Jerusalem, February 22, 2011 -- The portion of the brain responsible for visual reading doesn't require vision at all, according to a new study by researchers from the Hebrew University of Jerusalem and France.
Brain imaging studies of blind people as they read words in Braille show activity in precisely the same part of the brain that lights up when sighted readers read. The findings challenge the textbook notion that the brain is divided up into regions that are specialized for processing information coming in via one sense or another, the researchers say.
"The brain is not a sensory machine, although it often looks like one; it is a task machine," said Dr. Amir Amedi of the Hebrew University of Jerusalem, head of the team of researchers whose work on the topic is reported in the latest issue of Current Biology.
"A particular area fulfills a unique function, in this case reading, regardless of sensory input modality," he said. Amedi is affiliated with the Institute for Medical Research Israel-Canada and the Edmond and Lily Safra Center for Brain Sciences at the Hebrew University.
Unlike other tasks that the brain performs, reading is a recent invention, about 5,400 years old. Braille has been in use for less than 200 years. "That's not enough time for evolution to have shaped a brain-module dedicated to reading," Amedi explained.
Nevertheless, brain scans have shown that a very specific part of the brain, known as the Visual Word Form Area or VWFA for short (first discovered in sighted people by Dr. Laurent Cohen of Paris, a co-author of the current article), has been co-opted for this purpose. But no one knew what might happen in the brains of blind people who learn to read despite the fact that they've had no visual experience at all.
In the new study, Amedi's team, which included his doctoral student Lior Reich, used functional magnetic resonance imaging (fMRI) to measure the neural activi
|Contact: Jerry Barach|
The Hebrew University of Jerusalem