The Brain: The Story of You by David Eagleman
Pantheon Books, New York. 2015, 218pp., Illus. £13.60, h/b – ISBN 978 1 101 87053 2
Dr Eagleman directs the Laboratory for Perception and Action and the Initiative on Neuroscience and Law at Baylor College of Medicine, Houston. His research interests are neuroplasticity, time perception, synaesthesia, visual illusions and the developing field of neurolaw (the implications of neuroscientifically derived brain-mind findings for the basis on which we make laws, punish criminals and formulate methods of rehabilitation). He has authored or co-authored over 90 research papers, is the author of Incognito: the Secret Lives of the Brain (2011), co-athor with Dr Richard Cytowic, Clinical Associate Professor of Neurology, George Waashington University Medical Centre, of Wednesday is Blue: Discovering the Brain of Synesthesia, co-author with Dr Jonathan Downar, Assistant Professor, Department of Psychiatry, University of Toronto, of Brain and Behaviour: A Cognitive Neuroscience Perspective (2016) and was the writer and presenter of the six hour television series The Brain with David Eagleman.
This book, which includes numerous case histories to support his emergent mind from brain argument, is a model of lucid writing accompanied by excellent illustrations, chapter references and a glossary of terms. He discusses the relationship between brain and mind in six chapters headed Who am I? What is reality? Who’s in control? How do I decide? Do I need you? And Who will we be? Each chapter opens with a brief preface summarising the neurological imperative.
According to Eagleman the basic hypothesis of the neurosciences is that each human mind, and by inference each animal mind, is an emergent property arising from the coordinated activity of billions upon billions of densely packed nerve cells, their trillions upon trillions of interconnecting circuitries carrying billions of bioelectrical impulse frequencies throughout the brain without cease. Feed into this mix incoming impulses from all our sense organs, outgoing motor impulses activating our muscles to move our bodies, sensory return impulses from skin, joints and tissues saying what is happening to our perceptual body ‘out there’ together with the sympathetic and parasympathetic nervous systems controlling all our viscera, and one can obtain an impressionistic glimpse of our brains ‘humming’ with bioelectrical activity.
This hypothesis (well known, of course, to SMN members) that mind is an emergent property of brain is an inference based upon the huge volume of data accumulated over the last two hundred or so years from worldwide clinical investigations and laboratory research findings. We do not know how conscious awareness arises from physical brain processes but, the neurosciences say with one voice, this does not alter the fact that it does. Dr Eagleman emphasises the finding that for every mental experience there is a corresponding correlate of brain activity without known exception. While brain activity continues in the absence of consciousness no mental experience however spiritual or mystical has ever been reported in the absence of corresponding brain activity. Dr Jimo Borigin et al’s (2013) unexpected discovery of a short period of intense brain activity in dying rat brains, imply a possible neural correlate for human NDEs if all brains follow the same final trajectory preceding resuscitation. They summarise their findings by saying ‘These data demonstrate that the mammalian brain can, albeit paradoxically, generate neural correlates of heightened conscious processing at near-death’ (my emphasis). For the neurosciences mental activity is totally dependent upon brain activity. There is, they say, no other credible interpretation of their findings.
In his chapter on Who am I? Dr Eagleman says that our brain creates ‘Our thoughts and our dreams, our memories and experiences as all arise from this strange neural material. Who we are is found within the intricate firing patterns of electrochemical impulses. When that activity stops, so do you (my emphasis). When that activity changes character due to injury or drugs you change character in lockstep. Unlike any other part of your body if you damage a small piece of the brain, who you are is likely to change radically’. From birth onwards the brain endlessly reshapes its synaptic connections and therefore our mental processes and the ‘I-ness’ of who we are by forming new circuitries joining different parts of the brain together in ever changing functional unities.
Our personalities and resulting behaviour can be dramatically affected by brain pathology. On August 1, 1966, twenty five year-old Charles Whitman stood on the observation deck of the University of Texas Tower in Austin. Having killed his wife and mother the night before he fired down into the crowd killing thirteen and wounding thirty three others before the police killed him. Nothing about his everyday life indicated that he could possible become a mass murderer. He was an Eagle Scout and working as a bank teller to fund his engineering course. When a brain autopsy was performed the pathologist found a small tumour pressing against the amygdala nuclei that carry neural correlates of anger and aggression. As Dr Eagleman describes it ‘this small amount of pressure on the amygdala led to a cascade of consequences in Whitman’s brain, resulting in him taking actions that would otherwise have been completely out of character. His brain matter had been changing and who he was changed with it’.
There is no unchanging ‘I’ as each ‘I’ changes everyday throughout life in parallel with correlated changes in our brain in response to changing circumstances. Our familiar conscious ‘I’ has a limited daily existence only. When we become non-conscious as in deep sleep our daytime ‘I’ no longer exists and returns only when our brain ‘fires up’ again next morning. Today’s newly conscious ‘I’ then seamlessly reconnects with memory of yesterday’s conscious ‘I’ as if the intervening period of non-existent ‘I’ had never happened. If your brain does not wake up again, then nor does the emergent ‘I’ of you. All talk of immortal souls and a conscious life after death continuing in separate independence from your dead brain is therefore redundant.
