Developmental dyslexia: two right hemispheres and none left.
Developmental dyslexia may be associated with (i) bi-hemisphere representation of spatial functions, in contrast to the right-hemisphere specialization observed in normal children, and (ii) typical left-hemisphere representation of linguistic functions, as is observed in normal children. The bilateral neural involvement in spatial processing may interfere with the left hemisphere's processing of its own specialized functions and result in deficient linguistic, sequential cognitive processing and in overuse of the spatial, holistic cognitive mode. This pattern of cognitive deficits and biases may lead dyslexics to read predominantly with a spatial-holistic cognitive strategy and neglect the phonetic-sequential strategy. Such an approach in learning to read phonetically coded languages, such as English, many be inefficient and limited.