Cerebral localization and mechanism of writing in second language by early and late bilinguals / 中华行为医学与脑科学杂志

ABSTRACT

Objective To observe activated cerebral areas during the task of writing in second language by early and late acquisition bilinguals and explore the neuropsychological mechanism. Methods Twelve subjects were divided into group of early acquisition high proficiency bilinguals(EAHP) and group of late acquisition high proficiency bilinguals(LAHP). Each subject carried out the task of pseudo-writing and English writing. After functional imaging,statistical parametric mapping was used to compare data of the two tasks through paired- t test in both two groups. A conjunction analysis was conducted between the two groups also. Areas where the metabolism of glucose changed were analyzed. Then, the corresponding images about activated cerebral regions were obtained.Results Cerebral areas where the metabolism of glucose increased in EAHP: bilateral middle frontal gyrus( Z=4.35/2. 01 ), bilateral cerebellum ( Z = 2.97/2.53 ) and left head of caudate nucleus ( Z = 3.07 ), etc. Cerebral areas where the metabolism of glucose increased in LAHP: right superior frontal gyrus(Z=4.06), right cerebellum( Z=4.63), left putamen(Z=2.70) ,etc. Cerebral areas where the metabolism of glucose increased in compared data of LAHP with data of EAHP: right frontal gyrus ( Z = 2.92 ), right temporal lobe( Z = 2.31 ), etc. Conclusion Extensive cerebral cortex and subcortical structures participate the process of writing in the second language. Age of bilingual acquisition is one of the factors affecting cerebral localization of writing in second language.