we aren’t able to fashion a narrative of our experiences and therefore can’t remember them. The problem isn’t memory per se but the absence of language, which in our own case acts as a scaffolding for consciousness. The absence of language in animals casts considerable doubt on whether our cat or dog is conscious. While Fido may act in a myriad of ways that indicate his awareness that mealtime may be approaching, we risk anthropomorphizing our pet’s experience if we assume Fido is conscious of dinner in the same way that we are. We can anticipate with gleeful gusto the prospect of a juicy and succulent steak washed down with our favourite Merlot. But I think we can safely assume no such culinary preoccupations on the part of Fido as he pads in the direction of the dining room.

Nor is a fully satisfactory definition of consciousness possible without reference to attention and short-term memory. Suppose I ask you ‘What college did you attend?’ Presumably you weren’t thinking of your alma mater until I asked you about it. But does this mean that you were ‘unconscious’ of Oxford or Harvard until the moment I asked you where you studied? Freud, among others, placed such information into the preconscious – a mental vestibule in which thoughts reside until they ‘succeed in attracting the eye of consciousness’. The cognitive unconscious, in contrast to the preconscious, is inseparable from and inaccessible to consciousness even though it influences actions, judgements and feelings. Psychologist Timothy D. Wilson of the University of Virginia coined the term ‘adaptive unconscious’ to convey this concept that ‘nonconscious thinking is an evolutionary adaptation … Without these nonconscious processes we would have a very difficult time navigating through the world.’

As an example of Wilson’s point, consider what occurs if at this moment you decide to get up from your chair and walk across a room to get a drink from the fridge. Most of the actions you take on the journey will occur outside of conscious deliberation. You risk falling over your feet if you remain overly conscious of the act of walking. Similar considerations apply to dancing, driving a car, playing a competitive sport. In the initial stages of learning to do these things we enhance our performance by cultivating conscious awareness of the individual movements involved (practising the steps of the tango, holding the tennis racquet with the correct grip etc.). But at a certain stage in our efforts the relevant movements that underlie dancing, driving and playing a sport become automatic. When this happens the motor programmes responsible for these activities are shifted from the cerebral cortex where conscious activity is located to the subcortical nuclei, islands of brain tissue located deep below the cortex where automatic programmes are developed that replace conscious efforts at learning these skilled actions. When the programmes are fully developed there is no need for conscious awareness; indeed, one must avoid remaining conscious of the mechanics involved lest mishaps result.

Consciousness is a limited-capacity system that can prove a liability under circumstances demanding rapid responses. That’s because efficiency demands that many of the most interesting aspects of cognition, as with many of our behavioural responses, must occur outside of conscious awareness. Take, for instance, decision-making. We may pay a high price if we rely on conscious appraisal to decide whether the curved object on the ground in front of us is a stick or a snake. Instinctively (i.e. unconsciously) we leap back from the ambiguous object. Only seconds later do we consciously appraise our rapid response as unnecessary and kick the stick out of our path.

Even under conditions calling for a less hurried response, we remain ignorant of a great deal about the working of our brains. While we improve our golf game by regular practice, the mechanisms responsible for our improvement remain unavailable to consciousness. At some point explicit learning (holding the golf club in the correct grip) becomes less important than implicit learning (recruiting the relevant muscle groups into increasingly efficient cooperation).

This explicit–implicit dichotomy is especially noticeable when it comes to learning a language. Two processes are at work: consciously incorporating vocabulary terms with grammar and syntax, and unconsciously (i.e. implicitly) ‘just speaking’ the language. Children can automatically combine both processes and thus can easily learn multiple languages contemporaneously. We adults, in contrast, have a harder time learning a new language, partially because of our increased tendency to concentrate consciously on explicit rules of grammar and syntax. Modern techniques for teaching foreign languages to adults aim at correcting this tendency by exposing the adult language learner to various forms of ‘total immersion’. In this way the learner has no choice but to respond in the new language quickly and automatically.

When do we become conscious?

At what age does consciousness emerge? This question isn’t easily answered. It depends on the achievement of a working theory of mind – the awareness that other people have thoughts, beliefs and feelings just as we do. Prevailing theory holds that a theory of mind develops around the age of four. The basis for this assertion is the typical performance of four-year-olds on what is called the false-belief test.

In a typical false-belief experiment three- and four-year-old children observe a staged scenario during which a child, Chris, hides a piece of chocolate in a box and then leaves the room. A second child, Susan, enters the room and moves the chocolate into a nearby basket and then also leaves the room. When Chris returns to the room, where will he look for the chocolate: in the box where he originally placed it, or in the basket where Susan moved it to? In order to answer that question correctly it’s necessary to enter into Chris’s mind and see things as he does. Since Chris believes the chocolate is still in the box in which he placed it, he will look for it there. Most four year olds observing this experiment will respond correctly that Chris will look in the box where he originally hid the chocolate, based on the fact that Chris didn’t see Susan move it to the basket.

But a three-year-old will respond that Chris will look in the basket to which Susan moved the chocolate to. A three-year-old’s verbal response fails to distinguish between their own knowledge and that of another person. They assume that since they know from observing the experiment that the chocolate is now in the basket, Chris will know that too. In short, they don’t possess a well-developed theory of mind. Not until age four will the child be mentally capable of representing the situation from Chris’s point of view.

Additional research on the false-belief test provides an intriguing insight: children close to exactly three years of age actually looked in the correct location, even though they gave the wrong answer when asked where Chris would search for the chocolate. ‘The best explanation of this is that the looking and verbal responses reflect different kinds of knowledge that develop at different rates,’ according to psychologist Timothy D. Wilson.

In a sense the three-year-old is both conscious and unconscious of the correct answer to the question. Ask the three-year-old and she will tell you one thing; watch her eyes and she will tell you another. Seeing involves automatic, unconscious and implicit knowledge that doesn’t require consciousness. The verbal response, in contrast, depends on a conscious understanding and takes longer to develop. By three years and eight months the child will reconcile her responses and both look in the correct location and give the correct verbal response.

Similar discrepancies in regard to consciousness persist into adulthood. Numerous studies have shown that people participating in experiments can learn very complex response rules and use these rules to improve their performance without being able to access or explain them consciously.

The brain and consciousness

As a neurologist I regularly encounter examples of what can go wrong with consciousness as a result of brain damage. These changes vary along a spectrum ranging from mild decreases in alertness and wakefulness to states of profound coma. In addition to these extremes I’ve met paralysed people who, while in a state of full alertness, deny their paralysis and seem to inhabit a world where they are not conscious of their disability. Others have developed amnesia for large swathes of their past; some fail to recognize the identity of important people in their lives. In such cases, brain, mind and consciousness are so interwoven that damage to any one of them adversely affects the functioning of the others.

Among the brain areas important for consciousness, the prefrontal cortex and the anterior cingulate play prominent roles. These same brain areas function abnormally in obsessive-compulsive disorders that represent pathologic extremes of consciousness. Try as he might the obsessive cannot escape from the perpetual and mentally painful conscious thought that a door may have been left unlocked. Dostoyevsky captured the consequences of morbidly overdeveloped consciousness in his novel Notes from the Underground.

But neither the prefrontal lobes nor the anterior cingulate working alone makes us conscious. Indeed, there is no ‘centre’ for conscious experience. Rather than residing in a specific brain site, consciousness requires the coordinated action of widely distributed brain areas extending from the lower brain stem and ascending to the cerebral cortex. Stated somewhat differently, conscious experience involves the interplay of many discrete brain modules. Of course this leaves unanswered the question of how all of these modules are integrated into the experience of consciousness. One clue emerges from the differences found in hemisphere functioning, the so-called right brain–left brain dichotomy.

Decades of research have revealed that consciousness is more dependent on the left hemisphere than the right. Since language plays such a dominant role in our consciousness, and language is mediated primarily by the left hemisphere, it should come as no surprise to learn that consciousness is closely linked to left hemisphere activity. If I ask you, ‘What are you thinking about right now?’ you will use words to describe your current state of consciousness. That answer, in the form of your verbal response, depends upon the activation of your left hemisphere. To this extent the left hemisphere determines consciousness. Novelists such as James Joyce and Virginia Woolf captured the intimate linkage between inner language and consciousness in the fictional worlds of Ulysses and Mrs Dalloway. In these ‘stream of consciousness’ novels the characters, moment-to-moment thoughts pour onto the page in an inseparable linkage of consciousness and language. Indeed it is this inseparable linkage of language and consciousness that suggests animals and very young children cannot be conscious; they simply haven’t developed a language sophisticated enough to allow for self-talk. Awareness, yes, but not consciousness.

Monkey see monkey do

Habits comprise an interesting mix of conscious and unconscious processing. Take smokers, for instance. Neuroimaging reveals that, when a smoker watches another smoker in the act of smoking, activation occurs in an action observer network (AON) comprising areas in the superior parietal and lateral prefrontal areas. This does not occur when a nonsmoker observes smoking. The AON involves observation, planning and action. ‘Monkey see, monkey do’ is a shorthand mantra for the action of the AON. The AON is part of what brain researchers have termed the mirror neuron system, which was discovered by measuring the brain activity of a monkey while it observed another monkey eating a peanut. The same cells were activated in the brains of the monkey eating the peanut and the observer monkey.

While real-life observation of smoking reliably activates the AON of the smoker, questions remained about what would happen when smokers watched movies or videos of smoking behaviour. In a study aimed at determining this both smokers and nonsmokers watched a movie containing multiple smoking scenes. In order to lessen the chances of the participants guessing the purpose of the experiment, they were told a cover story that the goal was to discover events happening in the brain when people watch movies in general. No mention was made about smoking. This cover story increased the likelihood that the participants would not attribute any special relevance to the scenes in which the characters were smoking.

During the smoking scenes the brains of the smokers showed activity in the AON while no activation occurred in the brains of the nonsmokers. This finding helps to explain why merely observing smoking scenes in movies increases the likelihood that established adult smokers will light up soon after leaving the cinema.

The movie experiment is especially intriguing since the seemingly spontaneous and free choice of a cigarette upon leaving the cinema resulted from the activation of a network of neurons not under conscious control. (See Is Free Will an Illusion?) Despite the smoker’s conviction that he was responding to a conscious desire to smoke, the underpinning for that choice, whether stimulated by observing actual smoking or real-life smoking depictions, remained outside of conscious accession.

Measuring what it means to be conscious

Will it eventually be possible to correlate our conscious experience with the output of a measuring device? Perhaps such a correlation may someday be achieved for some elementary sensory processes. For instance, I’m currently fully conscious of a nice ripe banana sitting on the desk beside my computer. Sensory receptors in my eyes convert the light reflected from the banana into electrical signals sent to my brain where the banana’s yellowness is represented in the activity patterns of networks of neurons. It would not be too difficult to imagine that in the near future an imaging device will be capable of indicating that I am conscious of the banana. A similar reductionism may also be possible in regard to other slightly more complicated examples. But it is a dicey proposition to suggest that neuroscience will provide a totally satisfying explanation either of the nature of my consciousness as I am writing this sentence, or of your consciousness as you are reading it.

WHAT MAKES THE HUMAN BRAIN SPECIAL?

Looking under the hood

The capacity to plan for the future would seem at first glance to render the human brain special. But research dating from the 1990s found that, within a limited timeframe, future planning exists in some animals.

Hummingbirds can remember the location of a flower and how recently they visited it and then use this information as a guide for future behaviour. Primates, rats, corvids (crows, ravens and jays) and octopuses all also show some limited ability to plan for the future.

Future planning in our own species differs only quantitatively from these animals. While the animals foresee a future measured in frames ranging from a few seconds to a season (a squirrel gathering nuts in ‘anticipation’ of the winter), human planning can extend over a lifetime. As geographer Yi-Fu Tuan puts it,

A human being is an animal who is congenitally indisposed to accept reality as it is. Humans … do something extraordinary, namely ‘see’ what is not there. Seeing what is not there lies at the foundation of all human culture.

Prefrontal and frontal lobes

When we mentally project ourselves into the future, we’re using our prefrontal and frontal lobes. Massively developed in comparison to other living species, this critically important area at the far front of the brain is the key to what makes the human brain different and special in the ways that we value most. It is principally responsible for five control functions:

Executive control This is the one function that truly separates us from all other primates. We can anticipate the long-term consequences of our actions. (‘If I cheat on my income tax I may be discovered later if I’m selected for an audit.’) We can monitor the responses we are getting, and are likely to get in the future, from other people. (‘My wife seems to get angry whenever I criticize her mother so maybe I better knock it off.’) We can even envision how our actions in the present may influence the next generation and the generation after that.

Not all humans have equally developed frontal and prefrontal lobes. As a result, not everyone is equally skilled at projecting themselves into the future and making wise decisions based on what they foresee. A good percentage of people live strictly in the here and now; their decisions are impulse-driven and based on what appears to be immediately advantageous rather than what is more likely to be of long-term future benefit. Our prisons and courts are packed with such people whose inability to foresee the likely consequence of their actions leads them to commit crimes. So when we set out what is special about the human brain it’s important not to assume that what makes the human brain special is equally developed in all of the members of our species.

Future memory Despite the odd name, the basic concept is fairly simple. Lewis Carroll captured the essence of it: ‘It is a poor sort of memory that only works backwards.’ Future memory refers to the ability to keep future goals in mind in the present. Think of a law student who during all of the challenges and stresses of her law school and legal career motivates herself by envisioning herself as a future judge. No matter how tough things get, she hangs in there and sees herself someday wearing those black robes. When we speak of single-mindedness of purpose and determination against obstacles, we’re speaking in psychological terms of a frontal lobe-driven neurological process. Our ability to keep focused on the distant future – indeed even to conceive of it – is unique to the human brain and enables us to ponder our own future fates and the fates of others as well. (See Where Do Empathy and Altruism Come From?)

Drive In order to remain awake and alert to the events and people around us we must pay attention and remain focused. Although many animals exceed our ability to do this in the short term, only the human brain can do so over the long haul. As with executive function, focus and drive are unevenly distributed within the population. Young children and adults with attention deficit disorder experience great difficulty avoiding mental distractions and remaining focused and attentive.

Working memory If I had to pick one thing that makes the human brain special it would be working memory: keeping one thing ‘in mind’ while occupying yourself with another mental project. Working memory is often metaphorically compared to mental juggling. A skilled juggler simultaneously keeps several balls in the air. And working memory – like juggling – can be improved with practice. A working-memory impresario can retain several tasks on his mental radar screen and switch back and forth from one task to another. Since working memory is the most important component of enhanced intelligence it is well worth developing. (See Can We Build a Super-brain?)

Sequencing The human brain is especially equipped to handle sequential information, maintain it accurately in proper order and organize it for later processing. When we tell a friend the plot of a movie or a novel, sequencing is important lest the meaning unravel.

Although not exclusively mediated by the frontal lobes, another special function of the human brain is metacognition: the understanding and awareness of one’s own mental processing. Examples include remaining aware of your biases in dealing with certain people; retaining awareness that you are gradually becoming angry during a tense conversation with a colleague; freely relinquishing a coveted assignment to a colleague because you reluctantly acknowledge that he is more qualified. At even higher levels of metacognition the differences between humans and other animals are even starker. Only the human brain is capable of fathoming ‘To be or not to be, that is the question.’

Any comparison between animals and humans leads to a key question: at what point does a quantitative difference between the performance of the human and the animal brain become so great that it is best described as a qualitative one? So far, there is no universal agreement about the answer to that question.

Different brains, different worlds

The brain of every animal is special in its own way. And thanks to this specialness, it experiences a unique world. The brain of your pet dog, for instance, is special because of its focus on smell. When you walk your dog you’ve probably felt the occasional tinge of annoyance as the dog pauses at every lamp-post along the way. Such behaviour is annoying because to most human beings most lamp-posts seem pretty much the same. We feel that way because we get most of our information from vision, with smell providing only subtle background notes. For the dog, in contrast, each object and even parts of the same object provide a rich trove of olfactory information.

While the olfactory cortex accounts for less than 1 per cent of the total mass of the human brain, the olfactory cortex of a dog takes up 12.5 per cent. The dog brain also has more olfactory receptors: 300 million compared to our meagre 6 million. This imbalance in the number of receptors and the percentage of cortex devoted to smell explains why the dog’s experience of the world is fundamentally and, to us, sometimes mystifyingly different from our own.

Such refinements in olfactory perception are additionally aided by the distinct arrangement of the dog’s nostrils. While our nostrils are close together, a dog’s nostrils are wide enough apart for each of them to sample air from two discrete regions of space, thus allowing for the detection of even the faintest scent. This olfactory precision and acuity puts our feeble sense of smell to shame. While we can detect a dominant odour, the dog experiences a larger range of layered odours with each layer providing different information. The scent of another dog? When was it last here? How old is it? Is it a male or a female?

Thanks to the unique arrangement of the dog’s brain, with its emphasis on smell rather than sight, we can never experientially enter the world of our dog.

Other animals’ brains involve different sensory specializations that provide an experience of additional realities. Pythons, boas and pit vipers stalk their prey using heat-sensitive nerve endings capable of detecting infrared radiation and communicating the retrieved information (body heat from their prey) back to a part of the reptilian brain called the optic tectum. Bats employ echolocation: calculating the interval between their screeches and the return echo of the screeches, along with any changes resulting from the wave striking and bouncing off their prey. In one study some bats can accurately narrow down the distance between themselves and their prey to between 4 and 13 millimetres.

While the human brain cannot experience the world of a dog or a snake, the world of the bat – or at least the method used by bats to explore their world – has been duplicated to a limited extent by blind people who use canes to create sounds that they then interpret. Daniel Kish, blind since the age of 13 months when his eyes were removed due to retinal cancer, took echolocation to a new level by modifying it to navigate in the world by clicking his tongue and listening for the echoes that bounce back to him. Using this method he has taught himself and other blind people to hike and mountain-bike. But Kish and his students are exceptions. For the vast majority of us, vision not sound provides the greater sensory component of our experience of the world.

Language and subtlety

Despite periodic claims to the contrary based on primate research (more about that in a moment), the human brain is specially adapted for the use of language and has a particular ability for using language at the highest levels of abstraction. For example, only a human could compose Hamlet’s ‘to be or not to be’ soliloquy, or understand its existential message.

Although human superiority in language seems obvious, it was briefly called into question during the 1960s by research involving chimps taught to communicate using either American Sign Language or coloured plastic shapes representing words. The chimps lined up the plastic shapes on a metallic board to form simple sentences. Using this method the chimps soon learned to engage in simple exchanges (‘Sarah give apple to Mary’). Did such performances promise the emergence of language in chimps and perhaps other primates? While such claims were common in the later quarter of the 20th century, they turned out to be wrong because the experimenters had failed to appreciate what David Premack (the originator of the coloured plastic shapes approach) referred to as three different categories of mind.

In looking back on his own research and the research of others on animal ‘language’, Premack divided mind into three very different categories: simple imagery, abstract representation and syntactical language. While many animals are capable of simple imagery, only a small number of primates (Washoe and Sarah were the most famous), some birds (my African Grey Parrot Toby for one) and humans are judged capable of abstract representation. But none of the primates communicated their abstract representation skills to other monkeys, as would be expected if their performances were truly based on a language. And while this increase in abstract representation enabled them to handle more difficult problems, they did not reach the third and most critical plateau: learning how to use syntax or the rules that govern the ways words combine to form phrases, clauses and sentences. Syntax, it turns out, can be managed only by the human brain. That isn’t to say that the human brain doesn’t commit syntactical errors (‘After rusting in the driveway for years my neighbour finally had his old car towed away’) but the human brain (and only the human brain) can detect such errors as this misplaced modifier (the car rusts away, not my neighbour).

The combination of language and humour requiring a high order of abstraction is another quality unique to the human brain. ‘An aspiring novelist sent $20 for a book entitled All That You Will Need to Write Your Novel. A few days later a dictionary arrived in the mail with the attached note “Some assembly required”.’ Try getting a response to that from any creature other than a human.

Human language differs from any animal language in another important way: our use of default reasoning. Suppose I say to you: ‘Jim is a great sports fan and will watch any sporting event on television. Tonight is the seventh and deciding game of the World Series.’ What would you conclude? Most likely that Jim will be glued to his television set during the game that evening. From the strictly logical point of view this seems like the correct assumption to make. Perhaps an ape or a chimp could perform a similar bit of reasoning if the problem could somehow be converted into coloured shapes. But suppose I add, ‘Jim’s television is broken’, and, ‘As he was leaving work today, Jim’s boss gave him the task of presenting an important report at tomorrow morning’s sales conference.’ Armed with this additional information about Jim, you would likely modify your earlier conclusion by saying something like: ‘Jim will watch the ball game but only if he finishes the report prior to the game and if he finds some other location to watch it.’ This response conforms to default reasoning: drawing a conclusion based on the initial information provided and then modifying that conclusion in the light of additional information. When you learned that ‘Jim is a great sports fan and will watch any sporting event on television’, you didn’t conclude that Jim will watch absolutely every sporting event despite whatever else may be happening in his life. Thanks to default reasoning you’re pretty certain that Jim, unless he’s a very weird man, isn’t going to be watching a sporting event on television moments after his four-year-old has fallen down a few steps on the stairs, cut his knee and burst into tears, say. Only the human brain is capable of using default reasoning to intuit the subtle distinctions that must be made in regard to even the most logically constructed syllogism.

As another example of how the human brain parses language within context, consider this phrase: ‘I’m not saying, I’m just saying.’ Taken literally the phrase doesn’t make sense. The first part of the sentence is contradicted by the second part; the speaker appears to be doing exactly what he claims not to be doing. But most New Yorkers (I’ve only heard the phrase in New York) recognize it as a shorthand for saying: ‘I don’t believe that what I’m telling you is true; I’m just telling you that everybody else believes it’s true.’

Based on examples such as those mentioned above, I think it’s safe to conclude that certain subtleties of language are likely to remain beyond the powers of animal communication. So, don’t expect an animal version of the Declaration of Independence anytime soon.

The time-travelling mind

Mental time travel and theory of mind are two other uniquely human properties of thinking. During mental time travel we simultaneously entertain our present consciousness, past experience and an imagined future. ‘During the wedding the groom thinks for a moment of his unhappy first marriage and envisions himself happier the second time around.’ In this example the groom momentarily time travels from the present (his wedding) to a regretted past union while mentally envisioning himself happily married from this day forth.

This form of time travel is also involved when we mentally incorporate what we believe to be another person’s state of mind into our own. While primates can do this to a certain extent (monkeys have been shown to be capable of deceiving other monkeys), only humans are capable of what Michael C. Corballis refers to as ‘higher-order deception’. We alone are capable of such mental acrobatics as ‘I know that Mary knows that I know that she knows what I’m thinking.’ Henry James regularly employed such verbal sleight of hand – perhaps one of the reasons the world is still waiting for the first primate other than ourselves to show any enthusiasm for the cognitively demanding works of the Master in which present, past and future interpenetrate. Primates don’t, after all, spend time mulling over the question of whether or not they think.

In summary, what makes the human brain special isn’t any single quality that we possess but that animals fail to possess in some degree or another. Rather, what makes the human brain special is the combination of abilities that make it uniquely adapted for navigating the universe of symbols and signs that it has constructed for itself.

CAN BRAINS COMMUNICATE WITHOUT WORDS?

The secrets of body language

The use of words as the unit of communication developed late in evolution. With the exception of parrots and other ‘talking birds’ exposed to human speech, words haven’t evolved at all in other species. A number of attempts during the 1930s and 1940s to train apes to speak English all turned out to be spectacular failures.

Apes and other primates can’t learn to use the words of human language because they lack the anatomical vocal structures needed to imitate human speech. Parrots get around this limitation by a different vocal arrangement and, as any parrot owner knows, are capable of producing human-sounding speech. Of course, we should keep in mind a subtle point: not every creature that uses human words communicates in ways that we would accept as totally equivalent to our own.

Communication by sound

But meaning isn’t communicated only with words. Vocal communication can take place without either words or visual symbols. The calls of vervet monkeys alert other monkeys in the vicinity to the presence of a specific predator. A particular call is emitted when a leopard is spotted, prompting the other monkeys to scurry into trees. Another call is given in response to an eagle, cueing the other members of the vervet group to look skywards.

Among rhesus monkeys food-related vocalizations are similar in their contextual meaning to words: different vocalizations are specifically related to the emotional state of the monkey uttering the call, along with the condition of the food discovered by that monkey. Among Japanese macaques contact calls labelled ‘coos’ sound alike to human ears but differ when subjected to spectrographic analysis.

Thus if we restrict our definition of communication only to words we underestimate the complexity of communication systems based solely on sounds. Like the words in spoken language, communication based on vocalizations is embedded within the framework of specialized brain circuitry devoted to social communication. One clear difference emerges, however, when comparing any of these various monkey ‘languages’ with our own – humans can step back from our environment and reflect on our relationship to it.

But communication by vocalization isn’t restricted to primates. The vocalizations of song sparrows, canaries and finches all transmit information. The brain of each of these species is ‘wired’ to learn the specific vocal sounds of that species in order to attract mates and establish territory.

Perhaps it’s most economical to say that animal vocalizations of whatever species (parrots exempted) serve as devices for communication without human words. The process is similar to the predisposition of human infants to start with nonspeech vocalizations and proceed from there to learn the language to which they are exposed.

Infant language without words

Anyone who has ever been around a crying toddler can attest that they are quite intent on communicating even though they are months away from developing the fine motor coordination of the muscles of pharynx and larynx required for speaking words. But even though they can’t use words, toddlers satisfy their wishes quite well via gestures. At about ten months a child can obtain a toy by pointing in its direction and thereby directing an adult’s attention to it. Such highly communicative gestures occur weeks or even months before the corresponding words. While the first gesture is acquired by 12 months, the first spoken word lags behind by about a month.

But gestures are more than simply crude word substitutes; they are facilitators for language development. The greater the number of gestures the child learns between one and two years, the larger its verbal vocabulary at two and three years. That’s because gestures ensnare an adult’s attention and elicit verbal responses from them, which the child hears and learns. The gesture is the predecessor of words and, thanks to adults responding with additional words, the stimulus for learning new words. When a child flaps its arms in imitation of a bird in flight this gesture increases the chances a parent will say something like ‘Here comes the birdie!’ Subsequently the arm flapping is replaced by the child’s first verbal attempts at describing ornithological matters. Without the gesture the child’s verbal expression about birds would be at least slightly delayed but – and here’s the point – the child’s gestures and the responses they evoke in others show that the human brain from its early development is quite comfortable communicating without words.

Communicating in gestures

Spend a few minutes watching an attentive mother silently interacting with her infant or observe your pet’s response to the sight of a treat – and you will be in no doubt that brains can communicate without words. The next time you are driving notice that your communication with other drivers often relies on nonverbal signals involving primarily the hand. Some of these communications are purely functional such as indicating who has the right of way or which driver yields to another in a particular situation. Other communications are emotionally driven. In every culture certain hand signals convey rude gestures of contempt or scatological suggestion. At the most basic level, we are all communicating without words every day.

