Brain strategies for reading in the second language are determined by the first language

Brain activation associated with reading was investigated in ten normal Japanese volunteers (five highly literate in both Japanese and English) and ten American native English speakers (five highly literate in both English and Japanese) in order to determine the neuroanatomic substrates employed in reading the first language (L1), and to determine the effect of L1 on the neurosubstrates involved in reading the second language (L2). The study was performed using blood oxygenation level dependent (BOLD) contrast functional magnetic resonance imaging (fMRI) on a high-field (3.0T) system specifically optimized for fMRI. The activation patterns in Japanese subjects reading Japanese (L1) were substantially different from the patterns obtained in American subjects reading English text (L1). The activation patterns reading L2 were virtually identical to the patterns seen when reading L1 in both Japanese and English natives highly literate in both language systems. The results demonstrated that the neuroanatomical substrates underlying the cognitive processing of reading are differentially determined based on the language system. The study further indicates that the cognitive processes for reading in the second language involve the same cortical structures employed for the first language, supporting the hypothesis that the second language represents the cognitive extension of the first language.