Simultaneous movements of upper and lower limbs are coordinated by motor representations that are shared by both limbs: a PET study
Simultaneous movements of upper and lower limbs are coordinated by motor representations that are shared by both limbs: a PET study
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DOI：
10.1046/j.1460-9568.2000.00209.x
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发表时间：
2000-09-01
影响因子：
3.4
通讯作者：
Roland, PE
中科院分区：
文献类型：
--
作者：
Ehrsson, HH;Naito, E;Roland, PE
本研究的目的是检查大脑控制的同时运动的上，下肢。我们研究了两种关于大脑如何协调运动的假设：（i）通过参与四肢共享的运动表征;或（ii）通过参与特定的神经群体。我们使用正电子发射断层扫描来测量健康受试者的相对脑血流量，这些受试者进行腕关节和踝关节的单独周期性屈伸运动（即仅腕关节或踝关节运动）以及腕关节和踝关节的同时运动（也包括休息条件）。同时在相同方向（同向）和相反方向（反向）进行运动。这两种协调模式之间的大脑活动没有差异。在对侧腹侧运动前区、背侧运动前区、辅助运动区、顶叶盖和顶叶后皮质等几个运动相关区中，孤立腕运动的表征与孤立踝运动的表征重叠。重要的是，同步运动激活了在单独运动期间活跃的同一组运动相关区域。在对侧腹侧运动前皮层，背侧运动前皮层和顶叶盖，有较少的活动在同时的运动比两个孤立的运动的活动的总和（相互作用分析）。事实上，在腹侧运动前皮层和顶叶盖中，无论是只有手腕、只有脚踝还是手腕和脚踝都运动，活动几乎是相同的。总之，这些研究结果表明，肢体间协调是由两个肢体共享的运动表征介导的，而不是由特定的额外神经群介导的。
The purpose of this study was to examine the cerebral control of simultaneous movements of the upper and lower limbs. We examined two hypotheses on how the brain coordinates movement: (i) by the involvement of motor representations shared by both limbs; or (ii) by the engagement of specific neural populations. We used positron emission tomography to measure the relative cerebral blood flow in healthy subjects performing isolated cyclic flexion-extension movements of the wrist and ankle (i.e. movements of wrist or ankle alone), and simultaneous movements of the wrist and ankle (a rest condition was also included). The simultaneous movements were performed in the same directions (iso-directional) and in opposite directions (antidirectional). There was no difference in the brain activity between these two patterns of coordination. In several motor-related areas (e.g. the contralateral ventral premotor area, the dorsal premotor area, the supplementary motor area, the parietal operculum and the posterior parietal cortex), the representation of the isolated wrist movement overlapped with the representation of the isolated ankle movement. importantly, the simultaneous movements activated the same set of motor-related regions that were active during the isolated movements. In the contralateral ventral premotor cortex, dorsal premotor cortex and parietal operculum, there was less activity during the simultaneous movements than for the sum of the activity for the two isolated movements (interaction analysis). Indeed, in the ventral premotor cortex and parietal operculum, the activity was practically identical regardless whether only the wrist, only the ankle, or both the wrist and the ankle were moved. Taken together, these findings suggest that interlimb coordination is mediated by motor representations shared by both limbs, rather than being mediated by specific additional neural populations.