Lohse Keith R, Jones Matt, Healy Alice F, Sherwood David E
Department of Psychology and Neuroscience, University of Colorado.
Department of Integrative Physiology, University of Colorado.
J Exp Psychol Gen. 2014 Apr;143(2):930-48. doi: 10.1037/a0032817. Epub 2013 May 6.
Research on the focus of attention (FOA) in motor control has found a consistent advantage for focusing externally (on the effects of one's actions) compared to focusing internally (on one's body mechanics). However, most of this work has concentrated on movement outcomes, leaving open the question of how external attention changes the movement itself. Somewhat paradoxically, recent research has found that external attention also increases trial-by-trial movement variability. To explain these findings, we propose a theory of attention in motor control, grounded in optimal control theory, wherein variability is minimized along attended aspects of the movement. Internal attention thus reduces variability in individual bodily dimensions (positions and velocities of effectors), whereas external attention minimizes variability in the task outcome. Because the goal of a task defines a dimension in the movement space that is generally oblique to bodily dimensions, external attention should increase correlations among bodily dimensions while allowing their individual variances to grow. The current experiment tests these predictions in a dart-throwing task. External FOA led to more accurate performance and increased variability in the motion of the throwing arm, concomitant with stronger correlations among bodily dimensions (shoulder, elbow, and wrist positions and velocities) in a manner consistent with the task kinematics. These findings indicate a shift in the control policy of the motor system, consistent with the proposed theory. These results suggest an important role of attention as a control parameter in the regulation of the motor system, and more broadly illustrate the importance of cognitive mechanisms in motor behavior.
对运动控制中注意力焦点（FOA）的研究发现，与内部聚焦（关注自身身体力学）相比，外部聚焦（关注自身动作的效果）始终具有优势。然而，这项工作大多集中在运动结果上，外部注意力如何改变运动本身这一问题仍未得到解答。有点矛盾的是，最近的研究发现外部注意力也会增加逐次试验的运动变异性。为了解释这些发现，我们提出了一种基于最优控制理论的运动控制注意力理论，其中变异性在运动的被关注方面被最小化。因此，内部注意力减少了个体身体维度（效应器的位置和速度）的变异性，而外部注意力则使任务结果的变异性最小化。由于任务目标定义了运动空间中一个通常与身体维度倾斜的维度，外部注意力应该会增加身体维度之间的相关性，同时允许它们的个体方差增加。当前的实验在飞镖投掷任务中测试了这些预测。外部注意力焦点导致了更准确的表现，并增加了投掷手臂运动的变异性，同时伴随着身体维度（肩部、肘部和腕部的位置和速度）之间更强的相关性，其方式与任务运动学一致。这些发现表明运动系统控制策略的转变，与所提出的理论一致。这些结果表明注意力作为运动系统调节中的一个控制参数具有重要作用，并且更广泛地说明了认知机制在运动行为中的重要性。
