Being You: A New Science of Consciousness

by Anil Seth

Under profound anesthesia, the brain’s electrical activity is almost entirely quieted—something that never happens in normal life, awake or asleep. It is one of the miracles of modern medicine that anesthesiologists can routinely alter people’s brains so that they enter and return from such deeply unconscious states. It’s an act of transformation, a kind of magic: anesthesia is the art of turning people into objects.

Under general anesthesia, things are different. I could have been under for five minutes, five hours, five years—or even fifty. And “under” doesn’t quite express it. I was simply not there, a premonition of the total oblivion of death, and, in its absence of anything, a strangely comforting one.

General anesthesia doesn’t just work on your brain, or on your mind. It works on your consciousness. By altering the delicate electrochemical balance within the neural circuitry inside your head, the basic ground state of what it is to “be” is—temporarily—abolished.

For each of us, our conscious experience is all there is. Without it, there is nothing at all: no world, no self, no interior and no exterior.

Without consciousness, it may hardly matter whether you live for another five years or another five hundred. In all that time, there would be nothing it would be like to be you.

At each stage in this process, you exist, but the notion that there is a single unique conscious self (a soul?) that persists over time may be grossly mistaken. Indeed, one of the most compelling aspects of the mystery of consciousness is the nature of self. Is consciousness possible without self-consciousness,

This book is about the neuroscience of consciousness: the attempt to understand how the inner universe of subjective experience relates to, and can be explained in terms of, biological and physical processes unfolding in brains and bodies.

A science of consciousness is nothing less than an account of who we are, of what it is to be me, or to be you, and of why there is anything it is like to “be” at all.

I use the word “wetware” to underline that brains are not computers made of meat. They are chemical machines as much as they are electrical networks. Every brain that has ever existed has been part of a living body, embedded in and interacting with its environment—an

I will make the case that the experiences of being you, or of being me, emerge from the way the brain predicts and controls the internal state of the body. The essence of selfhood is neither a rational mind nor an immaterial soul. It is a deeply embodied biological process, a process that underpins the simple feeling of being alive that is the basis for all our experiences of self, indeed for any conscious experience at all. Being you is literally about your body.

By the end of the book, you’ll understand that our conscious experiences of the world and the self are forms of brain-based prediction—“controlled hallucinations”—that arise with, through, and because of our living bodies.

Our conscious experiences are part of nature just as our bodies are, just as our world is. And when life ends, consciousness will end too. When I think about this, I am transported back to my experience—my non-experience—of anesthesia. To its oblivion, perhaps comforting, but oblivion nonetheless. The novelist Julian Barnes, in his meditation on mortality, puts it perfectly. When the end of consciousness comes, there is nothing—really nothing—to be frightened of.

What is consciousness? For a conscious creature, there is something that it is like to be that creature. There is something it is like to be me, something it is like to be you, and probably something it is like to be a sheep, or a dolphin. For each of these creatures, subjective experiences are happening. It feels like something to be me. But there is almost certainly nothing it is like to be a bacterium, a blade of grass, or a toy robot. For these things, there is (presumably) never any subjective experience going on:

In philosophy, these properties are sometimes also called “qualia”: the redness of red, the pang of jealousy, the sharp pain or dull throb of a toothache. For an organism to be conscious, it has to have some kind of phenomenology for itself. Any kind of experience—any phenomenological property—counts as much as any other. Wherever there is experience, there is phenomenology; and wherever there is phenomenology, there is consciousness.

Consciousness is first and foremost about subjective experience—it is about phenomenology.

At various times in the past, being conscious has been confused with having language, being intelligent, or exhibiting behavior of a particular kind.

Like global workspace theory, higher-order thought theories also emphasize frontal brain regions as key for consciousness. Although these theories are interesting and influential, I won’t have much more to say about either in this book. This is because they both foreground the functional and behavioral aspects of consciousness, whereas the approach I will take starts from phenomenology—from experience itself—and

The definition of consciousness as “any kind of subjective experience whatsoever” is admittedly simple and may even sound trivial, but this is a good thing. When a complex phenomenon is incompletely understood, prematurely precise definitions can be constraining and even misleading.

The classic formulation of this question is known as the “hard problem” of consciousness.

How can we explain why there is something it is like to entertain a mental image, or to experience an emotion? It is widely agreed that experience arises from a physical basis, but we have no good explanation of why and how it so arises. Why should physical processing give rise to a rich inner life at all?

The easy problems cover all the things that beings like us can do and that can be specified in terms of a function—how

Even after all the easy problems have been ticked off, one by one, the hard problem will remain untouched.