At a slightly more abstract level, communication without words underlies many of the arts, where meaning and emotion is expressed in composition, movement, form, texture and melody. You only have to think of mime artists such as Marcel Marceau to appreciate the power of a gesture. Athletes too communicate without words via skilled movements. In some sports, such as professional tennis, verbal exchanges between the contestants are discouraged in the interest of eliminating bullying or distraction as a strategy for overcoming the skills of a stronger opponent. And yet very often, particularly in tennis, you will see nonverbal strategies deployed instead – bouncing the ball a few extra times before serving, gesturing for a towel just as your opponent wishes to serve, even sighing or gesticulating angrily at line decisions – all designed to put off one’s opponent.

Communication without words comes naturally to the body and can plainly be seen in many situations – but reading other people’s states of mind from their ‘body language’ requires more detailed observation.

Body language

Understanding a person’s ‘body language’ depends on detecting subtle micro-expressions given off by the facial muscles along with movements of muscles elsewhere in the body. When a person is in agreement with what someone else is saying, he signals his approval by unconsciously nodding his head. Disagreement is often expressed by a frown. More often than not we’re unaware of the bodily signals we give off and how easily they can be detected by others.

For example, earlier this morning I was sitting with a companion while listening to a third person read aloud from a rather dry financial report. Since I had another meeting within the hour I was becoming impatient, and I wanted to check the time but without drawing attention to the fact that I was looking at my watch. So I placed my left hand on my thigh and, a few minutes later and with what seemed to me a surreptitious movement, I looked down to check the time. As if on cue the reader looked at his own watch and announced, ‘I won’t be much longer.’ A coincidence? While that’s possible I think it’s much more likely that he had picked up on my bodily signs of impatience and this led to him noticing my surreptitious glance at my watch, despite my best efforts at concealment.

I don’t think I’m an exception here. Most people find it challenging to conceal from the skilled observer the bodily expressions signalling their intentions and thoughts. MIT Media Lab researcher Alex Pentland refers to involuntary difficult-to-fake responses as ‘honesty signals’. They include mirroring the gestures of another person and unconsciously imitating the variations in the tone and pitch of their voice. Such signals of agreement (and their absence as signs of disagreement) are perceived by the right hemisphere of the brain. This ‘reading’ forms the basis for the hunches and ‘gut feelings’ about people that play a large role in determining our responses to them.

‘Talk to the hand’

The next time you’re watching your favourite comedian on television turn off the sound. You won’t be able to hear the jokes but you’ll observe that humour depends very much on body language. Most comedians rely on their hands to convey subtleties. Tie their hands behind their back and their jokes will often fall flat. A similar use of the hand as a communicative tool takes place during disagreements when one person emphasizes his point by holding up his hand with the palm directed to his interlocutor who then, as the saying goes, has to ‘talk to the hand’. Linguists refer to this linkage of the body with intention as embodied language: the contribution to verbal communication made by facial expressions and gestures.

Even when at rest, our hand postures reveal a lot about us. Two resting hand postures are especially common. In the first, the grasping posture, the hands are largely free of contact with the rest of the body and the fingers are slightly flexed as if grasping something. In the second posture, the stationary posture, the fingers and palms rest flat on the knee or other body surface. We shape our hands into the first posture when we are about to pick something up or grasp it. The stationary hand posture occurs when we’ve completed our action. A similar use of the hands occurs during verbal communication. People shape their hands in the grasping posture when they wish to make a point. The grasping posture signifies: ‘Give me another few moments to talk and finish my point.’ When they are finished and the argument is concluded, the hands slowly open and shift to the stationary posture. Thus resting hand shapes are highly communicative to the keen observer and provide a subtle signal to others whether it is time to begin speaking or advisable to wait a bit longer.

Technology and nonverbal communication

Technological aids are now available that can provide sometimes unsettling insights into how other people may be responding to our speech and behaviour from moment to moment. Rosalind Picard at MIT’s Media Lab has developed special glasses that can reveal six emotional states: thinking, agreeing, concentrating, interested, confused and disagreeing. The glasses contain a small camera the size of a grain of rice linked to a tiny wire that wends its way down to a concealed computer about the size of a pack of cigarettes. The glasses are worn by the speaker and the camera monitors 24 sites on the face of the person being spoken to. It gathers information on head gestures, facial expressions, lip movements, brow furrowing and 20 other ‘feature points’ on the face. Fleeting micro-expressions from these sites are captured and compared with a database created by hired actors miming the emotional states.

If you are wearing a pair of Picard’s glasses you will be able to monitor my emotional responses to what you are saying. Even though I may be feigning interest, the glasses will see through my masquerade and detect my real feelings. The glasses are also equipped with an earpiece through which you will hear a voice summarizing for you that I am uninterested or confused in response to what you are telling me. And if that doesn’t prompt you to change your behaviour, the glasses also feature a built-in light system that only you can see. The colour provides you with information about my responses to you: green (I’m responding positively to what you are saying), amber (a neutral response) and red (you best stop talking or change the subject).

Reading other people’s emotional responses via technological aids can be both helpful and harmful. Since no more than 54 per cent of people can correctly interpret their conversational companion’s expressions, a large percentage of the population could obviously use some help in monitoring other people’s responses to them. The worst thing about bores and braggarts, for instance, is that they usually have little insight into how much their self-centred conversation is alienating other people. Technology holds promise to provide objective measurements of when it’s time to switch subjects or stop talking.

On the negative side, technologies such as Picard’s threaten to rob us of a valuable social lubricant: the concealment of our true feelings in the interest of preserving harmony. The technology may also lead to emotionally arid conversations. After all, there are times, such as when discussing complex topics, that confusion may be the proper response. Yet the speaker, when made aware of confusion on the face of his listener, may oversimplify his communications or move on to a less cognitively challenging topic. Even more troubling, some people may become depressed and anxious when, thanks to this kind of technology, they become aware of expressions of disagreement on the faces of people they have come to consider their friends and closest associates. Under such circumstances the brain’s ability to communicate without words may prove more of a liability than an asset.

While emotional facial recognition systems may not be popular staples in the general population as yet, they are already in use by companies interested in learning how their customers are responding to advertisements. As the technology becomes simpler, cheaper and less easy to detect, it will likely become an increasingly popular means of monitoring other people’s ‘real’ responses.

Body ‘leakage’

Reading intentions from body language instead of words is elevated to the status of a high performance art in activities such as poker. Skilled poker players look for ‘tells’: nervous tics, mannerisms or habits that help them read the strength of their opponent’s hand. Veteran World Series of Poker competitor James McManus describes the process in his book Cowboys Full:

Todd had slowly drawn a bead on Andy’s body language. How did his fingers release the chips when he was bluffing? Did his nose or mouth crinkle when betting a monster? … By zooming in on how Andy bet out or hesitated, then connecting that to the strength of his hand once they had seen his hole cards, the best of the Table 1 pros learned to translate his tiniest idiosyncrasies into lucrative information about how best to proceed in each pot.

Like poker players communicating the strength of their hands by involuntary ‘tells’, liars often unknowingly provide giveaway signals to the to keen observer. Most people learn in childhood some basic competency in the art of suitably composing their face when speaking an untruth. However, even though they may look the part of the sincere truthful communicator, their voice may be giving them away. Few people (other than actors) are fully aware of the information the human voice unintentionally conveys in the form of verbal inflections, hesitations, pauses, pitch changes and other aspects of prosody. That’s why a telephone conversation with someone you suspect may be lying to you may be more fruitful than a face-to-face meeting.

But these giveaway signals aren’t confined to liars; all of us emit them all the time. Who among us doesn’t on occasion utter inconsequential untruths in the interest of preserving social harmony? We say ‘You look lovely’ to our spouse even though we believe that another choice of outfit for the dinner party would look better. And in most cases, we remain blissfully unaware that our spouse has picked up on our innocent insincerity, and chosen to ignore it.

What happens in the brain?

The human brain is broken down into the left hemisphere, which is organized for language word processing, and the right hemisphere, which is organized for expressing and responding to these elements of speech known as prosody: the inflections, rhythms and emphasis associated with words. Thanks to the right hemisphere’s agility in detecting prosody, communication can occur very nicely without words. When you hear an agonized screech or an angry scream it’s your right hemisphere that responds, leading to an increase in your heart rate and a rush of anxiety. And it doesn’t matter what language accompanies that scream, we instantly conclude that someone is in distress. Words or language aren’t even necessary; communication occurs quite effectively in their absence.

Sarcasm and humour are other examples of prosody and involve a disconnection between the content of spoken words (interpreted by the left hemisphere) and the tone of voice employed (interpreted by the right hemisphere). ‘He’s a real genius!’ can be spoken either as a tribute to someone’s intelligence, or as a putdown implying stupidity. It all depends on the tone of voice employed.

A similar incompatibility between words and vocal emphasis can arouse emotional distress and, according to some psychotherapists, even lead to permanent mental illness, as with the future schizophrenic who as a child regularly hears from his mother such phrases as, ‘But you know I’m only doing this for your own good and because I love you,’ with the words spoken in a subtly venomous and threatening tone.

Disturbances in prosody regularly occur in patients with injuries or diseases of the right hemisphere. Although they can perceive other people’s emotional expressions, they cannot express the same emotions themselves. They say the right words but the accompanying emotional inflections just aren’t there. As a result, they impress others as robotic in their responses. (‘He says that he loves me but he doesn’t sound like he means it.’) Other patients with injuries elsewhere in the right hemisphere show just the opposite pattern: they can’t perceive the emotional content of other people’s spoken speech. They take literally expressions that are intended to be metaphorical: ‘If the boss talks to me like that again I think I’ll just shoot myself.’ Hearing such a statement from a colleague the person with a right hemisphere disturbance ponders whether he should summon the authorities.

Both those with receptive and expressive difficulties in processing emotions underscore a common point: a large proportion of our intended communication doesn’t depend on words at all.

So whether it’s body language or prosody revealing our unspoken feelings, rude hand gestures or ballet, our brain is not only capable of communicating without words but, under certain circumstances, prefers to do so.

WHAT IS THE ‘I’ IN OUR BRAIN?

The quintessential identity problem

Standing in front of a mirror I recognize myself. If you play a trick on me and substitute another person’s face in the mirror, no such recognition will take place. This is one of the ways in which we build up a sense of self, and it starts in the brain.

Similar self-recognition occurs when I look at a much less symbolically complex part of myself, such as my hand. While staring at my hand I experience a coherent impression made up of several elements: tactile, visual and proprioceptive (position information fed back from nerves in the hand). Thanks to this multimodal integration, I experience a feeling of ownership of my body that ultimately leads to a sense of self. But how does this occur?

Studies carried out on primates a decade ago led to the discovery of receptive fields in an anterior part of the brain known as the ventral premotor cortex (PMv). The PMv plays a key role in the integrative process that enables a monkey to locate its own limb in space. But since we can’t question monkeys, we can’t be sure that this integration of the various senses is accompanied by any subjective feeling of ownership on the part of the monkey.

Research on humans carried out at about the same time provided eloquent insight into how sense integration leads to self-recognition and self-ownership. Imagine yourself sitting at a table on which I have placed a rubber hand. Your own hands are out of sight under the table and resting on your knees. At this point you have no difficulty recognizing that the rubber hand isn’t your hand. But if I simultaneously run a tiny fine-haired brush over the rubber hand and one of your hands under the table, you will experience the rubber hand as your own. Indeed you will experience a very strong sense that the rubber hand actually belongs to you. Yes, I know it sounds weird. But this so-called rubber hand illusion (RHI) has been confirmed many times. What’s more, the RHI is accompanied by activation of the PMv. Thus activation of the PMv, along with a lesser contribution from the parietal lobes, correlates directly with the sense of body ownership of the rubber hand: ‘It is my hand that I’m looking at; it is “I” who is looking at my hand.’ Moreover, this psychological perception of an ‘I’ is mirrored on the neurological level – the PMv becomes more active when I’m simultaneously looking at the hand and experiencing a gentle touch applied to it, compared to the activation that results when I’m just looking at the hand. The more bodily senses involved, the stronger my sense of ‘owning’ the hand.

The rubber hand illusion is just one example of how our sense of an ‘I’ within our brain can be manipulated. Henrik Ehrsson, a neuroscientist at the Karolinska Institute in Stockholm, has taken the rubber hand illusion a good bit further. He has devised a method for creating an out-of-body experience where the ‘I’ within the brain disappears altogether. In his experiment the subject sits in a chair while wearing a pair of goggles displaying the view from a camera immediately behind him pointed at his back. Ehrsson then taps the subject’s chest with a plastic rod while synchronously using a second rod to prod at the camera. Thus the subject both sees and feels his chest being prodded at the same instant as he stares at a picture of himself taken from behind. ‘Within ten seconds I felt I was being pulled out of my real body and was floating several feet behind it,’ wrote a Nature journalist who volunteered to participate in Ehrsson’s out-of-body experiment. But Ehrsson didn’t stop there. He modified the experiment so that the goggles displayed the view from a camera mounted on the head of a mannequin looking at its own plastic torso. Ehrsson then simultaneously poked the abdomen of the mannequin and the abdomen of an experimental volunteer. After a few moments of poking, each of the volunteers became convinced that they were now the mannequin. I don’t mean intellectually convinced – they weren’t psychotic; they still recognized the mannequin as just a mannequin. Rather, their conviction was experiential. They didn’t really believe that their ‘I’ now inhabited the mannequin – it just felt that way, and with an eerie verisimilitude.

While Ehrsson’s experiments are the artificial creation of a laboratory experiment, we can easily call to mind everyday circumstances when an external object and our sense of ‘I’ become entangled. Pick up a pen and write with it: it becomes a functional extension of you. But the experience can become much more personal if you use the same pen all the time; eventually it seems to become part of you. That’s why when you lose a favourite pen the psychological sense of loss exceeds more practical matters such as the original cost of the pen. If you don’t use fancy pens, think instead of any favoured item (a tennis racket, a golf club etc.) and imagine your response to its loss. The longer you’ve owned it, and the more frequently you use it, the more you will grieve at its loss. That’s because the things that we use and value eventually become a part of the ‘I’ that resides in our brain.

The body schema

The term ‘body schema’ refers to the implicit knowledge that we all retain about the spatial relationships of our body. We’re able to avoid bumping against people passing us on a pavement because we’re able to estimate the available space separating our arms and shoulders from theirs quickly and unconsciously. We can do this because over our lifetime we have established in our brain a dynamic representation of our body and its extension in external space – the body schema. As we age and our body changes the body schema changes as well.

The most intriguing aspect of the body schema is that it includes more than just our body. When we drive a car along a narrow street and encounter another car with just inches to spare between the two cars, we’re re-enacting the same process as when we pass a person on a narrow pavement. We’re able to judge the available distance between our car and the other car because at that moment our car becomes a part of our sense of ‘I’, a component of our body schema. This incorporation of our car into our body schema influences not only our perception and behaviour but for some of us our emotional responses as well. A minor ping or dent on our car may elicit annoyance or even rage as a result of over-identification with the car, which our brain has incorporated into our body schema.

A similar process occurs among musicians and athletes. After years of practice their instruments and athletic equipment become part of their sense of who they are.

Language and the emergence of ‘I’

Our sense of the ‘I’ in our brain isn’t available to us until about two or three years of age. This is curious when you think about it, since during those first three years we are learning so much about the world; we are developing skills such as walking and talking and recognizing people by their faces, voices and gait. Yet our memories of what was happening to us during those early years remain lost to us. This failure in our autobiographical memory has been attributed to various causes. Freud dogmatically suggested that we don’t remember our earliest experiences because of ‘repression’ of sexual or aggressive impulses that we are ashamed to acknowledge. In time, Freud’s unsubstantiated theory came into disfavour. Today, most scientists point to brain maturation rather than repression for an explanation of why we don’t remember our first three years. Two structures stand out as of particular importance: the prefrontal cortex and the hippocampus.

The hippocampus is the portal through which information enters and undergoes consolidation. One tiny area of the hippocampus, the dentate gyrus, is especially critical. It is one of the two major divisions of the hippocampus that, thanks to its connection to the amygdala, is related to the development of both emotionality and identity. The dentate gyrus in our earlier years shunts incoming signals to the hippocampus and thereby helps us to form our sense of an ‘I’. We’re unlikely to remember anything happening before this structure is up and running – which is the reason we don’t remember experiences that occurred before we were two or three years old. A similar amnesia can occur in adults who suffer damage to the dentate gyrus as a result of a stroke.

Of equal importance to our earliest sense of ‘I’ is the development around 18–24 months of what neuroscientists refer to as the ‘cognitive self’: the appreciation that ‘me’ is distinguishable from ‘you’. This is informally measured by observing whether a young child recognizes herself as she stands before a mirror. Once this is achieved, the child will remember events over time.

Language provides the next avenue for the emergence of the ‘I’ in our brain. According to a study from the University of Leeds, the contents of our first memories depend on what age we were when we learned the words to describe those memories. Among adults requested to recall their first memory for a clue word (Christmas), their memories dated to around the age when they had first learned that word as a child. As one of the two co-investigators Catriona Morrison told a New Scientist reporter, ‘You have to have a word in your vocabulary before you’re able to set down memories for that concept.’

The emergence of a sense of self, when combined with the acquisition of language, allows the child to construct narratives about himself and the people and things around him. Memory for these narratives underlies the sense of an ‘I’ in our brain. This facility for narration increases in parallel with the child’s formation of autobiographical memory. Since narration implies a listener as well as a speaker, the mother or other caregivers play important roles in the establishment of a child’s nascent sense of self. The more time spent in speaking with the child, the richer the child’s autobiographical memory. That’s why it’s important to tell and read stories to a child between two and four years of age (when autobiographical memory typically begins). Reading to the child also helps to speed up the formation of autobiographical memory and, as a consequence, the child’s sense of self. So, whether the verbal encouragement takes the form of talking to the child or reading to her, the result will be a more robust sense of self along with an earlier autobiographical memory.

And it makes a good deal of difference how detailed these stories are. Children whose mothers provide them with richly detailed verbal descriptions and interactions possess an earlier sense of self compared to children exposed to less elaborate more repetitive verbal interactions with their mothers. It’s the difference between robotically repeating back the child’s words (‘Yes, that is a big ball’) and using the child’s words as a spring-board for questioning and eliciting additional verbal responses (‘Can you remember any other big balls?’).

Loss of the ‘I’

Interference later in life with the normal functioning of autobiographical memory leads to a diminution or disappearance of our sense of ‘I’. We are only what we can remember about ourselves. That’s the reason we become uneasy when others can remember events that we experienced along with them but we no longer recall. It’s as if our self or ‘I’ or autobiographical memory (think of them here as inter-related and not clearly distinguishable) has suffered a misfire. We ask ourselves, ‘Why do others remember an event or situation that I don’t?’

If the memory absence becomes widespread and persistent, the ‘I’ within the brain becomes inchoate and eventually vanishes. Like a novel halted midway in composition, our autobiographical memory can be interrupted at any point in our lives. The famous patient H.M. lost his autobiographical memory at the age of 27 following surgery involving the temporal lobe and hippocampus on both sides of his brain. After the surgery his sense of self became locked into the immediate present. Although he could remember some earlier events he could no longer encode any new information and thus couldn’t form new memories. On the day of the operation his autobiographical memory ceased functioning like a video camera that has ceased to record: one can watch the scenes from earlier footage but there isn’t any possibility of creating a new video narrative.

The greatest contributor to the loss of autobiographical memory in later life is Alzheimer’s disease. As a result of the build-up within the brain of abnormal by-products (plaques and tangles), the afflicted person initially experiences memory difficulties limited to proper names for people and objects. With further progression, the memory impairment extends to autobiographical memory: events from the personal past either cannot be recalled at all or are remembered as a fragmentary disjointed production that intermixes the distant past with the present.

Strokes, especially those involving the frontal and temporal lobes in the left hemisphere, can deprive their victim of both language and full awareness of self. Although the ‘I’ is not completely missing after a stroke, as can be demonstrated by tests not requiring verbal responses, it is severely stunted; the patient cannot communicate effectively in either spoken or written language. As another example, patients afflicted with fronto-temporal dementia act for the first time in their lives in socially unacceptable ways. The socially adept are cruelly transformed by fronto-temporal dementia into hopeless blunderers who do and say the wrong things. A person afflicted with fronto-temporal dementia insults people, speaks ‘his mind’ in situations where he would formerly have expressed himself diplomatically. Not only does he ‘tell it like it is’ but he may cease to bathe or change his clothes. In advanced stages of the illness, verbal aggression may escalate to physical assaults on people who disagree with or annoy the person with fronto-temporal dementia. (See What Happens When We Get Angry?) While a total loss of the ‘I’ within the brain doesn’t take place, the finer aspects of personal identity and autobiographical memory are morphed into a crude and offensive caricature.

Knowing and feeling

Throughout our lives our sense of an ‘I’ in our brain can take both cognitive and emotional forms – we can know something intellectually or we can know it from personal experience. Sometimes both factors are at work. On some occasions we must trust what we know; on other occasions we should trust what we feel; and sometimes we have to go with both thinking and feeling. Not only can we project our sense of ‘I’ into other people, but on occasion into creatures much different from ourselves as in this story about the Chinese seer Chuang Chou.

Chuang Chou and Hueitse had strolled onto the bridge over the Hao, when Chuang Chou observed, ‘See how the small fish are darting about. That is the happiness of the fish.’

‘Not being a fish yourself,’ said Hueitse, ‘how can you know the happiness of the fish?’

‘And you not being I,’ retorted Chuang Chou, ‘how can you know that I do not know?’

‘If I, not being you, cannot know what you know,’ urged Hueitse, ‘it follows that you not being a fish, cannot know the happiness of the fish.’

‘Let us go back to your original question,’ said Chuang Chou. ‘You asked me how I knew the happiness of the fish. Your very question shows that you knew that I knew. I knew it from my own feelings on this bridge.’

Both participants in this dialogue are correct but for different reasons. Hueitse was correct that Chuang Chou could not enter into the ‘mind’ of the fish and therefore his observation about the happiness of the fish was based on pure speculation. But Chuang Chou was correct as well. In what other ways would the happiness of the fish be expressed than in the animated darting behaviour that the two of them were observing from the bridge? We speak here of something close to empathy (see Where Do Empathy and Altruism Come From?) but with an important distinction – Chuang Chou’s identification with the fish is a cognitive one (‘This is how happy fish would behave’) rather than an emotional one (‘I can enter into the inner experience of the fish and this is how I would behave’), which is a subjective impossibility. Thus Chuang Chou’s phrase ‘my own feelings on this bridge’ would be better expressed as ‘my own thoughts on this bridge’.

The ‘I’ in our brain is at once the most elemental aspect of our existence and at the same time it can be modified in disturbing and even bizarre ways (as with the experiments of Henrik Ehrsson). Nor can our sense of ‘I’ always be distinguished from the things that are around us and, most importantly, from the things we consider most personal. In Henry James’s novel The Portrait of a Lady the character Madame Merle describes the intimate link between our identity and our possessions. ‘When you have lived as long as I you’ll see that every human being has his shell and you must take that shell into account.’ As examples of the shell, Madame Merle cites the clothes people wear, the homes they live in and the possessions they collect. Not only is each person’s shell unique but, without this shell, the ‘I’ is diminished and perhaps lost altogether as a cohesive unity.

IS FREE WILL AN ILLUSION?

Does our brain already know what we’re going to do?

We live at a time when our behaviour is increasingly predictable on the basis of information that we freely make available about ourselves. Websites such as iTunes and Amazon know what books and music we’ve chosen in the past and based on these choices can make uncannily accurate predictions about the books and music we’re likely to select in the future.

Predicting future behaviour from past behaviour is nothing new, of course, and doesn’t require technological assistance – we are creatures of habit. Although we don’t want to admit it, our spouse or good friend can often anticipate better than we can the action we are likely to take in a given situation. But, to be fair, they’ve spent a lot of time with us and have viewed our behaviour with more detachment than we can manage about ourselves. As a result, they’ve built up a catalogue of past performances on which to base their predictions about our future behaviour. What is new, however, is that websites such as Facebook now contain more information about us than is known by even our closest friends.

Behavioural prediction is currently based on widely available information technology. If you’re planning on attending a Lady Gaga concert tonight, you may feel that you freely decided to attend the concert. But efficient and accurate algorithms exist that could have estimated ahead of time the likelihood that you would choose to do so based on your purchasing patterns of Lady Gaga recordings and your past record of attendance at similar concerts. Algorithms can also predict how much you are likely to enjoy the concert based on the responses posted by your Facebook friends who attended the concert the evening before. If they are enthusiastic, this will increase the odds of you enjoying the concert too. And neuroimaging devices are currently available that could have predicted the likelihood of your eventual decision to attend the concert at the moment you first heard or read about it. Your freedom to attend and enjoy the concert may not be as much under the control of your own will as you are accustomed to assuming. But does that mean at the most basic decision-making level that you didn’t freely choose to attend the concert?

The brain and free will

Modern neuroscience began to influence our concepts of free will in 1983. In that year neurophysiologist Benjamin Libet published a paper demonstrating that brain activity can be detected about half a second prior to a voluntary decision – in the case of this experiment to make a hand movement. Since then other laboratory experiments have refined Libet’s research using fMRI to survey the whole brain (Libet’s experiment could look only at a limited area of brain activity). In one experiment carried out by John-Dylan Haynes, a neuroscientist at the Bernstein Center for Computational Neuroscience in Berlin, participants scanned a series of random letters while lying within the brain scanner. They were instructed to push a button with either their left or right hand at any moment of their choosing and to remember the letter displayed on the screen at the instant they decided to push the button. Haynes found that the decision to push the button was apparent in the brain about a second before the actual push (no surprise here in light of the earlier Libet experiment). What was surprising was finding a measurable pattern of brain activity leading up to the button push that predicted it by as many as seven seconds. Even before the subjects decided to choose, their brains had, in a sense, already decided for them.

Other researchers have come up with similar findings at the level of the single neuron. Activity can be detected in individual neurons about a second and a half before the volunteer makes the conscious decision to act. At about 700 milliseconds (thousandths of a second) before the button press the researchers can predict the timing of that decision with more than 80 per cent accuracy. As with the Libet and Haynes experiments, the decision to act is admitted into consciousness after the brain processing underlying the action is well underway. Some neuroscientists have concluded from these free-choice experiments that free will is an illusion; that our actions are predetermined by our brains with consciousness added on at a later point as a kind of afterthought. They conclude that our sense of autonomy and existential freedom must give way to the harsher reality of predeterminism.

But the free-will experiments are open to several criticisms. First, consciousness of our own behaviour exists on a continuum rather than occupying one side of an impermeable barrier. As you read this sentence you are not paying attention to the chair you are sitting on, until now, that is, now that I have called your attention to it.

Second, the research was based on an outdated model of how the brain operates. Instead of thinking of preparatory brain activity as a sequence like water buckets passed from one hand to another during a barn fire, think of multiple processes involving many areas of the brain working in parallel within a complex network where widespread interactions occur continually.

Third, acting only after a conscious decision has been made can, under certain circumstances, be more of a liability than an asset. If you come upon a snake while walking in the woods you’ll leap backwards before you experience any conscious effort to do so. In fact, it’s likely that you never experienced anything even approaching the thought ‘This is a snake so I’d better step backwards.’ And it’s best that the brain works that way under such emergency situations. If the ‘snake’ turns out to be a stick, you have lost only a few seconds instead of possibly your life.

