Working in Movement

Lots of people don't have all their senses, in the literal meaning of that term. The blind lack vision, the deaf hearing, for example. But researchers have found that areas of the brain normally dedicated to the missing sense can be recruited for processing info from other senses. A Canadian team recently demonstrated that some people born blind can hear much better than sighted people. The research indicates the parts of the blind-from-early-on brain that would have been dedicated to vision are used in hearing, giving more brain real estate than usual to that sense.

But it turns out that's not always the case. Esref Armagan is a Turkish painter who has been blind from birth, and whose brain does not detect any light at all. Despite never seeing a thing, Armagan paints very realistic pictures. You'd think the visual areas of his brain would show very little activity. But you'd be wrong. The Art of Seeing Without Sight describes recent brain scans on Armagan that show the visual areas lighting up almost normally.

When Armagan imagined items he had touched, parts of his visual cortex, too, were mildly activated. But when he drew, his visual cortex lit up as though he was seeing. In fact, says Pascual-Leone, a naive viewer of his scan might assume Armagan really could see.

It turns out that his sense of touch "informs" his drawing--he uses a device that raises the lines he draws so that he can monitor the drawing with his fingers. I would have expected the visual areas involved with touch, but the idea that his visual cortex "lit up as though he was seeing" is a surprise.

What's most interesting about Armagan to me is how he learned to draw and paint. Researchers ask him to draw a complicated road scene including poles along side the road. The results were startlingly realistic.

So, we ask, how do you know how long these poles should be as they recede? I was taught, he says. Not by any formal teacher, but by casual comments by friends and acquaintances. How do you know about shadows? He learned that too. He confides that for a long time he figured that if an object was red, its shadow would be red too. "But I was told it wasn't," he says. But how do you know about red? He knows that there's an important visual quality to seen objects called "colour" and that it varies from object to object. He's memorised what has what colour and even which ones clash.

The thing most adaptable in the human nervous system is its ability to learn, seemingly under almost any condition.