Tuesday, August 21, 2007

The science of magic of science of magic of...

"Now you see it, now you don't," says the magician, and that's because a) attention is a finite resource; b) cognitive processes will always take short-cuts when they can and; c) the brain will impose order on a set of stimuli when it can - finding patterns among objects that are alike, completing incomplete shapes, making figures out of empty space. These talents can be quite useful, for example we will perceive these shapes:

as rectangular. Why? Only the leftmost is, but we know they represent the same thing, a door, and we know a door is rectangular so... This is known as subjective constancy or perceptual constancy and it is an unconscious process that allows us to hear vowel sounds as the same, even with different voices and different regional accents, perceive colors as the same in changing light, understand that that tiny building that is in the distance, rather than a toy building that is close by...except when we're being tricked - illusions take advantage of this propensity our brain has for constancy and today's Science Times has a marvelous article on a group of neuroscientists attending a conference on consciousness in Las Vegas and being tricked by skilled magicians, just as we all would be - these are automatic processes. Another instance of the brain preferring a narrative about reality to what is actually going on, so don't blame me for getting lost in a book - my brain made me do it.

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