Fourth, and I believe most importantly, the free-will experiments that purportedly ‘prove’ that our free will is illusory involve artificial laboratory experiments. The conclusions are based on the dicey assumption that because our brain responds in short timeframes of seconds or milliseconds under the highly artificial conditions of a psychology experiment, it responds the same way when confronted with more weighty considerations.

Does it really make sense to compare decisions about trivial experimental determinations (‘at what exact second did the subject push the button?’) with, say, the decision whether to undergo surgery and chemotherapy for a tumour with an expected survival period of less than a year, with or without treatment? And just because the decision and its neurological underpinning can be shown to have occurred prior to conscious awareness does not imply that it was not ‘I’ who made that decision (see What Is the ‘I’ in Our Brain?).

Finally, and allied to that last point, such experiments don’t take into account the impulsiveness and simple whimsy that underlie many of our decisions. For instance, earlier today I was driving home from the office with the full intention of taking one particular route but at the moment I reached an intersection I impulsively decided on another route. I say ‘impulsively’ because I had no reason for changing my route: I just ‘felt like it’. Even now, looking back on my choice, I can’t explain why I changed my driving plans. So, if a researcher tells me that he detected a flurry of brain activity several seconds before my turning the wheel to the left instead of the right, I don’t think that proves much of anything. I have no doubt that my impulsive decision emerged out of a background of widespread cerebral activation. But it was still ‘I’ in my totality that directed the car one way rather than another. Just because my decision took some time to reach conscious awareness doesn’t prove that my action was predetermined.

What would be a more convincing scenario debunking free will? Let’s imagine neuroscience progressing to the point of developing a methodology that would enable someone to predict even before I left my office that when I reached that intersection I would change my route. Under those circumstances, it would be much harder to speak of a freely willed action. But at the moment such a scenario is pure fantasy; nor is such a prodigious feat of prognostication likely anytime soon.

William James anticipated the difficulty involved in determining assenting ‘free will’. He held that ‘the question of free will is insoluble on strictly psychological grounds’. For James, the first act of free will is to believe in free will:

When scientific and moral postulates war with each other and objective proof is not to be had, the only course is voluntary choice, for scepticism itself, if systematic, is also voluntary choice. Hence belief in free will should be voluntarily chosen from among other possible beliefs. Freedom’s first deed should be to affirm itself.

Randomness and indeterminacy within the brain

While many of the factors influencing our biology are deterministic (for example, certain physical features such as eye colour are determined by our genetic inheritance), a similar determinism isn’t possible when it comes to the brain. For one thing, the human genome contains too few genes to determine the brain’s structure and function. Besides, we know from experiments and video observations on the cellular level that a neuron’s ultimate placement within the brain depends on environmentally influenced nerve cell migration patterns. If these migrations occur normally, the result is a normal brain; deviations in nerve cell migration result in one of the numerous brain diseases.

At the level of its physiological functioning, each nerve cell is equally free from strict determinism. Neurons communicate by action potentials – a voltage spike – which transmit information along axons to other neurons. These spikes operate according to an all-or-nothing principle: the neuron either fires, thus generating a spike, or doesn’t fire. And yet the rates at which these spikes fire, and the timing of each individual spike, are entirely random. This means that great variation exists among neurons, their multiple connections and their firing rates – think of the brain as operating with an inherent randomness due to the randomness of its constituent neurons. Thus brain function at the cellular level is inherently nondeterministic.

Moreover there are practical limits to how much this nondeterminism can be reduced. For instance, at any given moment each neuron’s likelihood of firing cannot be computed. Now multiply this randomness of the individual neuron with the number of neurons in a typical network (somewhere between a few thousand and 20,000). But don’t stop there: the number of neurons in the whole brain – each behaving probabilistically – is estimated to be about 100 billion and, on top of this, each neuron forms synapses with at least one other neuron.

Since the number of these nondeterministic neurons is so mind-boggling, the picture is best conveyed by analogy. The adult human brain’s 100 billion neurons make one million billion connections. One million is about the population of a moderate-sized city. One billion (1,000 times a million) represents 1,000 of these cities. There are only about six billion people currently living on our planet – a tiny number compared with those 100 billion nerve cells and a paltry number compared with those million billion connections. Now think of these numbers solely in terms of their inherent unpredictability. ‘The system has so many degrees of freedom that it operates effectively as a nondeterministic system,’ writes Oxford Centre neuroscientist Edmund Rolls.

Charles Darwin’s auto-experiment on free will

Determining the existence or nonexistence of free will is also hampered by some of the conceptual confusions that beset our thinking on the subject. Certain automated responses are hardwired into our brain in ways that place biological restraints on our behaviour. Yet these restraints do not imply that we cannot act freely.

An experiment with the poisonous puff adder carried out by Charles Darwin in London’s Zoological Gardens nicely illustrates the constraint imposed on our behaviour by our brain’s organization. Darwin had decided to test his resolve by putting his face against the glass partition separating the deadly snake from the public and keeping his face there even if the snake struck at him.

I put my face close to the thick glass-plate in front of the puff adder … with the firm determination of not starting back if the snake struck at me; but as soon as the blow was struck, my resolution went for nothing, and I jumped a yard or two backwards with astonishing rapidity. My will and reason were powerless against the imagination of a danger which had never been experienced.

With all due respect to Darwin, his leaping back was not due to a failure of will but resulted from a protective reflex that proved more powerful than his reason (the snake couldn’t hurt him through the glass) and his will (the decision not to move when the snake lunged at his face). Free will is always contingent on the operation of deeper, more ancient brain structures tasked with life preservation.

Faced with certain death from the snake bite (no anti-venoms available then), Darwin’s brain was splintered into opposing impulses. Part of Darwin’s brain knew that he was protected by the glass panel; other parts of his brain responded self-protectively. Thus in a literal sense his reaction was predetermined: Darwin’s situation didn’t allow time for a conscious decision. But did Darwin exhibit an absence of free will when he recoiled from the snake? To answer that question in the affirmative is to put an unnatural and ultimately unhelpful spin on the concept of free will. Free will can be expressed only within the confines imposed by the organization and functioning of the brain. Better to think of the situation this way: Darwin’s reaction was dictated by the natural startle response that we all possess.

Scientists first learned about the startle response as a result of an amusing series of experiments carried out in the 1930s by two US psychologists, Carney Landis and William Hunt. Judged by today’s experimental standards their methods seem like something out of Laurel and Hardy. One of them would sneak up behind an unsuspecting subject on the street and fire a blank pistol while the other would film the subject’s response. Using this zany technique they discovered a reproducible startle pattern that varied little from one person to another: a general body flexion, eye blinking, forward head movement, a raising and drawing forward of the shoulders, a lifting of the upper arms away from the body, and a bending of the knees. In a word, the subjects acted reflexively; their response was not under the control of their will. But this does not equate with the claim that they lacked free will under circumstances that did not call into play automatic protective responses that are ‘hardwired’ in the brain. We do not claim someone lacks free will when they react reflexively without any opportunity for reflection.

Free will over the long haul

The responses in the Libet experiment (when to move the hand) and Darwin’s puff adder auto-experiment, along with other experiments omitted for the sake of brevity, rely on short timeframes in which people are asked to make ‘go’ or ‘no-go’ type decisions.

But establishing free will on the basis of either laboratory experiments or exotic self-experiments such as Darwin’s involves obvious oversimplifications. We don’t live in laboratories nor do we frequently come into contact with puff adders.

To truly disprove the existence of free will it would be necessary to come up with an experiment measuring brain activity over the course of minutes, hours, months and perhaps even years. For instance, I recently met a former monk who after three decades had left his monastery and resumed his former life as a teacher. He told me that he had realized his monastic ‘vocation’ at the young age of 16, entered a school run by his order and after a few years had taken his vows. Thirty years later he decided that the life of a monk was not really for him and he decided to leave the order.

Was he acting freely in each of these disparate decisions? To deny him freedom of choice would involve assuming that his life course was determined for him at age 16 by processes outside of his control; that his continued practising of the monastic life over those 30 years was based on a decision not freely chosen; that he didn’t freely decide that the life of a monk no longer suited him; and, finally, that he didn’t freely choose to leave the monastery.

Until neuroscience is able to comment upon the brain’s role in such situations extending over many years, I think it has a very limited role to play in determining the existence or nonexistence of free will. In the meantime, we’re left with the insightful observation of Samuel Johnson: ‘All theory is against the freedom of the will; all experience for it.’

WHAT IS THINKING?

Putting our minds to work

Thinking can’t take place without a topic: our thinking is always about something. We choose (or circumstances force us to choose) what we think about. Focused attention on a topic distinguishes thinking from daydreaming, in which we allow our mind to wander without any subjective sense of effort.

In contrast to letting the mind wander (see What Does a Brain do When It Is Doing Nothing?), thinking involves effort. The greater the thinking challenge, the greater the effort expended. Put simply, if the answer to the problem we are thinking about were easy to come by, we wouldn’t have to work so hard at thinking about it in the first place.

We jocularly talk of putting on our ‘thinking cap’ whenever we grapple with especially challenging problems. This idea that thinking may sometimes require specific conditions dates to the early 17th-century ‘considering cap’, first described in Robert Armin’s Foole upon Foole, written in 1605.

Whether we speak of a ‘considering cap’ or a ‘thinking cap’ some conditions are more likely than others to stimulate thinking. Most of us discover quite early in our lives that we think more efficiently when we’re provided with nonstressful, quiet and structured environments, among other practical arrangements. I say ‘most of us’ because there are exceptions, especially among those exposed during their early development to the Internet and other communication technologies (see Are Machines Scrambling Our Brains?). But for those people who aren’t comfortable simultaneously talking on a mobile phone, reading email and texting, they require more structured arrangements in order to think most efficiently.

But whatever the milieu required for its most efficient expression, thinking usually takes time in order for us to arrive at the solution to a problem. That’s how thinking is distinguished from creative insights that typically occur instantaneously. Not that this distinction is always a stark one. Sudden bursts of insight are usually preceded by deep thinking about a subject. In Louis Pasteur’s words, ‘In the field of observation, chance favours the prepared mind.’ My favourite quote along these lines is from Albert Hofmann, the discoverer of LSD: ‘It is true that my discovery of LSD was a chance discovery, but it was the outcome of planned experiments and these experiments took place in the framework of systematic pharmaceutical, chemical research.’

While many different criteria are essential for effective thinking, several are especially important: logic, precision, significance, scope and – most importantly – the willingness to evaluate the quality of one’s own thinking. This goal of ‘thinking about thinking’ requires objectivity, particularly hard to achieve when the thinker has a vested interest in the resulting conclusion. Consider as an example the philosopher Karl Popper’s criticism of psychoanalysis. Popper pointed out that for a theory to be considered scientific it must pass the test of falsifiability: it should be possible to prove it wrong on the basis of new information. ‘No human being has ever lived for 200 years,’ is a true but nonetheless falsifiable proposition. All that is required to prove it false is the discovery of one authenticated example of someone who lived for 200 years or more. So far that discovery hasn’t occurred and is unlikely to occur, but the statement at least remains falsifiable. Psychoanalysis, in contrast, is not falsifiable, according to Popper, because it is not possible for any information from whatever source to disprove the belief system underlying it. Whatever the patient says or does can be ‘explained’ by the analyst via an interpretation embedded within the context of psychoanalytic theory. If the patient accepts the analyst’s interpretation he is achieving insight; if he rejects the interpretation he is ‘resistant’; and if he has no reaction at all to the interpretation he is in ‘denial’.

Thinking and the brain

Traditionally, thinking is divided into deduction and induction. Deduction begins with a general rule and proceeds to specific examples. Induction involves generalizing from several examples to a general rule. Two sources of error are possible here. First, the generalization suggested by induction may be based on insufficient sampling. No matter how many white swans are observed it cannot be definitively concluded that a black swan doesn’t exist. (Only when the sampling error was overcome by more observation was the existence of black swans verified.) Second, if the generalization reached by induction isn’t correct, the actions taken based on that generalization may prove faulty.

Both induction and deduction require functionally intact frontal lobes, especially the lateral prefrontal cortex. Not surprisingly the left frontal lobe is most important for language-based reasoning, consistent with its well-known involvement in language and syntax. The left frontal lobe is also the principal centre for deductive reasoning.

Whatever the problem under consideration – practical or theoretical – thinking involves a multistage process. First, a problem or dilemma must attract your attention and arouse your interest. If you’re not aware of a problem or have no interest in solving it, you have no impetus to grapple with it. Next, you must formulate the problem in the form of unspoken questions or images. The clearer and more distinct the questions and images, the more likely you are to solve the problem. Posing vague or imprecise questions rarely leads to correct solutions. Good questions start with gathering relevant information. Possible solutions then present themselves; each one must be carefully considered. The frontal lobe’s executive powers are in full play during this stage of thinking. In instances of frontal lobe dysfunction at this stage of thinking, the person’s ability to formulate the likely consequences of applying one solution rather than another is impaired. Finally, in what might be called the synthetic stage, the various aspects of the problem are put together like the pieces of a jigsaw puzzle to create a composite and meaningful solution.

When thinking has concluded, the most important element now comes into play: acting on the decision that results from our thinking. Within the nervous system thinking is intimately linked with action. Indeed, you can consider thinking as the nodal point between sensation and movement. In animals – and in humans under conditions requiring a rapid-fire response in which there is no time for reflection – thinking is replaced by autonomic hardwired responses with limited degrees of flexibility.

Yet for some people making the decision to act based on the results of efficient thinking isn’t at all easy. The 19th-century psychologists had a marvellous word to describe people afflicted with a pathological inability to make a decision and act upon it. They referred to this state as ‘abulia’ and it is not at all rare. We all know people for whom thinking leads not to a crisp decision but to an endless series of ‘On the one hand … but on the other hand’ dilemmas. Instead of moving from conclusion to practical application, they demur and stall for time. Such people don’t make good surgeons or good airline pilots because in these professions thinking about a problem and solving it must be followed by swift and decisive action. But for the person afflicted with abulia the ordinarily smooth transition from thinking to deciding to act is stymied at the final step.

The abstract and the concrete

Thinking evolves along a maturational continuum starting in early childhood. The Swiss psychologist Jean Piaget was one of the first to postulate formally that thinking starts in young childhood and progresses by about the age of 12 to what he called the formal operational stage. In this stage the child can now think in abstract terms, follow logical propositions and reason by hypothesis. We don’t encounter many references to Piaget’s work today and for good reason. His research subjects were limited to children of relatively well-off European families (in fact, three of his principal subjects were his own children). This homogeneity in the choice of research subjects blinded Piaget to the vast influence of culture on thinking and intellectual development in general.

A contemporary of Piaget, the Soviet psychologist Alexander Luria, emphasized the importance of cultural rather than strictly genetic or developmental factors in determining thinking. His research in 1931 involved the inhabitants of a remote Russian village in the years prior to the introduction of widespread modernization. He discovered that these illiterate peasants who spent their lives working on cotton farms based their thinking on personal experiences rather than what we would call logical thinking involving abstraction and classes of knowledge.

‘In this mode of thought the primary function of language is not to formulate abstractions and generalizations but to revive graphic practical situations,’ wrote Luria. He provided this example of a peasant’s response to the question, ‘What do a fish and a crow have in common?’ Instead of responding, ‘They are both animals’, the peasants emphasized their differences: ‘A fish lives in the water. A crow flies. If the fish just lays on top of the water, the crow could peck at it. A crow can eat a fish, but a fish can’t eat a crow.’

For Luria’s subjects, abstraction and generalization were difficult or even impossible to express. But with greater education, the shift from primitive thinking to abstract thinking increased. In the 20th century this ability to think abstractly has resulted in an increase in IQ, as discovered by psychologist James R. Flynn. (See Are Machines Scrambling Our Brains?)

Disorders of thinking

Concrete rather than abstract thinking is only one example of a thinking defect. Other more subtle disorders of thinking are extremely common in everyday discourse and often provoke impatience and annoyance in others. ‘Get to the point’; ‘I don’t see how those two subjects you’ve just brought up are at all related’; ‘Your conclusion isn’t justified by the reasons you’ve cited’ – such comments are frequent responses to the seemingly inexplicable statements of someone afflicted with a subtle thinking disorder.

Other thinking idiosyncrasies take the form of thoughts that sound unreasonable or nonsensical on first hearing but make sense when put into a special context. ‘Should I take the bus today or pack my lunch?’ a husband asks his wife before heading off to work. Such a question remains maddeningly puzzling unless the wife remembers that on rainy days her husband drives his car and eats a packed lunch in his office but on clear days he takes the bus and eats at a nearby restaurant. In this example, anyone unfamiliar with the situation cannot process this highly compressed communication, which mixes buses, packed lunches, restaurant lunches, cars and the weather. If the husband addressed his question to anyone other than his wife, and expected that person to comprehend his question, he would seen to be suffering from a thinking disorder – his thinking would seem disordered to the listener. Many conflicts result from one person responding with dismay and even anger to seemingly nonsensical propositions and unspoken assumptions on the part of a person afflicted with similar subtle thinking disorders.

Another common thinking disorder involves thinking too much. A person afflicted with an obsessive-compulsive personality can’t stop thinking about and then carrying out senseless rituals in response to inner thoughts. Although obsessions (thoughts) are traditionally distinguished from compulsions (actions) the distinction isn’t always easy to make. The obsession of doubting commingles with the compulsion for checking – an obsession about cleanliness seamlessly merges into compulsive cleaning. And although extremes of obsession and compulsion are looked upon as neuropsychiatric conditions of varying severity, our culture remains conflicted about their milder manifestations. For example, we seek out lawyers and doctors who can be counted upon to obsess about fine points of law or possible diagnoses and then compulsively research our legal problem or illness.

Thinking things through

Great variations exist between and among people when it comes to thinking. When we describe someone as a ‘great thinker’ we acknowledge that their thinking varies from the average, both quantitatively and qualitatively. At the other extreme, we apply the soubriquet ‘mindless’ to someone who doesn’t ‘think things through’; who seems almost not to think at all when faced with a particularly demanding mental challenge; who reacts impulsively and without forethought to matters that call for the exercise of induction or deduction. The accusation that a person doesn’t ‘think things through’ implies that under ordinary circumstances thinking occupies a timeline – the more difficult the challenge the more time required for ‘thinking through’ our response. People with attention problems can’t think efficiently because they can’t maintain over time sufficient focus to consider different possible solutions. (See Is It Possible to Think of Two Things at Once?)

The medieval scholastics and others established over the centuries the discipline of logic as a set of rules for correct thinking. Although logic was at one time taught to students of widely differing backgrounds and interests (I remember logic as one of the required courses for students planning to take up medicine as a career), it isn’t studied much anymore except in philosophy departments. The discipline is based on the belief that one can achieve truth only if formally correct thinking is carried out; if the thinking isn’t precisely logical, errors occur. But such a belief creates problems of its own. Since machines can follow some of the rules of formal logic, machines can be said to think, when narrowly defined. For instance, if we accept rapid computation as thinking, then a supermarket register can think more efficiently than the majority of the customers. The computer program Deep Blue defeated the then world chess champion Garry Kasparov in 1997 and thus by formal definition was able to think more efficiently than one of the greatest chess players in the history of the game. But Deep Blue’s chess thinking depended on pure brute force based on speed and a vast repertoire of moves. This isn’t the method used by human players. Deep Blue ‘thinks’ in a different way.

Language as a determiner of our thinking

The linguist Benjamin Lee Whorf suggested in 1938 that language shapes the way we think and speak about the world. Certainly this view fits with everyday observation. After graduation from medical school or law school, doctors and lawyers employ commonly encountered words (‘headache’ or ‘property’) in more nuanced and sophisticated ways. A similar situation holds with adults who have learned to speak a second language. No matter how expert they become in the second language, confounding subtleties may arise. This is especially true when it comes to phrases or idioms that ‘don’t make sense’ in their native language. A friend of mine, a native French speaker with excellent fluency in English, was flummoxed when she heard a small liberal arts college described by one of her friends as a ‘dark horse’. The friend’s meaning (that the college perhaps wasn’t as desirable as one of the Ivy League colleges but it might prove ultimately acceptable) was lost on my friend simply because she had never encountered a French equivalent of the phrase ‘dark horse’.

But it’s not just idioms that influence one’s thinking. The way a person conceptualizes such elemental aspects of existence as time and space also differ from one person to another and, as a result, determines their thinking.

As an example of the influence of spatial metaphors on your thinking consider this situation. Imagine that you have just received and read this office email: ‘Next Wednesday’s staff meeting has been moved forward two days.’ On what day would you appear for the rescheduled meeting?

Your selection of either Monday or Friday is determined by whether you are operating under what psychologist Lera Boroditsky terms an ego-moving perspective or a time-moving perspective. If you think of yourself as moving forward through time (the ego-moving perspective), then moving the meeting forward means moving it in your forward-moving direction – from Wednesday to Friday. But if you think of time as an impersonal force that is moving towards you (the time-moving perspective), then moving the meeting forward means moving the meeting closer to you – from Wednesday to Monday. It also makes a good deal of difference what a person is doing when they are asked that question. People who travelled to an airport to pick up an arriving passenger are about equally likely to pick Monday or Friday, according to an experiment exploring that issue. In contrast, the arriving passengers, having experienced themselves during the flight as moving forward in space from their initial location to this final destination, overwhelmingly selected Friday. In this example, one’s processing of time is closely coupled with how a person envisions himself in space.

Despite our propensity when thinking to revert to spatial and temporal metaphors, we are the only creatures who can think about our thinking in context-free situations. This is both liberating and potentially perilous: don’t think enough and we are at the mercy of our impulses; think too much and we lose our freedom of thought and become tethered to obsessions, compulsions and other thinking disorders.

Like it or not, we are primarily thinking creatures. Thinking makes it possible for us to transcend the limitations of place, time and circumstance. ‘I think therefore I am,’ was Descartes’ pithy summation. Our thinking constitutes our very essence.

WHAT DOES A BRAIN DO WHEN IT IS DOING NOTHING?

The pleasures and perils of mind wandering

Actively doing something is linked to our sense of purpose. If we feel that we’re doing nothing it’s only too easy to assume that our brain is inactive as well. But our brain is always doing something even though we may sometimes feel that it’s not.

During our waking hours our mind takes the form of a stream of consciousness. When we’re asleep it’s only too easy to assume that our brain is inactive since we’re not conscious of events happening around us. But dreams have always cast doubt on this conclusion. It seems reasonable to assume that whenever one experiences a dream the brain must somehow be formulating that dream. But until the mid-20th century there was no way of proving this. What was needed was some way of explaining how the brain could be active during sleep since nothing is experienced – except in dreams – and nothing can be observed.

With the invention of the electroencephalogram (EEG) by Hans Berger in the 1920s, neuroscientists discovered that the brain is never quiescent and its rhythmic waves never cease. Even when a person is in deep sleep their EEG continues to show electrical activity, albeit a different kind of activity from wakefulness. Only at death do the brain’s oscillations completely disappear.

In the 1950s Nathaniel Kleitman, Eugene Aserinsky and William Dement provided a new vista on the study of dreams when they opened a laboratory in Chicago dedicated to dream research. They discovered that the waking and the dreaming brain possess their own distinctive EEG signatures. Thus the brain isn’t ‘doing nothing’ during sleep but, as these early sleep scientists showed, a lot of functional activity is going on within the brain of the sleeper. And this activity occurs even though – except during dreams – nothing is being experienced subjectively. Among other activities occurring during sleep, new memories are stabilized, long-term memories are consolidated and synapses are created and woven into circuits. (See Do Dreams Have Meaning?)

An important principle emerged from the research by Berger and by the Chicago group: we can’t rely on subjective experience as a determiner of whether the brain is doing anything at any given moment. To rely entirely on subjective experience for proof that the brain is doing something rather than nothing risks an inverse variant of the refrigerator light problem: a young child concludes that the refrigerator light must always remain on because he always finds it on whenever he opens the refrigerator door to check. By definition, whenever we wonder where our minds might go when they aren’t active we can be certain that our minds are active at that particular moment.

The default mode network

Until recently, determining exactly what the waking brain is doing when it seems to be ‘doing nothing’ was a difficult task. An answer was first suggested in 2002 when Marcus Raichle, a neurologist at Washington University in St Louis, used neuroimaging to study which parts of the brain become most active when people focused their attention on a specific mental task. As expected, brain activation varied with the task at hand: reading and memorizing and listening all led to enhanced activity in the brain areas specializing in those activities. But in addition Raichle discovered a network within the brain that engages when externally directed thought is absent (so-called ‘stimulus independent thought’). This network, which included part of the temporal lobe (important in memory), the prefrontal cortex (an area important in consciousness) and the cingulate cortex (an integration centre), showed its greatest activity during self-directed thought. The network Raichle discovered – dubbed the Default Mode Network or DMN – has been speculated to be the physical location of our sense of self.

The DMN becomes active whenever our mental activity involves personal recollections or imaginative scenarios of ourselves in hypothetical situations (sometimes called the Walter Mitty phenomena, named after the daydreaming character in James Thurber’s short story ‘The Secret Life of Walter Mitty’). Neuroscientists now speculate that the DMN network is important in the evolution of introspection. The DMN is also active whenever we imaginatively put ourselves into another person’s place – the basis for empathy. (See Where Do Empathy and Altruism Come From?) But when the focus of attention shifts from the inner to the outward world the network becomes less active.

Thus we have within our brain two complementary networks. First an attentional network for carrying out mental tasks that requires us to focus on the environment. Second the DMN, which becomes most active when the brain engages in internally focused processes such as mind wandering, autobiographical memory, envisioning the future and conceiving the world from the perspectives of others.

Developmentally, the DMN regions are functioning in a rudimentary fashion by early school age (seven to nine years of age). Over the next few years these regions integrate into a more smoothly cohesive interconnected network. The timing of this transformation corresponds with the child’s capacity for encoding and retrieving information, especially memories for specific experiences (episodic memory). Thanks to the maturation of their DMN networks, children become increasingly capable of self-reflection and ‘mentalizing’ about themselves: the so-called autobiographical self that is concerned with self-projection into the past and the future.

Time-wise, maturation of the DMN proceeds in parallel with the child’s awareness of personal responsibility for his actions. This occurs somewhere between seven and nine years old – roughly about the same time that the DMN begins its progression towards mature functioning. By about age five the child’s first inklings of consciousness appear; by adolescence, the DMN is well on its way to adult-level functioning. Since consciousness and the DMN develop in tandem, some scientists are speculating that the DMN may be an important network underlying consciousness.

One of my favourite accounts of the dawn of consciousness is in the novel The Elegance of the Hedgehog by Muriel Barbery. Early in the novel one of the main characters, the autodidact concierge Renée, reflects on her first day at school at age five. When her teacher first calls her by her name Renée undergoes a kind of epiphany in which she experiences consciousness for the first time:

We are mistaken to believe that our consciousness is awakened at the moment of our birth … The fact that for five years a little girl named Renée … lived in a state of utter unawareness, both of herself and of the universe, is proof if any were needed that such a hasty theory is wrong. For in order for consciousness to be aroused it must have a name.

