Consciousness used to be the crazy aunt in psychology's attic. Behaviorists and cognitive scientists alike practiced denial, but the squeaking floorboards troubled our dreams of a truly scientific discipline. Now, the old lady has been given pride of place in the parlor, with all the respectable scientific furnishing of societies and journals. But let's face it—she's still weird.
In some ways, the scientific study of consciousness has been a great success. We know more than ever about the relationship between specific types of conscious experiences and specific mind and brain states. Discouragingly, though, we are still no closer to solving the Problem of Big-C Consciousness. How is consciousness possible at all? How could the few pounds of gray goo in my skull give rise to my experience of the particular blue tint of the sky? Scientists and philosophers have suggested everything from quantum effects to information integration to brain-wave patterns. Some deny that consciousness exists at all; others argue that consciousness couldn't possibly be the result of just the brain. The scientific organizers of one of the principal consciousness conferences, in fact, deliberately let in woo-woo stuff about altered states and past lives on the principle that we have no idea where the answer might come from.
This may be less dispiriting when you realize we've been here before. The philosopher Patricia Churchland has pointed out that the problem of "Life" in the 19th century was much like the problem of "Consciousness" in the 21st. How could a few molecules ever give rise to breathing, moving, living creatures? The answer turned out to be that it was the wrong question. We now understand a great deal about the many different ways in which complex organisms with a multitude of different properties arise from much simpler chemistry. The Problem of Big-L Life has simply faded away.
Antonio Damasio is a neuroscientist who has done illuminating research on emotion, decision-making, and our perception of our own bodies. He was also one of the brave early researchers who tackled the problem of consciousness head-on, and he was rewarded by several successful popular books. Unfortunately, in Self Comes to Mind, Damasio seems to have jumped the shark. The book doesn't include either the new scientific research of the last 10 years or new philosophical clarity—although the style is readable, if a bit high-flown, it's often hard to make out the arguments. Instead, the book is a rather wandering and digressive restatement, with some minor variations, of Damasio's earlier views on consciousness.
Scientists should always think that what they study is the most interesting thing in the universe—why study it otherwise?—and Damasio believes that the key to consciousness lies, no surprise, in emotion, decision-making, and our perception of our own bodies. (Full disclosure: I am equally convinced that everything interesting can be explained by studying 3-year-olds.) He argues that the secret of capital-C Consciousness lies in the fact that brains are part of bodies. For Damasio, the neural process that tells us that our nose itches is at the root of even the most refined and ethereal spiritual experience. The body is the foundation of big-C Consciousness and provides the evolutionary bridge from even a primordial one-celled creature enveloping a speck of food to Damasio himself listening to Bach as he contemplates the Pacific Ocean.
The trouble with Damasio's hypothesis, as with all the hypotheses about capital-C Consciousness, is figuring out how you could test it. There is only one organism that I'm sure is conscious (namely, me), and there are only a few more organisms that tell me they are also conscious (namely, my fellow humans), though I'm pretty sure that my other fellow animals are conscious, too. Just to make things worse, the more you think about it, the less sure you are about the nature of your own consciousness, let alone that of other organisms. The philosopher Eric Schwitzgebel has collected many examples that shake your belief that you always know about your own experiences. For example, were you conscious a moment ago of the feeling of your feet in your shoes? You are now, of course, but were you before I made you think about it?
My fellow humans and I are (probably) conscious, and we do have bodily perceptions, emotions, decision-making capacities, and a sense of self, to be sure, but we also have all sorts of other abilities, capacities for complex visual perception, learning, attention, reasoning, etc., etc. Hardly any of those features can be independently manipulated. I can't rip my brain out of my body and see whether it experiences anything or genetically engineer a creature that had a mind but no body and examine its phenomenology. When consciousness shuts down altogether, as in sleep or coma, all of these other abilities shut down, too.
