Behavioral studies showed that AS, an English-Japanese bilingual, was a skilled reader in Japanese but was a phonological dyslexic in English. This behavioral dissociation was accounted for by the Hypothesis of Transparency and Granularity postulated by Wydell and Butterworth. However, a neuroimaging study using magnetoencephalography (MEG) revealed that AS has the same functional deficit in the left superior temporal gyrus (STG). This paper therefore offers an answer to this intriguing discrepancy between the behavioral dissociation and the neural unity in AS by reviewing existing behavioral and neuroimaging studies in alphabetic languages such as English, Finnish, French, and Italian, and nonalphabetic languages such as Japanese and Chinese.
Keywords: Behavioral dissociation; Dyslexia; English-Japanese bilingual; Language universality, specificity; Magnetoencephalography; Neural unity; Reading processes.