Book Review: Perplexities of Consciousness

July 31, 2011

http://www.nytimes.com

SUNDAY BOOK REVIEW- New York Times

Know Thyself: Easier Said Than Done
(Saya Mudah Lupa)

by Nicholas Humphrey
Published: July 29, 2011

A few days before a review of my latest book appeared in these pages, I wrote to my editor, saying I had seen an advance copy and how much I liked the color illustration of the yellow moon. He replied that I must be mistaken, since the Book Review doesnt use color. The next weekend he wrote to say he couldnt think what had come over him he reads the Book Review every week, and had somehow not noticed the color. Odd. And yet these lapses can happen to the best of us. Ask yourself what the Roman number four on the face of the church clock looks like. Most people will answer it looks like IV, but almost certainly the truth is it looks like IIII.

Why are we so bad at knowing in this case remembering what passes through our own minds? The philosopher Eric Schwitzgebel, in Perplexities of Consciousness, contends that our minds, rather than being open-access, are largely hidden territory. Despite what we believe about our powers of introspection, the reality is that we know awfully little about what our conscious experience amounts to. Even when reporting current experience, we make divergent, confused and even contradictory claims about what its like to be on the inside.

Consider binocular double vision, for example. Hold your index finger a foot in front of your nose, and look to the horizon. Some will say they see two ghostly fingers, but others will be sure they see just one. Note that people dont disagree about the external facts none of us think theres really more than one finger out there rather, we disagree at a level one step back: our private sensory experiences. And Schwitzgebel finds further examples across the range of mental life. Is joy sometimes in the head, sometimes more visceral, sometimes a thrill, and sometimes an expansiveness, or, instead, does joy have a single, consistent core a distinctive, identifiable, unique experiential character? We cant give a straight answer. What exactly is my sensory experience as I stare at a penny? Even in such a simple case, we cant agree.

Now, you might suppose that a likely explanation for these disagreements is that different individuals have differently constituted brains, so they are not having the same experience to begin with. Indeed it has been discovered recently that some humans have three times as much brain cortex assigned to receiving information from the eyes as others do. And this must surely be influencing the quality of their experience somehow. Yet Schwitzgebel (right) argues that brain differences, even if they exist, are probably beside the point. For there is plenty of evidence that people will give different interpretations of the very same events inside their heads.

He begins with the curious case of color in dreams. When people today are asked whether they regularly dream in color, most say they do. But it was not always so. Back in the 1950s most said they dreamed in black and white. Presumably it can hardly be true that our gr! andparen ts had different brains that systematically left out the color we put in today. So this must be a matter of interpretation. Yet why such freedom about assigning color? Well, try this for an answer. Suppose that, not knowing quite what dreams are like, we tend to assume they must be like photographs or movies pictures in the head. Then, when asked whether we dream in color we reach for the most readily available pictorial analogy. Understandably, 60 years ago this might have been black-and-white movies, while for most of us today it is the color version. But, heres the thing: Neither analogy is necessarily the right one. Dreams dont have to be pictures of any kind at all. They could be simply thoughts and thoughts, even thoughts about color, are neither colored nor non-colored in themselves.

This explanation is of a piece with Schwitzgebels general line. We are fantasists about our own mental experiences because we have little other choice. When we are probed by questions beyond our introspective competence, we have to make the answers up as best we can. Schwitzgebels message is very much in keeping with much writing in contemporary psychology that aims to knock us from our pedestals of Delphic self-assurance: to prove that we are, as Timothy Wilson says, strangers to ourselves.

This could all be true. We often do have trouble telling whats going on inside our minds. But still I cant say this is always because of feeble introspection. I suspect the real problem may be not that we know too little about our mental states but that we know too much. We are asked to say what its like to dream, to imagine, to feel as if there ought to be a simple answer: colored or not, single or double, in the head or in the heart. But, when it comes to it, the ri! ch total ity of our experience will not fit the Procrustean bed that philosophy, and everyday discourse also, tries to impose on it.

In the 1780s, Thomas Reid, a leading figure of the Scottish Enlightenment, chided his colleagues on just this score: for not appreciating the complex multilayered character of sensory experience. Reid argued that there are always two parallel threads to our experience: The external senses have a double province; to make us feel, and to make us perceive. Sensation is how we represent sensory stimuli at the surface of our bodies the mental representation of whats happening to me; perception, by contrast, is how we represent the outside world, whats happening out there. And these two processes have dissimilar characteristics: sensation is raw and immediate, perception more categorical and slow.

Question, then (its one of Schwitzgebels examples): When the lights go up on a complex scene, do we immediately see the whole scene? The answer can only be yes, and no. At the level of visual sensation, yes, its all there, every part of the field, every stitch of the tapestry, seems to be filled in at once. But at the level of perception, no, our picture of whats out there in the world gets built up over seconds. What exactly is my experience? If exactly means simply, this question is one to which theres no good answer.

Reid complained that the habit of confounding sensation and perception has been the occasion of most of the errors and false theories of philosophers with regard to the senses. While Schwitzgebel fails to pick up on the sensation-perception distinction where he should do, Id say there is one consequence of it that could play right into his hands. For, remarkably enough, research has shown we dont actually need sensation to perceive. There is a clinical syndrome known as blindsight, resulting from brain damage, where the subject to his own astonishment finds he can see the properties of things hes looking at, even though all visua! l sensat ion has been lost. He may indeed be able to guess what color an object is, without, as it were, seeing the color in color. Could the existence of blindsight help resolve the paradox of the color or lack of it in dreams? Do we indeed see blindly in dreams? I think we may. We dream of Joseph, and weave him an amazing technicolor coat; yet, like the emperor, he is really wearing nothing but ideas.

Nicholas Humphrey is school professor emeritus of psychology at the London School of Economics. His most recent book is Soul Dust: The Magic of Consciousness.