The emergent functioning of the DMN accompanies this nascent consciousness in children. (See What Does It Mean to Be Conscious?)

The view that the DMN is associated with consciousness is supported by its absence in brain-damaged patients in vegetative states in which the comatose patient shows no indications of consciousness. In contrast, the DMN functions normally in locked-in syndrome, a condition in which a person remains conscious but paralysed and unable to move anything but the eyes. (See Can We Have a Mind Without a Body?)

Mind wandering

Ever since its discovery neuroscientists have speculated on the purpose of mind wandering in humans. Several theories compete for dominance. Mind wandering may exist to provide a natural form of mental time travel that a person can use to synthesize his or her past, present and projected experiences. Or it may simply exist as a by-product resulting from the mind’s ability to divide attention and manage several mental tasks at a time. (See Is It Possible to Think of Two Things at Once?)

Mind wandering differs from person to person with some people reporting that they never daydream or mind wander at all. But, however often mind wandering occurs, it ceases whenever the person is forced to focus on something in the environment that captures his or her attention. In the face of pressing business or professional demands the DMN dampens down as we ‘lose ourselves’ in our work. But the DMN reasserts itself when the outer demand ceases and we are once again free to mind wander while mentally ‘doing nothing’.

At any given waking moment a low-key war is taking place between the forces of mind wandering and the forces of focused attention. As we increase our attentional focus, we increase our capacity to perceive increasingly subtle changes in the object of our attention. The art appraiser focuses on the painting under review and thereby increases the likelihood of picking up on a subtle clue that will distinguish a genuine Caravaggio from a fake. But no matter how hard we concentrate on something, our minds will tend to wander as a result of boredom and lack of engagement. Behavioural studies indicate that this mind wandering away from current concerns occurs during as much as half of our waking time. On such occasions we aren’t choosing to think two things at once; our mind simply drifts away.

Thanks to these attentional drifts our mental performance can undergo extreme fluctuations. Mental stamina, which varies from one person to another, can be understood as the capacity to monitor and suppress mind wandering. What’s more, mind wandering and everyday distractibility can be easily detected by measuring variations in the activity of only a few arbitrarily selected neurons from widely scattered parts of the brain. But mind wandering is most associated with the volume of grey matter in a localized region of the brain’s left parietal cortex. Scientists discovered the importance of this region by experimentally disrupting its normal functioning. During and shortly after stimulation of this region by a technique called transcranial magnetic stimulation, the affected person becomes increasingly susceptible to distraction or mind wandering. As a practical application of this research finding, measurement of the volume of the left parietal cortex provides an easily obtained measure of a person’s tendency to become distracted or mind wander.

Although scientists have revealed a lot about the cognitive and neurological aspects of mind wandering they haven’t been able, until recently, to discover the emotional benefits or liabilities that may accompany activation of the DMN. One of the reasons for this is that collecting real-time reports from people about how they’re feeling at any given moment is cumbersome and expensive. In addition, people may not always respond candidly about their thoughts, especially if their revelations have the potential to render them vulnerable to shame or embarrassment. In 2010, however, two Harvard researchers solved these procedural problems by developing an iPhone app with a database containing nearly a quarter of a million samples. From a total of 5,000 people residing in 83 different countries, 2,250 adults were randomly sampled and contacted at arbitrary moments during their waking hours. They were asked three questions. First, a happiness question (‘How are you feeling right now?’) to be answered on a scale from 0 (very bad) to 10 (great). Second, an activity question (‘What are you doing right now?’). Finally, a mind-wandering question (‘Are you thinking about something other than what you are doing?’) to be answered by one of four options: no; yes, something pleasant; yes, something neutral; or yes something unpleasant.

Analysis of the data revealed two pivotal insights. First, people’s minds wandered frequently, regardless of their activities at the time. Mind wandering occurred in 46.9 per cent of the samples. Second, people reported being less happy when their minds were wandering compared to when they were not. And it wasn’t just a matter of the topic their wandering minds were thinking about. Although people’s minds wandered to pleasant topics more frequently (42.5 per cent) than to neutral (31 per cent) or unpleasant ones (26.5 per cent), the mind wanderers were no happier when thinking of pleasant topics compared to when remaining focused on their current activity. Of course, this finding raised another question: which comes first? Does mind wandering result from current unhappiness? Or is mind wandering the cause rather than the consequence of unhappiness? To find out, the researchers plotted a time-lag analysis of the data. Mind wandering, it turned out, is the precipitant rather than the consequence of unhappiness.

The authors concluded: ‘A human mind is a wandering mind, and a wandering mind is an unhappy mind. The ability to think about what is not happening is a cognitive achievement that comes at an emotional cost.’ This conclusion may come as somewhat of a surprise to you but think of it this way: if a person is fully engaged in the activities of the moment he is doing what sages and gurus have been advocating for centuries – be here now; discipline yourself to become fully attentive to your current activities. But this dictum ignores a basic fact about the lives of many people throughout the world. They are not happy because their life circumstances (poverty, illness, personal and family problems) make happiness very hard to achieve if they keep themselves rooted in the here and now. For such people occasional mind wandering in the form of daydreaming helps them to envision a better world as well as take the steps necessary to make that world a reality.

Doodling and other mind wanderings

According to the Oxford English Dictionary a doodle is ‘an aimless scrawl made by a person while his mind is more or less otherwise applied’. The frequency of doodling isn’t known for certain but, according to David Greenberg, author of Presidential Doodles, at least 26 of the first 44 American presidents doodled, suggesting that the practice is not uncommon. According to a 1938 study that assessed over 9,000 doodles submitted to a competition sponsored by the Evening Standard newspaper in London, doodles are produced under states of idleness, boredom, expectation and indecision. When a person doodles, his or her brain isn’t turned off but is active in sometimes highly creative ways such as generating new ideas for solving problems, coming up with ideas for original works of art, literature or design, and so on.

But whether doodling leads to creativity or merely the temporary abeyance of boredom, it shares certain parallels with the brain activity observed during DMN. Doodling, as with DMN activation, takes place most frequently during daydreaming or mind wandering. Other repetitive rather ‘mindless’ activities besides doodling may serve as activators of the DMN. Among the American presidents, Ronald Reagan regularly chopped wood, while Jimmy Carter and George W. Bush jogged almost daily and periodically engaged in marathons.

‘Be here now’

With ageing, many mental functions decline, especially attention, information processing and working memory. The DMN also becomes less active, perhaps one of the reasons creativity and mind wandering declines as we get older. DMN activity is especially affected in Alzheimer’s disease and is accompanied by the indicators of degeneration (plaques) in all of the DMN network components. The greater the devastation wrought by the plaques, the greater the reduction in daydreaming and mind wandering. In many instances this isn’t obvious to the casual observer since the silence and social withdrawal of the person with Alzheimer’s superficially resembles introspection and deep reflection. But this is a mistaken interpretation based on superficial observations of the Alzheimer patient’s proclivity for taciturnity and silence. When the Alzheimer patient is asked what he or she is thinking about, the question is met with a vacuous stare: meaningful cognitive processing isn’t taking place at all.

It’s safe to say that mind wandering and the activity of the DMN exert both positive and negative effects on brain functioning. By thinking about our past experiences and linking them with our current situation we can gain a proactive attitude towards our future. Thus the DMN can provide the circuitry for creativity and innovation in our lives. It’s also a readily available antidote for unpleasant subjective experiences, an escape from the here and now at times when the here and now seems too painful to bear. At the same time, as suggested by the Harvard study, we should be cautious in allowing our minds to wander too far lest we foster an unhappy frame of mind. So perhaps on the whole we should resist the tendency to let our minds wander. Perhaps it really is wisest to heed those sages and philosophers who have advised over the centuries that for most of us most of the time our best chance of happiness comes from being fully engaged in the moment.

IS IT POSSIBLE TO THINK OF TWO THINGS AT ONCE?

The dangers of multitasking and thought suppression

I’m sitting at my computer writing this sentence. Meanwhile deep in the background of my mind I’m vaguely aware that I must get to a dental appointment later this morning. Since this is not a pleasant thought, I’m more than happy to keep it barely perceptible on my mental horizon. Yet, even though I try to put it out of my mind, I’m only partially successful. Despite my best efforts, I am thinking of two things at once.

The quintessential contemporary example of thinking of two things at once is multitasking. It has become such a staple of daily life that we hardly question it. Apply for a job and your multitasking abilities will be one of the first things you will be asked about. ‘If I can only learn to carry out several things at once more efficiently then my time pressures will disappear,’ we tell ourselves. At first, such a claim seems a reasonable response to our compressed, overly committed time schedules. Instead of limiting ourselves to one thing at a time why not do several things at once?

Actually multitasking isn’t efficient, sets you up for mistakes and reduces your overall effectiveness. With each switch in attention your frontal lobes – those executive centres towards the front of the brain – must change direction and activate new processing. This shift from one activity to another can take up to seven-tenths of a second – more than enough time for things to go seriously wrong.

Imagine driving to work while making and receiving mobile phone calls in order to avoid ‘downtime’. While your eyes are riveted on the road during those calls, your mind is elsewhere. And it doesn’t matter whether you’re using a handheld phone or a hands-free system: the splintering of your attention is the critical variable. As you give your full attention to a particularly challenging phone call, your driving ‘programme’ inactivates just long enough not to see that truck drifting into your lane.

On occasion the ‘accident’ plays out over a longer timeframe but with equally tragic consequences. For example, in the Forgotten Baby Syndrome (FBS) a parent or other caregiver forgets to remove a child under his or her care from a car. In a recent example here in Washington, DC, the mother of a preschooler was unable to drop her daughter off at day-care because of a work emergency. The child’s father, who had never previously driven to the day-care centre, offered to drop the child off on his way to the office. After securing the child in the back seat, he drove from the house on a hot summer’s day, becoming immersed in his routine work commute. Upon arrival, he parked in his usual place, grabbed his briefcase from the front seat, and dashed into the office building. Several hours later he remembered with horror that his daughter was still in the car. She was dead and he was charged with manslaughter. What could account for such inexplicable behaviour, which has affected over 200 children in the United States in the past 15 years?

According to neuroscientist Joshua Halonen, who has studied FBS, the areas of the brain involved in habit memory (the basal ganglia and the amygdala) suppress the activity of the brain areas (the prefrontal cortex and hippocampus) involved in the planning and execution of future actions. Under conditions of monotony and routine, such as the daily drive to the office, the habit-based functioning of the basal ganglia and amygdala override the planned actions (dropping the child at day-care). Despite the father’s expectations and best intentions, he really wasn’t capable of thinking of two things at once. Thanks to habit memory, he remained immersed in the overly practised pattern of getting himself to work in the most efficient manner. The take-home message from FBS is this: be especially wary when you are doing something that differs from your usual routine. Habit and routine are the default state: if you don’t make a special effort, you’ll do what you have always done before under the same circumstances.

Heavy multitasking

Since mobile phone usage while driving is a common example of multitasking, investigators have devised experiments to evaluate it. In one of them, volunteers responded to the ringing of a phone installed on the dashboard of their car. At the instant they heard the ring they had to do a quick numerical computation comparing a previously memorized number with a number displayed on a computer screen on the dashboard. If the two numbers were the same the volunteer pushed a button. In the meantime all traffic rules were to be obeyed and the car kept under full control. In all age groups tested, driving performance deteriorated (maximal interference occurred in drivers over 55 years of age).

In another test of multitasking not involving driving, volunteers simultaneously listened to sentences while mentally rotating pairs of three-dimensional figures. Scans showed brain activity dropped by 29 per cent compared to those carrying out the two mental activities separately. This decrease in brain activity was associated with a corresponding decrease in efficiency: it took them longer and they made more mistakes. Similar multitask-associated fall-offs in performance occur when activities are rapidly alternated, such as when switching between solving maths problems and identifying shapes. In experiments measuring this, the performance of people who switched from one activity to the other took a nosedive compared to the same people who carried them out several minutes apart. During a shift from one activity to the other the prefrontal cortex ‘disables’ or inactivates the brain circuits needed for the first activity while ‘enabling’ the circuits needed for the second activity.

From the subjective point of view the mind seems capable of thinking of two things at once – since two thoughts succeed each other in milliseconds we experience them as occurring simultaneously. However, electrophysiological studies show that what’s actually occurring is a rapid shift from one thought to the other. We have here another instance of a principle mentioned elsewhere (see What Does a Brain do When It Is Doing Nothing?): subjective experience isn’t a reliable indicator of brain processing.

All of which leads to a simple rule: despite our subjective feelings to the contrary, our brains work at their best when they focus on one thing at a time. Multitasking results in inefficient shifts in our attention.

People given to frequent multitasking usually have little insight into how multitasking adversely affects them. A study from Stanford University compared ‘heavy multitaskers’ with ‘light multitaskers’. Members of the two groups were tested on how well they could filter relevant from irrelevant information. This was measured by their speed of response when asked to change quickly from one mental operation to another. For instance, in one test they were required to look at a picture depicting rectangles and note any changes in red rectangles while ignoring – mentally filtering out – blue rectangles. In this test for mental filtering and cognitive control the heavy multitaskers consistently did worse on all measures compared to their light multitasking counterparts. Think about this research the next time you decide simultaneously to surf the Internet, listen to music and text or talk on the phone. You don’t think the Stanford findings are valid for you? Perhaps you consider yourself a likely exception? If so, you’re not alone.

According to Clifford Nass, the co-author of the Stanford study, ‘People who chronically multitask believe that they are good at it.’ This false sense of invulnerability creates an operational impasse. Like the alcoholic who doesn’t share other people’s view that he has a drinking problem, the heavy multitasker continues to display various expressions of cognitive dysfunction without the slightest awareness that anything is wrong.

In addition to denial there is the tendency to project the problem on other people or circumstances. In my clinical practice I’ve encountered many victims and perpetrators of multitasking-induced car-versus-pedestrian accidents. Typically, the driver on a mobile phone blames the pedestrian whom he has struck at the intersection: ‘Without any warning whatsoever he stepped right out in front of me.’ The pedestrian has quite a different take on what happened: ‘I saw he was on a mobile phone so before I stepped into the intersection I looked him in the eye to make sure he saw me. He looked right back at me as I stepped off the kerb so I knew he saw me but then he proceeded to run into me.’ In such situations neither the driver nor the passenger is lying: the driver saw the pedestrian but it didn’t register. As a result of multitasking he simply couldn’t switch cognitive tasks quickly and efficiently enough. In the case of mobile phone-using pedestrians, they are so absorbed in the phonecall they ‘tune out’ the nearby flow of traffic.

The central bottleneck

A neural network within the frontal lobes acts as a ‘central bottleneck’ of information processing that severely limits our ability to multitask, according to researchers at Vanderbilt University who carried out experiments on multitasking. Since the brain actually processes information sequentially rather than concurrently, multitasking always involves negative performance consequences. The more people multitask the worse they do; they’re more distractible; they can’t reliably distinguish relevant from irrelevant information; they are more disorganized.

A study involving Microsoft employees found that it takes about fifteen minutes for a worker to return completely to mentally challenging work after splitting his attention between the job at hand (computer code, for instance) and answering email or instant messages. This has costly effects on information processing and knowledge acquisition since the typical computer-based information worker checks email 50 times a day and sends or receives 77 instant messages. Not only does multitasking decrease efficiency (estimated at 650 billion US dollars a year) but it impairs a person’s ability to apply sufficient concentration and attention to do his or her job and develop original ideas. Depth, clarity and cohesion of thought take time and require focused attention. Failures in any of these factors lead to degradations in the quality of knowledge. Skim-talking and skim-reading lead to skim-thinking. So, if you find it a strain to mentally juggle more than two things at once don’t despair. Your brain is functioning perfectly normally.

Dualistic thinking

We often speak of having ‘two minds’ on a particular topic. But when we use that phrase we usually mean that our reasoning is leading us in one direction while our feelings are taking us in another. (See What Happens When We Get Angry?)

Another example of ‘two minds’ involves conscious versus unconscious mental processing. For example, I’ve kept journals for many years and one of the benefits of reviewing them is the opportunity to observe how I unknowingly repeat certain actions and patterns of behaviour on the same dates in different years. Since these dates are not holidays or special occasions, there isn’t any reason I would select today, say, to visit the same rarely visited restaurant that I did a year or two ago on this date. From conversations with other people who keep journals I’ve discovered that these unconscious repetitions aren’t at all unusual. On occasion they may perhaps be explained simply on the basis of the running of two separate mental processes: a stimulus (a sunny day) leading to a repetitive response (a trip to the beach). At such times we are thinking of two things at once but not really processing them as such. ‘It’s a nice day and I think I’ll go to the beach’ is consciously experienced while we remain unconscious of the other thought that determines our behaviour: ‘It’s a nice day; I had a good time when I went to South Beach at about this time last year; I think I’ll go to that beach again.’ If last year’s trip to the beach had turned out to be an unpleasant experience would that decrease the chances we would elect to go back on the same day a year later? While one can’t be certain of such things, I think it’s safe to say that either going or not going to the beach involves thinking of two things at once but being conscious of only one of them.

Freud, of course, was the first to bring the concept of the unconscious to popular attention. We speak of a ‘Freudian slip’ when someone unintentionally says something that expresses their true feeling more accurately than the phrase they intended to say. Of course, many of these Freudian slips are based on simple pronunciation and syntactical errors. But on occasion they strongly suggest that the perpetrator is thinking of two things at once and admitting to only one of them.

Internal monologues

Other examples of dualistic thinking are harder to uncover because people are frightened or ashamed of them. It’s not that uncommon for a perfectly normal person to experience an internal monologue involving a nameless anonymous voice that comments on ongoing events and people in the immediate vicinity. In schizophrenics this monologue takes the form of a voice either emanating from somewhere in the external world (an auditory hallucination) or originating from an internal critical observer who controls the person’s thought processes and on occasion issues commands that must be obeyed (command hallucinations).

In people unaffected by psychiatric illness the internal monologue generally consists of a stream of critical comments that the person recognizes as originating from his own mind rather than (as with the schizophrenic) attributing them to something or somebody in the environment. Fatigue and stress are the principal generators of internal critical companions. But whatever their cause or the frequency of their occurrence, for the person experiencing these internal commentaries, two thoughts seem to be occurring at the same time in polyphonic disharmony. Many times the comments are sarcastic or sadistic or otherwise out of synch with one’s usual thought patterns. Because of their oddity the internal comments are mildly disturbing and, as a result, not everyone will admit to them. No one wants to be accused of mental instability or ‘hearing voices’.

Try not to think about it

Paradoxically, the more effort expended in trying to silence inner comments and not think two things at once, the harder they are to control. This phenomenon was labelled the ‘paradoxical effects of thought suppression’ in a famous paper by that name written by Daniel M. Wegner, a psychologist and expert on the psychology of mental control. The term refers to the increasing difficulty one experiences when trying to drive a particular thought ‘out of mind’. You can experience this for yourself right now by trying not to think of a white bear. Put down this book for five minutes and think of anything you want except a white bear … How did you do?

The paper was the result of an experiment testing people’s ability not to think of a white bear. According to the paper, ‘People not only found it hard to suppress the thought in the first place but that attempt to do this made them especially inclined to become absorbed with the thought later on.’ And this tendency to compulsively think about topics one has determined not to think about carries practical implications. Dieters try not think about snacks; alcoholics try not to think about alcohol; rape victims and war veterans try not to think of the traumas that they previously endured.

‘I have been doing my best not to think about it, but by trying so hard not to think about it, I can’t stop thinking about it,’ said former New York Yankee shortstop Paul Zuvella during his 0-for-28 batting slump at the start of the 1986 season.

But trying to force oneself not to think of something carries an additional liability, according to Wegner. He refers to the so-called abstinence-relapse phenomenon where the unwanted thought returns with a vengeance. In the white bear experiment many of the participants reported thinking of white bears more frequently than they had ever done before. They experienced first-hand the stress that can result when their brain is thinking of two things at once.

Our difficult time with thought suppression comes when in the sequence of conscious thoughts we get the idea to suppress a current thought. The suppression metathought (‘I’d rather not think of a white bear’) is here, but the thought (‘white bear’) is here, too.

Both the thought (the bear) and the metathought (the desire to get rid of the thought of the bear) occur together in a shared but conflicted moment of consciousness. Consciousness is therefore caught in a paradox.

What can be done to reduce the power of unwanted thoughts interrupting our principal train of thought? If attempts at wilful suppression don’t work, what does? Simple distraction is probably the most frequent approach to getting the brain to rid itself of diverting and unwanted thoughts. Instead of concentrating on not thinking of that white bear – and thereby strengthening that line of thought – the affected person should think of something else, such as an upcoming holiday. But distraction is nothing more than a quick and dirty approach that works only up to a point. The intrusive thought eventually reasserts itself. Another approach suggested by Wegner involves letting the thought occur, giving in to it, observing it and – most importantly – not suppressing it or getting upset about it. Once we stop suppressing thoughts then, by definition, we no longer have thoughts we do not want.

Turning off suppression, it turns out, is the ultimate technique for helping the mind to rid itself of the unwanted thought and return to thinking of one thing at a time. ‘In embracing our unwanted thoughts, we escape the tyranny that suppression can hold over us,’ according to Wegner. ‘We no longer must worry about our worries, no longer wish our thoughts away, no longer believe that we are plagued by images that we cannot overcome. When we turn towards these things and look at them closely they can disappear.’

In summary, it seems that we can’t think of two things at the same time (or at least not consciously, however much it feels like that). And attempting to do so can be highly inefficient, as with extreme multitasking, or distressing, in the presence of unwanted thoughts. So when we try to think more than one thing at a time, we should consider the consequences.

WHAT IS KNOWLEDGE?

What do we know and how do we know that we know it?

We pride ourselves on living in the age of information. Thanks to the Internet and its various search engines we have ready access to more information than at any time in recorded history. But information is not the same thing as knowledge.

While learning an isolated fact may provide us with information that we didn’t formerly possess, it doesn’t provide knowledge, which requires context: some way of making sense of the information and putting it to use. Think of a continuum starting with information and progressing to knowledge and finally, at the opposite end of the continuum, to wisdom.

At the low end of the information–knowledge–wisdom continuum is the ‘factoid’: a piece of information without a context. ‘Taller people are more prone to cancer’ is a factoid. Standing alone, it serves only to stimulate curiosity and speculation. The factoid becomes real information only when it is put into a context. In this case: a greater level of growth hormone may, as an undesirable by-product in taller people, stimulate cancer cells. Only after we have enriched our understanding of the factoid by exploring its meaning in the larger picture, can we begin to speak of knowledge.

Most knowledge is language-mediated such as when we respond to a question like ‘Who was the 16th president of the United States and what were his accomplishments?’ But not all knowledge is dependent on language. The athlete or the musician transfers knowledge and skills first learned from instruction and conscious intention into automated performance. The knowledge becomes embedded into the nervous system so that conscious effort isn’t required. For instance, I’ve watched my friend former United States chess champion Lubomir Kavalek play simultaneous chess with several gifted chess players while at the same time holding a conversation with my wife about cooking. Kavalek can do this because he processes his chess knowledge too rapidly for it to be based on conscious deliberation. Athletes refer to this automatic processing as ‘muscle sense’ but it’s more correctly designated ‘brain sense’ since it’s based on the formation of neuronal circuits that, after their establishment, can operate without conscious effort. Much practice and effort is required to form these circuits and thus reach the level of proficiency required of a professional.

Direct and indirect knowledge

Knowledge in one sphere or at one level may not be applicable under other circumstances. For instance, a distinction must be made between the knowledge of quantum physics and the knowledge of everyday life. As the mathematician G.H. Hardy phrased it: ‘A chair may be a collection of whirling electrons, or an idea in the mind of God: each of these accounts of it may have its merits, but neither conforms at all closely to the suggestions of common sense.’

Bertrand Russell made another important distinction in regard to the knowledge that is available to us: knowledge by acquaintance and knowledge by description. In The Problems of Philosophy Russell gives as an example our knowledge of Julius Caesar:

Thus when we make a statement about Julius Caesar, it is plain that Julius Caesar himself is not before our minds, since we are not acquainted with him. We have in mind some description of Julius Caesar: ‘the man who was assassinated on the Ides of March’ … Thus our statement does not mean quite what it seems to mean, but means something involving, instead of Julius Caesar, some description of him which is composed wholly of particulars and universals with which we are acquainted.

Knowledge is a kind of possession as suggested by such synonyms for knowing as ‘apprehending’. What the mind cannot somehow ‘grasp’ must remain unknown and cannot be transformed into knowledge. The situation is very different from knowledge gained at the level of physical sensation: what the senses cannot detect may still become objects of knowledge thanks to technological instruments that do the detection for us (space telescopes, microscopes etc.).

When the mind seeks to understand itself, things become especially interesting. The mind’s exploration of its own workings renders the mind an object of knowledge as well as the mediator of that knowledge. Furthermore, the knowledge acquired when the mind examines itself varies with the conceptual framework adopted. If the discussion is limited to the discussion of neurons and circuits and neurotransmitters, one kind of knowledge is acquired. If the discussion concerns faculties of the mind such as memory, imagination and intelligence without any reference to the embodiment of these faculties, another kind of knowledge is acquired. The goal of modern neuroscience is somehow to meld these two kinds of knowledge into a sort of metaknowledge. But, as pointed out by Oxford philosopher Gilbert Ryle, any cheeky optimism that this ambitious undertaking can be successful must be tempered by the sobering fact that neurons and mental faculties represent different orders of discourse.

In what sense can a thought be equated with a pattern of neurotransmitter interactions? Only in the correlative sense: when you think a thought or make a decision the neuroscientist may be able to approximate where the thought or decision first arose in your brain. But correlations between these two processes can go only so far. The Arabic proverb ‘A chameleon does not leave one tree until he is sure of another’ cannot be explained at the level of circuits and molecules. This dichotomy between words and symbols on the one hand and brain anatomy and physiology on the other puts some limits, it seems to me, upon the self-knowledge we can achieve. Thanks to introspection and the observations of others about us, we can learn quite a bit about ourselves. But that practical knowledge may not be translatable into neurological terms.

Obstacles to knowledge

When true and reliable knowledge becomes threatened from whatever source, the door is open to various forms of false knowledge: stereotypes, superstition, atavistic beliefs, prejudices etc. For instance, prior to the discovery of disorganized electrical discharges within the brain, epileptic attacks were attributed to the influence of witches, demons and other malevolent forces. Although we’ve come a long way since then, the need to revise commonly accepted but incorrect explanations never ends. No generation including our own is exempt from deficiencies or distortions of knowledge. One generation’s knowledge is another generation’s foolishness or mythology. ‘The religion of one age is the literary entertainment of the next,’ wrote Ralph Waldo Emerson.

