Brain-based help for adults with dyslexia

Intensive phonics instruction literally gets into the heads of adults with dyslexia, according to a new brain-imaging study. After completing such training, these individuals display modified brain activity that apparently fosters their improved performance on reading tests, concludes a team of neuroscientists led by Guinevere F. Eden of Georgetown University Medical Center in Washington, D.C.

Dyslexia manifests itself primarily as a severe reading difficulty in people of at least average intelligence. Phonics techniques, which match appropriate sounds to written letters, have boosted reading skills in children with dyslexia but hadn’t previously been studied in adults with the condition.

Eden and her coworkers recruited 19 adults with good reading skills and 19 adults with dyslexia. A functional magnetic resonance imaging (fMRI) scanner measured blood flow throughout participants’ brains as they listened to spoken words and tried to repeat each of them without its initial sound. For example, the correct response after hearing “cat” was to say “at.” A left-brain region already implicated in decoding alphabetic scripts exhibited particularly low blood flow, suggesting reduced neural activity, in those with dyslexia.

Ten of the adults with dyslexia then completed 8 weeks of phonics-based training. The rest received no instruction. When again asked to repeat words minus their initial sounds, the volunteers who had undergone training displayed greater activity in the reading-related part of the left brain than they had before instruction and also boosts in several right brain areas that may contribute to reading, the scientists conclude in the Oct. 28 Neuron.

Bruce Bower has written about the behavioral sciences for Science News since 1984. He writes about psychology, anthropology, archaeology and mental health issues.