How does first language (L1) influence second language (L2) reading in the brain? Evidence from Korean-English and Chinese-English bilinguals.

To examine how L1 influences L2 reading in the brain, two late bilingual groups, Korean-English (KE) and Chinese-English (CE), performed a visual word rhyming judgment task in their L2 (English) and were compared to L1 control groups (i.e., KK and CC). The results indicated that the L2 activation is similar to the L1 activation for both KE and CE language groups. In addition, conjunction analyses revealed that the right inferior frontal gyrus and medial frontal gyrus were more activated in KK and KE than CC and CE, suggesting that these regions are more involved in Korean speakers than Chinese speakers for both L1 and L2. Finally, an ROI analysis at the left middle frontal gyrus revealed greater activation for CE than for KE and a positive correlation with accuracy in CE, but a negative correlation in KE. Taken together, we found evidence that important brain regions for L1 are carried over to L2 reading, maybe more so in highly proficient bilinguals.