While knowledge usually leads to an increase in freedom and autonomy, some prejudices and stereotypes – if they are held firmly enough – may prove resistant to increased knowledge. For one reason, knowledge and belief are not always easy to distinguish from each other. Indeed is knowledge anything more than belief? Although ‘How do we know that we know?’ is more of a philosophical than a psychological or neurological question, distinguishing knowledge from mere belief remains a perennial challenge. For example, in 2011 a panel, the National Science Board, associated with the National Science Foundation (NSF), altered the two true–false questions it had been using for two decades to measure scientific literacy in the general population. The original true–false statements were ‘Human beings, as we know them today, developed from earlier species of animals’ and ‘The universe began with a huge explosion’. The revised version of each statement begins, respectively, ‘According to evolutionary theory, human beings …’ and ‘According to astronomers, the universe began …’. The purpose of these changes is to distinguish clearly between knowledge and belief. ‘Knowledge and belief are not the same,’ said a member of the panel in defence of the change in wording.

Neither is knowledge, even detailed and highly reliable knowledge, always sufficient to change behaviour. A person would have to be living on another planet not to know that smoking causes cancer, or that a diet heavy on saturated fats increases the chances of a heart attack, or that an overly sedentary lifestyle leads to a plethora of health problems later in life. Yet a distressingly large proportion of the citizens of the most literate and technically advanced societies on Earth continue to smoke, drink to excess, consume more fat than is good for them and engage in little or no exercise.

Technology and knowledge

Technology is changing our relationship with knowledge. It is doing this by influencing how information becomes available to us. Traditionally when we wanted information on a topic we were forced to consult sometimes inconvenient written sources (libraries, texts etc.). Now we can open our iPad and look up the information in seconds by consulting our favourite search engine. Yet this convenience exacts its own price: since the advent of search engines we have been reorganizing how we remember things. We are much less likely to remember information we’ve learned online compared to learning it from another source. It’s as if the brain were operating according to the principle, ‘Why remember something if it can be looked up online whenever the need for that information arises?’ According to research carried out at Harvard on our changed informational habits, we are more likely to remember the computer file where we have stored some information than to remember the information itself. Google and other search engines are now serving as personal memory banks that make it unnecessary for us to memorize and remember specific pieces of information: the so-called Google Effect. The Internet is providing not only increasingly vast amounts of knowledge, but it’s also organizing it in different ways. Think of the Internet as a prosthesis that both strengthens and weakens the brain’s power and efficiency. It strengthens it by increasing the amount of knowledge available for individual consumption; it weakens it by increasing the user’s dependency on external rather than internal management resources such as memory.

How much information is the Internet providing? How much information is the brain capable of processing? In order to answer either question it’s necessary to make an important distinction between information as we colloquially use the term and information as defined by so-called information theory. According to information theory, information is defined as processed, stored or transmitted data. This contrasts with the colloquial everyday use of the word ‘information’, which is equated with facts derived from study, experience or instruction.

As an example of this distinction, imagine watching a streaming two-minute video of the orchid sitting on my desk. Nothing is happening on the video, just the orchid sitting there. Compare this experience with listening on the radio to a half-hour debate about global warming featuring two well-informed experts on opposite sides of the issue. Which of these two sources contains the most information? It depends on how you define information. Even though you learned more information, as we usually colloquially employ the term, from the global warming exchange, the video of the orchid involved the transfer of many more bytes and therefore according to information theory conveyed more information.

While we live in an information-rich society, only a small percentage of this information can be transformed into knowledge. We can do that only with information that challenges our attention, memory, judgement and other cognitive operations. Consider aphorisms, which are cognitively complex: neurologists use them to test higher cognitive processing ability, with an emphasis on knowledge, abstraction and wisdom. For example, ‘Neurosis is a secret that you didn’t know you were keeping’ (Kenneth Tynan). That short sentence transforms simple information into an abstract form, in order to convey knowledge and accumulated wisdom.

Currently the Internet provides the greatest challenge to transforming information into knowledge. Electronic media are ill suited to the slow processes required for acquiring knowledge. ‘They supply information, but not knowledge or meaning, and the facts alone are not enough to establish real understanding, which requires context and reflection,’ says social commentator and author Winifred Gallagher. In such an environment the importance of information is inverted: the trivial consistently trumps the important.

‘Trivial information pushes out significant information,’ writes Neal Gabler, a senior fellow at the Annenberg Norman Lear Center at the University of Southern California. ‘We have become information narcissists,’ Gabler claims and warns that ‘what the future portends is more and more information – Everests of it.’ Such a climate does not favour the accumulation of knowledge, much less the formation of wisdom generated from that knowledge.

Obtaining knowledge

Our ability to acquire different categories of knowledge varies according to time and circumstances. If we’re reading in a noisy chaotic environment it’s difficult to remain focused and not give in to distraction. Other environmental impacts remain more controversial. As I learned during a visit to Monticello, Thomas Jefferson was convinced of the power of diurnal variations to influence knowledge acquisition. Borrowing from Francis Bacon, who emphasized that the mind can be divided into discrete ‘faculties’, Jefferson believed in a correspondence between the faculties of Memory, Reason and Imagination, and the three principal categories of human knowledge: History, Philosophy and Fine Arts. He believed that although knowledge may exist as a unity, it is apprehended by different parts of the mind (the ‘faculties’) and that each of these faculties is subject to diurnal variations in efficiency. ‘A great inequality is observable in the vigour of the mind at different periods of the day. Its powers at these periods should therefore be attended to in marshalling the business of the day.’ Accordingly, he recommended that specific categories of books should be read at different times of the day and night. Jefferson suggested the following schedule:

Before eight in the morning: Physical Studies, Ethics, Religion, Natural Laws

Eight to noon: Law

Noon to one: Politics

In the afternoon: History

From dark to bedtime: Belles-lettres, Criticism, Rhetoric, Oratory

In cataloguing his vast library of 6,700 volumes Jefferson employed a complementary arrangement.

Knowledge as the precursor of wisdom

If we progress sufficiently in our knowledge gathering throughout our lives, we may be fortunate enough to transform what we’ve learned into wisdom. Wisdom is a deeper form of knowledge involving our reflections on our accumulated life experiences. Not everyone makes that transition from knowledge to wisdom. English novelist John Cowper Powys wrote:

If by the time we’re sixty we haven’t learned what a knot of paradox and contradiction life is, and how exquisitely the good and the bad are mingled in every action we take, and what a compromising hostess Our Lady of Truth is, we haven’t grown old to much purpose.

The late Paul Baltes of the Max Planck Institute in Berlin defined wisdom as ‘a state of knowledge about the human condition, about how it comes about, which factors shape it, how one deals with difficult problems, and how one organizes one’s life in such a manner that when we are old, we judge it to be meaningful’. Wisdom-related criteria include: an accumulation of factual and procedural knowledge about life (what to do under a given circumstance and how to go about doing it); an appreciation of the likely meaning of events; an ability to put things in context and take a long overview rather than a narrow here-and-now approach; and an acceptance of the inherent ambiguity and uncertainty in any complex situation.

Under ideal circumstances the information that we gather over our lifetime is transformed into something larger and more meaningful: knowledge, both practical and theoretical. And if we’re really lucky, we will successfully reach the furthest end of the continuum where the knowledge that we’ve gained will be ultimately transformed into wisdom.

HOW DO WE STEP OUT OF THE HERE AND NOW?

Processing the past and the future

Our brain enables us to envision things that haven’t yet come about, things that occurred long in the past, things that have yet to occur, and even things that could never occur. This capacity to envision a reality beyond our immediate perception is, as far as we can know, unique to us – certainly when taking the long view.

While animals can be trained to anticipate the short-term consequences of their actions (carrot or stick), only humans are capable of picturing the consequences of today’s action or inaction extending over a lifetime. Imagination is the principal prerequisite for the successful time travel required to step out of the here and now. In some, this takes the form of elaborate visual images of the desired future; for others, the images may be replaced by presciently accurate ‘hunches’ about how to get from an unsatisfactory present to a desired future. A person who cannot imagine a more hopeful future lays himself open to apathy, depression and self-destructive behaviour. The same holds true for society: imagining a brighter future can serve as an antidote to the darkness of boredom, cynicism and pessimism. Thus stepping out of the here and now through the exercise of imagination is individually and collectively liberating. Although if imagination isn’t coupled with thought and effort, it risks becoming mere dreaming.

The time-travelling mind

Mental time travel is the process of projecting ourselves into the past or the future. In the process, parts of the brain are used that link memory fragments from our past with novel scenarios about our future. This is possible only because of the fluidity of episodic memory: every time we remember something and think about it, we create a new and slightly different memory that we then store for future retrievals and future additional modifications. Thus our past doesn’t exist like a DVD that offers an unvarying sequence of sounds and images. When we share a memory with another person his questions and comments bring about changes in the way we remember the past event. This memory fragility is one of the objections to eye-witness testimony: the witness’s memories are undergoing modification during the process of cross-examination. For example, the question ‘Did the truck ignore the red light?’ can alter the witness’s original memory of the intersection, which involved a ‘Stop’ sign and not a set of traffics lights.

Only humans can imaginatively explore what the possible consequences for the present and future might be if something hadn’t happened. This ability to imagine counter-factual events makes us unique among organisms (see What Makes the Human Brain Special?). While apes and other higher primates may be capable – to an unknown extent – of projecting themselves into an imagined future, they’re not able to imagine, say, what life might have been like if they had been born and raised in another colony. But we do this kind of imaginative thinking all the time.

For most of us, thought about the future serves a range of adaptive functions, for example, planning and decision-making. Our imaginative productions about the future also carry distinctive emotional valencies, with positive imaginings occurring more frequently and more vividly than negative ones (one of the reasons few of us spend much time imaginatively envisioning our death). Autobiographical memory – recall of events that have happened to us in the past – can be used for mental time travel (and usually is) but we’re also free to mentally picture ourselves pursuing other paths. This can make it easier for us to become the person we want ourselves to be – the mantra expressed in one form or another by self-improvement programmes. Sometimes the modification created by stepping out of the here and now can be quite extreme, as with a patient of mine who in his 30s began thinking of himself as a herself, the prelude to the sex-change operation that reconciled a lifetime of mental time travel imaginings about a new gender identity.

The ability to time travel via imaginative scenarios varies from one person to another. Some people can set their sights on a distant goal and, until it is achieved, never veer from their chosen path over many arduous and demanding years. Others, in contrast, seem locked in the here and now, seemingly unable to maintain in their mind the achievement of any goal that requires them to imaginatively envision themselves beyond their immediate circumstances.

The brain and the here and now

Recent brain research has defined an area of the frontal lobes, the medial prefrontal cortex (mPFC), as the brain area that determines a person’s ability to step out of the here and now. Normal functioning in this area is essential for a person’s capacity to take the ‘long view’, to prefer greater rewards later rather than lesser rewards now. Psychologists refer to the character trait of making choices based solely on current circumstances as ‘temporal discounting’. Young children – in whom the medial prefrontal cortex hasn’t matured – are notorious practitioners of temporal discounting: they’ll take what’s offered in the present no matter how meagre the offer rather than waiting in the interest of garnishing a richer reward that will come after a delay. As the child grows older and the prefrontal cortex becomes functionally active, the tendency for temporal discounting decreases. Unfortunately, there are enough exceptions to this rule (i.e. impulse-driven behaviours) to keep casinos and racing tracks in business.

In addition to lessening the tendency for temporal discounting, the medial prefrontal cortex is responsible for another uniquely human ability: vividly imagining possible future scenarios. Both functions operate in tandem and mutually support each other: the more clearly a future reward is envisioned (so-called episodic prospection) the easier it is to put aside temporal discounting and await the larger reward.

The importance of the medial prefrontal cortex was first suggested on the basis of the effects of injuries or diseases on this area. Impairment of normal medial prefrontal functioning leads to short-sighted behaviour tightly tethered to the here and now. Due to this foreshortened time perspective, the frontally compromised person’s choices are based on a world view aptly summed up by the aphorism ‘A bird in the hand is worth two in the bush.’

It is not coincidental that prescience about future choices should depend so much on the medial prefrontal cortex. A high density of nerve fibres, each with an increase in dendritic spines (contact points for connection with other neurons), makes this area uniquely suitable for integrating information from areas throughout the brain. Especially important are the impulses (or information) coming to the medial prefrontal cortex from brain areas specializing in the processing of emotion and those autonomic states (pulse rate, breathing patterns, unconsciously perceived outputs from the inner organs) that generate one’s inner feelings. The neurologist Antonio Damasio has labelled the sum total of these influences as a ‘somatic marker’, the basic inner feeling one has about the ‘rightness’ of allowing future rewards to temper current impulsions. Thus both the microscopic structure and the linkage patterns of the prefrontal cortex underlie our ability to step out of the here and now.

Working memory

Stepping out of the here and now demands sound judgement and the ability to maintain a clear vision of where one is at the moment and where one wants to be in the future. In this way, past, present and future form an experiential continuum. The journey along this continuum is facilitated by cultivating the art of memory since stepping out of the here and now frequently requires us to revisit the past as well as envision the future.

Short-term working memory was first localized to the prefrontal cortex based on experiments involving monkeys performing what neuroscientists refer to as delayed-response tests. The neuroscientists discovered that monkeys could view a flash of light on a screen, hold this location in mind (the delay phase), and then return to this spot when prompted.

In another, more demanding test of a monkey’s ability to hold information ‘online’ in working memory, the monkey is shown a novel object, say a blue disc, under which it finds a peanut reward. A screen then descends and obscures the monkey’s view for a time period ranging from seconds to minutes. During this ‘delay phase’ a new object such as a red disc is introduced beside the blue disc. The peanut reward is now hidden under the new red disc rather than the blue disc. When the screen is raised the monkey, in order to get its peanut, must learn to reject the previously seen blue disc in favour of the novel red disc. Because each trial uses a new combination of coloured objects, the monkey must hold in memory the object it has previously seen so as to be able to recognise the new object under which it will find the peanut reward. If the monkey couldn’t hold in working memory the previously seen coloured object, it wouldn’t be able to switch to the new object where the peanut reward is now hidden. The researchers who originally carried out these working-memory experiments discovered that during the delay phase, activation occurred in neurons located in the lateral prefrontal cortex.

While specific areas of the brain are known to be involved in short-term working memory (part of the prefrontal cortex and the parietal lobes), the location of long-term working memory is a bit less well defined, but it too involves the frontal lobes. The neuroscientist Donald Stuss refers to the process as ‘future memory’: mediating between ‘present events and their anticipated consequences, between the image of a goal and the acts that will lead to it’.

Thanks to the mental time travel made possible by our frontal lobes, long-term working memory becomes possible. We can imagine ourselves as older or younger, richer or poorer, living under similar or different circumstances. We perform this mental sleight of hand by means of long-term working memory. Working memory is often compared to mental juggling. Just as juggling involves keeping a varying number of balls in the air, working memory involves simultaneously keeping a number of items in mind. While working memory usually refers to short timeframes (such as remembering where you were in a conversation while attending to a momentary distraction), long-term working memory involves keeping in mind two or more mental scenarios over an extended period of time.

Executive control

Working memory is only one component of what neuroscientists refer to as executive control (also known as executive function). Think of an executive such as the CEO of a large multinational company. The CEO coordinates activities at the highest level in order to gain maximum productivity for her company. Among the qualities required of a successful CEO are an enthusiasm for testing out new ideas, a response pattern marked by taking carefully considered rather than impulsive responses to challenges, and, most important of all, an ability to remain focused in the face of distractions. All of these qualities can be developed and enhanced through effort and practice. Four qualities are especially critical to success: creativity, flexibility, self-control and discipline.

While functioning as the brain’s CEO, the frontal lobes oversee and interact with all of the other brain regions in order to plan and anticipate the consequences of behaviour. They initiate and inhibit all of the brain’s responses and they link past and present experience with future expectations. Overall, the frontal lobes construct meaning and purpose by reconciling the possible to the actual, the past to the future, and the individual to the universal.

As an example, Hamlet remembers Yorick while gazing at his skull in the graveyard. A ‘fellow of infinite jest and most excellent fancy,’ he recalls him. In remembering how Yorick appeared and acted before death and reconciling that memory with the skeleton before his eyes, Hamlet is employing his working memory at the highest level of abstraction. He engages with the present, remembers the past and, I think we can reasonably assume, foresees his own future, thus creating an encompassing vision of the universal principle of mortality.

Impairments in frontal lobe functioning are marked by a pervasive inability to step out of the here and now. A person with frontal lobe dysfunction is imprisoned in the present without the ability to envision themselves existing in situations different from their current circumstances. This is at least a partial explanation for those errors in judgement that regularly accompany impairments in frontal lobe function. Typical of this so-called dysexecutive syndrome is a famous patient identified in neurological literature as Elliot (not his real name). Elliot was a happily married accountant described by his colleagues as reliable and responsible. After surgery for a brain tumour in his frontal lobes that Elliot developed in his late 30s, his personality took a distinct turn for the worse. Soon after the surgery Elliot turned impulsive and easily influenced by passing whims. He divorced his wife, rapidly remarried and then divorced again. He alienated many of his friends over tactless and inconsiderate remarks. Previously a shrewd businessman, Elliot could no longer manage his financial affairs, invested in ill-advised ventures, lost all of his money and, finally, had to declare bankruptcy.

Elliot’s downward spiral illustrates the loss of all of the executive control functions of the frontal lobes that previously enabled him to step out of the here and now. He was no longer able to see beyond the immediate present thanks to severe disruption in his ability to plan. A similar disability occurs in psychopaths, even those who are highly intelligent and temporarily successful. Failing to step out of the here and now by mentally envisioning the eventual consequences of their actions, they propagate scams or other crimes that people with properly functioning frontal lobes instinctively recognize as likely to lead to detection. The psychopath isn’t totally incapable of imaginatively projecting himself beyond the immediate present. Rather, thanks to limitations in the functioning of the frontal lobes, his horizon is limited to those consequences he wants to see.

A balance is required

While the ability to step out of the here and now is indispensable for efficiently managing one’s life, it can also entail some painful consequences. Have you ever known someone suffering (the verb suffering isn’t chosen casually here) from an obsessive-compulsive disorder? If you have, you’ve personally observed the negative aspects of the ability to move via mental time travel beyond the here and now. The obsessive ruminates about dire events that will never come about. (‘My life has been full of terrible misfortunes most of which have never happened,’ as Montaigne wryly described the process.) Just like a cow that repeatedly chews the same cud of grass (the origin of the word ‘ruminate’), someone plagued by obsessive-compulsive thought patterns plays over and over in their mind the same repertoire of imagined invariably negative mental scenarios. Similar propensities accompany depression. ‘Catastrophizing’ is the apt term used by psychotherapists for this tendency to imagine oneself needlessly (and usually inaccurately) in a future comprised of the darkest and most hopeless of circumstances.

Fortunately, fixes exist for overextending oneself beyond the here and now. Eastern thinkers especially in the Buddhist tradition suggest that we should live in the moment, which is an entirely different experience from living for the moment. While the psychopath lives within the limited horizon of the present, the Zen meditator attends to currently available sights and sounds or, via an alternative technique, to focused concentration on the intake and expulsion of breath.

Any consideration of the positive and negative aspects of stepping out of the here and now cannot omit reference to religion. There isn’t any doubt that religion serves throughout the world as mankind’s primary vehicle for transcending the here and now. Putting aside the question of whether any basis exists for religious belief (a hugely important question that I prefer to beg since it is incidental to my point), religion is probably the most universal inspiration for mental time travel. The religious devotee is encouraged to expand his mind beyond present tribulations and urged to think of some future accountability before a perhaps stern and inflexible god or goddess. These otherworldly goals certainly call upon all of the considerations we’ve discussed in this chapter (the frontal lobes, working memory, mental time travel etc.). The key question, of course, is this: when we employ religion as the vehicle for stepping out of the here and now, where exactly are we stepping into? A better world than we now inhabit, or a delusory creation based on our own imagining?

WHERE DO EMPATHY AND ALTRUISM COME FROM?

Seeing ourselves in others

When we empathize with someone we mentally establish an emotional link between ourselves and that other person. We can’t really empathize with that person unless we somehow become that person. And this extends beyond mere sympathy.

A sympathetic person may express concern or sorrow for another person’s situation but nonetheless hold that other person at an emotional distance. Empathy requires imaginatively ‘walking in the other person’s shoes’ (as it is metaphorically expressed). To empathize with another person doesn’t require that we have experienced something in our own life similar to their experience (although that helps a lot). Even if the person’s experience is totally foreign to us we can still empathize by a deliberate act of imagination.

In an experiment measuring empathy, volunteers watched a man strapped to a machine that at irregular intervals appeared to deliver painful shocks to the man’s hand (a sham since no shocks were actually involved). Some of the observers were told simply to watch and make observations about the man’s responses; others were told to imagine how the man was feeling and how they would feel if they were in his situation. The volunteers who engaged in these deliberate acts of imagination showed greater empathetic responses as measured physiologically (palm sweating and blood vessel contraction) along with their self-reports. Even though none of the volunteers had ever been personally involved in a similar situation, their imagined scenarios were sufficient for an empathetic response.

Think of empathy as operating like a dimmer switch (as opposed to an on/off switch), capable of varying intensities of illumination. The strength of the empathetic response varies with the degree of identification we’re able to muster. Strong identification (someone who looks like us or someone with whom we can easily identify because of age, race, religion etc.) can lead to a fully developed empathy; weak identification (a terrorist blown up while in the process of making a bomb) leads to weak or nonexistent empathy.

The capacity for empathy is not evenly distributed throughout the population. Some people seem to be more empathetic than others. Why? In an experiment aimed at answering that question a woman was placed in an fMRI machine with her boyfriend sitting beside the machine. While lying in the machine the woman can see on a computer screen her boyfriend’s hand, which, along with her own hand, is hooked up with an electrode. Periodically the electrode delivers a moderately painful jolt to the hand of one of them (the shocks were real – it is an experiment that I think pushes the ethical envelope somewhat). A message on the computer monitor inside the fMRI informs the woman whose hand will be zapped next and how intense that shock will be. When the woman receives the shock herself two parts of her brain light up: the somatosensory cortex (corresponding to the hand area in her brain) along with other areas that process her emotional experience of the pain. But when she watches her boyfriend receiving a shock to his hand (as predicted moments before on her monitor) her brain’s response changes dramatically. While her somatosensory cortex remains quiescent (she wasn’t physically experiencing the shock), the emotional centres flare up significantly. Sixteen other couples participated in the same macabre experiment, and with similar results (see What Is This Thing Called Love?). Interestingly, the intensity of the women’s emotional responsiveness to this experiment varied according to how well they scored on standard questionnaires gauging empathy: the higher the score, the more intense the fMRI activation in the emotional centres.

These experimental findings mirror our everyday observation. Whether we like to admit it or not, all of us have our emotional limits when it comes to our empathetic responsiveness, even to the sufferings of those who are closest to us. For instance, it’s been my observation over the years that marital harmony or disharmony is often determined by the rightness of ‘fit’ between the empathetic powers of the two partners. If one partner is overly empathetic, the other partner may experience a sense of being emotionally strangled, suffocated or engulfed. At the other extreme, if one of the partners is endowed with meagre empathetic resources, the other partner feels unloved and rejected. Empathy, as with magnetic attraction, must be maintained at just the right distance – if two magnets are too closely approximated, they fuse together; if they’re too far apart, no attraction exists at all. The goal with the magnets – as with the emotional balance between the partners – involves maintaining just the right amount of attraction, not too much, not too little.

The neurology of empathy

Empathy is processed via two separate pathways within the brain. The first involves networks beneath the cortex that are important in emotional experience. Since this pathway processes raw emotion it acts quickly and reflexively when I encounter someone who arouses my empathy. The second, the cortical route, takes longer to respond because it involves an intellectual appraisal and evaluation of the plight of the person with whom one is empathizing. Think of the cortical route as the thinker and the subcortical route as the emotional experiencer.

The neurological underpinning of both empathy and altruism is widely distributed throughout the brain, including the inferior right parietal lobe, the anterior cingulate, the insula and the thalamus. All of these areas are more activated during deliberate acts of imagination than by observation alone. And this arrangement makes sense since empathy, when fully developed, results from imaginatively identifying with the person with whom we empathize.

The empathetic infant

As an indicator of the importance of empathy we come into the world with an innate ability to respond to our mother’s or caregiver’s face. An infant will look at a human face (usually the mother but any face will do) in preference to anything else that comes within sight. Coupled with this is an evolving sensitivity to facial expressions of emotion. Infant researchers have demonstrated this in playroom experiments dating back more than four decades.

In one experiment three-month-old babies became seriously perturbed when they saw their mothers (at the experimenter’s request) sitting stony-faced and unresponsive. The baby looked to its mother and smiled. If she didn’t smile back the baby became distressed and looked away. In another experiment involving one-year-olds, if the mother posed a face of joy, the infant approached and explored a toy handed to it by a stranger. But if the mother expressed concern – wrinkled her brow, narrowed her eyes – the infant wouldn’t go near the toy.

A similar sensitivity exists in infants when it comes to voices. In an experiment dating from the 1980s, mothers spoke to their eight-month-old babies in vocal tones expressing anger, fear or joy. The babies stopped crawling towards a toy if the mother’s voice expressed any hint that things might not bode well. But this hesitancy could be reversed: if their mother took on a happy voice, the babies started crawling to the toy again and grasped it.

The baby experiments confirm a claim made by the philosopher David Hume in his Treatise on Human Nature. Hume invoked an inborn ‘propensity’ or ‘sympathy’ (we would say empathy), which most of us possess, to pick up on the ‘inclinations and sentiments of others however different from or even contrary to our own’. He postulated that our minds are mirrors that reflect others’ passions and sentiments.

Perceiving and generating emotions

Imitation, it turns out, plays a role in empathy. When we look at a smiling face we activate the same muscles on our own face even though we aren’t consciously aware that we’re doing so. This makes us feel like smiling too, so we smile back. Why? Because perceiving an emotion activates not only the relevant muscles but the same brain circuits used to generate that emotion. Thus when we return the smile directed at us, we also experience a similar feeling of happiness. On occasion this process goes amiss, as when a stranger directs a leering or suggestive smile at us. Instead of feeling uplifted we’re momentarily nonplussed or even angered. As a result, we don’t smile back. Even among friends we may choose not to reciprocate a smile as a way of conveying that we’re not feeling all that happy at the moment.

Empathy often contains elements of mimicry: we naturally tend to mimic the people with whom we come into contact. Furthermore, this imitation typically occurs too fast for conscious intention. Based on evidence dating back a couple of decades, we know that people are capable of automatically mimicking and synchronizing movements, postures, faces and vocal pronouncements with people with whom they interact. Not only do they do this with blitz-like rapidity, but all of these components are synchronized in a split second. For instance, in an experiment college students synchronized their movements within 21 milliseconds. To put that speed of response into perspective, the lightning-fast Muhammed Ali at the top of his fighting form needed 190 milliseconds to detect a signal light and another 40 milliseconds to throw a punch in response.

