Weiss Peter H, Rahbari Nuh N, Lux Silke, Pietrzyk Uwe, Noth Johannes, Fink Gereon R
Department of Neurology - Cognitive Neurology, University Hospital, RWTH Aachen, Aachen, Germany.
Hum Brain Mapp. 2006 Dec;27(12):1004-14. doi: 10.1002/hbm.20239.
The left hemispheric dominance for complex motor behavior is undisputed. Clinical observations of complex motor deficits in patients with right hemispheric lesions, however, suggest an additional contribution of the right hemisphere to higher motor control. We assessed, using functional MRI (fMRI), which brain regions are implicated in processing the spatial aspects of complex, object-related actions. Using a blocked, factorial design, 17 healthy volunteers were asked to detect either spatial or sequential errors (factor ERROR) in complex activities of daily living, presented as video sequences with the appropriate object(s) or as pantomimes (factor STIMULUS). Observing complex actions (irrespective of stimulus type) activated a bilateral frontoparietal network. Observing actions with objects (relative to pantomimes) differentially increased neural activity in the fusiform gyrus and inferior occipital cortex bilaterally. Observing pantomimes, i.e., the same actions but without any object, differentially activated right prefrontal cortex, anterior cingulate cortex, the precuneus, and left cerebellum. The left cingulate cortex was differentially activated when subjects assessed the sequencing of actions. By contrast, assessing the spatial configuration of complex actions differentially increased neural activity in right posterior parietal cortex. A significant interaction of ERROR and STIMULUS was revealed for the right inferior parietal cortex only. These findings suggest a specific role of the right hemisphere, especially of right posterior parietal cortex, in processing spatial aspects of complex actions and thus provide a physiological basis for the observed apraxic motor deficits in patients with right hemispheric damage.
左半球在复杂运动行为中占主导地位这一点毋庸置疑。然而，对右半球病变患者复杂运动缺陷的临床观察表明，右半球对高级运动控制也有额外贡献。我们使用功能磁共振成像（fMRI）评估了哪些脑区参与处理复杂的、与物体相关动作的空间方面。采用组块析因设计，让17名健康志愿者在日常生活的复杂活动中检测空间或顺序错误（因素“错误”），这些活动以带有适当物体的视频序列或手势的形式呈现（因素“刺激”）。观察复杂动作（无论刺激类型如何）都会激活双侧额顶叶网络。观察有物体的动作（相对于手势）会使双侧梭状回和枕下回的神经活动有差异地增加。观察手势，即相同的动作但没有任何物体，会有差异地激活右前额叶皮质、前扣带回皮质、楔前叶和左小脑。当受试者评估动作顺序时，左扣带回皮质会有差异地被激活。相比之下，评估复杂动作的空间构型会使右后顶叶皮质的神经活动有差异地增加。仅在右下顶叶皮质发现了“错误”和“刺激”的显著交互作用。这些发现表明右半球，尤其是右后顶叶皮质，在处理复杂动作的空间方面具有特定作用，从而为观察到的右半球损伤患者的失用性运动缺陷提供了生理基础。
