|A book by|
William H. Calvin
UNIVERSITY OF WASHINGTON
SEATTLE, WASHINGTON 98195-1800 USA
The Cerebral Symphony|
Seashore Reflections on the
Structure of Consciousness
Copyright ©1989 by William H. Calvin.
You may download this for personal reading but may not redistribute or archive without permission (exception: teachers should feel free to print out a chapter and photocopy it for students).
Varieties of Consciousness:
From Coma to Reverie
[C]reation is still going on,... the creative forces are as great and as active to-day as they have ever been, and... to-morrow's morning will be as heroic as any of the world.Creation is here and now. So near is man to the creative pageant, so much a part is he of the endless and incredible experiment, that any glimpse he may have will be but the revelation of a moment, a solitary note heard in a symphony thundering through debatable existences of time. Poetry is as necessary to comprehension as science. It is as impossible to live without reverence as it is without joy.the American natural historian Henry Beston, 1928I stand in awe of my body, this matter to which I am bound has become so strange to me.... Talk of mysteries! -- Think of our life in nature -- daily to be shown matter, to come in contact with it,-- rocks, trees, wind on our cheeks! the solid earth! the actual world! the common sense! Contact! Contact! Who are we? where are we?the American essayist Henry David Thoreau, 1864
Eastham is as far east as you can go around here. The Outermost House is somewhere outside Eastham on the Cape's elbow, the isolated cabin from which Henry Beston chronicled a year in the life cycle of the Cape in his 1928 book The Outermost House. Parts of the Cape north of the elbow have since been made into a national park of sorts, a patchwork of crazy compromises officially known as the Cape Cod National Seashore. Earlier, Beston's beach cabin was designated a National Historic Site.
Asking directions from the park ranger reveals that the Outermost House no longer exists. It lasted a half-century, the great winter storm of 1978 having swept it away while rearranging the sand dunes. That is, as Beston pointed out, part of the life cycle of beaches (and, he might have added, offshore barrier islands such as Palm Beach and Miami Beach): to be rearranged every century or so. Anyone who builds within walking distance of a beach has to accept the consequences as part of the price of admission. Not that they always do: Like the people who build in the flood plain of a river, some expect the lawmakers (i.e., the other taxpayers) to protect them from erosion, as if it were some sort of manufacturing defect for which there ought to be warranty recourse.
Beaches are swept clean daily by the tides, and the sand dunes are cleaned out by the storms on a less regular schedule (even National Historic Sites); it is part of the charm of the place, what makes it so different from Woods Hole. There, alas, it is hard to find any original beach or headlands. The stony beaches have been covered here and there with imported sand. The Woods Hole headlands have been plastered with rows of giant boulders, to protect the houses that someone lacking foresight built too close to the water; though more neatly arranged than most riprap jobs, it's all very ersatz, something like those German forests where the trees grow only in orderly rows and not a scrap of undergrowth is to be seen.
This Atlantic Coast is very different. I was attracted here by Beston's 1928 description of Coast Guard Beach:
At the foot of this cliff a great ocean beach runs north and south unbroken, mile lengthening into mile. Solitary and elemental, unsullied and remote, visited and possessed by the outer sea, these sands might be the end or the beginning of a world. Age by age, the sea here gives battle to the land; age by age, the earth struggles for her own, calling to her defence her energies and her creations, bidding her plants steal down upon the beach, and holding the frontier sands in a net of grass and roots which the storms wash free. The great rhythms of nature, to-day so dully disregarded, wounded even, have here their spacious and primeval liberty; cloud and shadow of cloud, wind and tide, tremor of night and day. Journeying birds alight here and fly away again all unseen, schools of fish move beneath the waves, the surf flings its spray against the sun.
I'm not sure Beston would recognize the place today. I just saw someone riding a little motorized dune buggy, put-putting up the beach like a lawn mower, chewing away at the sand with its tractor tires (if that happened on a national park beach on the West Coast, a crowd of indignant hikers and bathers would probably rise up and throw the offending vehicle into the surf). But there was no point in my complaining to the nearest park ranger: The person riding the thing was a park ranger on patrol. That's an inauspicious sign.
