功能磁共振成像在人脑数字及汉字认知加工中的初步研究

目的应用功能磁共振成像(fMRI)对比研究人脑在数字和汉字认知刺激下脑功能活动,探讨其精确脑区定位及其可能机制。方法母语为汉语的12例右利手健康志愿者(男5例,女7例)进行了数字和汉字的看及默读实验,使用MRI仪以BOLD法采集脑部数据,用SPM99等软件后处理,获得脑功能活动图像。结果看数字和汉字均能激活双侧纹外视区、枕上回、顶叶及额下回少部分区域;默读数字和汉字额上回及额中回激活较明显;处理汉字比处理数字在额叶激活的面积更大;还发现在汉字的认知加工过程中有豆状核、丘脑及小脑的参与。结论数字及汉字的认知加工激活脑内不同区域,额叶在汉字的处理过程中起更重要作用。fMRI是研究活体人脑语言功能十分有效的方法。

A functional magnetic resonance imaging study of human brain processing figures and Chinese characters

Aim To study the brain functional activation under the stimulation of figures and Chinese characters with functional magnetic resonance imaging (fMRI), and to investigate the location and the possible mechanism.Methods fMRI was used to investigate the brain activation under the stimulation of figures and Chinese characters by looking and reading silently in 12 healthy right handed volunteers, 5 males and 7 females, aged 21- 30 years old, whose mother tongue is Chinese.Results Under the stimulation of looking figures and Chinese characters the activated cortical areas included bilateral extrastriate, superior occipital gyrus,parietal lobe and partial inferior frontal gyrus.Under the stimulation of reading figures and Chinese characters silently the activated cortical areas included superior frontal gyrus and middle frontal gyrus, which were activated significantly. The activated area of Chinese characters processing was larger than that of figures processing.Putamen, thalamus and cerebellum were found to involve in the cognitive process of Chinese characters. Conclusions Figures and Chinese characters activate different cerebral areas in the cognitive process respectively.Frontal lobe plays a more important role in the processing of Chinese words. fMRI is an effective method to study the language function of human brain.