小脑汉字词语处理相关脑区的功能磁共振研究

Functional MR Imaging about Cerebellar Activated Areas in Chinese Character Processing

目的:运用功能磁共振成像(fMRI),以假词为对照,初步探讨小脑在汉字词语语义处理中的作用。并根据Schmahmann小脑皮质的分类法,初步确定在汉字词语语义处理中小脑的激活区域。材料和方法:25例健康、母语为汉语的受试者参加了本实验,其中男性18例,女性7例。年龄在22～30岁,平均为25.7岁。所有受试者均为大学本科以上学历,受试者实验前均接受Snyder和Harris制定的利手确定问卷,得分在40分以上,确定为右利手。采用fMRI技术,模块设计(block-design)的刺激模式,运用听觉呈现的方法,每名受试者参加两组实验:假词实验组及真词实验组。结果:假词实验组激活的脑区包括双侧颞上回、双侧额下回及左侧角回。真词实验组激活的脑区包括双侧颞上回、双侧额下回、双侧辅助运动区、两侧小脑半球、两侧尾状核及右侧丘脑和左侧角回。双侧辅助运动区、两侧小脑半球、两侧尾状核及右侧丘脑仅在真词实验组中被激活。两侧小脑半球激活区域多位于偏后外侧的区域。结论:小脑半球偏后外侧区域(Ⅵ、ⅦB、ⅧA、C_(rus)Ⅰ、C_(rus)Ⅱ)是特征性与汉字词语语义处理有关的区域。

Purpose： We investigate the Chinese character semantic processing function of cerebeller by Functional MRI with the control of pseudowords. To initially determine the cerebellar activated areas in Chinese character semantic processing on the basis of the Schmahmann＇ s categorization method of cere-bellum.Materials and Methods： Twenty-five normal volunteers（eighteen males and seven female） whose native language was Chinese participated in the study. The mean age of subjects was 25.7, raging from 22-30. All the subjects were strongly right handed as judged by the handedness inventory devised by Synder and Harris. All subjects had scores higher than 40. All were undergraduates or graduates. Every subject performed two tests including the real word experiment and pseudowords experi-merit. Results： All subjects performed the experiment successfully. In pseudowords experiment, the activated areas in brain included bilateral superior temporal gyrus, bilateral inferior frontal gyrus and left angular gyrus. In real word experiment, the activated areas in brain included bilateral superior temporal gyrus, bilateral inferior frontal gyrus, bilateral motor areas, bilateral cerebellum, bilateral nucleus caudatus, left angular gyrus and right thalamus. Bilateral motor areas , bilateral cerebellum, bilateral nucleus caudatus and right thalamus were only activated in the real word experiment. The posterior lateral cerebellum hemispheres are activated in real word experiment. Conelusion： The posterior lateral cerebellum hemispheres （Ⅵ、ⅦB、ⅧA、CrusI、CrusⅡ） are the sites specifically involved in Chinese character semantic processing.