Asynchrony of cerebral systems activated during word recognition: comparison of dyslexic and typical readers.

The aim of this study was to extend our understanding of the "asynchrony" phenomenon by examining the existence of several additional differences in brain activity. The differences which were investigated were the difference between the left and right hemisphere processing, the anterior and posterior areas processing and the differences between the different stages of information processing. These differences could account as an additional explanation for word decoding failure among individuals with dyslexia. The research utilized behavioral and electrophysiological (ERP - Event Related Potentials) measures in skilled and dyslexic university students. The subjects performed a lexical decision task presented in the visual and auditory modalities. The dyslexics exhibited a larger processing time interval between the activation of the P2 and P3 components, between the left and right hemisphere and between posterior and anterior regions of the cortex. Disharmony of the dyslexic brain is suggested as a possible explanation for the dyslexia phenomenon.