School of Psychology, The University of Adelaide, Adelaide, Australia.
Exp Brain Res. 2010 May;203(1):131-45. doi: 10.1007/s00221-010-2218-2. Epub 2010 Mar 26.
Humans make rapid, goal-directed movements to interact with their environment. Saccadic eye movements usually accompany rapid hand movements, suggesting neural coupling, although it remains unclear what determines the strength of the coupling. Here, we present evidence that humans can alter eye-hand coordination in response to risk associated with endpoint variability. We used a paradigm in which human participants were forced to point rapidly under risk and were penalized or rewarded depending on the hand movement outcome. A separate reward schedule was employed for relative saccadic endpoint position. Participants received a monetary reward proportional to points won. We present a model that defines optimality of eye-hand coordination for this task depending on where the hand lands relative to the eye. A comparison of the results and model predictions showed that participants could optimize performance to maximize gain in some conditions, but not others. Participants produced near-optimal results when no feedback was given about relative saccade location and when negative feedback was provided for large distances between the saccade and hand. Participants were sub-optimal when given negative feedback for saccades very close to the hand endpoint. Our results suggest that eye-hand coordination is flexible when pointing rapidly under risk, but final eye position remains correlated with finger location.
人类会做出快速、有目标导向的动作来与环境互动。扫视眼动通常伴随着快速的手部运动，这表明存在神经耦合，尽管尚不清楚是什么决定了耦合的强度。在这里，我们提供的证据表明，人类可以根据终点变化的风险来改变眼手协调。我们使用了一种范式，其中人类参与者被迫在风险下快速指向，并根据手部运动的结果受到惩罚或奖励。为相对扫视终点位置采用了单独的奖励计划。参与者根据赢得的分数获得相应的金钱奖励。我们提出了一个模型，该模型根据手相对于眼睛的位置定义了这项任务中眼手协调的最优性。将结果与模型预测进行比较表明，参与者可以在某些条件下优化性能以最大化收益，但在其他条件下则不能。当没有关于相对扫视位置的反馈，并且当扫视和手之间的距离较大时提供负反馈时，参与者会产生接近最优的结果。当对手部终点非常接近的扫视提供负反馈时，参与者的表现不佳。我们的结果表明，在快速指向时有风险时，眼手协调具有灵活性，但最终的眼睛位置仍然与手指位置相关。