Emotional contagion

On occasion all of us are exposed to an emotion in another person that we don’t want to empathetically experience ourselves. When we speak of a person giving off good or bad ‘vibes’ we are describing the emotions they are projecting and our automatic responses to those emotions. But on some of these occasions – and despite our best efforts – a powerful resonance is established between the other person’s emotions and our empathetic response to those emotions. Just sitting in a room with a glum person can be a sufficient stimulus for us to ‘catch’ their negative mood. Try as we might, we feel ourselves empathetically locked into the very emotion that we’re attempting to defend ourselves against. Psychologists refer to this process as ‘emotional contagion’. As a physician I’m regularly at risk of emotional contagion based on my daily exposure to other people’s negative emotions (fear, anger, frustration, sorrow etc.). For many doctors, especially those practising specialties such as neurology or psychiatry, the emotions are almost always negative. No patient comes in talking about how wonderful they feel or how well things are going in their lives. Problems and pains and low moods are the currency of exchange between patient and doctor. This flood of negativity presents the doctor with a special challenge. If he is too empathetic – personally experiencing every pain and low mood in its full intensity – he risks being overwhelmed and as a consequence is unable to help his patient. But if on the other hand the doctor erects a self-protective emotional wall between himself and the patient, the patient rightly experiences the doctor as cold and emotionally unavailable.

But you don’t have to be a doctor to experience the conflicting forces that underlie emotional contagion. We all know people that we would prefer to avoid if given a choice – they are always gloomy or cynical, always elaborating on how hopeless everything is. If we engage with such people often enough or for long enough we begin to pick up on and respond to their negative vibes. In order to avoid those vibes, we avoid the people projecting them.

Emotional contagion results from an imbalance in the cortical/subcortical arrangement of nerve centres within the brain. While the cortical route maintains clear distinctions between the empathizer and the person with whom he is empathizing, the subcortical pathway isn’t so good at making these distinctions. Thanks to the cortical pathway, mental flexibility is maintained and emotional contagion is avoided – I can experience empathy while maintaining a firm distinction between myself and the person arousing my empathy. Not everyone is equally skilled at maintaining an optimal balance between emotional contagion (losing oneself in the emotions of others) and remaining so detached that empathy cannot take place at all. In general, people with good control over their own emotional arousal are best at this. Optimal levels of arousal and the ability to make firm self/other distinctions involve the inferior parietal and prefrontal areas. Both of these areas mature late – one of the reasons why children often have difficulty responding empathetically.

In discussing emotional contagion I’m introducing an aspect of empathy that is rarely emphasized: empathy has its dark side. Although we usually think of empathy in positive terms, it can have negative consequences or even be used with harmful intent. ‘Empathy involves getting into the mind and feelings of the other person – once you have that information you can put it to good or bad uses,’ as the late psychoanalyst Heinz Kohut mentioned to me during a conversation more than 20 years ago. Kohut was referring to the empathy required of a successful interrogator. As I learned later Kohut was correct. Here is how a security service interrogator explains his method: ‘You have to know instinctively the right time to shout, when to speak loudly, when to speak quietly, and when not to speak at all and just sit and look at him – for hours if necessary. These things are instinctive.’

The link with altruism

Empathy and altruism are natural partners. A person’s ability to discriminate and label other people’s feelings is a prerequisite to anticipating and supplying the other person’s needs. Of course, altruism doesn’t always emanate from empathy. The motivation of a philanthropist may relate more to ego concerns: letting everyone know how much more he can afford to give compared to others in his social circle. While this may be an altruistic response, it doesn’t qualify as an empathetic response.

A story – attributed to various wealthy noblemen in the 19th century – provides an example of an empathetic failure based on responding to one’s own sense of distress rather than focusing on the distress of the other person. One day the nobleman ordered his servants to disperse any beggars who appeared at his door. When the nobleman was asked why he insisted on turning beggars away from his door even though, as a very rich man, he could easily afford a charitable response to people less fortunate than himself, he replied: ‘I do this because I cannot bear the pain of witnessing their misery.’

People who experience difficulty regulating their own emotions are more likely to respond like the nobleman because they find it too emotionally demanding to be empathetic and altruistic. And as with the nobleman, their ultimate goal is a selfish one: relieving their own distress. Such a response is not uncommon. As you listen to a friend recount how she was recently was made redundant from her job you may start thinking of how you would feel if you lost your own job. As your friend’s narrative continues, you begin to feel the first rumblings of inner distress. Within only a few moments you move from other-centredness to self-centredness. You may become so personally distressed that you lose all interest in comforting your friend and begin to look instead for excuses to break off the conversation. If this isn’t possible, you may begin to experience and express annoyance and impatience. In a word, your response, as with the nobleman’s, is most un-empathetic.

If you have personally undergone such an experience or can readily identify with it, don’t despair – you are not alone. In some people the first stirrings of empathy trigger personal distress: they envision only too well how they would feel in such a situation. Feeling smothered and trapped, they seek escape; when escape isn’t possible impatience and anger are aroused. Empathy must be balanced by the maintenance of a certain emotional distance, lest one become over-identified with that person. Altruism emerges from identifying but not merging with the object of your empathy.

The evolution of empathy and altruism

In recent years social behaviours such as empathy and altruism have been increasingly viewed in the context of evolution. Stephen Porges of the University of Illinois at Chicago makes the best case for understanding empathy and altruism from the evolutionary point of view. Central to his thinking is the concept of neuroception: how neural circuits distinguish whether situations or people are safe, dangerous or life-threatening. This is done on an unconscious level. Even before we consciously experience discomfort around certain people or situations, our body has already initiated approach or avoidance procedures. We distance ourselves from threats and get closer to people and places that appeal to us and pose no threat. Body proximity and vocal volume serve as proxies for our emotional states.

An ancient parable makes the point. Many centuries ago a master asked his students, ‘Why do we shout when we are angry?’ When none of his students came up with a suitable reply, he responded,

When two people are angry at each other, their hearts are distant and to make up for that distance they must shout at each other. But when two people fall in love, they don’t shout but talk softly, because their hearts are close. When they love each other even more and become soulmates, they need not even whisper, because they can look at each other and understand each other.

Important to the development of empathy and altruism is the autonomic nervous system (ANS), a two-way communication system ferrying messages back and forth between the brain and the rest of the body. According to Porges, as mammals coevolved with their reptilian ancestors, certain anatomical structures developed for social communication. These structures include: the cranial nerves (12 pairs of nerves arising from the brain stem that conduct sensory and motor impulses to and from the brain); the nerves and muscles of the face that provide the means for facial expression and auditory communication; and the sympathetic and parasympathetic branches of the ANS, which monitor and respond to the animate and inanimate world. If one of our ancient ancestors detected a lion in the brush the sympathetic arm of the ANS fired up the ‘fight or flight response’, culminating in battle or a hasty retreat. Hours later while our ancestor was resting under the stars the parasympathetic branch of the ANS provided a soothing calming inhibition of the sympathetic system that made it possible to engage with other members of the tribe.

But vocal communication with other people wouldn’t have been possible without the evolution of our ability to detect sounds in the frequency of the human voice. Accompanying this newfound ability to hear the human voice came speech, which was based on modifications of the muscles and nerves of the face. Thanks to such modifications a mother was able to hear and respond to the distress calls of her children. She was also able to express her own feelings and detect the feelings of others based on mutual readings of facial expressions and vocal intonations.

Empathy’s underpinnings, therefore, include the muscles that give expression to our faces, intonation to our voices, direction to our gaze and meaning to our head gestures. All of this is possible thanks to the neural pathways that run from the cortex to the nerves regulating the muscles of the face and head. These are sufficiently developed that a newborn baby can soon smile in response to its mother’s smile and thus establish the first fragile bonds of empathy.

Throughout one’s life empathy can arise when, thanks to the action of these muscles of the face and head, social distance is reduced. Empathy is furthered by establishing eye contact, vocalizing with appealing inflections and rhythms, and modulating the muscles of the middle ear in order to best distinguish the human voice from background sounds. Empathy is hindered, on the other hand, when the opposite actions are performed: the eyelids droop (breaking eye contact), the voice loses its inflection, appealing facial expressions disappear, and less attention is paid to vocal inflections.

In summary, it’s fair to say that the forerunners of empathy and altruism – mutual aid among members of the same species – arose as by-products of evolution. Furthermore, empathy and altruism are indispensable for the mind’s normal development and survival. Without them we exist in lonely isolation, deprived of the means of altering our internal states in response to the internal states of others.

WHAT IS THIS THING CALLED LOVE?

Addiction, pure sex, evolutionary necessity or a beautiful relationship?

The power of love has been compared to magnetic attraction. ‘Romeo wants Juliet as the filings want the magnet,’ wrote William James, ‘and if no obstacles intervene he moves towards her by as straight a line as they.’

James seems to be suggesting that the powerful attraction exerted by love cannot be resisted (see Is Free Will an Illusion?). Yet a modification of circumstances can transform love’s impulsion to indifference. ‘But Romeo and Juliet, if a wall be built between them, do not remain idiotically pressing their faces against its opposite sides’ – like iron filings separated by partition.

For Freud the correlate of magnetic attraction is the power of the sexual instincts: ‘The nucleus of what we mean by love naturally consists … in sexual love with sexual union as its aim.’ Freud’s reductionism is miles away from the views of theologians who identify human love with God’s love for his creatures. To love another person is to participate in the divine union that links God and man, according to the gospel of St John. ‘Beloved, let us love one another, for love is of God; and everyone who loveth is born of God, and knoweth God … he that dwelleth in love dwelleth in God, and God in him.’

A full understanding of love would seem to require some middle ground between Freud and St John. Certainly love occurs under different guises: the love of Prince Andrew and Natasha in War and Peace; Swann and Odette in Remembrance of Things Past; Othello and Desdemona; Dante and Beatrice; Aschenbach and the young Venetian boy in Death in Venice. Perhaps the safest thing to say about love is that it is a demanding emotion. ‘There can be no peace of mind in love,’ writes Proust, ‘since what one has obtained is never anything but a new starting point for further desires.’ As Proust describes elsewhere in his masterpiece Remembrance of Things Past, love is associated with appetite and desire; the lover wishes to possess the beloved; love when repulsed can transform into hate.

Not everyone experiences love, of course. People with strongly narcissistic features may not even be capable of love; or their love may merge with infatuation, dependency needs or a desire to bolster a lagging self-esteem. But almost everyone expresses the desire to experience love at some time in their lives. Our language is filled with statements and questions articulating this desire. ‘It is better to have loved and lost than never to have loved at all.’ ‘Is it wiser not to love than to love not wisely?’ One thing is indisputable: the love experience is notoriously difficult to explain to those who have never been in love. Love is felt rather than thought.

Falling in love is counted by those who have experienced it as one of life’s most delightful pleasures. The world seems a happier place; people are easier to get along with; each new day induces pleasurable expectation. When we’re in love we concentrate all of our attention and energies on our beloved; we think about him or her with a regularity that interrupts our everyday routines.

But falling in love has its downsides as well. Our judgement is distorted: we see only the good traits about the person we love; we ignore personal liabilities that are immediately obvious to our friends; we’re overconfident in our ability to manage our feelings and underestimate the depth of our infatuation. At the same time, we experience changes in our emotional landscape: decreases in appetite accompanied by increases in yearning and sexual desire. While our moods are uplifted we are at the same time more vulnerable to sudden emotional upheavals, oftentimes induced by the most trivial things. A change in the weather – a snowstorm or heavy rainfall – can send us into a tailspin because such changes lessen our chances of getting together with the object of our obsessive preoccupation.

Love addiction

Recent neuroscience findings confirm that romantic love is not only a kind of obsession but also shares many of the qualities of an addiction. In one study couples who described themselves as ‘madly, deeply and passionately in love’ were placed in an fMRI. When the subject viewed pictures of their beloved’s face, the activity recorded from their brains was similar to the way the brain responds to cocaine or heroin. The researchers also found similarities to the brains of people afflicted with obsessive-compulsive disorder. This may help to explain the hurt and emotional anguish that accompanies break-ups. Usually one partner is more active than the other in seeking an end to a romantic relationship. In response to the resulting emotional pain, the spurned lover is 40 per cent more likely to develop a clinical depression. He or she may beg and plead for another chance at making the relationship work, or engage in obsessive emailing, crying, drinking or drug taking (briefly activating the circuits formerly involved in the love experience). The rejected lover may make unwanted appearances at the former loved one’s home or workplace in order to beg and plead for a reunion. He may express anger or avowals of love that are no longer reciprocated. Sometimes the obsession – for it is now clearly an obsession – leads to destructive acts directed at the former beloved. All the while, these increasingly unreasonable possessive behaviours are rationalized as expressions of ‘love’.

Fortunately, not every spurned lover undergoes such experiences. A less tumultuous response is likely if he or she can step back and reappraise the relationship, acknowledging some of the former lover’s less favourable personal traits and behaviour. With further distancing, the rejected lover will disengage sufficiently that new love relations become possible.

Our fascination with beauty

While ‘beauty is in the eye of the beholder’, some agreement exists across cultures about standards of beauty. For example, if men are asked to create on a computer an image containing the qualities they consider most important in defining a beautiful woman, certain features stand out: a relatively short lower face, a small mouth and full lips. This male standard for female beauty is the polar opposite of the female standard for male beauty: a stronger (i.e. longer and broader) jaw, a wide chin, accentuated cheekbones, well-defined eyebrow ridges and a lengthened lower face combined with a forward central face.

An fMRI study of men and women of various ages found more activation of the human medial orbital frontal cortex (a mediator of pleasant as opposed to unpleasant stimuli) in response to conventionally attractive compared to unattractive faces. This predilection for attractive faces exists even in infants. When shown slides of attractive and less attractive women babies will gaze at the attractive women for a longer time. A similar predilection for attractive people was demonstrated in a rather bizarre experiment where strangers wore professionally created masks; the infants seemed more contented, withdrew less and were more playful with the strangers wearing the attractive masks. Infants will also play longer with an attractive compared to an unattractive doll.

Our collective fascination with beauty moulds our behaviour: we judge and respond more positively to attractive children and adults compared to those who are less attractive. We are less likely to complain about someone or adversely criticize them if we find them attractive. And our negative appraisals of people on the less attractive end of the beauty spectrum hold true even when we’re personally familiar with the less attractive person and readily acknowledge their positive characteristics. It seems that even when we know better we just can’t shake our fascination with physical attractiveness. Furthermore, according to a paper called ‘Maxims or myths of beauty’, published a decade ago in Psychological Bulletin, attractive children and adults tend to be friendlier and generally display more positive behaviours and personality traits than their unattractive counterparts.

Certain emotional and social traits render men more attractive to women. Financial resources, power and wealth play huge roles, according to D.M. Buss in his study of sex differences in human mate preferences across 37 cultures and involving more than 10,000 participants. In Buss’s study women consistently placed more value on financial resources (100 per cent more) than men. Lest this finding sound like cynical male chauvinism, Buss was quick to add that wealth may be valued by women because it is an indicator of the resources the man will be able to provide for her offspring. And since control of resources is directly linked with status, it should come as no surprise that women find men of high social status attractive.

When first reading Buss’s controversial findings I must admit I found his conclusions unsettling. We aren’t as comfortable in the first quarter of the 21st century with the kinds of neat breakdowns between men and women that Buss found in 1989, the year that he published his study. Much has happened since then when it comes to the relationship between the sexes. In addition, it’s important to point out that Buss was writing from an evolutionary perspective. ‘Sex differences in human mate preference: evolutionary hypotheses tested in 37 cultures’ was the title of Buss’s paper.

So when reading the remainder of the factors that I’m going to mention as important in male and female preferences, remember that the factors that have played important roles in evolutionary development in Western culture may exert far less of an influence on contemporary human behaviour. For instance, few of us when selecting a mate spend a lot of time pondering over which of several mate choices will be the most genetically advantageous. Yet evolutionary theoreticians claim that we unconsciously make such choices all the time. Thus the woman (or man) who holds out for a partner possessed of specific endowments, whether physical or mental, may be unwittingly selecting for favourable genetic traits that increase the odds of survival and achievement.

Certain preferences in mates are shared by both men and women. Symmetry in regard to bilateral features (ears, hands, arms, feet) is attractive because (we’re talking evolution again) they reflect good uterine development, a nontraumatic birth, good nutrition and freedom from disease. Asymmetry suggests interference with normal development resulting from genetic or environmental abnormalities. As with the other evolutionary criteria mentioned above, the process operates outside of conscious awareness. I doubt that many readers can recall deliberately comparing prospective mates in terms of the symmetry of their ears, hands or feet. Yet statistics suggest such comparisons take place – albeit unconsciously. On average, more symmetrical men report more lifetime partners, presumably a reflection of the fact that women rate men as more attractive if they possess a high degree of symmetry.

Another one of the weaknesses of explaining mate selection on evolutionary principles is the fact that our biology might favour different choices at various stages of our lives. In youth we may be influenced most by infatuation, romantic love and sex; later we want a more stable relationship in order to give us time to advance our careers, accumulate money and raise a family; still later we may be most interested in companionship and the sharing of intellectual interests. ‘Marry in hast, repent at leisure’ serves as an aphoristic acknowledgement that, when infatuation wears off, one may discover that one’s partner is a liability when it comes to advancing one’s career, co-parenting children or serving as an intellectually and emotionally satisfying companion. Thus not only do different factors influence mate selection at different life stages, but these factors aren’t necessarily of equal value in establishing short-term versus long-term partnerships.

The neurology of love

On the neurological level love is associated with identifiable changes in the brain and nervous system. In a famous paper ‘Love: An emergent property of the mammalian autonomic nervous system’, evolutionary psychologist Stephen Porges (mentioned in the previous chapter) suggests that changes in the autonomic nervous system (ANS; a.k.a. the visceral nervous system) led to the emergence of two components of love. The first, the appetitive component, is responsible for courting and seductive behaviour; the second, the consummatory component, is associated with passionate sexual behaviour and the establishment of stable pair-bonds, i.e. couples.

Courting and seduction start within the cerebral cortex, where can be found the recognition of the standards of beauty that make one person more physically appealing than another. This is a highly subjective judgement although as mentioned above certain preferred physical characteristics exist within the general population. From the cortex, nerve tracts descend to regulate the facial expressions and vocalizations that serve to announce one’s availability to a prospective mate. In this first stage in the establishment of love, facial and verbal communication play the principal roles. If skilfully used, these facial and vocal signals will induce the romantic partners to move closer to one another, become more relaxed and engage in mutually pleasurable interaction. But if the initial approach is perceived as intrusive – or is unacceptable for one reason or another – eye contact is broken, the parties move farther away from each other and disengagement rather than engagement ensues. Physical proximity thus serves as a proxy for emotional proximity.

Trust and a feeling of safety are central to any love relationship. If one of the partners feels uneasy or threatened, this creates an imbalance in the influence exerted by the sympathetic and parasympathetic arms of the ANS. Think of these two components of the ANS as vying with each other in a winner-takes-all battle for control: a person cannot simultaneously experience fear and relaxation. We put distance between ourselves and the person who frightens us; we move closer to the person who puts us at ease.

If Porges’s theory is correct – and in my opinion it explains a lot – then some of the axioms we’ve all heard throughout our lives about love are probably incorrect. For instance, although it may be true that in some love matches ‘opposites attract’, it’s more likely that the differences will often eventually lead to conflicts, feelings of hostility and in extreme cases fight followed by flight (divorce). Put differently, the more lovers have in common the greater the likelihood that they will perceive their partner as safe, nourishing and understanding. In order to maintain this state, the parasympathetic system must remain firmly in control, resulting in a normal pacing of the heart and an accompanying tranquillity of mind.

Love is encoded in the brain not only neuroanatomically (the ANS) but chemically as well. One hormone, oxytocin, is especially critical. Oxytocin is a calming hormone important for such things as the establishment of attachment behaviours between mother and offspring, and between romantic partners. Sometimes called the ‘trust hormone’ oxytocin is a powerful stimulus for enhancing socialization. Animals injected with oxytocin into their amygdalae tend to cluster together and touch each other more often. In humans, oxytocin helps to establish social cooperation. And since the hormone is also associated in humans with social proximity and touching, many neuroscientists consider it the closest neurological candidate we have to a love potion.

Let’s talk about sex

When we talk about love we can’t help but talk about sex. Indeed, we often confusedly use the word ‘love’ when really we mean sex. We describe someone as visiting a ‘love hotel’ when their intention is to obtain anonymous, often financially compensated, sex. We speak of a man or woman as having many ‘lovers’ when we actually mean multiple sex partners. Thanks to this conceptual and linguistic confusion, it’s not surprising that neuroscience has provided more insights into sexual than love relationships.

For instance, in a series of experiments worthy of an XXX movie rating a woman underwent fMRI imaging while masturbating. Not surprisingly huge swathes of the brain became active with special involvement of the prefrontal cortex (PFC) and anterior cingulate. The self-stimulation followed a sequence starting with the general sensory projection zone of the cortex and spreading to the limbic structures (insula, anterior cingulate, amygdala, hippocampus) involved in the emotional response. At the start of orgasm, activity in the frontal cortex and cerebellum increased – thought to be related to the fantasies elaborated by the frontal cortex and the increase in muscle tension partially controlled by the cerebellum. During orgasm the hypothalamus and the nucleus accumbens reached their highest level of activity.

The fMRI images show that orgasm is a whole-brain experience with practically every structure involved at some point in the process. Hidden among this whole-brain response interesting distinctions can be observed. Orgasm brought about by self-stimulation involved greater excitation in the prefrontal cortex than when orgasm was brought on by a partner’s stimulation. This difference may reflect the role that imagination and fantasy play during self-stimulation, according to the researchers from Rutgers University who carried out the orgasm experiments. A second notable finding from this research is that the precise locations within the brain’s sensory cortex differ for the clitoris, vagina and nipples. Such anatomical distinctions provide support for the traditional belief among sexologists that women can experience orgasms originating from either the clitoris or vagina. No surprise here: women have been telling their partners this as far back as sexual partners have spoken about such matters. The studies also provided support for some women’s experience that nipple stimulation can be as effective as clitoral or vaginal stimulation in bringing on orgasm. This is due to a direct link shown on fMRI between the nipples and the genitals.

While the orgasm research described above is undoubtedly intriguing, you might wonder ‘What does it contribute to our understanding of love?’ If you think along those lines you’re engaging in a bit of Cartesianism: conceptualizing love as somehow disembodied and sex as … well, you know … sex. But this dichotomizing ignores an important point: the bestowal of mutual pleasure is part of the love experience and sex provides the most direct and physically intense of pleasures. But making a distinction between love and sex isn’t entirely wrong either. Love doesn’t necessarily require sex or sexual elements; love isn’t adequately explained as a sublimated form of sexuality (pace Freud). For instance, sex is absent from the love of a parent for a child. Perhaps it’s fairest to leave it at this: although sex can be an important component of some love relationships it plays little or no part in others.

What is this thing called love? The question is best answered experientially. When we’re in love and look into the eyes of our beloved, we see wonderful things and experience pleasurable emotions. And, even more marvellous, we love ourselves more as a result of loving someone else.

WHAT HAPPENS WHEN WE GET ANGRY?

Fury and the frontal lobes

Anger is an emotion we are encouraged to repress. And from the practical point of view that makes good sense. Social interaction wouldn’t go at all smoothly if people felt free to fly off the handle in response to every person or situation that annoyed them.

Most damagingly, anger impairs a person’s ability to think clearly and retain control over his behaviour. The angry person loses objectivity in evaluating the emotional significance of the person or situation that arouses his anger.

Not everyone experiences anger in the same way; what angers one person may amuse another. The specific expression of anger also differs from person to person based on biological and cultural forces. In contemporary culture, at least in the West, physical expressions of anger are considered too socially disruptive to be tolerated. We no longer sanction duels as an appropriate expression of anger stemming from one person’s perception of insulting behaviour on the part of another. And police routinely arrest both parties engaged in fisticuffs rather than attempting to adjudicate or decide at the scene who initiated the fracas.

Some people have great difficulty expressing anger or detecting and responding to the angry responses of other people. In extreme cases, they may be afflicted with what is referred to as alexithymia (from the Greek for ‘without words for feelings’). In a phrase, they are ‘completely out of touch’ with their anger. On those occasions when they appear to be angry (speaking in a raised voice, employing overemphasized gestures), everyone around them recognizes that they are angry, but they don’t.

The neurological origins of anger

Anger begins in the amygdala, a complex of nerve fibres within the limbic system and located at the anterior tip of the hippocampus on each side of the brain. While neuroscientists have never agreed entirely about the definition of the limbic system, some general consensus exists that it includes the amygdala and other components comprising a network lying beneath the cortex and associated with emotions both good and bad.

From the amygdala nerve impulses associated with anger rapidly pass on to other components of the limbic system. They then veer up via the thalamus to the cortex, which elaborates the symbolic basis of anger: the psychological interpretation that one has been offended, wronged or provoked. While the amygdala provides the raw ‘feel’ of anger, the cortex provides an explanation for the physiological responses that we experience when we are angry. So which comes first?

Although researchers have traditionally emphasized the activation of the amygdala and other components of the limbic system in the experience and expression of anger, recent research has led to recognition of the importance of the cerebral cortex in expressing anger too. People with diseases that affect the frontal lobes or other parts of the cortex such as fronto-temporal dementia or Alzheimer’s disease often first signal their affliction by rage outbursts. The source of these outbursts is multifactorial: there is no ‘anger centre’ in the brain. Rather, anger can be generated from any of several structures within the limbic system. Anger can also arise from the cerebral cortex. We’ve all had the experience of ruminating or obsessing about something until we reach a point where we’ve worked ourselves up into a state of anger. Even though we’ve started off calmly enough, just thinking about the perceived offence leads us to become increasingly angry.

‘Fight or flight’

Anger is accompanied by distinctive facial expressions – the face flushes, brow muscles contract, nostrils flare and the jaw clenches. And by measurable physiological responses – blood pressure rises, pulse and breathing increase. This heightened level of arousal in the angry person results from an increased secretion of stress hormones from the adrenal glands coupled with contributions from the pituitary gland. Acting together, these hormones provide the chemical basis for the ‘fight or flight’ response: the body is primed for immediate action.

This so-called ‘flight or fight’ response is the sympathetic nervous system at work and it is always involved in anger and other ‘dark’ emotions such as anxiety. The positive emotions, in contrast, are more linked with the action of the parasympathetic nervous system. Because of this division, certain emotions cannot be experienced simultaneously. You can’t be both angry and relaxed at the same moment. If you are angry your tense muscles and elevated blood pressure and pulse will counteract the calming ‘laidback’ influence of the parasympathetic nervous system, which induces relaxed muscles and normal blood pressure and pulse.

Offensive and defensive anger

Anger can also be identified in the brain, where the electrical activity changes. Under most conditions EEG measures of electrical activity show balanced activity between the right and left prefrontal areas. Behaviourally this corresponds to the general even-handed disposition that most of us possess most of the time. But when we are angry the EEG of the right and left prefrontal areas aren’t balanced and, as a result of this, we’re predisposed to react. And our behavioural response to anger is different from our response to other emotions, whether positive or negative.

Most positive emotions are associated with approach behaviour: we move closer to people we like. Most negative emotions, in contrast, are associated with avoidance behaviour: we move away from people and things that we dislike or that make us anxious. But anger is an exception to this pattern. The angrier we are, the more likely we are to move towards the object of our anger. This corresponds to what psychologists refer to as offensive anger: the angry person moves closer in order to influence and control the person or situation spurring his anger. This approach-and-confront behaviour is accompanied by a leftward prefrontal asymmetry of EEG activity. Interestingly, this asymmetry lessens if the angry person can experience empathy towards the individual who is eliciting the angry response. (See Where Do Empathy and Altruism Come From?) In defensive anger, in contrast, the EEG asymmetry is directed to the right and the angry person feels helpless in the face of the anger-inspiring situation.