I set off walking down Coast Guard Beach in the other direction, toward where the Outermost House was last seen, if only to get away from the road end. The cluster of well-oiled bodies and mindless radios on the beach, while repelling me, has attracted a buzzing pest circling around them. And a rather large one at that. The labored-sounding airplane is towing an advertising banner around an endless circle in the sky, promoting one of the fast foods whose throwaway containers contribute both to litter and the depletion of the ozone layer (via the "refrigerator"-type gas used in the construction of the foamlike boxes). And the depletion of ozone will let more ultraviolet light through, making beaches like this uninhabitable and driving cities underground.
Grumble, grumble. Advertising promoting the destruction of the environment, and this supposedly a park. What will the National Park Service allow next? Park rangers on trail bikes zooming past hikers at Mount Rainier, all in the name of "efficiency"?
A QUARTER-HOUR WALK south of the road end, and suddenly there are no more people for a long while (fortunately, many of the people who come to the beach for a suntan tend to cluster together). There are, however, plenty of the natural inhabitants. I sit and watch a sea gull watching me. It sits there in the sand, moving only its head. Every ten seconds or so, it rotates its head suddenly to a new position. Within a minute or two, it covers the whole horizon, left around to right, just like a well-trained lookout on the bridge of a ship at sea. Occasionally, it breaks the regularity of the advance, coming back to look at something. Unless I move, it seems to ignore me, apportioning its attention equally to all points of the compass.
Washed up on the shore nearby is the shell of a horseshoe crab, a Limulus no more. It is upside down, its vulnerable underside exposed to the sun, and it might have died that way, as an inverted Limulus can have some trouble righting itself, what with that flaring skirt of armor. The wider the skirt, the more resistant to flipping -- but the more serious the consequences if he does flip.
Sounds familiar, like knights in ever-heavier armor when knocked off their horses -- and more recent nuclear-tipped "defensive armaments" with their ever-more-suicidal scenarios if a computer makes a mistake. It's too bad that there aren't any Limulus on the West Coast where all of those aerospace companies are located, to serve as a "Star Wars" warning (come to think of it, West Coast museums are also poor places to see displays of medieval suits of armor, escalating from chainmail up through behemoth walking coffins).
[Because aircraft carriers are so vulnerable, defenses are] the first order of business -- the loss of a carrier would be an unthinkable catastrophe, an unbearable humiliation -- and protective systems are layered and lavished upon the carrier group with unstinting prodigality. In such fashion, the modern carrier group is slowly evolving toward a splendid solipsism, plying the seas in isolated grandeur, ever more invulnerable and ever more harmless, its own final cause and final end, the realization in the modern world of the Hegelian nous, the ultimate self-regarding system.the American writer Charles R. Morris, 1988
But it's a nice day, and the sea air is soporific, and I am far enough upwind to hear the droning airplane no longer, far enough away now to turn my back on the offensive advertising. It's time to think great thoughts. (This may sound grandiose, but it is really just a technique. Long ago, I developed a mental strategy for dealing with advertising jingles that kept running through my head: What I do is recall the Grand March from Aida, which triumphantly silences even the worst jingle). What will it be, to displace the distasteful thoughts -- shall I solve the origin of life, the balance-of-payments problem, or the fate of the universe? Let's see now. Perhaps I should solve the problem of consciousness -- something like that, appropriate to the seashore.
The danger is instead lapsing into unconsciousness while contemplating the problem, given the sun and wind and sighing surf. Alas, unconsciousness doesn't provide a very satisfying definition of consciousness. Being asleep is very different from being in coma (readily arousable versus total lack of response to even painful stimuli), but neither has an opposite that tells you very much about higher consciousness.
