Bilinguals' Mechansim Of Numeral, Chinese Number Words Processing And Language Selection

Three experiments were conducted to explore bilinguals' mechansim of numeral, Chinese number word processing and language selection employing fMRI(functional magnetic resonance imaging) and ERP(event-related potential) technology.In the first experiment,fMRI was employed to explore the relation between language processing and numeral processing by observing the effect of Arabic number and Chinese number words on figure size comparison task.The result revealed that different codes affect the number processing mode.Compared with the Arabic numerals task,more activations were found in the fusiform gyrus while less activation were found in parietal lobe which is the core region of numerical processing during the Chinese numerals task.The specific role the fusiform gyrus played in the Chinese numerical processing supports the viewpoint that numeral processing is closely related with the language ability.In the second experiment,to address cross-family language swtiching,event-related potentials(ERPs) were compared,induced by language selection and task selection processes during image naming.ERPs were collected from Chinese English bilingual subjects while tested in two different contexts:a monolingual task selection context(TSc) where a post-stimulus cue instructed subjects either to name the image or generate a corresponding verb in their first language(L1),and a bilingual language selection context(LSc) where the cue indicated to name the image either in the first or the second language.The findings indicated that the first ERP differences accounting for the diverging processes involved appeared 175 ms after the cue.The findings also suggested that in the 375-500ms,the average amplitude of Chinese-English language switching was significantly greater than that of inter-Chinese language switching.The estimation by source localisation of brain regions accounting for these differences pointed to an increased activation during LSc in the leftmiddle frontal-precentral gyri,supramarginal and angular gyri.The results suggest that the neural mechansim of code switching differs from the transformation of the internal information in a language.The third experiment intended to explore the interference of English-French homographs on unskilled Chinese trilinguals.The findings show that language context and the word frequency of the homographs in respective languages have significant effect on language activation and inhabination.To conclude,(1) language and numbers promote each other with separate characteristics in the activation of the brain;(2) cross-family language selection is based on the common cognitive processing together with language selection processing networks;(3) language context and the word frequency have significant effect on the language access.