Why do we get angry?

It would seem as a matter of ‘common sense’ that a person would have to have a reason for anger and only then respond in an angry manner. Actually common sense is often wrong: when we get angry our anger frequently begins in the amygdala milliseconds prior to our searching at the cortical level for reasons to attribute our anger to a specific source. The amygdala is the initial flashpoint followed in short order by the cortex, which then elaborates the reason for the angry response. Variability exists from one person to another when it comes to elaborating or not elaborating reasons for getting angry. This variability helps to explain why the same situation that drives one person into a rage elicits a laugh from another who doesn’t take himself as seriously.

Neuroscientists discovered this counter-intuitive arrangement about anger (experiencing and expressing it before knowing the reason for the anger) by studying anxiety, a close cousin of anger. We often experience faint feelings of anxiety prior to our later identification of what we’re anxious about, for example, a vague inexplicable anxiety the day before a dental appointment is scheduled for the next morning. Other people are less prone to such premonitory anxiety and are able to go about their day while putting out of mind the prospect of the next day’s dental appointment. A similar situation holds for anger. Some people are comparatively unflappable while others may easily fly off the handle.

In humans, perceptions and symbols are the major contributors to anger. The angry person may feel humiliated, shamed (‘loss of face’), wrongfully offended or denied. Or the angry person may perceive himself as provoked and experience an uncomfortable sense of being driven – indeed compelled – to respond to the provocation. Except in cases of neuropsychiatric illness this drive to correct a perceived wrong via an angry response can be controlled to an extent that varies from one person to another. But the distinction between normal and neuropsychiatrically impaired is often more a matter of degree – a quantitative rather than a qualitative distinction. People with a low sense of self-esteem, for instance, are prone to perceive slights when no slight was intended and lash out with an angry verbal outburst or, on occasion, a physical assault against the perceived provocation. As the person’s anger increases, a vicious circle quickly becomes established: the subjective sense of anger works as a feedback to generate even more anger. This is the basis for the claim commonly made by the angry person that he or she is ‘losing control’. What’s happening in such circumstances is that the sympathetic nervous system is going into overdrive.

Anger management

Treatment of people with inordinate tendencies towards anger involves various ‘anger management’ techniques aimed at increasing the influence of the parasympathetic nervous system. This can be brought about by encouraging the angry person to concentrate on slowing their breathing and relaxing their muscles. At the same time, the angry person is asked to mentally reframe the situation stimulating the angry response (‘Close your eyes and try to see this situation in your mind’s eye from the point of view of the person who is making you angry’). This reframing technique calls on the frontal and temporal lobes to use images as the basis for developing an alternate anger-free strategy. In the angry person the amygdala and other components of the limbic system have wrested control over the frontal lobes’ capacity for putting things in perspective. Anger management programmes suggest ways to maintain the supremacy of the frontal lobes.

The Roman philosopher Seneca provided an early prototype for the advice offered today in anger management classes. First, check on ‘speech and impulses and be aware of particular sources of personal irritation’. In other words know your own sensitivities: those flashpoints that have angered you in the past. Seneca next suggests that ‘when someone appears to slight you … you should put yourself in the place of the other person, trying to understand his motives and any extenuating circumstances’. Although Seneca knew nothing about the frontal lobes, his advice in fact provides a means for re-establishing the dominance of the reflective frontal lobes over the reactive amygdalae.

To simplify all of this neuroscience somewhat, think of the frontal lobes as an inhibitor of the expression of anger. When we feel that upsurge of anger we should allow the frontal lobes to kick in and provide the ‘voice of reason’, which counsels us not to take the situation so seriously.

City versus country anger

As noted previously, anger is closely related to anxiety and fear. Typically anything that we fear will – if our fear isn’t addressed – eventually arouse an angry response in us. We hate flying because we fear an air crash, so we arrive at the airport tense and shirty; we’re unusually impatient, abrupt and easily aroused to anger, even by trivial occurrences.

Because of their frequent co-occurrence, sociological studies on anxiety are also useful in understanding anger in different populations. People who live in large cities are more given to anxiety and are more likely to express anger than their rural counterparts. Of course, there are exceptions but the major studies demonstrate those links.

In one study comparing city dwellers with people from rural areas, brain differences emerged on both the anger and anxiety dimensions. A study from Germany’s Central Institute of Mental Health compared how members of the two groups responded to criticism as they worked at solving maths problems: ‘Please understand that these experiments are very expensive, so if you could just try at least to be above the bottom quarter of the curve we’d appreciate it.’

Although both city and rural dwellers found such criticisms annoying, their brains responded differently. The urbanites showed greater activation in the amygdala. Further, the more time spent in a city and the larger the city, the greater the amygdala response. In addition, communication was less efficient between the amygdala and the cingulate cortex that helps control it. In essence, city dwellers showed heightened levels of brain activity in areas signalling social distress.

Consider this research finding in the context of the increasing numbers of people throughout the world currently moving from rural to urban centres. Perhaps it shouldn’t be surprising that much of the turmoil and violence throughout the world is emanating from cities. And this increase in violence doesn’t result from rural citizens moving into cities; in most instances, the flare-ups are hatched and spawned among long-term urban dwellers. And now we just might know the reason: the brains of city dwellers seem to be organized differently, research is now suggesting, when it comes to the experience and expression of anger.

Predispositions to anger

Folk wisdom as well as everyday observation suggests that physical traits may be associated with a greater propensity for anger. Seneca believed that ‘red-haired and red-faced people are hot-tempered because of excessive hot and dry humors’. Although neuroscience hasn’t as yet come up with a more sophisticated physiognomic profile for anger predisposition, we all recognize instinctively from their manner – if not their appearance – that it’s best not to antagonize some people.

Animal research suggests that genetics may play a greater role than physical appearance in determining the ability to keep anger under control. Genes that encode for a propensity towards anger are well established among rats. Selective mating can result in anger-fuelled rats that throw themselves against the bars of their cages if anyone approaches them.

In our own species brain damage is probably the greatest contributor to the overt expression of anger. Over my years as a professor of neurology I have examined and treated thousands of people with head injuries and I have never ceased to be amazed at the transformations such injuries bring about in the management of anger. After the injury a formerly docile person often flares up at the slightest provocation and occasionally with no identifiable provocation at all. Such transformations are especially common after injury to the orbital frontal part of the frontal lobes.

Today the correlation between impairment of the frontal lobe and loss of emotional restraint is sufficiently established that courtroom defences based on alleged frontal lobe injury (the ‘frontal lobe defence’) are increasingly being advanced in trials for murder and other violent offences. Although intriguing, these courtroom jousts over guilt or innocence are only marginally relevant to the topic of anger. The vast majority of angry outbursts don’t lead to physical violence. Indeed, some of the most violent of activities, such as warfare and sports, especially boxing, involve situations where giving in to anger and responding impulsively increases the likelihood of defeat.

In some instances the impairment of the frontal lobes is temporary rather than permanent. A ‘bad drunk’ – someone who turns nasty after a few drinks – is an example of a temporary alcohol-induced lessening of the restraining influence on anger normally exerted by the frontal lobes. Epilepsy, especially that called episodic dyscontrol, can transform a mild-mannered law-abiding citizen into a pugnacious anger-propelled intimidator. But one doesn’t have to be suffering some form of brain damage to exhibit wide variations in the experience and expression of anger.

While anger is usually associated with a loss of control, some people can use anger as a means of controlling other people. This works because, according to some studies, people with angry facial expressions are perceived by others as more powerful and occupying a higher social position. As a result, people tend to concede more to the negotiator who becomes angry when his demands aren’t met. Thus some advantages may accrue to the person who can successfully feign or exaggerate anger. But not everyone can successfully employ anger as a means of manipulating others. Feigned anger easily slips out of control and into the real thing, especially when the performance isn’t quite convincing enough to avoid detection by others.

All of us face the same challenge in regard to anger: maintaining our brain’s prefrontal control over our limbic impulses and thereby controlling our anger. As Aristotle phrased it, ‘Anybody can become angry – that is easy, but to be angry with the right person and to the right degree and at the right time and for the right purpose, and in the right way – that is not within everybody’s power and is not easy.’

DO DREAMS HAVE MEANING?

Random noise or vital insight into the unconscious?

Dreamers throughout history have speculated about the meaning of their dreams. ‘It is very queer,’ wrote D.H. Lawrence to his friend Edward Garnett in 1912, ‘but my dreams make conclusions for me. They decide things finally. I dream a decision. Sleep seems to hammer out for me the logical conclusions of my vague days, and offer them to me as dreams.’

One of the reasons that dreams are so hard to interpret is that ‘They are often the most profound when they seem most crazy,’ as Freud wrote in The Interpretation of Dreams. In addition, we tend to interpret dreams in the context of the events and situations that are most pressing at the moment. Although a dream about something from our past may arouse our curiosity, we aren’t likely to spend much time mulling it over compared to a dream that suggests a course of action for current concerns. This may be one of the reasons that over 80 per cent of dreams relate to things that are happening in the present rather than the past. Perhaps our dreams really are helpful to us, but in ways that we usually can neither understand nor explain.

But even when the dream situation is perfectly mundane it often contains stark departures from logic and everyday causality. ‘But why does your reason [upon awakening] reconcile itself with such obvious absurdities and impossibilities with which your dream was crowded?’ asks the narrator in Fyodor Dostoyevsky’s The Idiot. ‘You smile at the absurdity of your dream, and at the same time you feel that in the intermingling of those absurdities some idea lies hidden … all this you can neither understand nor remember.’

Dream interpretation is further complicated by the fact that a dream often incorporates seemingly random fragments drawn from different times. For example, in the aftermath of my mother’s death I dreamed of her on several occasions. In one dream she looked in her late 40s and I could see her with a clarity that no act of deliberate daytime imagination could have achieved. At a different point in the same dream she looked the way she did during her last years and death at age 94. Such a contrapuntal organization of time is typical of dreams: only in a dream can we experientially encounter the same person as they looked both at the time of their death and 50 years earlier.

In addition, dream encounters are marked by an intensity that equals and sometimes exceeds what one experiences in ‘real life’. Talk to someone afflicted with post-traumatic stress disorder (PTSD) and they’ll tell you that it is the dreams that they fear the most. I’ve interviewed soldiers with PTSD who sit up late into the night rather than fall asleep and risk experiencing a dream incorporating their battle experiences. Only in a dream can one be experientially engaged in a deadly fire fight in Iraq while in bed in a household in the suburbs. Even the most vivid daytime imagination can’t evoke a past situation with this degree of power. Thanks to their immediacy and intensity, dreams are unlike any of the other processes carried out by the human brain.

Perhaps it’s best to think of dreams as fragments, shards of a previous daytime existence scattered at random. We arrange the pieces and impose meaning upon them. Some people don’t attempt any interpretation of their dreams because they believe dreams are meaningless. Others are convinced that dreams are meaningful. According to the Gospel of St Matthew, the wife of Pontius Pilate experienced a vivid and frightening dream the night before Christ’s arraignment before her husband. The dream so frightened her that she sent a message advising her husband to ‘have nothing to do’ with the attempts to crucify Christ.

Many believers in the significance of dreams remain haunted by their dreams. One of my PTSD patients, a subway driver, dreamed repeatedly of seeing the face of a woman who had thrown herself under his train as it arrived at the station platform. The night dreams later became part of a kind of waking dream in which he thought he saw her during daytime activities such as when shopping or driving his car. He recovered when he accepted the fact that the woman was not trying to communicate with him from beyond the grave; that his dreams were not that abnormal under the circumstances; and that if he could resist the impulse to resist them they would go away. His acceptance of the dreams didn’t come easily but with acceptance came healing. Indeed, the acceptance of disturbing or distressing dreams is a prerequisite for freeing one’s self from them. Fighting the dreams only further establishes them in the psyche. (See Is It Possible to Think of Two Things at Once?)

On occasion disturbing dreams can be controlled, even mastered, while the dreamer is still asleep and in the process of experiencing the dream. During these so-called lucid dreams the dreamer consciously enters the dream and changes it: if he is being chased in the dream by a vicious dog, he simply turns around and chases it.

Searching for meaning

The earliest writings about dreams date from the ancient Egyptian Chester Beatty Medical Papyrus dated 2050 BC and now in the British Museum. It contains reports of some 200 dreams accompanied by the interpretations provided by priests devoted to the god Horus. The Egyptians at that time put a great emphasis on dream interpretation. They believed that dreams provided a window into the future as well as a conduit for the gods to compel acts of submission, to warn of threats and to answer questions. By 1200 BC references to the soul or boa began to appear. The boa left the body during dreams and was thought to roam within the world of spirits, as described in the Theban Book of the Dead.

The Greeks and Romans, like the Egyptians, relied on special priests to interpret the meaning of their dreams. Homer, Virgil and Ovid believed that dreams have prophetic value, as described in their masterpieces the Iliad, the Aeneid and Metamorphoses. The Romans achieved the pivotal insight that dreams are not visitations from the gods but, in the words of Petronius, ‘each of us makes them for himself’.

Both internal and external stimulation can generate dreams. In the 19th century a zany investigator, Louis Maury, hired an assistant to perform, while Maury slept, such actions as pinching him, dripping water on him, opening perfume bottles under his nose. Frequently these stimuli were incorporated into Maury’s dreams.

By 1845 the concept of an unconscious as the driving force behind dreams emerged from the work of Ernst von Feuchtersleben, a precursor of Freud who, like Freud, lived and worked in Vienna. He considered dreams as ‘the precursor and accompaniment of diseases’ and that ‘the interpretation of dreams deserves the attention and study of the physician’. Freud picked up on this insight and in 1899 published The Interpretation of Dreams, which brought to the world’s attention the fascinating connections that exist within dreams between conscious and unconscious thought processes. Freud was quite taken with his theory that ‘the dream is the fulfilment of a wish’ and that dreams therefore provided the psychoanalyst with the ‘royal road to the unconscious’. He wrote to his friend Wilhelm Fliess, ‘Do you suppose that someday a marble tablet will be placed on the house, inscribed with these words: “In This House on July 24, 1895, the Secret of Dreams Was Revealed to Dr Sigmund Freud”?’ No such tablet has so far been emplaced. As Freud’s disciples soon discovered, theories about dreams are as evanescent as the dreams themselves.

Freud was not the first (nor is he likely to be the last) to formulate an explanation about dreams that was displaced after an interval of enthusiasm by equally promising theories from other sources. This is not a dismissive indictment; even the most promising of scientific ideas eventually gives way to new theories. Indeed, such revisionism distinguishes science from ideology or fanciful speculation. But the lifespan of dream theories has been unusually short, and for good reason. The psychoanalyst who employs Freudian interpretations to his patient’s dreams faces a disheartening fact: different analysts will produce entirely different analyses when told the same dream. Dream interpretation – Freudian or otherwise – has wandered down many paths, but none of them has led to an objective verification of its success, a prerequisite for the label ‘science’.

Avatars and symbolic analogues

Dreams can contain elements inconsistent with the life and circumstances of the dreamer. For instance, people born deaf report dreams in which they engage in conversations; paraplegics dream of walking, running and swimming. Since these impaired dreamers cannot perform such activities in waking life – and those who are congenitally deaf or paralysed have never done so – how and why do they dream of doing these things? One theory holds that dreams tap into representations of sensory organs and movements that exist in the brain unrelated to waking reality, as in instances when the dreamer’s body is physically incapable of carrying out the activity dreamed about. This is true even with those without physical impairments: the dreaming brain can generate experiences that aren’t possible in waking life. Flying dreams, for instance, are common and immensely enjoyable (I’ve had them for years) despite the inability of humans to fly.

But dreams aren’t entirely foreign to our mindscape; they share certain qualities with waking consciousness. For instance, our ability to identify in waking life with symbolic analogues of ourselves (pictures or avatars) speaks to our capacity to envision ourselves in disembodied ways. In dreams such displacements are extended even further: the perspective of a first-person experiencer is transformed into that of a third-person observer. The Chinese philosopher Chuang Chou provides an example of this in the book Zhuangzi:

Once upon a time, I, Chuang Chou, dreamed I was a butterfly, fluttering hither and thither, to all intents and purposes a butterfly. I was conscious only of my happiness as a butterfly, unaware that I was Chou. Soon I awakened, and there I was, veritably myself again. Now I do not know whether I was then a man dreaming I was a butterfly, or whether I am now a butterfly dreaming I am a man.

Embodiment (the sense of oneself being localized within a specific body) is routinely altered within dreams, leading sometimes to disturbing or troubling responses. A male patient of mine dreamed of himself as a woman, that his wife and sister had been transposed and that he was married and sleeping with his sister. (A Freudian analyst would no doubt make much of such a dream.)

Creativity and dreams

Dreams can serve as problem-solvers or sources of inspiration. The German neurophysiologist Otto Loewi discovered the existence of the neurotransmitter acetylcholine in a dream. He woke from the dream in the middle of the night and rushed to his laboratory where he performed the confirmatory experiment establishing the chemical identity of acetylcholine.

August Kekulé discovered the molecular arrangement of the benzene ring when he dreamed of a signet ring fashioned in the form of two intertwined snakes biting each other’s tails. He had seen this ring many years before but had forgotten about it. His dream of the ring prompted him to come up with benzene’s chemical structure: a six-layered arrangement composed of carbon and hydrogen atoms suspended like charms from a bracelet.

Similar insights can come to any of us from our dreams. When we reach an impasse in our own creative efforts, we may garner a creative insight by ‘sleeping on it’ and in the morning trying to remember our dreams. For example, consider this question given to his students by dream researcher William Dement: ‘What word is suggested by this sequence of letters: H, I, J, K, L, M, N, O?’

If the answer to that puzzle doesn’t occur to you, think about it just before falling asleep tonight. You may have dreams similar to Dement’s students, who dreamed of snorkelling, scuba diving, sailing or swimming. The common theme in all of these dreams is WATER, which has the chemical formula H_2O, which corresponds to the letter sequence ‘H to O’. Despite the fact that the students’ dreams seemed meaningless, they contained clues that hinted at the answer.

Neuroscience and dreams

Since the development of neuroscience, the emphasis has shifted in regard to dreams from the Freudian unconscious to the cognitive unconscious, which involves information processing on a much broader front than suggested by Freud. Many of our dreams involve events that we hadn’t paid sufficient attention to during our waking hours; other dreams involve people we haven’t encountered or thought about in years. But if we barely noticed these things in our waking life, how is it that we dream about them? It’s because unconscious cognitive processing is the rule rather than the exception within the brain: the lion’s share of our brain’s activity in both waking and sleeping takes place outside of our awareness.

But despite extensive neuroscientific research on dreams over the past three decades, an overall explanation of the purpose of dreams remains elusive. This much is agreed upon: if you awaken a sleeper when his eyes can be observed to be moving rapidly (rapid eye movement or REM sleep), the sleeper often reports elaborate and detailed dreams. This doesn’t occur if you awaken the person during the other stages of sleep when the eyes are quiescent (non-REM sleep). But however vivid dreams may be, they are quickly forgotten; if the sleeper is awakened only minutes after the end of an REM period, he or she recalls few if any of the dreams that were presumably taking place during the preceding REM period.

But here is a conundrum that has always troubled me about dreams: if dreams are important enough to provide answers to problems with which we are grappling, as well as insights into the decisions we should make about the future, why do we remember so few of them? It would seem that evolution would have favoured dream-remembering, yet special efforts must be made to remember them. One finding perhaps provides an answer: the dreams that are best remembered occur in the early morning when we are beginning to wake up. This suggests that memory storage in the brain is normally turned off during sleep and only gradually comes back ‘online’ as we slowly begin to awaken. Such an arrangement serves an adaptive purpose: we do not use up memory capacity on random dream representations but, as a consequence of this economy, we remember few of our dreams.

A related hypothesis of dreams was advocated by the late Francis Crick (of DNA fame) and Graeme Mitchison. They speculated that dreams perform an ‘unlearning’ mechanism by which patterns of brain activity that are no longer useful are erased by random activation. Another variation of this theory holds that dreams represent ‘random noise’ that arises when the influence of the prefrontal cortex becomes less effective during sleep than in the waking state. This change allows for the emergence of bizarre and inexplicable states. While such theories provide plausible roles for REM sleep, they fail to provide answers to the questions most frequently asked about dreams: why am I experiencing this dream now? What does it mean that I dreamed of someone last night with whom I’ve had no contact in three decades?

Dreams and encoding

The events of a dream are encoded differently from anything happening in the waking state: time, place, person and circumstances bear different relationships from each other in dreams than they do in the waking state. This is no doubt another explanation why most of us remember few of our dreams. This is certainly true for me. If I awaken from a dream I immediately dictate a narrative of it into a small flash-recorder I keep by my bedside. I’ve found out from personal experience over the years that no matter how intriguing and captivating a dream, and despite my determined intention to remember it, I will not be able to recall it the next morning – hence the flash-recorder.

If you are interested in dreaming more and recalling more of your dreams it’s only necessary, as Harvard sleep researcher Allan Hobson told me a decade ago, to make a silent resolution when going to bed that you would like to experience a dream. According to Hobson it will take about three weeks of such nightly wishes for you to start dreaming. Another technique is to set an alarm for about an hour earlier than you intend to get up and then allow yourself to doze off. During the twilight state between sleep and wakefulness you are more likely to dream and – most importantly – to remember your dream.

Another conundrum concerns the relation of dreams and brain activity at the level of cells and circuits. This is a subcategory of the even more basic question, ‘What is the relationship of mind to brain?’ (see Can We Have a Mind Without a Body?). As described more fully in that chapter in the discussion of ‘category mistakes’, such questions represent the conflation of two orders of discourse into a single oversimplified one. In other words, a dream takes the form of a story and must be dealt with according to the rubric of narrative; a neurological explanation involves the firing of neuronal circuits and the swirl of synaptic neurotransmitters and synapses – two very different orders of discourse.

So what attitude should we hold towards our dreams? I’d suggest a kind of agnosticism: perhaps we can’t seem to make sense of dreams because they are inherently nonsensical. That would help to explain the incongruities of setting, the peculiar juxtaposition of symbols, the fantastic behaviours that render many dreams so improbable. In other words, perhaps an explanation doesn’t really exist. But that conclusion flies in the face of a very big problem: if dreams are meaningless, why is it that every civilization so far has generated various theories or schemes (or scams) that suggest otherwise? Dreams seem somehow – if only for their complexity and symbolism – to demand some kind of interpretation, however humble. No matter how puzzling or inexplicable the dream, you can ask yourself, ‘Why now? Why this dream? Should I act on this dream or just forget about it?’

But don’t look to neuroscience for any specific insight to answer those questions. Instead, acknowledge that a dream cannot be explicated like an equation. But, at the same time, mentally entertain the concept that when it comes to interpreting your dreams you should trust the originator and author of all of your dreams: your own brain.

DOES THE MIND PLAY TRICKS?

Illusion, reality and the mind

Does the mind play tricks? That is perhaps the most important question in this book. If the mind plays tricks – especially tricks that escape our attention – then how can we be certain at any given moment that we aren’t being fooled?

Type the words ‘Enigma Leviant’ into your favourite search engine. You will retrieve the painting Enigma, the creation of the artist Isia Leviant. Stare at it for a few minutes. Almost everyone who looks at the arrangement of circles and bars experiences a powerful impression of circular motion. Yet nothing is moving in Enigma: the sense of movement elicited by the image is entirely illusory and subjective.

Visual illusions such as Enigma have always interested me. In one of my earlier books, The Playful Brain, I teamed up with puzzle and illusion creator Scott Kim to explore the basis of the tricks the brain plays on us. We found that some of the tricks start in the sensory system (see How Do We Make Sense of Sensation?). Leviant’s illusion, for instance, starts in the eye.

Neuroscientists Stephen L. Macknik and Susana Martinez-Conde, who share an interest in the neuroscience of magic, recorded people’s eye movements as they looked at examples of illusory motion such as Leviant’s Enigma. They found their subjects’ subjective sense of motion in the images varied directly with the rate of tiny eye movements that occurred during visual fixations (so-called microsaccades). During faster motion periods the number of microsaccades increased. During slower motion periods the microsaccades decreased. Based on these findings, they concluded that the perception of illusory motion starts in the eye not the brain.

Think about the implications for truth-finding presented by a situation where motion is detected yet no motion is occurring. And I’m not talking here about complicated cognitive processes (which we will get to in a moment). The Enigma illusion and others like it illustrate that our brain can fool us even on the level of our most elementary sensations.

Pattern recognition

Everything we perceive enters the brain through patterns. In the visual sphere our brain processes patterns starting with lines, edges and corners. At the next highest level of processing, our visual neurons fire in response to contours and movement. Some neurons fire when the object of interest moves up or down; others fire in response to moving edges or to edges aligned in a specific direction. Finally, the brain works with colours, size, perspective and the relations of objects to each other. This hierarchical arrangement from lines and edges via movement to colours and objects makes possible our everyday world of objects, scenes, people and events. This arrangement also makes us vulnerable to the brain playing tricks on us.

Optical illusions arise based on the arrangement of our eyes: two eyes mounted side by side, leading to different projections on each of the two retinas. This binocular arrangement explains why what we see and what a camera sees are fundamentally different. A camera ‘looks’ through one lens while we look (most of us most of the time) through two eyes. The resulting stereopsis is one of the reasons why our visual apparatus processes a three-dimensional scene of which we are always a part. We can think of ourselves as biological sensing devices operating in a complex three-dimensional world. And what we see is always related to our expectations. As British artist David Hockney puts it, ‘The eye is always attached to the mind.’ As an unintended consequence of this dependency, the mind predetermines what it believes the eye is seeing. And that predetermination can be wrong.

For example, type ‘princess card trick demonstration’ into an Internet search engine and watch one or more renditions of this trick. Please try to do this before reading any further. If you aren’t able to go on the Internet at the moment, here is what happens in the trick: You are shown five cards and asked to ‘mentally select one card’. The five cards are then shuffled and turned over. One card is then removed. When the remaining four cards are turned up, your chosen card is now missing.

The ‘princess card trick’ was devised by magician Henry Hardin in 1905. It’s based on what contemporary psychologist Ronald A. Rensink refers to as change blindness, alternately referred to as inattentional blindness. This is defined by Rensink as ‘a failure to notice a fully visible but unexpected object because attention was engaged on another task, event or object’.

Here is how the princess card trick works. When you were shown the original five cards and asked to mentally pick one, your attention remained fixed on that card; you paid no attention to the other cards. And while you were concentrating on your chosen card, the magician surreptitiously substituted four new cards. You were then shown these cards and asked if your mentally selected card was among them and, of course, it wasn’t. But it wasn’t just your selected card that had disappeared: all of cards in the original five-card arrangement had gone missing. Thanks to your change blindness you are left with the impression that the magician was somehow able to intuit which card you mentally selected – and then make only that card disappear! The princess card trick is so cleverly designed that fewer than 10 per cent of subjects shown the trick can explain what happens even after multiple performances.

