维吾尔族熟练维-汉双语者语言活动区的功能磁共振成像

Cerebral Activation Patterns of fMRI in Uygur-Chinese Bilinguals

目的利用功能磁共振成像(fMRI)研究以维吾尔语(L1)为母语,汉语(L2)为第二语言(6岁以前学习汉语)的新疆维吾尔族人大脑语言功能激活区的异同,并探讨维吾尔族人加工这两种语言的优势半球。资料与方法所有受试者均来自新疆中心方言区健康维吾尔族人,其中18名6岁以前开始接触汉语,给予单个汉字任务视觉刺激,另19名维吾尔族人给予维吾尔文视觉刺激,分别对每个字进行语义联想同时行fMRI,所有数据经统计参数图SPM5脑fMRI处理软件包处理,对相关脑皮质激活区进行个体分析及组分析,生成受试者脑激活图,对于组内数据采用配对t检验,组间数据的比较采用两独立样本t检验。结果 L1语义加工有其特异性激活区,如左侧颞中回及右侧颞上回,L2激活了双侧额上回、右侧额内侧回以及右侧顶上下小叶,而这些区域L1加工未见明显激活。两种语言左侧大脑半球激活体积大于右侧。结论利用血氧水平依赖(BOLD)-fMRI通过视觉刺激进行词义理解时,发现维-汉双语者维文与中文有部分激活区重叠,但也有各自的特异激活区。中文激活范围较维文弥散,无论是维语还是"早双"汉语,语义加工优势半球均在左侧大脑半球,两种语言的偏侧化程度未见差异。

Objective To determine the cerebral activation patterns in Uygur-Chinese bilinguals.Materials and Methods Eighteen native Uygur bilinguists who had acquired the second language before 6 years old,performed semantic tasks in Chinese（secondary language,L2）,and 19 native Uygur bilinguists performed semantic tasks in Uygur words（primary language,L1）.Echo-planar fMRI were underwent at 1.5 T.Individual and group functional datasets were analyzed using Statistical Parametric Mapping software and overlaid on T1-weighted anatomic images.Results The distinct activation regions of L1 located in the Left middle temporal gyrus,right superior temporal gyrus.The bilateral superior frontal gyr,right medial frontal gyri,right superior and inferior parietal lobules were induced by only L2 stimulation.Activation areas of both L1 and L2 language tasks were bigger in left cerebral hemisphere than in right cerebral hemisphere.Conclusion The neural networks utilized for semantic language processing in the nonnative language may not be as same as those in the primary language.Both two language tasks demonstrate left cerebral dominance.There was no difference between Uygur and Chinese tasks in left hemispheric lateralization.