The Ravenous Brain: How the New Science of Consciousness Explains Our Insatiable Search for Meaning (2 page)

BOOK: The Ravenous Brain: How the New Science of Consciousness Explains Our Insatiable Search for Meaning
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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 relatives, 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.
Consciousness is the shining, gold-plated experimental laboratory of our mental mansion where we can analyze virtually anything to great depths. So as not to waste time and energy-intensive neural resources, our brains have to be extremely picky about what they let into this prized place. Attention is the gatekeeper of our awareness, only pushing through those items from our senses or inner cogitations that have the most pressing biological salience, and especially those unexpected features that offer us the greatest potential insights.
The space inside this playground of experiences, though, is frustratingly cramped. Our consciousness can only simultaneously deal with about four items, fully processed. But the magic arises by the amazing variety of ways that we can manipulate what resides within our conscious minds, and it is in these shuffling mental actions that we can learn profound truths about the world.
 
Crucially, our rich experiential landscape reflects the fact that awareness isn’t concerned with just any raw snippet of data. In fact, the absolute opposite is the case, as illustrated by the following curious, niggling conundrum: When most animals have fed well and found a safe place to stay, they normally then make the eminently sensible decision to rest. Admittedly, some species occasionally play in ways that look perfectly like practice for hunting or fighting. But that’s about it. Humans, in striking contrast, when all biological needs are met, reach for a sudoku puzzle or a games console—or we may even peruse a science book. Astoundingly, a few of us see the extended crossword puzzle of scientific research as a wonderful hobby. We therefore get the biologically perverse situation of Albert Einstein converting the fiendish cryptic clue of the whole universe into the neat five-character solution of
E
=
mc
2
—in his spare time!
Thus, one defining characteristic of humanity is its ravenous appetite for facts. But we don’t hunger for any old ragbag of information—no, we especially crave that small subset of knowledge that involves patterns. Uncovering the hidden structure in a puzzle may seem like a trivial idiosyncrasy of the human mind, as far removed from our evolutionary drive for survival as it is possible to be. But looks can be deceptive. This chronic mental hunger might dabble occasionally in intellectual play, rather like a thoroughbred horse that spontaneously chooses to gallop, just to exercise its sinewy, muscular frame. Much of the time, though, our restless, roving curiosity will latch onto real wisdom—not the limited, quiet wisdom of an old man imparting measured advice, but, in a broader meaning of the term, any bold innovation that suddenly empowers us with impressive new tools of understanding and control. Consciousness as a ravenous appetite for wisdom led us to discover fire, farming, and, indeed, all the modern products of science and technology that make our lives easier, longer, and more entertaining. On a smaller scale, this hunger for innovation, burning with a particularly bright restlessness when we’re young, guides us toward our first words and then toward the myriad stepping stones of knowledge needed to negotiate adulthood in a complex, modern world.
 
Consciousness is that choice mental space dedicated to innovation, a key component of which is the discovery of deep structures within the contents of our awareness. Latching onto this patterned, meaningful form of information processing is an immensely powerful way to learn, which accounts for why human consciousness has enabled us to take such great strides in every intellectual field we explore. By discovering the hidden rules in nature, by linking disparate ideas together according to their underlying common informational structure, we can weave a vast tapestry of meaning inside us. One consequence of this patient, piecemeal endeavor is that when we spot a chair, we don’t see it according to its basic sensory features. Instead, we unavoidably recognize it
as a chair
, and immediately have access to a pyramid of meaning relating to this one object—what forms chairs take, what functions they serve, their relationship to other furniture, the rooms and buildings they inhabit, and so on. In fact, as we gaze around our world, our unconscious minds might be busily processing the basic sensory properties of each feature, but within the citadel of our awareness, we ineluctably view each component of the scene via the dense filter of the structure of knowledge we’ve acquired throughout our lives. Every single object on which we cast our eyes triggers a conscious wave of understanding, its own pyramid of meaning.
This roving appetite—not only for knowledge, but for profound patterns—is both the mechanism of innovation and the signature feature of human consciousness. DNA-based “ideas” cannot be conscious, partly because they are constrained to represent only the most basic facts of the world. Even chimpanzees struggle to understand hierarchies of meaning, but human consciousness thrives on this mental architecture, which enables us to understand and control the world with unique depth.
 

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