两种语言任务脑功能区激活的功能磁共振成像比较

Comparison of fMRI on the Cortical Organization Using Two Language Tasks in Normal Subjects

目的对照两种不同模式语言任务的血氧水平依赖性功能磁共振成像(BOLD fMRI)脑功能区激活图,探讨这些功能区在语言加工过程中的意义。方法对8名右利手健康志愿者,分别在执行图片命名及词语联想任务时进行BOLD fMRI扫描。所得原始图像数据经神经功能影像分析软件处理,生成两种任务的脑激活图后进行对照研究。结果词语联想激活的脑区主要有双侧额叶内侧面辅助运动区(SMA)、双侧中央前回运动区(BA6)(左侧较右侧显著)、左侧枕叶皮层(BA18、19)、左侧额叶下回(BA45、47)、左侧岛叶(BA13)、双侧小脑上部。图片命名激活的脑区主要有双侧额叶内侧面SMA区、左侧额叶下回(BA44)、双侧枕叶上中部皮层(BA18、19)、双侧中央前回(BA6)、双侧小脑上部。图片命名激活枕叶的范围比词语联想明显;而词语联想对语义语音加工相关脑区的激活比图片命名明显,且具有明显的优势半球偏侧化特征。结论上述两种语言任务能激活参与语言加工的由多个脑区组成的神经网络。两种语言任务的脑区激活特点反映了各自具有相对独特的认知成分及加工过程。

Objective To comparatively study the cortical organization using two different language tasks by BOLD-fMRI in normal subjects. Methods BOLD-fMRI scan was performed in 8 healthy volunteers with right handiness during executing the two language tasks： picture-naming and word-generation. The AFNI software was used to analyze the functional data and to generate the statistical parametric maps for comparatively studying the activation areas of each task. Results Both activation patterns for two language tasks shared a common brain network dispersed in frontal, parietal, and occipital lobe. The activation areas of occipital lobe for picture-naming was more obvious than those for word-generation. By contraries, the areas related to language processing for word-generation was more active than picture-imaging. Compared with picture naming, the activation patterns for word-generation was mainly left-lateralized. Conclusion Both of two tasks can activate the brain network which dedicate to language processing, but each of them has its own characteristics according to the processing patterns.