Coherence of hemispheric function in developmental dyslexia.

Left parieto-occipital EEG leads record a frequency spectrum in dyslexics that is consistently different from the spectrum obtained from normals. It is suggested that these effects represent significant differences in the functional organization of these areas. EEG coherence values indicate that normals have significantly greater sharing between hemispheres at symmetrical locations. Dyslexics demonstrate significantly greater sharing within hemisphere than do normals. The data supports developmental dyslexia being a functional hemispheric disconnection syndrome.