From the July 8, 2010 issue of the Economist, comes an intriguing story about learning to read. According to Stanislas Dehaene, a cognitive neuroscientist at the French medical-research agency, INSERM, learning to reading involves forcing the brain to unlearn an earlier pre-wired fundamental survival skill, the ability to recognize an object and its mirror image as identical. Dr. Dehaene believes learning to read also means sacrificing some facial recognition ability.
His studies suggest that one small area of the brain’s visual system is particularly activated by the written word. Dr Dehaene calls this the visual word form area (VWFA). Researchers debate the extent to which this area is specialised for word recognition, since it also responds to pictures. But Dr Dehaene thinks the VWFA evolved for object recognition and is requisitioned for word recognition. Unfortunately, it has one property that, though valuable when recognising objects, is not helpful for reading: more than other parts of the visual system it is activated both by an object and by that object’s mirror image.
Dr. Dehaene's theories shed new light on dyslexia.
It was thought that only dyslexic children were prone to confusing “b” and “d”, and “p” and “q”, and occasionally writing their names back-to-front, but Dr Dehaene has found that all children make this error.
If Dr. Dehaene is right, dyslexia is a consequence of normality, not an aberration. It is reading that is distinctly “abnormal.” The wonder may be that so many of us successfully learn to read.
(Dehaene) suggests the error happens because when learning to read children first have to unlearn that older survival skill. If he is right, then in adults the VWFA should be insensitive to which of two mirror images it is viewing when it comes to pictures, but sensitive to that distinction when viewing words and letters. This is indeed the case.
Dr. Dehaene's results could point to new reading instruction methods.
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