The Ravenous Brain: How the New Science of Consciousness Explains Our Insatiable Search for Meaning

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The Ravenous Brain: How the New Science of Consciousness Explains Our Insatiable Search for Meaning Page 1

by Bor, Daniel




  Table of Contents

  Title Page

  Dedication

  Introduction

  Chapter 1 - Conceptual Conundrums of Consciousness

  TECHNOLOGICAL TELEPATHY

  PHILOSOPHY VERSUS SCIENCE

  DESCARTES AND THE MIND-BODY DUALITY

  MODERNITY ARRIVES AND GHOSTS LEAVE

  THE IMPENETRABILITY OF “WHAT IT IS LIKE”

  CAN A PROGRAM HAVE FEELINGS?

  CAN A LAPTOP REALLY UNDERSTAND CHINESE?

  THE MOST COMPLEX OBJECT IN THE KNOWN UNIVERSE

  THE CASE FOR ARTIFICIAL CONSCIOUSNESS

  ERODING THE WALLS OF SUBJECTIVITY

  OUR INDOMITABLE SPIRIT

  Chapter 2 - A Brief History of the Brain

  THE FIRST LESSON IN NATURE IS FAILURE

  THE ESSENCE OF EVOLUTION

  BREEDING CHEMICAL COMPLEXITY AND REBELLIOUS OFFSPRING

  LIVING ON THE EDGE OF CHAOS

  WETWARE

  A UNIVERSAL RECIPE AND A UNIVERSAL LANGUAGE

  EXTRA INNOVATION IN DESPERATE TIMES

  MUTANTS, SEX, AND DEATH

  EVERY CREATIVE TRICK IN THE BIOLOGICAL BOOK

  COOPERATION AND DIFFERENT LEVELS OF INFORMATION PROCESSING

  GENIUS CELLS

  INTERNAL EVOLUTION

  THE COMPUTATIONAL LANDSCAPE OF A BRAIN

  VAST INTERNAL WORLDS

  Chapter 3 - The Tip of the Iceberg

  A HOLIDAY FROM AWARENESS

  UNPEELING EVOLUTIONARY HISTORY IN THE BRAIN

  UNCONSCIOUS NEURONS MARCHING IN STEP

  LEARNING ON THE OPERATING TABLE

  UNCONSCIOUS BETTER THAN CONSCIOUS?

  FEELING YOUR WAY TO KNOWLEDGE

  EAT POPCORN: THE UNCONSCIOUS TAKES CONTROL

  UNCONSCIOUS DECISIONS AND THE FREEDOM TO CHOOSE

  ASPIRING TOWARD FREE WILL

  Chapter 4 - Pay Attention to That Pattern!

  DANGEROUS DAYDREAMS

  ATTENTION FUNNELING RAW DATA TO BUILD EXPERIENCES

  NOT SPOTTING THE WOOD, THE TREES, THE BIRDS, THE SOIL, THE FLOWERS, THE . . .

  A BRIGHTER, MORE VIBRANT WORLD

  THE ATOMS OF THOUGHT

  ATTENTION AS A BRUTAL NEURONAL WAR

  ATTENTIONAL VICTORIES EMERGING INTO CONSCIOUSNESS

  OVERESTIMATING THE VALUE OF EMOTIONS

  LAYERS OF AWARENESS

  FOUR COMPARTMENTS TO AWARENESS AND NO MORE . . .

  . . . BUT EACH CONSCIOUS COMPARTMENT CAN HOLD OBJECTS OF GREAT COMPLEXITY

  BELITTLING THE RICHNESS OF EXPERIENCES?

  CHUNKING AND CONSCIOUSNESS

  LANGUAGE—JUST ONE KIND OF CONSCIOUS CHUNKING?

  THE FRUITS OF CHUNKING AND AWKWARD SELF-CONSCIOUSNESS

  Chapter 5 - The Brain’s Experience of a Rose

  QUIT WHILE YOU’RE AHEAD?