The other reported danger is merging with the environment, participating in things so much as to lose one's identity. This too gets called consciousness:
The view of nature which predominated in the West down to the eve of the Scientific Revolution was that of an enchanted world. Rocks, trees, rivers, and clouds were all seen as wondrous, alive, and human beings felt at home in this environment. The cosmos, in short, was a place of belonging. A member of this cosmos was not an alienated observer of it but a direct participant in its drama. His personal destiny was bound up with its destiny, and this relationship gave meaning to his life. This type of consciousness -- which I [call] "participating consciousness" -- involves merger, or identification, with one's surroundings, and bespeaks a psychic wholeness that has long since passed from the scene.... Plato's own psychological ideal was that of an individual organized around a center (ego), using his will to control his instinct and thereby unify his psyche. Reason thus becomes the essence of personality, and is characterized by distancing oneself from phenomena, maintaining one's identity. Poetry, mimesis, the whole Homeric tradition, on the other hand, involves identification with the actions of other people and things -- the surrendering of identity. For Plato, only the abolition of this tradition could create the situation in which a subject perceives by confronting separate objects. Whereas the Jews saw participating consciousness as sin, Plato saw it as pathology, the archenemy of the intellect.the American historian Morris Berman, 1981
CONSCIOUSNESS IS A VERY OVERUSED WORD, the same string of syllables being used to designate a multitude of meanings. It's much worse than the multiple meanings of brain, which, besides denoting the three pounds of nerve cells inside our heads, is also used as a verb (to club, aiming at a head), as the opposite of brawn, as a surname in England, as a term for a studious student or the chief planner of an enterprise, and more recently to designate something as inanimate as a computer. Being a neurophysiologist, I tend to avoid the non-neurological uses of the word, but I doubt that I'll convert the rest of the English-speaking world to my more restrictive usage.
The multiple-meanings problem is an order of magnitude worse for consciousness. Compounding the problem, there is a lot of willful ambiguity here for some puzzling reason: People actually go out of their way to muddy the issues. It is reminiscent of when people intentionally confuse the letter O and the number 0 on a telephone dial (try telling someone your phone number is "two-three-zero-eight" and most of them will repeat it back to you for verification as "two-three-oh-eight"). I'm not really worried about the inaccuracy, except insofar as it confuses foreign visitors confronting American telephones, but the perversity of insisting on ambiguity is indeed very much like discussions of consciousness that I've heard among scientists. You'd think that they wanted to keep things sloppy, to prevent clarity.
And since there is not a more restrictive meaning of consciousness among the professionals, it is very easy for everyone to talk at cross-purposes: There is no agreed-upon term equivalent to "zero" to which we can all retreat when consciousness confusion threatens, the way that we can retreat to using zero when reading off a mixed letters-and-numbers automobile license plate. While I have no ambition to propose a rigid definition (they seldom solve problems), attempting a definition usually allows one to sort things out better, set the stage for clearer thinking about the problem.
Are there any uses of the word consciousness that we can dismiss as trivial? Well, one person's triviality is another person's favorite subject, but I'd certainly spin off non-unconsciousness. Sleep and wakefulness are so important as to deserve their own terms, and their description can do nicely without consciousness; neurologists already tend to avoid the word and talk instead about a graded spectrum of arousibility from coma to stupor to drowsiness to wakefulness.
BUT THAT AROUSIBILITY USAGE is closely related to another one that is not so easily dismissed: awareness. I am conscious of the breeze blowing on my face. We talk of "consciousness-raising" when we want to sensitize a troglodyte to a problem to which he remains oblivious. A budget-conscious shopper is one particularly sensitive to price tags; we talk of being conscious of our heartbeats in times of stress, even though unaware of them normally. There is selective attention, including altered states of consciousness such as hypnotic trances, which limit awareness in odd ways. We cannot be conscious of our blood pressure at all (except with the aid of external instruments), and the same is true of a whole host of involuntary autonomic functions regulated by our brains such as body growth and digestion.
Awareness is a little tricky because we sometimes cannot report being aware of something, yet have our brain register the information and make use of it. The classic cases involve patients with damage to their visual cortex: While functionally blind according to the standard tests, they can navigate around obstacles much better with the lights on than with the lights off. Ask them to guess where a light is and -- while denying that they can see anything -- they'll guess pretty accurately. At some subcortical level, the visual information is accessible -- but to the narrator of their conscious experience, if the usual connections from visual cortex don't have the information, they'll report it isn't there. Which may, of course, be why we cannot report on our blood pressure either -- it's just not handled by cerebral cortex.
Consciousness is said to be about the nonroutine aspects of our mental life; as Karl Popper noted, posing alternatives seems especially "conscious":
Much of our purposeful behaviour (and presumably of the purposeful behaviour of animals) happens without the intervention of consciousness.... Problems that can be solved by routine do not need consciousness. [The biological achievements that are helped by consciousness are the solution of problems of a non-routine kind.] But the role of consciousness is perhaps clearest where an aim or purpose... can be achieved by alternate means, and when two or more means are tried out, after deliberation.
