Cerebellar involvement in anticipating the consequences of self-produced actions during bimanual movements
Cerebellar involvement in anticipating the consequences of self-produced actions during bimanual movements
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DOI：
10.1152/jn.00662.2004
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发表时间：
2005-02-01
影响因子：
2.5
通讯作者：
Ivry, RB
中科院分区：
文献类型：
--
作者：
Diedrichsen, J;Verstynen, T;Ivry, RB
当参与者一只手拿着一个物体，然后用另一只手举起它时，可以观察到双手动作期间的预期姿势调整（阿帕）。用于固定物体的姿势力在预期卸载时会减少，这表明对载荷变化的准确预测。我们检查了单侧或双侧小脑损伤的患者，以及两个人缺乏胼胝体的双手卸载任务。无胼胝体的患者表现出完整的阿帕，这表明在双手动作过程中，皮层下整合运动信号进行预期调整。与小脑对于预测和补偿我们行为的后果至关重要的假设相反，我们发现，在这项任务中，小脑患者中学习良好的阿帕基本上完好无损。然而，小脑损伤取消了阿帕的短期适应，患者无法在类似但以前未经训练的情况下获得阿帕。这些结果表明，虽然过度学习的预期调整后保留小脑病变，适应这种反应和收购一种新的协调需要同侧的姿势手小脑。此外，这种结构似乎是必不可少的准确的时间以前学到的行为。小脑损伤的患者表现出不良的时间调整，阿帕开始早于健康参与者。
Anticipatory postural adjustments (APA) during bimanual actions can be observed when participants hold an object in one hand and then lift it with the other hand. The postural force used to hold the object is reduced in anticipation of unloading, indicating an accurate prediction of the change in load. We examined patients with unilateral or bilateral cerebellar damage as well as two individuals lacking the corpus callosum on the bimanual unloading task. The acallosal patients showed an intact APA, suggesting subcortical integration of motor signals for anticipatory adjustments during bimanual actions. Contrary to the hypothesis that the cerebellum is critical for predicting and compensating for the consequences of our actions, we found that the well-learned APA in this task was largely intact in cerebellar patients. However, cerebellar damage abolished short-term adaptation of the APA, and the patients were unable to acquire an APA in a similar but previously untrained situation. These results indicate that while over-learned anticipatory adjustments are preserved after cerebellar lesions, adaptation of this response and the acquisition of a novel coordination requires the cerebellum ipsilateral to the postural hand. Furthermore, this structure appears to be essential for the accurate timing of previously learned behaviors. The patients with cerebellar damage showed poorly timed adjustments with the APA beginning earlier than in healthy participants.