van Eimeren Thilo, Wolbers Thomas, Münchau Alexander, Büchel Christian, Weiller Cornelius, Siebner Hartwig Roman
NeuroImage Nord, Department of Neurology, University Medical Center Hamburg Eppendorf, Germany.
Neuroimage. 2006 Jan 1;29(1):286-94. doi: 10.1016/j.neuroimage.2005.07.014. Epub 2005 Aug 8.
We used functional magnetic resonance imaging to examine neuronal activity reflecting the dynamic interplay of external and internal guidance of action. Participants performed a choice reaction time task based on spatial visual cues with their right and left middle and index finger. In a given trial, the cue either fully determined the motor response (no-selection) or indicated the number and location of alternative responses (selection). Compared with fully determined responses, the selection among (two to four) alternative responses activated a widespread bilateral parieto-premotor-prefrontal cortical network along with the cerebellum. Within this network, task-related activity patterns allowed to delineate two sets of brain areas. In the anterior part of rostral dorsal premotor cortex (PMd), the rostral cingulate and supplementary motor area and the right dorsolateral prefrontal cortex, the increase in activity was independent of spatially defined restrictions. In contrast, there was an additional increase in activity in the posterior part of rostral PMd, superior parietal lobule and parieto-occipital sulcus bilaterally as well as in the right anterior intraparietal sulcus, when the visuospatial cue imposed specific constraints on response selection. We propose that the latter set of dorsal parieto-frontal areas subserves rapid implementation of spatial information during visually guided response selection.
我们使用功能磁共振成像来检测反映动作的外部和内部引导动态相互作用的神经元活动。参与者用右手和左手的中指和食指根据空间视觉线索执行选择反应时任务。在给定的试验中，线索要么完全决定运动反应（无选择），要么指示替代反应的数量和位置（选择）。与完全确定的反应相比，在（两到四个）替代反应之间进行选择激活了一个广泛的双侧顶叶 - 运动前区 - 前额叶皮质网络以及小脑。在这个网络中，与任务相关的活动模式可以勾勒出两组脑区。在喙背运动前皮质（PMd）前部、喙扣带回和辅助运动区以及右侧背外侧前额叶皮质，活动增加与空间定义的限制无关。相比之下，当视觉空间线索对反应选择施加特定限制时，喙PMd后部、双侧顶上小叶和顶枕沟以及右侧前顶内沟的活动会额外增加。我们提出，后一组背侧顶叶 - 额叶区域在视觉引导的反应选择过程中有助于空间信息的快速实施。
