Developmental dyslexia : neuropsychological and cognitive-neuropsychological analysis

Abstract

    We analyzed Japanese developmental dyslexia using neuropsychological and cognitive-neuropsychological methods. First, we prepared the standardized data for normal children on reading and writing tests. Second, we selected 22 developmentally dyslexic children, 20 male and two female, using reading and writing tests. Their average IQ using WISC-III or WISC-R was 102 (VIQ 102, PIQ101) . Regional cerebal blood flow (rCBF) in the left temporo-parietal lobe accoding to the Patrak method showed greater than 10% rCBF reduction compared with the same area of the right hemisphere. The subjects manifested lower scores in tests of both phonological and visual information processing. As a result, we assume that developmental dyslexia is a higher brain dysfunction, accompanied by disorders in both phonological and visual information processing.