We are unaware of most of the things that go on in our heads, and sometimes that's better, as in Zen archery. You sometimes even have to avoid thinking about a problem. When I try consciously to adjust my stride to step over an approaching puddle of rainwater, I usually foul it up; if I instead take note of the puddle from afar and then go on to think consciously of something else, my stride adjusts automatically so as to place one foot at the leading edge of the puddle and the other foot at its far edge. Heaven forbid that I should attempt to tell my liver what to do; I'd turn yellow within minutes.
Consciousness involves our operating on the margins, against the enormous background of automatic things. It's something like civilization, where we can drive a car without understanding a carburetor, use a radio without being able to build one, improvise jazz without being able to tune a piano, create electronic music without understanding the innards of the black boxes. Consciousness doesn't always involve creativity and choice, but they're close relatives, much more so than mere awareness.
Indeed, aware is perfectly adequate in most cases where one says semiconscious or conscious of or losing consciousness or consciousness-raising (and the word aware is even shorter -- though I predict that the "zero-oh" type of perverse replacement of "aware" by "conscious" will persist).
There are, however, some variants on the theme of awareness that have a big following among psychologists and neuroscientists who comment on consciousness. I am conscious of that sea gull watching me -- I caught him staring at me this time (I probably brushed away a fly and so disrupted his lookout routine). I recognize him as a particular kind of bird. I recognize his search routine, and the significance of its interruption. I know that if I stand up, he'll be conscious of me. Perception, cognition (those mental processes we are "conscious" of), and selective attention aren't trivial at all: Figuring them out is a major problem, as each is likely to be more complex than the sleep-wakefulness spectrum.
Perception/cognition are processes shared in large part by that meditating seagull, by that inquisitive ant exploring my big toe, and by those primitive Limulus wandering around offshore, trying to keep from getting tipped over by a wave crashing ashore. We can even argue about whether that wildflower poking out of the sand dune is "conscious of" the sun: It does, after all, unfold in the morning, follows the sun around the sky pointing as surely as a bird dog, and then folds its petals back up just before sunset. There are some higher aspects of cognition that a flower surely doesn't share with me, such as my ability to tell a Picasso from an Edward Hopper or a Winslow Homer painting, but recognition abilities do seem to lie on a plain-to-fancy spectrum. Having learned something from Descartes' mistake, I wouldn't want to define consciousness as uniquely human, but the term should capture something of our advanced abilities rather than covering the commonplace.
I go along with Julian Jaynes on this one: He says that the narrator of our personal experience is the really nontrivial aspect of consciousness, and that perception/cognition ought to be pared off from the problem just as sleep/wakefulness is. In comparison to the narrator who spins scenarios, choosing between alternative future courses of action, I think that perception and cognition will prove easy to understand mechanistically. But I have a hard time believing that hallucinations were the primitive form of consciousness (as Jaynes postulates for the pre-Odyssey mentality in The Origin of Consciousness in the Breakdown of the Bicameral Mind) or that "participating consciousness," the identification of self with the environment, was either (which Morris Berman in The Reenchantment of the World tends to treat as essential to reintegrate somehow). Identifying too closely with the environment, or listening to a bush "speaking" to you, tends to result in being eaten by a predator, or falling off a cliff. It seems more likely that animism and its descendants are cognitive mistakes to which we are prone when agriculture removes us from the wild environments in which we evolved (Homeric times, about 1200 B.C., were nonetheless seven thousand years after agriculture started up at the end of the last ice age).
Yet the limits of self -- how much you consider yourself a part of your environment when making choices -- is surely an important element of the consciousness discussion, even if one treats animism and its descendants as naive mistakes to be avoided. The Australian aborigines see themselves as stewards of their land in ways that go considerably beyond the shortsighted European settlers who are displacing them. The inventor of the throw-away Styrofoam cups that litter this beach will hopefully be considered seriously retarded by the standards of some future consciousness, because of fouling his own nest. Even if we limit our use of the word consciousness to choosing between alternative futures, the biodegradable movement's "consciousness raising" still qualifies.
