A functional magnetic resonance imaging study during sentence reading in Japanese dyslexic children.

A functional magnetic resonance imaging (fMRI) study during Japanese 'kana' readings was performed on Japanese dyslexic children. Five dyslexic children (aged 9-12 years) and five healthy children (aged 9-11 years) were investigated. The fMRI examination was performed by getting these children to read sentences constructed from Japanese phonograms, 'kana', compared with staring at meaningless figures as a control task. All control subjects showed activation of the left middle temporal gyrus. In the dyslexic children, the activation of the middle temporal gyrus was rather vague. However, other distinctively activated regions were detected as follows: the bilateral occipital cortex in two dyslexics, the inferior part of the frontal regions in two other dyslexics, and both the bilateral occipital cortex and the inferior part of precentral gyrus in the remaining one. These results indicate compensatory management processes for the unskilled reading ability of dyslexic children. The present results were similar to previous ones for adult dyslexia with the Roman alphabet, and suggest that brain malfunction in dyslexia during the task of reading must be common despite differences in languages.