Shifting our perceptions

Of course, change blindness can be helpful. Imagine living in a world where your brain registered every subtle change in your surroundings. Perhaps that magazine on your coffee table was placed at a slightly different angle yesterday, or your car wheels pointed towards the kerb this morning but straight forward the morning before. If our brains registered things at that level of detail we would be awash in trivia. So, change blindness is best thought of as the optimal arrangement under most circumstances. We just have to remain aware of its existence lest our mind play tricks on us.

Our mind can play tricks by shifting our perceptions so that only one of two equally probable interpretations is possible at any given time. In the Necker Cube designed by Swiss crystallographer Louis Necker in 1832, two-dimensional lines forming a cube are interpreted by the brain as a three-dimensional object. You can view the Necker Cube by typing ‘Necker Cube Optical Illusion’ into a search engine. One site, www.youramazingbrain.org, has both an illustration and an explanation.

When looking at the Necker Cube, notice that it remains ambiguous – it can be interpreted from two different perspectives. After some practice, you can learn to shift back and forth rapidly between these two interpretations but, however hard you try, you cannot perceive both of them simultaneously. Your mind is playing a trick on you: even though you know there are two possible perceptions of the cube, you can see only one of them at any given moment.

In contrast to Enigma, the image of the cube remains stable until it is replaced by the other image; no actual movement appears to be taking place on the page. This back-and-forth shift in the interpretation of the cube is based on timing variations in the firing rates of the neurons responsible for the two interpretations of the cube. Think of it as a cycle of fatigue and refreshment. As the brain circuit responsible for one interpretation fatigues, the brain circuit for the other interpretation activates. And while it’s possible to influence the process wilfully so that one interpretation is dominant, the other interpretation eventually ‘breaks through’.

Art provides numerous examples of the mind playing tricks. This is especially evident in the work of artists such as the Spanish surrealist painter Salvador Dalí. Dalí’s painted illusions result from his manipulations of perspective, scale, spatial dislocation, vanishing points and three-dimensional illusionism. Together, these techniques create a hallucinatory sense of disorientation. In one of my favourite works by Dalí, The Phantom Cart, the silhouettes of two desert buildings in the distance can also be seen as two occupants of a covered cart approaching a small village. As with the Necker Cube the observer’s perspective shifts back and forth between two interpretations of Dalí’s painted illusion.

Dalí’s fascination with illusions originated with his observation and interpretation of the slow metamorphosis undergone by clouds or a moving skyline as observed from a small rowing boat.

All the images capable of being suggested … appear successively and by turn as you change your position … As we moved forward with the characteristic slowness of a row-boat all these images became transfigured … a camel … a rooster.

Another person observing the same clouds would detect different figures depending on the tricks played by his brain.

Psychologists take advantage of this fact that each brain plays different tricks depending on the psychological make-up of the observer. In the Rorschach test subjects look at inkblots of ambiguous figures and report what they see. Although the test is rarely used today because of its impressionistic nature and the resultant difficulties in interpretation, the Rorschach remains an artful demonstration of how the brain perceives patterns based on the personality of the observer, cultural context and experience.

Cognitive tricks

Our mind-brain plays tricks on us that not only involve our senses but our thoughts as well. These cognitive illusions arise from our difficulties in quantifying and dealing with probabilities. Despite our wishes and beliefs to the contrary, we are not inherently logical creatures. Mathematics, rational deduction and causal connection do not come naturally to us; instead, we must learn them.

Here’s an example of my point. Hank is a former marine, a volunteer firefighter, holds advanced degrees in several martial arts and regularly participates in triathlons. Question: Is Hank more likely to be a member of the Special Forces or a librarian?

If you identified Hank as most likely a Special Forces member you were wrong. But don’t feel too badly about your choice; most people – even some statisticians – often ignore probability and answer that question on the basis of stereotypes. The key reason why you should answer librarian is that there are many more librarians than members of the Special Forces. In fact the numbers are so astoundingly asymmetrical that if I had told you nothing at all about Hank and asked you to choose his profession you would have answered the question correctly without any hesitation. Instead I played a mental trick based on your stereotype of librarians. But admit it, how much do you really know about librarians? In their private lives, can they not be firefighters, martial artists and triathlon participants? And you are probably even less knowledgeable about members of the Special Forces.

Mentalism, magic and the brain

Magic provides the most entertaining examples of how the mind plays tricks. I’ve been a member of the International Brotherhood of Magicians for over 25 years and have met and learned from some of the stellar performers in mentalism and close-up magic. From mentalist-magician Alain Nu I’ve learned that it isn’t true that the hand is quicker than the eye. Instead, magicians rely on attention management: force-focusing the observer’s attention away from where the actual trick is taking place. As an example, take Apollo Robbins who advertises himself as the ‘Gentleman thief’ based on his ability to pick your pocket even after you have been given notice that he is about to do so. When asked how he operates Apollo speaks of ‘frames’, by which he means windows of space and time that he creates to localize the attention of his ‘mark’ or target of the magic trick.

In one demonstration that I personally witnessed, Apollo took a man’s hand and placed a coin in his palm. ‘Squeeze hard,’ Apollo told the man. ‘Do you have the coin?’ asks Apollo? ‘Yes,’ the man responds. ‘Open your hand,’ says Apollo. When the hand opens, it is empty. ‘Is that the coin on your shoulder?’ Apollo asks him. When the man looks towards his shoulder, he discovers the coin there.

How did Apollo move the coin from the man’s hand to his shoulder? Well, actually he didn’t. The coin was never in the hand. Instead of placing the coin in the hand, Apollo merely pressed it firmly against the palm and then removed it. The stimulation of the sensory receptors in the palm led to the perception that the coin remained in the palm. This is called a lingering sensory after-image. When the man participating in the coin trick squeezed his hand the sensory after-image of an illusory coin was further intensified.

Apollo’s request to ‘squeeze hard’ also introduced the second element in the trick: redirecting the mark’s focus of attention towards his hand, thus providing Apollo with the precious few seconds needed to place the coin on his shoulder.

A pickpocket takes advantage of the sensory after-image when stealing a watch. He briefly squeezes the wrist just above the watch band. This creates an after-image by reducing the sensitivity of the touch neurons in the skin and spinal cord and thereby maintaining the perception that the watch is present long after it has been pilfered.

‘Active and passive misdirection’, ‘attention management’, ‘attentional control’, ‘inattentional blindness’, ‘the parenthesis of forgetfulness’ – these are some of the terms used by magicians and mentalists to take advantage of the tricks that our minds play on us.

At all times our brains make guesses about meaning based on patterns garnered from past experience. I’m looking now at a lighthouse in one of Edward Hopper’s pictures of Maine. I see a three-dimensional object silhouetted against a blue sky. Yet the three-dimensional object of the lighthouse is the result of a double illusion: Hopper applied his paint onto a two-dimensional canvas; and it’s a two-dimensional image that falls upon each of my retinas. In order to create this double illusion leading to my perception of a three-dimensional object, my brain at various levels of operation amplifies, suppresses, converges and distributes the visual information travelling from my eyes to my brain.

Yes, on occasion the mind does play tricks on us. But in most instances, as with illusions, magic, mentalism and the Hopper painting, these tricks are based on our own sensory and cognitive misinterpretations of our inner and outer worlds.

ARE MACHINES SCRAMBLING OUR BRAINS?

Thinking in new and different ways

Machines, broadly defined as pieces of equipment that perform a particular job, have been influencing the brain for a long time. It started in earnest with the Industrial Revolution with its emphasis on efficiency and productivity. Mass production methods from that time fragmented the production process, increased depersonalization and, as decried by Karl Marx, often alienated the worker from the product of his work.

Later, automation led to the elimination of jobs and the displacement of workers from long-established niches. For instance, not so many years ago men (they were invariably men) in uniforms sat on tiny chairs and manually operated individual lifts in department stores and office buildings. Their jobs disappeared with the widespread introduction of automated lifts. At about the same time, legions of telephone switchboard operators (almost all women) met a similar fate brought about by automated dialling and other telephone advances. This process of technologically driven redundancy continues today within certain sectors of the economy such as banking, which, thanks to ATM machines and online transactions, is currently shedding a steady contingent of workers.

With unemployment and its accompanying loss of identity and self-respect come increasing poverty, mental illness, substance abuse and violence. All four factors, individually and collectively, are associated with impairments in brain health and functioning. Poverty begets brain-stunting malnutrition among infants and young children; alcohol and drug abuse induce brain damage among adolescents and adults. A malnourished or damaged brain is prone to dysfunctional performance.

Of course, social changes and their ensuing effects on the brain weren’t brought about solely by the introduction of machines and subsequent technological advances. But starting with the Industrial Revolution and continuing up to our current technologically driven information-based culture, machines have been inducing alterations in the human brain.

For example, technology is contributing to the atrophy of certain cognitive skills such as mathematics. Simple maths is now beyond the capacity of many intelligent and well-educated people because they have become accustomed to using calculators and more recently mobile phones, instead of doing sums in their heads. Memory is another casualty. If you want to access an item of information quickly, you don’t have to depend on your memory but can resort to Google and come up with it in seconds. General information retrieval is thus becoming increasingly ‘outsourced’ from the brain. In certain areas, the brain’s superiority over the technology it has created is rapidly shrinking. In 1997 Deep Blue, created by the computer engineers at IBM, defeated one of the greatest chess champions in history. In 2011 Watson, the product of another team from IBM, outperformed the two biggest money winners on the TV show Jeopardy! since the show’s creation in 1964.

In tandem with these developments, changes have come about in the brain’s organization and functioning: we’ve learned to use our brains in new ways.

Technology and the new brain

Over the past hundred years an impressive increase in IQ scores has occurred in the world’s industrialized countries. In the period from 1947 to 2002 Americans gained 24 points in the area of IQ testing to do with object similarities (‘In what ways are a table, a chair and a coffee table alike?’). This discovery (the so-called Flynn Effect named after the intelligence researcher James Flynn) is the result of a progression from concrete to abstract levels of thinking and understanding (i.e. a table, a chair and a coffee table are alike not because they all have four legs – a concrete response – but because they are all items of furniture).

This shift from concrete to abstract styles of thinking has been further advanced by the special requirements of the information society. The technology of mobile phones, laptop computers, iPads (and other tablets) has led to changes in our experience of space and time. It is now routine to occupy more than one cognitive space simultaneously: when we’re talking on a mobile phone, we may be more engaged with someone half a world away than with the companion sitting across the table from us in a restaurant.

Advances in communication technology are bringing about other fundamental changes in the ways we relate to each other. For example, one of my friends reads and transmits all of her emails via her mobile phone. As a result, her messages are terse and laconic, missing any of the asides, humour or subtleties that can make written communications challenging and fun. When I write back to her I’m acutely aware that my message will be displayed on a tiny smartphone screen and that anything longer than a sentence or two may well go unread. Since there isn’t tolerance under these circumstances for anything beyond raw information, my own thinking starts to become limited in scope whenever I write to her – the creativity of both of us is diminished.

The power of images

Images speak directly to the brain – primarily the right hemisphere, especially for emotionally arousing images – and exert a much more powerful and immediate effect than even the most eloquent of sentences. Thanks to its organization, the brain is always more receptive to images than to words. Ivan Turgenev captured the essence of this in his novel Fathers and Sons: ‘A picture shows me at a glance what it takes dozens of pages of a book to expound.’ Technology furthers this imbalance between words and images. Compare a newspaper story to the televised coverage of the same event: ‘Riot in Mogadishu’ is far less likely to capture our attention than a live HD videocast of the riot as it’s taking place.

As another distinction, reading is a skill that must be learned; it depends on one’s social and educational background (you can’t read a sentence in a language you don’t understand). In addition, reading is a solitary activity that rarely involves large numbers of people tackling the same text at the same. Looking at an image, in contrast, is frequently a communal activity (for example, televised sporting events) that doesn’t depend on the language spoken or one’s education, social background or life experiences.

With the development of ever more realistic images – thanks to developments over the past two decades in camera and video technology – images have increasingly become the common currency of exchange. That’s because of the immediacy and impact of the image. And when images are combined with spoken or written communication, it’s usually the image that gains the most attention: the image of a child killed by a drone attack will attract more of our attention than the accompanying article discussing the inevitability of ‘collateral damage’.

But our increasing exposure to and reliance on images comes at a price: a lessening of our brain’s capacities for information analysis, critical thinking, imagination and reflection. ‘Make it quick’ – the timeframe for scanning a picture – is becoming the preferred pace for cognitive processing. ‘Our attention span is similar to our attention span on Facebook,’ according to Elias Aboujaoude, who heads the Impulse Control Disorders Clinic at Stanford University. ‘The more we become used to just sound bites and tweets, the less patient we will be with more complex, more meaningful information. I think we might lose the ability to analyze things with any depth and nuance.’

Privacy in the image-driven society

In the age of the image, privacy has become an outmoded concept. Photo capability is built into our mobile phones; ever-expanding portions of the urban landscape are coming under surveillance by police cameras; we can’t enter a shop or an apartment building without our image being ‘captured’ on video. Such image-based intrusions alter our brains towards thinking of ourselves always as the subject of someone’s observation. And this technologically based assault on privacy begins early. More than three-quarters of public high schools in the United States use video surveillance. The students have become so used to video cameras that they no longer hold expectations of privacy. This may partially explain the students’ ready acceptance and enthusiasm for social media sites. If everything is being observed anyway, why not willingly put even one’s most private concerns out there for everyone else to see?

The Internet and the brain

When we’re online we can rapidly scan large amounts of data as we ‘surf’ from topic to topic. This sometimes frantic activity replaces two of our brain’s most powerful functions, concentration and focus, with distraction created by the steady stream of sensory input from the hands, eyes and ears.

While our hands and fingers are engaged in typing, scrolling and clicking, our eyes respond to a steady flow of visual images and text and are often drawn by hyperlinks that distract our attention from our original purpose. Meanwhile, our ears remain alert for audio signals that herald the arrival of a new email, tweet or instant message. All of these sensory inputs vie with each other for limited attentional resources within our brain. In the process, multiple stimuli delivered over several sensory channels rewire our neuronal circuits in response to the brain’s plasticity. ‘The Net delivers precisely the kinds of sensory and cognitive stimuli – repetitive, intensive, interactive, addictive – that have been shown to result in strong and rapid alterations in brain circuits and functions’, writes Nicholas Carr in his book The Shallows: What the Internet Is Doing to Our Brains.

Most affected are those attentional brain circuits (a vast network that includes the frontal, parietal and insular cortex plus the anterior cingulate) most susceptible to the sensory overload and multitasking that accompanies Internet use. And technology-induced attention failures are increasing thanks to the growing popularity of portable devices. Distraction is everywhere: pedestrians crossing streets with their eyes pointed downwards at their mobile phones; students texting one another in classrooms during lectures; friends only partially participating in conversations because of the mutually perceived need to remain alert for the vibrations of their mobile phones. Short attention spans are becoming the communication norm. I was recently asked to speak to the officers of an international corporation who wanted to learn ‘everything’ about the human brain – I was told my talk couldn’t take longer than 15 minutes.

More information, less knowledge

When we’re on the Internet we’re reading and thinking in a different way. According to a study carried out by the British Library, visitors to two popular websites exhibited ‘a form of skimming activity’ marked by jumping from one source to another and rarely returning to a source previously visited. The authors of the study concluded that ‘Users are not reading online in the traditional sense; indeed there are signs that new forms of “reading” are emerging as users “power browse” … going for quick hits. It almost seems that they go online to avoid reading in the traditional sense.’ In this new form of reading, quantity is valued over quality: our brain is prodded to take in as much information as possible by connecting with as many external sources as it can. What’s missing in all this is synthesis and integration of the gathered information.

Network think

Social networking sites such as Facebook and LinkedIn are challenging traditional concepts of privacy by compiling profiles of our habits, buying patterns and political leanings – all based on information we freely submit. Instead of thinking of ourselves in the traditional way as a separate private entity we are encouraged to become part of a kind of ‘hive mind’ where opinions are primarily based on instant ‘impressions’ arrived at by canvassing other people for their impressions as a way of forming one’s own. ‘Tell me what you think so I can decide what I think.’ This wasn’t always so. Originally, social networking sites were used to establish a network of online ‘friends’. When you wanted to learn what your friends were up to you went on Facebook or a similar site. But gradually the emphasis has shifted towards social networking sites being shapers of what their members watch, hear, read and buy. While such ‘sharing’ is indisputably helpful for advertisers, it may be less beneficial to users.

What changes are brought about in the brain when a person begins to think of himself as a member of a huge network instead of a single unique person? Although no one knows the answer to this question – at this point the necessary research has yet to be carried out – it seems likely that, with the development of ‘network think’, changes will take place in people’s attitudes towards personal responsibility and free will. (See Is Free Will an Illusion?)

Certainly technology is currently stimulating new attitudes to the exchange of personal information. Imagine yourself in a bar talking to someone you’ve just met. You want to talk longer but you have to leave for an appointment. In such situations in the past you would have exchanged business cards or telephone numbers hastily scribbled on scraps of paper. Now you can acquire extensive dossiers about that person you’ve just met thanks to Quick Response (QR) codes – square chequered prints resembling bar codes that can be scanned with a smartphone. QR codes are now available on bracelets connected to a personalized site containing whatever personal information the wearer wants to put there. If both you and your conversational companion are wearing these bracelets and want to learn a lot about each other, you only have to scan each other using your smartphones and later study the retrieved information at your leisure.

Social networking and mobile phone data are also being increasingly relied upon to provide real-time snapshots of our habits and whereabouts. Research sampling about 50,000 people using social networking data suggests that most of our day-to-day movements are highly predictable. An individual’s location can be predicted – based on the analysis of past location and itinerary data – with an accuracy of over 90 per cent to within one kilometre of a mobile phone mast. And this high degree of predictability about daily mobility patterns applies not just to people with routine patterns of travel (from home to work and back), but it applies just as well to people who move about more freely. Thus electronic monitoring is supplying valuable information that we can use to understand ourselves and – perhaps less comfortingly – be understood by others. But to take advantage of this information we have to ignore the discomfort we may initially feel in response to the discovery that many of our seemingly spontaneous decisions (visit a friend, go to a movie) may now be highly predictable thanks to technology.

Technological assessments of who and where we are

Thanks to Internet communication we are learning interesting things about our individual and collective selves. Twitter is proving especially useful to scientists seeking to gather information about the behaviour and thought patterns of large numbers of people. For instance, in 2011 Michael Macy and his graduate student Scott Golder used a Twitter protocol to download more than 500 million tweets originating from 84 countries. They then searched these messages for roughly 1,000 words known to be associated with positive emotions (agree, fantastic, great) and negative emotions (afraid, angry, fear). Their goal was to obtain insight into people’s mood changes during the 24-hour cycle. In the study, positive emotions were found to be higher in the morning, decline throughout the day and improve in the evening. Changes in day length brought about the kinds of changes in mood that many people can readily identify with: positive emotion increases as the days get longer and decreases during the other half of the year when the days are shorter. What makes the Macy study unique is the large database made available through the use of a social media site. Using Twitter to track mood changes is being compared to using satellites to provide information about the atmosphere. But interpreting the data provided by Twitter and other social networking sites isn’t always easy.

Consider the following question: are vaccination rates higher or lower in parts of the world where Twitter is commonly employed as a means of communication? Most people (myself included when I was asked this question) respond that the rates will be higher. The reasoning goes something like this: the volume of tweets within a given population provides one measure of the availability of information within that population. A more extensive dissemination of information should make it more likely that people will be aware of the benefits of vaccination and therefore more likely to have their children vaccinated. But that doesn’t turn out to be the case. Vaccination rates are actually lower. Why? Because Twitter provides a readily available medium to disseminate negative anti-vaccination tweets. If a parent takes their child for vaccination and a day later the child comes down with a skin rash (later shown to be unrelated to the vaccination) the parent is more likely to send out an anti-vaccination tweet than is the parent of a child whose post-vaccination experience was uneventful. In this instance the increased spread of false information made it less likely that other parents would elect to have their children vaccinated.

The Twitter vaccine study neatly illustrates the dangers of assuming that the greater access to information provided by technology necessarily helps our brain make more informed decisions.

When considering the transition of machines from early labour-saving devices to current information and entertainment providers, it’s helpful to remember that the influence of machines on the human brain isn’t a morality tale. There are no good or bad machines. The situation is much more nuanced; simple dichotomies won’t do. Whether machines are scrambling our brains or restructuring them along beneficent lines will depend on what we do with our machines. And that choice is up to us.

GLOSSARY

amygdala An almond-shaped structure in the temporal lobe that forms an important component of the limbic system. The amygdala plays a major role in fear along with contributing to other emotional perceptions and responses.

anterior cingulate cortex A cortical structure located in the midfrontal lobe that is part of the limbic system. It is associated with error detection, attentional control and the resolution of conflicting information.

aprosodia The inability to endow speech with emotional colour and resonance. It typically arises from the right hemisphere and results in a monotonic or ‘robotic’ speech pattern.

autobiographical memory Memory of one’s personal experience.

autonomic nervous system (ANS) Sometimes referred to as the visceral nervous system, it consists of all of the nerve cell circuits that control the heart, the digestive system and the glands. It is divided into the sympathetic and parasympathetic systems.

axon The extension of a nerve that carries the action potential travelling from the nerve cell body to the dendrite of another nerve cell.

basal ganglia A group of cell structures lying deep below the frontal lobes that plays a role in the regulation and coordination of movement. Included here are the caudate, putamen, globus pallidus, subthalamic nucleus and the substantia nigra.

basic emotions These are the emotions that are innate, present in all cultures, evolutionarily old and shared with other species. Basic emotions are expressed by particular physiological patterns involving such things as heart rate and breathing patterns. Basic emotions are also expressed by facial expressions.

behaviourism The psychological theory that emphasizes the importance of direct observable behaviour as opposed to inferring unobservable internal mental states.

blindsight Some blind individuals are able to identify the location of visual stimuli when forced to guess. It’s speculated that this capacity is based on the processing of visual stimuli along alternative pathways.

brain The cerebral hemispheres and the brain stem.

central nervous system The brain and spinal cord.

cerebral cortex The superficial grey matter of the cerebral hemispheres. It forms a thin ribbon of cells over the hemispheres.

cerebral hemispheres The two halves of the cerebrum.

cerebrum The largest part of the brain in humans and other mammals consisting of the two cerebral hemispheres and located at the ‘top’ of the brain.

change blindness Also referred to as inattentional blindness. It is a normal phenomenon that involves failure to notice specific alterations in a changing scene.

chunking A memory technique of breaking up a large amount of information into smaller clusters to facilitate memorization.

cocktail party effect The selective focus of attention on one particular speaker while tuning out other nearby conversations.

cognition All ‘higher order’ mental processes involved in learning. It includes thinking, knowing, remembering, comparing, judging and problem-solving.

cognitive styles The distinctive ways that different individuals perceive, organize and respond to their internal and external environment.

declarative memory Sometimes referred to as explicit memory the term refers to memory that is available to consciousness and can be expressed by language.

dendrite The extension of a nerve that receives information from the axon of another nerve cell.

emotion A spontaneously occurring mental state marked by strong feelings and often accompanied by physiological and behavioural changes.

emotional contagion A tendency to mimic and synchronize one’s own facial expressions, vocalizations, postures and movements with those of another person and consequently to converge emotionally (see also empathy). The ‘Emotional Contagion Scale’ is a psychological test that assesses people’s susceptibility to ‘catching’ from others love, fear, anger, anxiety, sadness, joy, happiness and depression.

empathy The internal representation by one person of the internal mental state of another. This is similar to mentalizing (also called theory of mind), which enables one person to imaginatively experience the mental state of someone else. Empathy has also been depicted as ‘feeling into’ another individual’s emotional state, taking another person’s perspective and imagining how that person would feel in a particular situation.

episodic memory A form of declarative memory consisting of autobiographical remembrances based on personal experiences.

facial feedback hypothesis Charles Darwin was among the first to suggest that emotional experience is strongly affected by feedback from the facial muscles. He wrote about this effect in The Expression of the Emotions in Man and Animals.

‘fight or flight’ response A grouping of bodily responses triggered by the sympathetic branch of the autonomic nervous system that prepares the body to face and deal with a threat or to escape from it. It includes increased blood flow to the muscles of the limbs along with increases in breathing and heart rate.

hippocampus A seahorse-shaped structure towards the tip of the temporal lobe that initially encodes new information prior to its dissemination to the rest of the brain and its conversion into long-term memory.

hypothalamus A small collection of critically important neurons lying beneath the thalamus that are devoted to the maintenance and control of bodily processes, such as temperature regulation, reproduction and hormone production.

implicit memory Memory recalled unconsciously during physical performance.

limbic system A series of cortical and subcortical structures concerned with emotional experience and expression.

mind blindness A failure of empathy that involves an inability to infer accurately or in some cases even to recognize the existence of other people’s feelings and thoughts.

negativity bias Individuals react more strongly to losses than to gains.

neural Darwinism A term coined by Nobel laureate Gerald Edelman to describe the process whereby neurons that receive stimulation grow and endure while neurons deprived of stimulation atrophy and die off.

neurotransmitter A chemical released at synapses responsible for the transfer of information from one nerve cell to another.

perception Subjective awareness of the external or internal environment. It involves some degree of interpretation of the information provided by sensation.

pituitary gland An endocrine structure within the brain that produces hormone-secreting cells and chemicals (neuropeptides) produced by neurons in the hypothalamus.

plasticity The ability of the brain to change in response to experience.

prefrontal cortex The anterior frontal lobe thought to be heavily involved in reasoning, planning, judgement, empathy, abstract concepts and conscience.

premotor cortex Part of the prefrontal cortex located anterior to the primary motor cortex; involved in planning movement.

proprioception Signals from the muscles, joints and skin that indicate the relative position of body parts. Despite the rarity of this term in everyday discourse, it’s a simple concept. Raise your right hand above your head. Now close your eyes and mentally picture the position of your hand in space. While you are doing that you are depending on proprioception.

semantic memory Stored knowledge of general facts and information.

serial processing The transmission of information along a chain of neurons with each neuron excited in sequence.

stimulus An environmental change that may evoke a reaction from the brain.

sympathy An emotional response to another person’s emotional state or condition. It is not equivalent to emotionally experiencing the other person’s state or condition (empathy) but consists rather of feelings of concern or compassion for the other. Sympathy merges into empathy and in some cases the distinctions are not sharply defined.

synapse The tiny gap separating the axon terminals of two neurons.

thalamus A way station for nerve impulses on their way from the periphery to the cerebral cortex. Taken from the Greek word for ‘inner room’, the thalamus is located just outside the main entrance to the cerebral hemispheres.

theory of mind Also referred to as mentalizing. The ability to put oneself into the mental state of another. Although similar to empathy, theory of mind refers more to cognitive processes while empathy primarily involves feelings and emotions.

vagus nerve The major communication pathway between the brain and the body’s organs. It is part of the parasympathetic branch of the autonomic nervous system.

working memory The active process of temporarily maintaining and manipulating information in your short-term memory: keeping one thing ‘in mind’ while doing something else.