Role of the cerebellum in movements: control of timing or movement transitions?
Role of the cerebellum in movements: control of timing or movement transitions?
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DOI：
10.1007/s00221-004-2088-6
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发表时间：
2005-03
影响因子：
2
通讯作者：
R. Spencer;R. Ivry;H. Zelaznik
中科院分区：
文献类型：
--
作者：
R. Spencer;R. Ivry;H. Zelaznik
小脑损伤患者的一系列定时任务都会受到影响。然而，最近的研究表明，对时间生产任务的损害仅限于不连续的运动。本实验旨在比较这些患者在产生不连续运动时观察到的时间变异性增加的两种解释。首先，对不连续运动的损害可能是与运动开始和偏移之间的转换相关的要求的结果，这是不连续运动生产所特有的要求。其次，损伤可能反映了以定时、不连续的运动来表示时间目标的要求。患有单侧或双侧小脑病变的患者和匹配的对照受试者执行了按键任务。在一种情况下，参与者按下并立即释放该键。其他条件要求参与者按下按键，并在 550 毫秒或 950 毫秒延迟后释放按键。小脑损伤的个体在两种时间条件下均受到损害。这些结果不支持转变假设。相反，它们与小脑对于需要精确的类似事件时间控制的任务至关重要的假设是一致的。
Patients with cerebellar damage are impaired on a range of timed tasks. However, recent research has indicated that the impairment on temporal production tasks is limited to discontinuous movements. The present experiments were designed to compare two accounts for the increased temporal variability observed in these patients when producing discontinuous movements. First, the impairment on discontinuous movements may be the result of the requirements associated with transitioning between movement onsets and offsets, requirements unique to discontinuous movement production. Second, the impairment may reflect a requirement to represent the temporal goal in timed, discontinuous movements. Patients with unilateral or bilateral cerebellar lesions and matched control subjects performed a key-pressing task. In one condition, the participants pressed and immediately released the key. The other conditions required the participants to press the key, and after either a 550-ms or 950-ms delay, release the key. Individuals with cerebellar damage were impaired on the two timed conditions. These results do not support the transition hypothesis. Rather, they are consistent with the hypothesis that the cerebellum is essential for tasks requiring precise event-like temporal control.