Saturday, July 26, 2008

Brain Magic

Magician Keith Barry, who has made a number of appearances on various tv shows, recently did a performance at TED, in which he show-cased a number of cool 'mindreading' and 'mind-control/misdirection' tricks.

A number of psychologists and philosophers have started looking into these cognitive tricks to gain insight into the workings of the mind and have produced a pretty interesting body of literature (I just hope they're not putting magicians out of their jobs).

When I took theory of mind last year we read a good article by Dennet, Explaining the Magic of Consciousness, which was a rather valiant attempt by Dennet to dismantle or you could say dethrone Chalmers' so called hard problem of subjectivity. In the article Dennet uses a famous trick by Ralph Hull called 'the Tuned Deck' to demonstrate how words themselves can often mislead our minds.

The tempting idea that there is a Hard Problem is simply a mistake. I cannot prove this. Or, better, even if I can prove this, my proof will surely fall on deaf ears, since CHALMERS, for instance, has already acknowledged that arguments against his convictions on this score are powerless to dislodge his intuition, which is beyond rational support. So I will not make the tactical error of trying to dislodge with rational argument a conviction that is beyond reason. That would be wasting everybody's time, apparently. Instead, I will offer up what I hope is a disturbing parallel from the world of card magic: The Tuned Deck.

For many years, Mr. Ralph Hull, the famous card wizard from Crooksville, Ohio, has completely bewildered not only the general public, but also amateur conjurors, card connoisseurs and professional magicians with the series of card tricks which he is pleased to call "The Tuned Deck"...

Ralph Hull's trick looks and sounds roughly like this:

Boys, I have a new trick to show you. It's called 'The Tuned Deck'. This deck of cards is magically tuned [Hull holds the deck to his ear and riffles the cards, listening carefully to the buzz of the cards]. By their finely tuned vibrations, I can hear and feel the location of any card. Pick a card, any card... [The deck is then fanned or otherwise offered for the audience, and a card is taken by a spectator, noted, and returned to the deck by one route or another.] Now I listen to the Tuned Deck, and what does it tell me? I hear the telltale vibrations, ... [buzz, buzz, the cards are riffled by Hull's ear and various manipulations and rituals are enacted, after which, with a flourish, the spectator's card is presented].

Hull would perform the trick over and over for the benefit of his select audience of fellow magicians, challenging them to figure it out. Nobody ever did. Magicians offered to buy the trick from him but he would not sell it. Late in his life he gave his account to his friend, HILLIARD, who published the account in his privately printed book. Here is what Hull had to say about his trick:

For years I have performed this effect and have shown it to magicians and amateurs by the hundred and, to the very best of my knowledge, not one of them ever figured out the secret. ...the boys have all looked for something too hard [my italics, DCD].

Like much great magic, the trick is over before you even realize the trick has begun. The trick, in its entirety, is in the name of the trick, "The Tuned Deck", and more specifically, in one word "The"! As soon as Hull had announced his new trick and given its name to his eager audience, the trick was over. Having set up his audience in this simple way, and having passed the time with some obviously phony and misdirecting chatter about vibrations and buzz-buzz-buzz, Hull would do a relatively simple and familiar card presentation trick of type A (at this point I will draw the traditional curtain of secrecy; the further mechanical details of legerdemain, as you will see, do not matter).

His audience, savvy magicians, would see that he might possibly be performing a type A trick, a hypothesis they could test by being stubborn and uncooperative spectators in a way that would thwart any attempt at a type A trick. When they then adopted the appropriate recalcitrance to test the hypothesis, Hull would 'repeat' the trick, this time executing a type B card presentation trick. The spectators would then huddle and compare notes: might he be doing a type B trick? They test that hypothesis by adopting the recalcitrance appropriate to preventing a type B trick and still he does "the" trick - using method C, of course. When they test the hypothesis that he's pulling a type C trick on them, he switches to method D - or perhaps he goes back to method A or B, since his audience has 'refuted' the hypothesis that he's using method A or B.

And so it would go, for dozens of repetitions, with Hull staying one step ahead of his hypothesis-testers, exploiting his realization that he could always do some trick or other from the pool of tricks they all knew, and concealing the fact that he was doing a grab bag of different tricks by the simple expedient of the definite article: The Tuned Deck.

I am suggesting, then, that David Chalmers has (unintentionally) perpetrated the same feat of conceptual sleight-of-hand in declaring to the world that he has discovered “The Hard Problem”. Is there really a Hard Problem? Or is what appears to be the Hard Problem simply the large bag of tricks that constitute what Chalmers calls the Easy Problems of Consciousness? These all have mundane explanations, requiring no revolutions in physics, no emergent novelties. They succumb, with much effort, to the standard methods of cognitive science. I cannot prove that there is no
Hard Problem, and Chalmers cannot prove that there is. He can appeal to your intuitions, but this is not a sound basis on which to found a science of consciousness. We have seen in the past – and I have given a few simple examples here – that we have a powerful tendency to inflate our inventory of “known effects” of consciousness, so we must be alert to the possibility that we are being victimized by an error of arithmetic, in effect, when we take ourselves to have added up all the Easy Problems and discovered a residue unaccounted for. That residue may already have been accommodated, without our realizing it, in the set of mundane phenomena for which we already have explanations – or at least unmysterious paths of explanation still to be explored.

The “magic” of consciousness, like stage magic, defies explanation only so long as we take it at face value. Once we appreciate all the non-mysterious ways in which the brain can create benign “user-illusions”, we can begin to imagine how the brain creates consciousness.

1 comment:

johnnyc said...

Sometimes I think we are just "a bunch of tubes" to quote an old friend of mine; but having kids and watching them grow has not helped that belief (though I realize for some it might). A very interesting article nonetheless from the abstract and your presentation here. I'll read the whole thing. "I Am A Strange Loop" is also an interesting read (though he's excruciatingly pedantic and could have gotten his points across in 10 to 20 pages) whic you might find interesting aside from that tragic flaw. It's not as good as his "Godel, Escher, Bach" though.