Dyslexia, an imbalance in cerebral information-processing strategies.

Reading ability seems to involve analytic-sequential processing of selected letters and a holistic-simultaneous perception of the salient features of the entire word. The dyslexic child, being normal in intelligence, is most likely deficient in either one of the two processes while being normal in the other. To test this hypothesis, 28 reading disabled children, on the basis of the nature of errors made in a writing from dictation task, were divided into groups: analytic-sequential deficient and holistic-simultaneous deficient. Further testing showed that the first group was poor in processing a sequence of digits but normal on holistic-simultaneous memory tasks. The opposite pattern of performance was shown by the second group. A control group of 14 normal readers did not show such an imbalance.