The three great elemental sounds in nature are the sound of rain, the sound of wind in a primeval wood, and the sound of outer ocean on a beach. I have heard them all, and of the three elemental voices, that of ocean is the most awesome, beautiful, and varied. For it is a mistake to talk of the monotone of the ocean or of the monotonous nature of its sound. The sea has many voices. Listen to the surf, really lend it your ears, and you will hear in it a world of sounds: hollow boomings and heavy roarings, great watery tumblings and tramplings, long hissing seethes, sharp, rifle-shot reports, splashes, whispers, the grinding undertone of stones, and sometimes vocal sounds that might be the half-heard talk of people in the sea. And not only is the great sound varied in the manner of its making, it is also constantly changing its tempo, its pitch, its accent, and its rhythm, being now loud and thundering, now almost placid, now furious, now grave and solemn-slow, now a simple measure, now a rhythm monstrous with a sense of purpose and elemental will.the American natural historian Henry Beston, 1928
TIME TO GET UP AND STRETCH, walk a little farther down the beach; the seagull will just have to get along without me. Now I was aware of that decision to stand up before I actually moved -- or was I? My fellow neurophysiologist Ben Libet has, to everyone's consternation, shown that the brain activity associated with the preparation for movement (something called the "readiness potential," a tiny electrical wave that one can measure atop the frontal lobes starting more than a third of a second before a movement actually can be observed) starts a quarter of a second before you report having decided to move. You just weren't yet conscious of your decision to move, but it was indeed under way; the technician watching the brain waves probably became aware of your decision to move about the time that you did.
Is this voluntary-movement aspect of awareness-type consciousness something that we can get our teeth into, something a little closer to the "little person inside the head" than mere pattern recognition, bridging the gap between the lower consciousness of arousibility and awareness and the higher consciousness of narrators and subconscious scenarios that we use to plan shopping trips and careers?
This intriguing issue is all mixed up with the sticky subject of time, what physicists since Einstein have called the simultaneity problem, because the theory of relativity shows that there is no such thing, or at least no way to measure if two events are truly synchronous, without worrying about how long messages take to get from here to there. The brain has simultaneity problems in a big way, if only because messages move faster in some directions than others. Unlike electrical signals in a computer, which travel at nearly the speed of light (about 300,000,000 meters/second), neural messages propagate using a burning-fuse effect, which is very slow in comparison (the faster-conducting nerves use a string-of-firecrackers scheme; just imagine the firecrackers daisy-chained). When I start to move my right leg, a message starts out from my left frontal lobe. It travels down to my back and then out the nerves to my leg, usually taking more than a tenth of a second just in travel time. The same message is also sent over to my right brain, just to keep it informed about what's going on.
But the speed at which the two messages travel is very different: Messages between regions of cerebral cortex travel much more slowly (1-5 meters/second, even using the firecracker-chain scheme) than messages down to the spinal cord (more like 20 meters/second, but sometimes 100), even if they just involve two different branches of the same nerve cell. Like the commonplace observation that it takes about as long for the postal service to deliver a letter on the other side of town as it does for it to deliver a letter on the far side of the country (sometimes it takes four days either way), so a neural message takes about as long to travel from one half of the brain to the other as it does to travel all of the way down to the leg (nearly a tenth of a second either way)! I call this the paradoxical postal principle of the central nervous system, and it may explain some of the apparent paradoxes of consciousness, such as being unable to report decision-making until the neural antecedents of the movement are already under way.
I try not to think about this too much as I stand up and brush off the sand, for fear of falling flat on my face. I remember that cautionary poem:
The centipede was quite happy
Until the toad in fun
Said "Pray, which leg comes after which?"
Which brought its mind to such a pitch
It lay distracted in a ditch
Considering how to run.
SHORT-TERM MEMORY as a basis of consciousness? That's Marvin Minsky's claim ("agents that are engaged in using and changing our most recent memories... lie at the roots of consciousness."). Again it doesn't seem to have much of the qualities that make the ant a fancier form of life than the Venus's-flytrap (that carnivorous plant indeed has a form of short-term memory). And which make us fancier than the ant.