  MY CONSCIOUS MIND IS MY CONSCIOUS BRAIN

  OPENING THE FLOODGATES

  BLINDSIGHT PATIENTS LEADING YOU UP A BLIND ALLEY

  VISUAL HIGHWAYS TOWARD CONSCIOUSNESS

  SCANNING CONSCIOUSNESS AS CANDLES BECOME FACES

  PATIENTS AND THE PREFRONTAL PARIETAL NETWORK’S OFFICIAL JOB

  STILL CONSCIOUS, BUT ONLY OF THINGS ON THE RIGHT

  CONSCIOUSNESS SHRINKING TO A SMALL POINT

  BRAIN-SCANNING THE PREFRONTAL PARIETAL NETWORK

  THE PREFRONTAL PARIETAL NETWORK, CONSCIOUSNESS, AND CHUNKING

  HARMONIOUS EXPERIENCES

  CONSCIOUSNESS, IN THEORY

  EXPLAINING EXPERIENCES

  Chapter 6 - Being Bird-Brained Is Not an Insult

  TENDER CHIMPS, CAPRICIOUS BONOBOS

  CRAFTY CROWS

  CAN A BIRD ADMIRE ITSELF IN A MIRROR?

  GAMBLING ON CONSCIOUSNESS

  ANIMAL CHUNKING

  INFANT AWARENESS

  MEASURING CONSCIOUSNESS IN ANIMAL BRAINS

  CHAUVINISTIC ANATOMICAL BOOTSTRAPPING

  QUANTIFYING CONSCIOUSNESS

  ETHICAL IMPLICATIONS

  DIFFERING QUALITIES AND QUANTITIES OF EXPERIENCE

  Chapter 7 - Living on the Fragile Edge of Awareness

  JUST TOO COMPLEX?

  A TORTUOUS BATTLE OF UNCERTAINTY

  A THIN VEIL BETWEEN LIFE AND DEATH

  VIEWING CONSCIOUSNESS FROM WITHIN

  COMMUNICATION BY BRAIN ACTIVITY

  CHECKING THE INTEGRITY OF CONSCIOUS NEURAL HIGHWAYS

  THE DIFFICULTY OF REPAIRING HUMPTY DUMPTY

  Chapter 8 - Consciousness Squeezed, Stretched, and Shrunk

  SHARP FRACTURES IN AWARENESS

  AUTISM AND OVER-CONSCIOUSNESS

  UNHEALTHY SLEEP, UNHEALTHY CONSCIOUSNESS

  WORKING MEMORY NOT WORKING

  CHEMICAL CASCADES UNBALANCING AWARENESS

  BUILDING THE CONSCIOUSNESS MUSCLE

  A SEESAW OF STRESS VERSUS CONSCIOUSNESS

  A WIDER, PURER OCEAN OF AWARENESS

  HEALING CONSCIOUSNESS FROM MANY ANGLES

  Epilogue

  Acknowledgments

  Notes and References

  Illustration Credits

  Index

  Copyright Page

  Dedicated to the memory of my father,

  Rayle Jonathan Bor, with much love

  Introduction

  On the night of Thursday, May 8, 1997, my father had a stroke. I’d been repeatedly reassured that the stroke was “very minor.” Nevertheless, when I visited him in the hospital, I felt profoundly disturbed by what I witnessed. This sluggish, exhausted man in front of me looked like my father, but I knew, deep down, that he wasn’t.

  There were subtle clues that betrayed this impostor. Some changes verged on the comical, such as his newfound obsession for Kit Kats—he would eat nothing else for days. Others were more disconcerting. These differences could generally be characterized as a reversion from a sharp, responsible man into a confused child. Even more bizarrely, his attitude toward me would radically alter depending on whether I sat on the right or left side of his bed. When I sat on his right, he would take an interest in me, and we’d have a semi-coherent conversation. When I went instead to his left, it was as though I wasn’t in the room. He simply wasn’t aware of my presence.

  I found myself morbidly wishing that he’d suffered a mild heart attack instead of a stroke. Then, at least, my dad would still be alive, as my dad. As it was, if this situation persisted, a portion of my father would already have died, and every time he spoke, I would be reminded of that fragment of his identity that was lost.

