Biological evidence

Sunday, March 06, 2005

Medical doctors first diagnosed dyslexia more than 100 years ago. In 1896, an article in The British Medical Journal described dyslexia as a case of someone having accurate vision, mental acuity but an inexplicable inability to read.

Today that inability has been mapped using brain scans from a new technique called functional magnetic resonance imaging. Scientists have mapped the regions of the brain that receive more blood during reading.

Yale neuroscientist Sally Shaywitz found dyslexics relay on a slow analyzer at the front of the brain for decoding world bit by bit, while skilled readers use a speedy automatic recognition system at the back of the brain to process words whole.