Bimanual coordination as task-dependent linear control policies
Bimanual coordination as task-dependent linear control policies
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DOI：
10.1016/j.humov.2008.10.003
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发表时间：
2009-06-01
影响因子：
2.1
通讯作者：
Dowling, Noreen
中科院分区：
文献类型：
--
作者：
Diedrichsen, Joern;Dowling, Noreen
当我们在日常生活中用双手执行动作时，协调必须根据任务目标快速变化。在这里，我们研究这些任务相关的变化，使用双手达成的任务，参与者移动两个单独的光标到两个视觉目标，或移动一个光标，显示在两只手的平均位置，到一个单一的目标。在运动过程中，其中一只手被扰动在一个随机的方向使用粘性旋度场。我们之前已经表明，反馈控制，噪声的结构，和适应这两个任务之间的变化预测的最优控制理论：反馈控制是独立的，当手控制两个光标，但变得依赖于当他们一起移动一个光标。即使在没有给出关于光标位置的视觉反馈的试验中也观察到相同的变化。在这个模型中的一个假设是，协调电机命令可以被描述为一个线性函数的状态的左手和右手。在这里，我们测试的假设，通过研究反馈校正的25个力场的组合施加到两只手。我们的研究表明，反馈增益是恒定的，在所有级别的力场强度，提供了强有力的证据表明，这项任务的手间协调可以准确地解释最佳的任务相关的线性反馈增益。(C)2008 Elsevier B.V.保留所有权利。
When we perform actions with two hands in everyday life, coordination has to change very quickly depending on task goals. Here, we study these task-dependent changes using a bimanual reaching task in which participants move two separate cursors to two visual targets, or move a single cursor, displayed at the average position of the two hands, to a single target. During the movement, one of the hands is perturbed in a random direction using a viscous curl field. We have previously shown that feedback control, the structure of noise, and adaptation change between these two tasks as predicted by optimal control theory: feedback control is independent when the hands control two cursors, but becomes dependent when they move one cursor together. The same changes are observed even on trials in which no visual feedback about the cursor position is given. One assumption in this model is that coordinative motor commands can be described as a linear function of the state of the left and right hands. Here we test the assumption by studying the feedback corrections for 25 combinations of force fields applied to the two hands. Our study shows that feedback gains are constant across all levels of force fields strength, providing strong evidence that intermanual coordination for this task can accurately be explained by optimal task-dependent linear feedback gains. (C) 2008 Elsevier B.V. All rights reserved.