Activity in the supplementary motor area related to learning and performance during a sequential visuomotor task
Activity in the supplementary motor area related to learning and performance during a sequential visuomotor task
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DOI：
10.1152/jn.00638.2002
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发表时间：
2003-02-01
影响因子：
2.5
通讯作者：
Quessy, S
中科院分区：
文献类型：
--
作者：
Lee, D;Quessy, S
在一个系列反应时间任务中训练猴子根据视觉目标的变化位置产生手部运动。在大多数试验中，目标重复遵循相同的序列，而在其他试验中，目标出现在随机位置或在两个替代序列之间不可预测地切换。记录尾侧辅助运动区（SMA-proper）的单个单位活动。基于与随机运动序列相关的活动，评估手的位置和运动方向的影响。60%的神经元的活动受手的位置的影响，51%的神经元的活动受手的运动方向的影响。此外，37%和71%的SMA神经元分别在给定试验和跨试验的连续运动中表现出非平稳性。这种非平稳性正在进行的神经活动和性能相关变量的影响进行了评估，使用回归模型和学习相关的活动变化分开。大约三分之一的SMA神经元显示出与试验中运动序列相关的神经活动的逐渐变化。此外，大约四分之一的SMA神经元在个体试验中表现出类似的变化。当频繁重复的运动序列中包含的个体运动意外引入时，神经活动中与学习相关的变化减少，这表明许多SMA神经元改变了与学习特定运动序列相关的活动。这些结果表明，参与运动序列控制的皮层网络中的神经活动模式可以通过经验不断修改。
Monkeys were trained in a serial reaction time task to produce hand movements according to changing locations of visual targets. In most trials, targets followed the same sequence repeatedly, whereas in other trials targets were presented in random locations or switched unpredictably between two alternative sequences. Single-unit activity was recorded from the caudal supplementary motor area (SMA-proper). Based on the activity associated with random movement sequences, effects of hand position and movement direction were evaluated. Activity was influenced by the hand position in similar to60% of the neurons, and the movement direction influenced the activity of 51% of the neurons. In addition, 37 and 71% of SMA neurons displayed nonstationarity in their activity across successive movements within a given trial and across trials, respectively. Such nonstationarity in the ongoing neural activity and the effects of performance-related variables were evaluated using a regression model and separated from learning-related activity changes. About a third of SMA neurons displayed gradual changes in neural activity related to experience with a movement sequence across trials. Furthermore, about a quarter of SMA neurons showed similar changes within individual trials. When the individual movements included in the frequently repeated movement sequences were introduced unexpectedly, learning-related changes in neural activity were reduced, indicating that many SMA neurons changed their activity in relation to the learning of particular movement sequences. These results suggest that the pattern of neural activity in the cortical network involved in the control of movement sequences can be modified continuously by experience.