  Amid my sense of shock at this new person that wasn’t Dad, and my chest-gripping anxiety that he would never fully recover, I couldn’t help examining his symptoms dispassionately. My father’s stroke had struck a few weeks before my university finals. I was studying philosophy and biological psychology, and consciousness was a hot topic in both fields. On the one hand, I was revising elegant philosophical arguments proposing that consciousness was nonphysical and had little to do with brains. On the other hand, I was poring over the evidence for whether consciousness lay in this cortical region or that, and learning the details of “neglect”—the common stroke condition my father showed by ignoring the left side of space.

  Sitting by my father’s bedside, I felt sure that the esoteric philosophical position was alien—so mistaken as almost to be offensive. Here was a man I loved dearly, robbed of his identity because a small clot on his brain had potently wounded his consciousness. Of course consciousness is a physical thing, I thought,
as I sat on his left, achieving the painful magic trick of turning invisible. I didn’t exactly know why the philosophical arguments were flawed, or which brain theory of consciousness was most compelling at the time, but I did know which road I wanted to take to find out.

  Although previously I was considering a PhD in the philosophy of mind, now there was no contest—a PhD in the neuroscience of consciousness it was. Soon afterward, I was accepted to study this at the University of Cambridge. I’ve been investigating this and related fields ever since, mainly at Cambridge, but also recently at the newly opened Sackler Centre for Consciousness Science at the University of Sussex. From the first painful glimpse of my father’s fractured consciousness, I understood how vital and fundamental this field is, but over the years I’ve increasingly discovered its fascinating and far-reaching twists and turns. Now I want to share each of these facets with you.

  There is nothing more important to us than our own awareness.1 We see the breathtaking beauty of snowcapped mountains, the exhilarating grace and speed of a cheetah on a hunt. We hear melodic birdsong in our gardens. We fall in love, or experience the joy of our child’s first smile. We compose and appreciate music, art, and literature. We talk and laugh with our friends and family. All these, and everything else we care about, are conscious events. If none of these events were conscious, if we weren’t conscious to experience any of them, we’d hardly consider ourselves alive—at least not in any way that matters.

  When I’m reveling in a glowing pleasure, or even if I’m enduring a sharp sadness, I always sense that behind everything there is the privilege and passion of experience. Our consciousness is the essence of who we perceive ourselves to be. It is the citadel for our senses, the melting pot of thoughts, the welcoming home for every emotion that pricks or placates us. For us, consciousness simply is the currency of life.

  However, the scientific study of consciousness, for most of its existence, claimed the prize for the most vital, intimate, meaningful topic with the smallest research interest. Never before have we come within touching distance of understanding the history of our universe, its shape and form, the laws that govern every sparkling star and every dancing atom. Never before have we realized that within every cell in our bodies there lies, coiled up, the code that both defines us and connects us with all life on this planet. All of our wonderful toys of technology and all of our shining scientific discoveries have conscious endeavor to thank for their existence. Yet, until only a couple of decades ago, virtually no one was interested in the science of consciousness, and very little was understood about how the brain generates our experiences.

  Historically, it was not scientists who grappled with the conundrum of consciousness, but philosophers. Nearly four hundred years ago, Descartes asserted that consciousness was an entirely personal, subjective entity, impenetrable both to the physical sciences and the minds of other people. When I listen to a Beethoven piano sonata, the sounds I hear, the way that the notes move me, is something that I can only ever imperfectly communicate via the crude medium of words. No one else can ever truly know what I experience—at least that’s what many people assume. The peculiarity and power of this observation is highlighted when consciousness is contrasted with any physical entity. Take any object one would care to name, from a subatomic particle to a brick to a star: Thousands of people all could, in principle, explore the same object from different angles, yet uncover an identical set of facts about it. For consciousness, it seems that there is no objectivity. Nor are there multiple viewpoints: There is only one viewpoint—mine.

  Modern philosophers have expanded on this foundation, providing arguments for the position that consciousness is elevated beyond the pedestrian whirrings of our brains. Similarly, they claim that the sumptuous, varied menu of feelings and knowledge we experience simply cannot be reduced to some tawdry computer or machine. I begin this book by addressing these stances, rooted in history. There’s no denying their intuitive and emotional appeal, but this should always be trumped by the picture that the empirical evidence paints. Indeed, when the light of science shines with forensic detail on this set of philosophical positions, their seeming validity dissolves. Instead, I argue, the most plausible view is that consciousness is a product of the brain, which is a form of computer.

