Wednesday, 23 November 2005

Magic and the Brain

From th Guardian :
First there's shock tinged with disbelief. A moment of wonder follows. Then, a desperate scramble to rack your brains and work out just how you've been had. There's no denying the effects of a good magic trick. From the great escapes of Houdini and the surreal mental trickery of Derren Brown to the conjurors at children's parties, the appeal is universal.

"Magic's been around for a very long time and it improves over time," says Richard Wiseman, a professor of psychology at Hertfordshire University. "What you're looking at when you see a finished piece of magic is a great deal of expertise, and I think psychologists have a lot to learn from that."

But, not content with just enjoying the tricks, psychologists are now using their effects on the mind to work out how we handle the floods of sensory information coming into our brains and process it into a mental picture of the world around us. Magic is a deception, a disruption of that orderly mental picture where things seem to float in mid-air or coins and cards vanish in front of our eyes. Scientists now believe that, by mapping out how our brains are deceived, they could even help to unlock some of the mysteries of consciousness itself.

"Over the last five years, there's been a reawakening as we look at things like change blindness [a failure to see large changes in a visual scene] and at the fact that consciousness is a construction and may even be an illusion," says Wiseman, himself an accomplished magician and member of the Magic Circle. "Now there's a recognition that magicians are doing something very special."
"Magicians are manipulating your consciousness. They are showing you something impossible," says Wiseman. "They're getting you to construct a narrative, which simply isn't true. So that means they know how to make you aware of certain things and blind to other things. What I'm hoping is that magic, this entertainment vehicle that has been around for a long time, will give us a real insight into the deep mysteries of consciousness."

Our brains filter out a huge amount of the mass of sensory input flooding in from our environment. Kuhn explains that we see what we expect to see and what our brains are interested in. "Our visual representation of the world is much more impoverished than we would assume. People can be looking at something without being aware of it. Perception doesn't just involve looking at an object but attending to it."
It is known that we only receive high-quality information from the area we are fixated on, right in the centre of our field of view. If you stretch out your arm, it is about two thumbs' width at the centre of your vision - everything else is pretty much blurred. The way we compensate for this is to move our eyes around to fill in the gaps and create a better picture of the world around us.
"With the ball experiment, we discovered that people aren't just looking up at the ball, they're looking at facial clues to judge where the ball is going to end up," says Kuhn. "If the magician doesn't look up in the air, the trick doesn't work. People feel that they're watching the ball but what they are doing is monitoring the magician's face and cues and using that information to guide their eye movements."

This leads to an interesting idea -could some people be immune to some of the effects of magic? People who suffer from autism, for example, tend to have difficulties gauging facial cues, so their attention is less influenced by where somebody is looking. "You'd expect that somebody who suffered from autism would be more likely to spot the cigarette trick," agrees Kuhn.

The next step is to look at the brain directly. Working with psychologists Tim Hodson and Ben Parris at Exeter University's Centre for Cognitive Neuroscience, Kuhn plans to put people in functional magnetic resonance imaging machines to study which parts of the brain activate when they watch magic tricks.

"We're very interested in the part of the brain that detects cause and effect relations," says Parris.

In particular, the experiments will monitor the dorsal lateral pre-frontal cortex, which is known to be the bit of the brain that registers surprise, and the anterior cingulate, which is activated whenever something incongruous happens in our immediate environment.

Of course, magic is more than just surprise, so the researchers will be looking for something more. "When you're watching magic, there is just a split second when you're in disbelief and that's what we're looking for, that exact moment," he says. "The magic spot."

"No one's done this and it's unclear whether it'll be a single part of the brain or a network," says Parris.
I know all about the "shock tinged with disbelief." And the "moment of wonder". I'm still doing the "desperate scramble to rack your brains" bit working out what the heck happened since May. It's the Geek in me, just can't accept what appears to be a miracle without trying to peek behind the curtain. If it is psychological, or mainly so, how come what appears to be objective evidence exists? Or am I seeing patterns in that too that aren't really there? If so, everyone else seems to be too, including the camera lens.

Anyway, that's a background task, I have bigger fish to fry at the moment. But it's nice to have an interesting puzzle to contemplate in my off hours. And to live in such a strange and sometimes inexplicable Universe. The wonder won't ever fade completely, and I rather like that.

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