Results from fMRI suggest that there are at least two pathways for reading in the brain: inexperienced readers use one pathway, whereas a second, faster pathway takes over in more skilled readers. Both involve three key areas in the left side of the brain: a region at the front of the brain known as Broca's area; and at the rear, the parieto-temporal and occipito-temporal regions (see diagram). Broca's area has long been known, from studies of patients with brain lesions, to be required for normal speech and writing. Novice readers seem to use the parieto-temporal region to dismantle words for step-by-step phonological analysis; more experienced readers apparently rely on the occipito-temporal region to recognize whole words instantly8.
Map reading: the brain regions that are involved in deciphering text.
With her husband Bennett and other Yale colleagues, Shaywitz has used fMRI to compare the brains of dyslexics to those of normal, healthy readers as they perform reading tasks such as trying to identify nonsensical words in rhyming pairs and real words in non-rhyming pairs. When the words used were nonsensical ('jeat' and 'lete', for example), they could not instantly be recognized, and so all the volunteers were forced to sound out the words in their heads, phoneme by phoneme. In 1998, Shaywitz and her colleagues reported that dyslexics and non-dyslexics differ in their patterns of brain activity9. "We found a clear neurological signature for dyslexia," she says.
Via Winners Education