Children with developmental dyslexia and acquired alexia with agraphia especially for disorders involving kanji writing

Abstract

In this study, we investigated the points in common and differences between developmental dyslexia and acquired alexia with agraphia in terms of timing of localization of the functions of reading/writing in the brain, using neuropsychological assessments and functional MRI. The participants were several children with developmental dyslexia who had abnormal activation area in the left temporo-parietal junction and two children with acquired alexia and agraphia who had left brain damage including inferior parietal lobule at the age of eight. The results suggested that reading/writing functions are localized in the left inferior parietal lobule before the age of eight. The findings also suggested that the functions of reading/writing develop independently from manipulation of non-verbal figures before eight years of age.