ABSTRACT
PURPOSE@#To evaluate the neural mechanism of second language processing in Korean-English bilingual children using functional MRI (fMRI).@*MATERIALS AND METHODS@#The study was conducted on 20 Korean elementary school children who were learning English as a foreign language. fMRI was performed during short-passage comprehension tasks in Korean and English languages. We analyzed which brain areas were activated according to the language, English proficiency, and task difficulty.@*RESULTS@#Higher activities were observed in the dorsolateral prefrontal cortex, supplementary motor area, precentral gyrus, left basal ganglia, and left temporoparietal and occipital lobes during English comprehension than during Korean comprehension. The low English proficiency group showed higher activities than the high English proficiency group in the frontotemporal cortex, including the prefrontal cortex. Higher activities were observed in the right inferior frontal gyrus and right temporoparietal lobe during the English comprehension task of intermediate difficulty compared to that of low difficulty. However, the brain activities significantly decreased while performing a high-difficulty English task.@*CONCLUSION@#Brain activities significantly increased during English comprehension in the lower English proficiency group while performing an intermediate-difficulty task. However, brain activation decreased when the task difficulty exceeded the moderate comprehension level. These results suggest that a proper level of education is important to learn a second language.