The recent scientific approaches to consciousness emphasize different aspects of conscious experience and different brain and mind states that are correlated with those experiences. We might divide them into "inside" approaches and "outside" approaches. For a philosopher, the quintessential conscious experience is to sit in the proverbial armchair and look inside your own mind. Since Descartes, some philosophers have argued, on the basis of this sort of reflection, that to be conscious is to have a sense of oneself. If I am conscious of the blue of the sky, I must know not only that there is a blue sky but that there is an "I" looking at it. This is the type of consciousness you experienced when you tried to decide whether you were conscious of your feet in your shoes. It involves that mysterious inner "I" who is also your inner eye, your autobiographer, and your chief executive officer. Other "inside" approaches emphasize focused attention and intentional planning. Psychologists like Stanislas Dehaene and Bernard Baars describe consciousness as a "workspace," a kind of phenomenological desktop on which that mysterious "I" places, arranges, and manipulates information. We've learned a lot about this inside type of consciousness. We know, for example, that the workspace has a limited capacity; we can crowd only so many things on that desktop. And we even know some of the brain networks, involving parts of the frontal cortex, that support attention, planning, reflection, and our sense of the self.
For Damasio as well, some sense of self is essential for consciousness. His contribution has been to suggest, plausibly enough, that our experience of the abstract Cartesian self has its roots in our perception, literally, of the inside of our bodies. In some not very clear way, the more primitive sense of self that comes with having a body is elaborated into the reflective self of philosophical consciousness. Perceiving my mind in the armchair depends on perceiving my behind in the armchair. And, in some other not very clear way, this allows us to evolve from being a mere bodily organism to a creature with awareness.
"Outside" accounts of consciousness, on the other hand, tend to come from scientists, like Christof Koch, who study visual perception and who (no surprise again) think that perception is the key to consciousness. For a vision scientist, the quintessential conscious experience is to look out the window and simply see the blue of the sky, irrespective of the body, the self, attention, planning, reflection, and all the rest. The philosopher Ned Block calls this type of consciousness "phenomenal consciousness," in contrast to the "inside" "access consciousness" of introspection. It includes all of our perceptions and experience, everything that we feel at all, the blue of the sky, the coo of the birds, the fuzzy stuff at the periphery of our vision. It even includes the very annihilation of self we experience in the moments before sleep or in some dreams, or when we're blissfully absorbed in a book. It's the feeling of my feet in my shoes before I turn around to think about them. Phenomenal consciousness is more pervasive than access consciousness, but it is also more elusive. We've learned a great deal about how these types of conscious experience are related to the brain and mind—about exactly why the sky looks different in different lights or why the world looks colorful by day but black and white by night.
Damasio suggests that phenomenal awareness depends on the sense of a self. But, actually, there is evidence that the two types of consciousness may even be in tension with one another. For example, Rafael Malach and colleagues have studied what happens when people watch an absorbing Clint Eastwood movie in a brain scanner. In those circumstances, the frontal "self" network actually shuts down while the more purely visual parts of the brain are activated. This mirrors our experience. When we watch an absorbing movie we lose the sense of our selves, but we are vividly and profoundly conscious of the movie itself. In fact, shutting off planning and attention, by sitting still and inhibiting our sense of self, can lead to enhanced awareness of the world outside, as in some types of meditation. Babies and young children, who have a much more attenuated sense of self than we do, may actually experience the world outside them more vividly. For them, consciousness may be a kind of lantern illuminating everything around them, rather than the narrow-beamed flashlight that the grown-up philosophical self, like an X-files detective, keeps waving about to fitfully illuminate the psychological darkness within.
Which kind of consciousness is primordial? Is the self fundamental for consciousness, as Damasio suggests? Or does awareness come when we take in information without having to do anything about it, and is the attending and planning self merely an elaborate construction on top of that, as the Buddhists or David Hume would argue?
I suspect that the answer will turn out to be that the dichotomy between inside and outside is itself too simple. It may be that, as in the case of "life" in biology, self-reflection, attention, dreaming, planning, vision, bodily perception, emotion, and all the rest are simply too varied to have a single explanation. Helping to solve the separate pieces of the puzzle, as Damasio did in his earlier work, may always be more satisfying than speculating about a single grand design.