Seitz R J, Canavan A G, Yágüez L, Herzog H, Tellmann L, Knorr U, Huang Y, Hömberg V
Department of Neurology, Heinrich-Heine-University Düsseldorf, Germany.
Eur J Neurosci. 1997 Feb;9(2):378-89. doi: 10.1111/j.1460-9568.1997.tb01407.x.
The aim of this study was to identify the cerebral areas activated during kinematic processing of movement trajectories. We measured regional cerebral blood flow (rCBF) during learning, performance and imagery of right-hand writing in eight right-handed volunteers. Compared with viewing the writing space, increases in rCBF were observed in the left motor, premotor and frontomesial cortex, and in the right anterior cerebellum in all movement conditions, and the increases were related to mean tangential writing velocity. No rCBF increases occurred in these areas during imagery. Early learning of new ideomotor trajectories and deliberately exact writing of letters both induced rCBF increases in the cortex lining the right intraparietal sulcus. In contrast, during fast writing of overlearned trajectories and in the later phase of learning new ideograms the rCBF increased bilaterally in the posterior parietal cortex. Imagery of ideograms that had not been practised previously activated the anterior and posterior parietal areas simultaneously. Our results provide evidence suggesting that the kinematic representations of graphomotor trajectories are multiply represented in the human parietal cortex. It is concluded that different parietal subsystems may subserve attentive sensory movement control and whole-field visuospatial processing during automatic performance.
本研究的目的是确定在运动轨迹的运动学处理过程中被激活的脑区。我们测量了8名右利手志愿者在右手书写学习、执行和想象过程中的局部脑血流量（rCBF）。与观看书写空间相比，在所有运动条件下，左运动皮层、运动前区皮层和额内侧皮层以及右小脑前叶的rCBF均增加，且增加与平均切向书写速度相关。在想象过程中，这些区域的rCBF没有增加。新的观念运动轨迹的早期学习和字母的刻意精确书写均导致右侧顶内沟内衬皮层的rCBF增加。相反，在过度学习轨迹的快速书写过程中以及在学习新表意文字的后期阶段，后顶叶皮层的rCBF双侧增加。之前未练习过的表意文字的想象同时激活了顶叶前部和后部区域。我们的结果提供了证据，表明书写运动轨迹的运动学表征在人类顶叶皮层中存在多重表征。得出的结论是，不同的顶叶子系统可能在自动执行过程中为注意力感觉运动控制和全视野视觉空间处理提供支持。
