Cerebral Activation Areas with Respect to Word and Sentence Production by Early and Late Korean-English Bilinguals: Event-Related fMRI Study

摘要

This study was conducted to investigate the cerebral areas related with word and sentence production shown in event-related fMRI. Specifically the current study has an intention to enlighten the difference between native and foreign language processing by early and late Korean-English bilinguals. Two experiments were performed to confirm the areas related with each level of word and sentence generation. The experimental tasks comprises picture naming and sentence production tasks in which subjects were asked to name the picture and to produce a sentence to describe the picture in Korean or in English. While performing the task, event-related activation areas were confirmed. The results showed that inferior frontal gyrus (IFG; BA 44, 45) activated in both early and late Korean-English bilinguals. However the activation areas were reduced in English-presented condition compared to Korean-presented condition as a native language. Additionally as compared with the activation areas in English-presented condition as a foreign language, the late Korean-English bilinguals have more activation than the early. Such results suggested that the different acquisition time of foreign language could result in the different cerebral activation.