Visual Function, Visual Perception and Visual Recognition in Japanese Children with Developmental Dyslexia

Abstract

We analyzed visual information processing in Japanese children with developmental dyslexia systematically to reveal the cognitive dysfunction underlying their disorder. We evaluated visual function, visual perception, visual recognition and visual memory in 59 normal and 20 developmentally dyslexic children. The experimental results suggest that visual function abnormalities do not affect accuracy of reading and writing. All developmentally dyslexic children showed significantly lower scores than the control group in a visual perception task about orientation of lines and a visual memory task. Eight of the 20 developmentally dyslexic children exhibited dysfunction in both the visual magnocellular system and the parvocellular system relating to visual perception. Our results suggest that Japanese children with developmental dyslexia differ from their overseas counterparts, as reported, in that they demonstrate dysfunctions of both visual pathways, magno- and parvocellular.