Why is the performance of these functions accompanied by experience?”

physicalism. This is the idea that the universe is made of physical stuff, and that conscious states are either identical to, or somehow emerge from, particular arrangements of this physical stuff. Some philosophers use the term materialism instead of physicalism,

At the other extreme to physicalism is idealism. This is the idea—often associated with the eighteenth-century bishop George Berkeley—that consciousness or mind is the ultimate source of reality, not physical stuff or matter.

Functionalism is the idea that consciousness does not depend on what a system is made of (its physical constitution), but only on what the system does, on the functions it performs, on how it transforms inputs into outputs. The intuition driving functionalism is that mind and consciousness are forms of information processing which can be implemented by brains, but for which biological brains are not strictly necessary.

Brains are very different from computers, at least from the sorts of computers that we are familiar with. And the question of what information “is” is almost as vexing as the question of what consciousness is,

Panpsychism is the idea that consciousness is a fundamental property of the universe, alongside other fundamental properties such as mass/energy and charge; that it is present to some degree everywhere and in everything.

The main problems are that it doesn’t really explain anything and that it doesn’t lead to testable hypotheses.

Mysterianism is the idea that there may exist a complete physical explanation of consciousness—a full solution to Chalmers’s hard problem—but that we humans just aren’t clever enough, and never will be clever enough, to discover this solution, or even to recognize a solution if it were presented to us by super-smart aliens.

One of the more beautiful things about the scientific method is that it is cumulative and incremental. Today, many of us can understand things that would have seemed entirely incomprehensible even in principle to our ancestors,

One of the most common challenges to physicalism is the so-called “zombie” thought experiment.

A philosophical zombie is a creature that is indistinguishable from a conscious creature, but which lacks consciousness.

The zombie argument, like many thought experiments that take aim at physicalism, is a conceivability argument, and conceivability arguments are intrinsically weak.

Whether something is conceivable or not is often a psychological observation about the person doing the conceiving, not an insight into the nature of reality. This is the weakness of zombies. We are asked to imagine the unimaginable,

According to the real problem, the primary goals of consciousness science are to explain, predict, and control the phenomenological properties of conscious experience. This means explaining why a particular conscious experience is the way it is—why

In short, addressing the real problem requires explaining why a particular pattern of brain activity—or other physical process—maps to a particular kind of conscious experience, not merely establishing that it does.

The existence of subjective experience, as opposed to no experience, is the dominion of the hard problem. No matter how much mechanistic information you’re given, it will never be unreasonable for you to ask, “Fine, but why is this mechanism associated with conscious experience?”

The real problem accepts that conscious experiences exist and focuses primarily on their phenomenological properties. For example: experiences of redness are visual, they usually but not always attach to objects, they seem to be properties of surfaces, they have different levels of saturation,

these are all properties of the experience itself, not—at least not primarily—of the functional properties or behaviors associated with that experience. The challenge for the real problem is to explain, predict, and control these phenomenological properties, in terms of things happening in the brain and body.

why an experience, such as the experience of redness, is the particular way it is, and not some other way. Why it is not like blueness, or toothache, or jealousy.

Physicists have made enormous strides in unraveling the secrets of the universe—in explaining, predicting, and controlling its properties—but are still flummoxed when it comes to figuring out what the universe is made of or why it exists.

It could equally be that a mature science of consciousness will allow us to explain, predict, and control phenomenological properties without ever delivering the intuitive feeling that “yes, this is right, of course it has to be this way!”

The gold-standard definition of a neural correlate of consciousness, or NCC, is “the minimal neuronal mechanisms jointly sufficient for any one specific conscious percept.” The NCC approach proposes that there is some specific pattern of neural activity that is responsible for any and every experience, such as the experience of “seeing red.” Whenever this activity is present, an experience of redness will happen, and whenever it isn’t, it won’t.

all you need to do is concoct a situation in which people sometimes have a particular conscious experience, and at other times do not, while making sure that these conditions are otherwise as closely matched as possible. Given such a situation, you then compare activity in the brain between the two conditions, using brain imaging methods such as functional magnetic resonance imaging (fMRI) or electroencephalography (EEG).* The brain activity specific to the “conscious” condition reflects the NCC for that particular experience.

When we are able to predict (and explain, and control) why the experience of redness is the particular way it is—and not like blueness, or like jealousy—the mystery of how redness happens will be less mysterious, or perhaps no longer mysterious at all.

Vitalists thought that the property of being alive could be explained only by appealing to some special sauce: a spark of life, an élan vital. But as we now know, no special sauce is needed. Vitalism today is thoroughly rejected in scientific circles.

Reproduction, metabolism, growth, self-repair, development, homeostatic self-regulation—all became individually and collectively amenable to mechanistic explanation.

in this book I will focus on level, content, and self as the core properties of what being you is all about.

Conscious level concerns “how conscious we are”—on a scale from complete absence of any conscious experience at all, as in coma or brain death, all the way to vivid states of awareness that accompany normal waking life.