The answer to What is Reality? is that as far as your experiential reality is concerned it is a construct of the brain that, from babyhood onwards, has been genetically programmed to use its huge computational capacity to interpret the messages pouring in from its senses to create a psychologically emergent picture of the outside world and your experiential body moving within it. This applies to all species according to their survival needs. As Eagleman describes it the inferred physical reality as explored by physics is ‘colourless, odourless, tasteless and silent. Outside your brain there is just energy and matter. Over millions of years of evolution the human brain has become adept at turning this energy and matter into a rich sensory experience of being’ and later ‘All of your sensory experiences are taking place in storms of activity within the computational material of your brain’ which ‘has no access to the world outside. Sealed within the dark, silent chamber of your skull, your brain has never directly experienced the external world and it never will’. The brain translates all incoming sensory impulses into a common currency of electrochemical signals, passes them through intermediate stages of incredibly complex computation that is completed by the cerebral cortex to create an emergent mental reality of experiencing. But in neurological reality Eagleman says that ‘Everything you experience – every sight, sound, smell – rather than being a direct experience, is an electrochemical rendition in a dark theater’.
So ‘Who’s in control? As you will have guessed by now the answer is our brain. You are totally dependent in everything you do from ‘standing, walking, driving a car, recognising a friend, getting a joke, feeling hungry or thirsty’ on ‘vast computations happening below your conscious awareness. At this moment, just like in every moment of your life, networks in your brain are buzzing with activity, billions of electrical signals are racing along cells, triggering chemical impulses at trillions of connections between neurons. Simple acts are underpinned by a massive labour force of neuron activity. You remain blissfully unaware of all this activity but your life is shaped and coloured by what is happening under the hood: how you act, what matters to you, your reactions, your loves and desires, what you believe to be true and false. Your experience is the final output of these hidden networks’. Having said that Dr Eagleman then asks rather surprisingly ‘So who exactly is steering the ship?’ In brief, and sticking with this nautical analogy, the emergent consciousness of you with your awareness of the world around you is the captain and steersman who decides on your course based upon the outcome of interacting variables of emergent emotions, memories, imagined future scenarios, desired goals and logical thinking as to how to get there. Without an emergent awareness of the world your brain and body cannot survive.
How Do I Decide? It seems that the brain is a battleground of competing neural networks linked to the emergent you of likes and dislikes and decisions as to whether, for example, your love of cream buns is greater than your desire to cut down on sugar for the sake of your waist line. An emotional desire to come to a decision is essential as without it you remain in a state of indefinite indecision. This depends upon an intact relationship between your orbito-frontal cortex that contain the neural correlates of intellectual assessment and imaging of possible future scenarios of what must be decided and the midbrain emotional centres feeding information on the emotional pros and cons. If this relationship is damaged following orbito-frontal cortical damage then a decision becomes almost impossible.
Do I Need You? The short answer is ‘Yes’. ‘Normal brain function depends upon the social web around us. Our neurons require other people’s neurons to survive.’ ‘We are social creatures and an enormous amount of brain circuitry has to do with other brains’. Perhaps Eagleman should have said ‘the emergent ‘I’s of other brains’.
Who Will We Be? Eagleman discusses recent advances in digital technology and wonders whether an emergent ‘I’ could ever be preserved by being transferred by brain-digital interface to run on a comparable computational platform other than neurons. Eagleman’s frustration concerning the transitory nature of our emergent I’ is summed up in the following quote ‘When my friend and mentor Francis Crick was cremated I spent some time thinking about what a shame it was that all his neural matter was going up in flames. That brain contained all the knowledge, wisdom and intellect of one of the heavyweight champions of twentieth-century biology. All the archives of his life – his memories, his capacity for insight, his sense of humour – were stored in the physical structure of his brain, and simply because his heart had stopped everyone was content to throw away the hard-drive’.
This way of thinking about ourselves and all animals as temporary brain activity→emergent mind organisms based upon sensory system input may well become common currency in society, at least in the Western world. Dr Eagleman’s standpoint can be dismissed as ‘neuroscientific hubris’ but, in counterclaim, he will say it is based on findings from ever increasing research confirming this inescapable brain-mind relationship.
What remains unresolved is the nature of the emergent ‘I’. Is it a physical property of the same bioelectrical nature as our brain? Does it consist of a daily emergent field of physico-mental energy with new properties of ‘I-ness’ including, as many claim, telepathy and other psychic phenomena? This would allow for brain-emergent mind interaction. Instead, is the ‘I’ a non-physical mental phenomenon whose nature and properties, including possible psychic abilities, are different in kind to the brain? If so, this leaves the problem of brain/mind interaction possibly unsolvable as neither would seem to possess the property necessary to act upon the other. Is the dilemma caused by incorrect interpretation of what we perceive as ‘physical’ and ‘mental’? Is death in the sense of extinction the same for all species possessing a brain or are humans an exception? If so, how and why? The social, ethical and moral implications of neuroscientific research concerning the nature of the ‘I’’ of this present life let alone any other are profound.
An extended version of this review is available from the editor.
Borigin, J. et al. (2013) Surge of neurophysiological coherence and connectivity in the dying