参与随意运动脑区的一侧化分布

目的:系统研究右利手被试者执行右手手指序列运动时,全脑运动有关区域的一侧化特点.方法:利用事件相关功能磁共振成像(fMRI)技术,结合右手手指的序列运动任务,研究8名右利手被试者脑区激活的一侧化特点.使用AFNI软件的反卷积程序生成激活图,计算一侧化指数并进行统计检验.结果:所有运动脑区,包括先前认为只与运动准备有关的区域,都参加了执行过程.从激活图上看,大脑各运动区激活呈左侧化,小脑激活呈右侧化特点.进一步的统计检验发现,大脑的初级运动区(M1)、辅助运动区(SMA)、后顶叶(PPC)激活呈左侧化趋势,运动前区(PMC)、扣带回、基底神经节(BG)一侧化不明显,小脑呈右侧化.结论:虽然运动脑区激活的一侧化特点在个体间表现细微的差别,但仍可见一侧化趋势.以往研究只在个别区域观察到一侧化激活特点,可能与任务难度和实验设计方式等有关.

Lateralized distribution of motor areas involved in voluntary movement

Objective: To investigate the brain functional laterality in motor areas during motor execution systematically.Methods: Functional magnetic resonance imaging(fMRI) was employed combined with right hand sequential finger movement task to investigate brain activation pattern and laterality in 8 right-handed subjects.3dDeconvolve program of AFNI was used to estimate the hemodynamic response function and to generate activation maps.Then the laterality index(LI) was calculated and tested statistically.Results: All motor areas including the areas which were previously considered to be engage in movement preparation only were activated in movement execution.In the activation map,it appeared left lateralization in cerebra and right lateralization in cerebella.After further statistical test,it was found that in primary motor area(M1),supplementary motor area(SMA)and posterior parietal cortex(PPC),there were left lateralization.While in premotor cortex(PMC),cingulate gyrus and basal ganglia(BG),the lateralization tendency was not obvious.The activation in cerebella is characterized with right lateralization.Conclusion: Though there are tiny differences among subjects,most of the motor areas appear lateralized activation.Past studies only observed laterality in several motor areas.It may be due to the difficulty of the task or the experimental design.