Cerebral Activation Patterns Of English And Chinese In Native Chinese Bilinguists By FMRI

OBJECTIVES: As the medium of thinking, language is considered to be one of the most essential attributes shared by all human beings, which is closely associated with other cerebral cortical functions, such as perception, attention, memory and so on, and thus emphasized by researchers from interdiscipline and multi-level. Through integration of neural actions and higher-order resolution technique of MRI, fMRI can picture higher-order cortical function centers for human brain accurately, which makes possible the determination of high cortical actions of cerebrum from function and morphology under living conditions. In our experiment, fMRI is going to be employed to define the cerebral activation patterns concerned with processing of Chinese and English in native Chinese bilinguists, determinating distribution of associated cortical centers for such processes and working strategy for both hemispheres, and so we would reach a novel perspective for in-depth understanding of human cognitive patterns.METHODS: 12 native Chinese bilinguists with confirmed right-handedness were divided into two groups, namely English-specialized and non-English-specialized, equally shared by each group. By means of hearing, these subjects were required to finish semantic judgement tasks of English and Chinese words separately. Block designing was performed in this experiment. Every subject should fulfill two run tasks, one was for Chinese and the other for English. Based on BOLD efficacy, fMRI was available to collect functional images with EPI. The goal was to identify the cerebral activation distribution patterns under such two kinds of language tasks for every subject and the differences and similarities between them. With analysis of ROI (regions of interest), voxel percentage of the right hemisphere was obtained to determine its working strategy in both tasks. And also, the differences and similarities of working patterns for both tasks between specialized and non-specialized group should be available.RESULTS: All subjects demonstrated significant activation of associated cerebral regions. Except for classical regions involved in language actions, such as Wernicke and Broca areas, there appeared other activated cerebral regions, including cerebellum, limbic system and basal ganglial nucleus, etc. Various activation distribution patterns of cerebral regions were shared by every subject in both language tasks. To sum up, there were apparent overlap for cerebral activation distribution and no specific processing areas for Chinese or English in both tasks. The analysis of ROI implied that subjects in specialized group were more dependent on the right hemisphere to operate English words task than deal with Chinese task. Besides, we found one case with dominant hemisphere for language on the right side in both tasks.CONCLUSIONS: For most subjects with right-handedness, language cognition is dominated by the left hemisphere, which is also concerned by right hemisphere to various degrees and thus two hemispheres work by ways of both dissociation and coordination. It is possible that working strategy of the right hemisphere in English task is related to proficiency of the second language. A variety of distinctions are shared by each subject for language cognitive patterns. As a sensitive and effective equipment, fMRI would present us with great advantages in exploration of cerebral cognitive functions in the future.