  Placing consciousness within the framework of a computational brain suggests a connection between awareness and information processing, since data analysis is the overriding purpose of our inner neuronal world. This general context also implies that our capacity to experience might have an evolutionary heritage, just as our neural machinery does.

  Indeed, the common waters between consciousness, information, and biology run deep. A fundamental feature of nature is its ability to store and manipulate information. Evolution ensures that every life-form is a master at hoarding useful “ideas” about the world—not consciously, but via the blind representation of information in its chemical makeup. Consequently, there are countless examples to illustrate that animals aren’t the only clever organisms around. Plants have spikes, poisons, and a plethora of other ingenious tools to ward off predators. Even bacteria have an incredibly sophisticated arsenal of weapons designed to infiltrate a host, or thwart a potential assailant. These strategies are written in the language of deoxyribonucleic acid (DNA), a recipe of implicit beliefs about how best to function in the world. But how does this DNA-based system “learn” to build and adapt such accurate blind concepts in the first place?

  In any form of learning, from bacteria becoming resistant to antibiotics, to a child making the tentative transition from crawling to walking, there is a tension between holding on to the familiar—to an existing bank of beliefs, a known way of life—and moving toward something new. This novelty injects a bit of chaos into the mix to shake up existing, stubborn ideas. These stumbling movements can potentially make matters worse, but, crucially, they at least allow for the possibility of improvement.

  DNA is a fantastic medium for maintaining those stable implicit concepts about the world, and undoubtedly this is why it became the universal carrier for the recipe of life. But there are also mechanisms that can rearrange the letters of the DNA recipe, so that a new collection of ideas can be written in future generations. When the world has moved on without you, when you and your current DNA-based beliefs are heading toward extinction, new concepts become essential, and this random mixing of the DNA pot might just create a few surviving organisms amid the many that fail. Such winners will in their DNA be carrying successful novel insights to steer them through these difficult times. In other words, this section of the species has blindly learned, over the generations, to innovate its way around a dangerous obstacle.

  Without this ability to innovate, albeit in a random, cruel, inefficient manner, life simply would not have persisted on earth, and so this skill of nature to track the changing tides, and to exploit any advantage it can latch onto, is in some ways the essence of evolution. It’s no wonder, therefore, that such a fundamental attribute of life would burst the seams of its original DNA dam and spill into new territory. And the premier example of this expansion of learning dimensions is the evolutionary invention of a bundle of specialist computational cells that constitute a brain. Now an extra, panoramic range of innovations can occur within a single organism in a pointed, purposive way as it mentally probes the environment and stores within its neurons any new information, not coded in its DNA, that is relevant for survival.

  Humans, too, are clearly cast in evolution’s intense furnace of the fight for survival. Although our mental life sometimes appears opaque by its sheer complexity, evolution has carefully finessed the foundations of every facet of our biological makeup—including our most sophisticated emotions and most inspired ideas.

  Although humans are only one tiny strand of the web of life, we have a unique place in nature because of the vigor of our intellect and the extent of our awareness. We can muster up only about a fifth of the physical strength of our nearest r
elatives, the chimpanzees; even the sharpness of our senses is feeble compared to our chimp cousins. And yet, along with our supreme consciousness, we in some ways encapsulate evolution’s fundamental driving force by being absolute masters of innovation. Every species pushes to control and dominate its environment. But we, via our own ingenuity, have reshaped a staggering portion of the globe for our own benefit.

  I will propose that innovations, those brightest of information-processing gifts, are the main purpose of consciousness. But it’s certainly not the case that all flavors of neural information will reach awareness. Many basic computational functions, such as the control of our breathing, can tick along perfectly well without any input from our conscious minds. Widespread, though simple, statistical learning constantly occurs without the aid of our awareness. Also, importantly, if we’ve previously consciously mastered some skill, such as walking, then our unconscious minds can almost entirely take over such tasks. In all these cases, the staid, pedestrian parts of information processing are handled by our unconsciousness, while our conscious minds are freed to dwell on newer, more difficult topics. And for any lesson involving even a smidgen of novelty or complexity, we simply have to engage our conscious minds to learn it.

 

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