How does your brain learn to see?

Allison Loudermilk

How do we learn to see? Tim Flach/Getty

Last fall I was blind, if only for an hour. I had gone to "Dialog in the Dark," a performance that gives you a brief but lasting glimpse of what life might be like without your eyes. It's so dark in the exhibition space that you can have your eyes wide open and not see your hand in front of your face. After the performance, I stepped into the light, and my brain started processing all that assaulting visual information lickety-split. Thanks, brain.

Sometimes, though, your brain has to learn how to see. It's a weird thought, like learning how to breathe, but that's the deal for formerly blind people whose sight is restored. How does your gray matter accomplish this monumental task? A bunch of MIT neurophysicists have tried to figure it out. For their experiment, they found three participants ranging in age from 3 to 29 who had regained their sight. (One interesting sidenote: Doctors used to think the brain couldn't learn how to see once you were older than 5 or 6, but the 29-year-old participant proved them wrong.)

The researchers asked their small subject pool to identify shapes on a computer screen. They found that the people had a much easier time identifying moving shapes, rather than stationary ones. Motion is key. It's kind of surprising. You'd think when the brain began processing visual information it would have an easier time processing something standing still rather than moving about, but no. The MIT site does a nice job of simply summarizing the experiment, if you're interested.

Another cool thing? One of the PIs on the study is leading a project in India called Project Prakash, aimed at locating and treating children who go blind from routine childhood ailments like pink eye. It may not happen that much in the U.S., but it happens a lot elsewhere.