Independent on-line control of the two hands during bimanual reaching
Independent on-line control of the two hands during bimanual reaching
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DOI：
10.1111/j.1460-9568.2004.03242.x
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发表时间：
2004-03-01
影响因子：
3.4
通讯作者：
Ivry, RB
中科院分区：
文献类型：
--
作者：
Diedrichsen, J;Nambisan, R;Ivry, RB
许多关于双手协调的研究表明，人们更倾向于镜像对称的运动。我们证明，当对视觉目标进行双手到达运动时，这种约束是不存在的。我们调查了当一个或两个目标在运动的初始阶段被移位时，人类在这种运动中进行在线调整的能力。在双手操作中，调整与单手操作一样有效，即使当一个目标在双手状态下移位时，必须同时进行两次调整时，到达该目标的手也能有效地调整到移位。然而，在另一只手的轨迹中也观察到了一个小的瞬时扰动。这种摄动方向与位移方向相同，而不是镜像对称方向。一项对照实验表明，这些干扰可以仅由视觉信息引起，但它们也受到另一只手的轨迹是否需要调整的影响。我们的结果表明，在视觉引导的伸展过程中，两只手臂几乎是独立控制的。观察到的手臂之间的微妙干扰反映了视觉坐标中与目标相关的表征之间的相互作用，而不是关节或肌肉坐标中与运动相关的表征之间的相互作用。
Many studies on bimanual coordination have shown that people exhibit a preference for mirror-symmetric movements. We demonstrate that this constraint is absent when bimanual reaching movements are made to visual targets. We investigated the ability of humans to make on-line adjustments during such movements when one or both targets were displaced during the initial phase of the movements. Adjustments were as efficient during bimanual as unimanual movements, even when two adjustments had to be made simultaneously When one target was displaced in the bimanual condition, the hand reaching to that target adjusted efficiently to the displacement. However, a small transient perturbation in the trajectory of the other hand was also observed. This perturbation was in the same direction as the displacement, rather than in mirror-symmetric direction. A control experiment demonstrated that these perturbations could be elicited by visual information alone, but that they were also influenced by whether an adjustment was required in the trajectory of the other hand. Our results demonstrate near independent control of the two arms during visually guided reaching. The subtle interference observed between the arms reflects interactions between target-related representations in visual coordinates rather than between movement-related representations in joint- or muscle-coordinates.