There are all sorts of advantages to a memory system that allows one to analyze the past, as Minsky points out in The Society of Mind, especially for an animal like us that does a lot of non-routine problem-solving. But metabolism is essential for consciousness too, and I put memory in a similar low-level category. What constitutes an appropriate level of explanation? When one says basis or foundation and is talking about a presumably hierarchal system like the brain, one usually means the immediate subjacent level, not the utility basement-- certainly physics is a foundation of biology, but biochemistry is the immediately subjacent level whose analyses are more relevant than quantum mechanics. Indeed, these levels are sometimes seen as a way of defining consciousness as the ultimate level:
"Causal decoupling" between the levels of the world implies that to understand the material basis of certain rules I must go to the next level down; but the rules can be applied with confidence without any reference to the more basic level. Interestingly, the division of natural sciences reflects this causal decoupling. Nuclear physics, atomic physics, chemistry, molecular biology, biochemistry, and genetics are each independent disciplines valid in their own right, a consequence of the causal decoupling between them.... Such a series of "causal decouplings" may be extraordinarily complex, intricate beyond our current imaginings. Yet finally what we may arrive at is a theory of the mind and consciousness -- a mind so decoupled from its material support systems that it seems to be independent of them -- and "forgot" how we got to it.... The biological phenomenon of a self-reflexive consciousness is simply the last of a long and complex series of "causal decouplings" from the world of matter.the American physicist Heinz Pagels, 1988
SCENARIO-SPINNING is more promising as a foundation for consciousness. It fits in well with another defining-by-variants aspect of consciousness that I've barely mentioned: subconsciousness. Preconscious and subconscious and Freud's unconscious are most helpful in defining consciousness a little better, because they indicate that there is far more going on than just autonomic-type unawareness: there is really something creative happening in the background, something nonroutine and unique, of which we get snapshot glimpses occasionally. And movies every night: the stream of consciousness in glorious Technicolor, uninterrupted by commercial breaks as our censor jumps in to remind us that our dream's new story line is sheer nonsense, which is what happens to our daytime dreams we call thought. In dreams we have a series of "visual bursts" that we attempt to integrate into a story line.
An impressive amount of problem-solving goes on subconsciously. One of the classic characters of Woods Hole science was Albert Szent-Györgyi, who, among other things, discovered vitamin C. He commented:
I have to think very hard about a problem but this thinking never leads me anywhere; it is but a necessary priming process. Finding myself unable to solve the problem, I let it sink into my subconscious. How long it stays there varies. Then, unexpectedly, the solution is passed into my conscious mind. My brain must have done as the Hungarian laxative which was advertised: "While you sleep it does the work."
Without memory of the past problems and solutions, we'd never get much better at problem-solving. But then, neither would the kitten who eventually learns about hidden objects that wiggle blankets or newspapers, learns to peer behind or underneath rather than just attacking frontally. Our mental life, and our various powers, involve a lot of processes. If we call them all conscious, we dilute the word into meaninglessness, one of those words like thing or stuff. We already have enough difficulties thinking about thought without the burden of self-imposed ignorance.
Personally, I would say that the only aspects of our mental life that deserve singling out as peculiarly conscious are those associated with the narrator, with self-conscious and subconscious and stream of consciousness; the others are important in their own right, likely essential foundations, but not to be confused with "the real thing."
SO THERE YOU HAVE THE RATIONALE for why I am restricting myself to "What shall I do next" as the main aspect of consciousness that I will consider here. I don't mean it in the narrow sense of motor-systems neurophysiology (whose physics-addicted practitioners assiduously avoid the word consciousness for fear that someone might confuse them with psychologists), but rather in the broad sense stretching from the next second to the millennium. Hereafter when you see consciousness used in this book, it will probably mean planning for the future, spinning alternatives and selecting among them for one's next act.
It might be objected that this is an excessively "movement oriented" view of consciousness, that it takes insufficient account of the "awareness" connotation of the word. Surely one can contemplate the sensory inputs without making movement plans? Or fantasize visual objects without movement? Well, maybe not -- lots of things betray themselves by little movements, as when someone's eyes turn leftward when reacting emotionally to a "pure thought." My grandmother Calvin had a tendency to flex and extend her knee whenever she was "rearranging the truth a little" in telling a story (this involuntary movement was known to the whole family). And one of the lessons of sensory-systems neurophysiology is that the movement-directing nerves descending from brain to spinal cord also have little branches to the ascending sensory pathways, serving to adjust sensory bias or communicate an expected sensory input from the about-to-be-ordered movement (so-called efference copy) for comparison purposes.
