功能磁共振成像分析多语者的母语语言区

Brain language area of native tongue in multilinguals: A functional MRI analysis

目的:观察多语者用母语识别汉字时,脑语言区的活动变化。方法:实验于2006-10/12在解放广州军区广州总医院磁共振室完成。①18名母语为广州话的大学生,用广州话对汉语单音节实物名词进行默读,在完成词汇默读过程中,进行功能成像扫描。②设计:Block设计,每个字呈现1500ms,注释点“+”1500ms。③扫描方法:应用Siemens Sonata1.5T超导型磁共振仪进行扫描,首先进行全脑轴位T1WI扫描,然后在其进行记忆任务及对照任务时采集其血氧水平依赖性信号,采用的是梯度回波结合单次激发回波平面成像技术。④评估:用统计软件AFNI2004版软件对数据进行统计分析,脑的激活阈值为0.05水平,并激活脑区与以往单一语言者的实验结果进行比较。结果:18名被试的数据全部进入结果分析。呈现名次默读任务时,18名被试结果平均后,相对于基线条件,在左侧额叶下部,即Broca区(BA47)出现激活,比单一母语者激活面积小;此外左额叶BA6,右额前回下部,左侧颞回上部,右枕叶BA31激活,其他脑区未表现出显著激活。结论:①汉字的处理主要与左侧大脑半球有关,多语者在语言区左额叶的激活较单一语言者弱化。②多语者与语音有关的左侧颞回活动加强。

AIM： To explore the brain activation during naming Chinese characters with native tongue in multilingual subjects. METHODS： The experiment was carded out in the Division of Magnetic Resonance Imaging, Guangzhou General Hospital of Guangzhou Military Area Command of Chinese PLA from October to December in 2006.①Eighteen university students, native speakers of Cantonese, were subjected to read Chinese single characters with native tongue silently, and functional magnetic resonance imaging （fMRI） was recorded to examine the brain activation.②Block design： Every character was present for 1 500 ms with a ＂＋＂ remark.③Scanning： MRI was performed with a 1.5 T superconductive MR scanner （Siemens Sonata）. Firstly the whole brain was scanned according to T1-weighted images, and then blood oxygenation level dependent signals ware collected by gradient echo combined with single-shot echo planar image when subjects performed memory and control tasks. ④Statistical analysis was conducted using Analysis of Functional Neuroimage. The threshold of activation was 0.05, the activated brain area was compared with previous monolinguals. RESULTS： Eighteen subjects ware all involved in the result analysis. According to the rank in the silent reading presentation, the activated brain areas included left inferior frontal cortex （BA47）, left frontal lobe （BA6）, right inferior frontal cortex, left superior temporal gyrus, and right occipital lobe （BA31）. The activation area of BA47 in native speakers of one language was smaller than in monolingual subjects. CONCLUSION： ①Chinese word processing is closely related to the left hemisphere. The less activated area is found in multilinguals than in monolinguals.②There are more activities in left temporal gyrus related to phone processing in multilinguals.