Sensory prediction errors drive cerebellum-dependent adaptation of reaching
Sensory prediction errors drive cerebellum-dependent adaptation of reaching
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DOI：
10.1152/jn.00266.2007
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发表时间：
2007-07-01
影响因子：
2.5
通讯作者：
Bastian, Amy J.
中科院分区：
文献类型：
--
作者：
Tseng, Ya-weng;Diedrichsen, Jorn;Bastian, Amy J.
小脑是神经网络的重要组成部分，参与适应目标导向的手臂运动。这种适应可能依赖于两种不同的信号：感觉预测错误或运动校正。感官预测错误发生时，产生的初始运动命令，但预测的感觉结果不匹配的观察值。在某些任务中，这些感觉错误被监控，并随着运动的进行而导致在线校正运动输出。在这里，我们问是否小脑依赖的适应达到依赖于感觉或在线运动校正。健康对照组和遗传性小脑共济失调患者在两种条件下的视觉干扰中达到：没有在线校正的“射击”运动和允许在线校正的“指向”运动。感官（I）例如，视觉）误差。结果表明，除了运动校正不影响控制对象的适应，这表明只有感官错误需要学习。小脑受试者在这两种适应条件下相对于对照组都有明显的受损，尽管在线运动校正异常且不一致。具体来说，在线运动矫正不良与小脑受试者的适应缺陷无关（即.例如，适应没有恶化），进一步表明只有感官预测错误影响这一过程。因此，对视觉扰动的适应取决于小脑，并由运动命令的预测和实际感觉结果之间的不匹配驱动。
The cerebellum is an essential part of the neural network involved in adapting goal- directed arm movements. This adaptation might rely on two distinct signals: a sensory prediction error or a motor correction. Sensory prediction errors occur when an initial motor command is generated but the predicted sensory consequences do not match the observed values. In some tasks, these sensory errors are monitored and result in on- line corrective motor output as the movement progresses. Here we asked whether cerebellum-dependent adaptation of reaching relies on sensory or on- line motor corrections. Healthy controls and people with hereditary cerebellar ataxia reached during a visuomotor perturbation in two conditions: " shooting" movements without on- line corrections and " pointing" movements that allowed for on- line corrections. Sensory ( i. e., visual) errors were available in both conditions. Results showed that the addition of motor corrections did not influence adaptation in control subjects, suggesting that only sensory errors were needed for learning. Cerebellar subjects were comparably impaired in both adaptation conditions relative to controls, despite abnormal and inconsistent on- line motor correction. Specifically, poor on- line motor corrections were unrelated to cerebellar subjects' adaptation deficit ( i. e., adaptation did not worsen), further suggesting that only sensory prediction errors influence this process. Therefore adaptation to visuomotor perturbations depends on the cerebellum and is driven by the mismatch between predicted and actual sensory outcome of motor commands.