[Brain mapping studies in dyslexia]

Brain EEG mapping has been recorded during three different conditions, rest closed eyes, rest open eyes, and reading task, in a group of 22 dyslexic children, age mean 9.3 years, range 8-11, and control group of normal readers of the same age. All the subjects were right-handed, and laterality was assessed through the Edinburgh test. The individual maps in dyslexic and controls were averaged, and mean maps of both groups were obtained for a very different experimental condition. Rest closed eyes maps of dyslexics and controls disclose a powerful and symmetric alpha over occipital areas, with higher energy peak at 8.5-9.5 Hz., without significant differences in both groups. Brain maps centered in the fast beta band, 18-25 Hz., disclose significant differences in control group versus dyslexics, with more power in control group over all areas. Our findings suggest less adequate brain activation in dyslexics during reading tasks.