There's a lot of feedback from muscle tension and limb position into consciousness that affects our "will"; I remember how surprised the neurologist Oliver Sacks was when he had his shoulder muscles electrically stimulated -- whereupon he felt as if he wanted to shrug his shoulders expressively, as in, "So?" The electricity was interfering with his will! His own movement-production system, by tensing those muscles in the usual way, could have perhaps achieved the same effect. The sensory and movement systems are a good deal less independent than we originally thought; while movement-planning language may not serve as a universal description of what's going on in consciousness, it seems less prone to the tangles in which sensory-oriented descriptions land us (see the tortured debates on "representations" in any cognitive science treatise).
THE NARRATOR ASPECT brings me up short, because the little person inside the head is a fallacy that psychology and neuroscience have long tried to combat. We tend to imagine the eyes as some sort of television camera projecting onto a screen inside the brain -- watched by...? Who is doing the watching? Before I make the narrator's neural machinery into the seat of consciousness, I had better watch out for the pitfalls of all such "central viewpoints," as they have led a whole series of thinkers, including Descartes, down blind alleys.
In my first year as a physiology instructor, I taught a discussion group for a large lecture course. And when we covered the optics of the eye, a medical student asked the question that was probably on everyone else's mind too: If the floor is projected onto the top of the eyeball, and the sky onto the lower part (in the usual inverted image, just as in your camera), then "how does the image get turned back right side up, so the world doesn't appear upside down to us?" In an instant camera's photograph, you just turn it over with a flick of the wrist, probably without ever realizing that the photograph was upside down in the first place. In the wiring connecting the TV camera with the TV screen, camera top is simply connected to screen bottom, and vice versa, without anyone noticing the switch-around. So where in the brain is the wiring switched around? (If this concern seems excessively quaint, remember that even Leonardo da Vinci worried about this problem, tried to figure out an optical scheme to reinvert the image using the clear jelly that fills the eyeball).
Now the usual professorial answer to this philosophical question about "why isn't our visual world inverted?" is to say that it's all a matter of convention: You can "get used to anything," as when someone wears inverting spectacles and eventually learns to move around in the upside-down world (and gets so used to the inverted perspective that, upon removing the inverting prisms several weeks later, the real world seems inverted!). But the real problem is the assumption of a central viewpoint, a place where something does the viewing, as if we had a voyeur-puppeteer hiding out in a central cave, pulling our strings. The little-person-inside problem is so old that it has a Latin name: the homunculus fallacy.
What controls the brain? The Mind.
What controls the Mind? The Self.
What controls the Self? Itself.
a parody related by Marvin Minsky
What we usually say is that the brain as a totality produces the illusion of a central viewpoint, a virtual center, just as the physicist can often represent the earth's gravity as an attraction to the center of the earth rather than the more complicated problem of dealing with the separate attraction of the many individual atoms, some nearby, one in the center of the earth, and some on the opposite side of the world. As Minsky points out, "the idea of a single, central Self doesn't explain anything. This is because a thing with no parts provides nothing that we can use as pieces of explanation." The Romans even coined a slogan out of this notion: Ex nihilo nihil fit ("You can't make something out of nothing"). But, nonetheless, we have a unity of conscious experience; even if comprised of many functional subunits, our mental life somehow arrives at the virtual equivalent of a narrator. Sometimes even more than one, as in the case of multiple personalities.
It's not an easy explanation, with what we replace this center-of-it-all concept. And neurophysiologists are themselves always falling prey to overenthusiastic reductionism -- as when we fall once again into a trap we call the Grandmother's face cell fallacy. I'm not sure that I'm up to explaining this fallacy on such a nice day as today, especially if even Minsky feigns incomprehension of it. Yet I'll have to do it sometime, if only to convince people that a narrator's unity of consciousness can be produced without a physical center of it all, a seat of the soul. I'll first have to digress into some nuts and bolts (we neurophysiologists prefer to call them synapses and nerve cells), step back and survey the parts that we can use as pieces of explanation.
Only human beings guide their behaviour by a knowledge of what happened before they were born and a preconception of what may happen after they are dead; thus only human beings find their way by a light that illuminates more than the patch of ground they stand on.Peter B. Medawar and Jean S. Medawar, 1977
|The Cerebral Symphony (Bantam 1989) is my book on animal and human consciousness, using the setting of the Marine Biological Labs and Cape Cod.||AVAILABILITY is limited.