Laboratory of Sports Sciences, Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan.
Research Fellow of Japan Society for the Promotion of Science, Tokyo, Japan.
Sci Rep. 2021 Mar 25;11(1):6899. doi: 10.1038/s41598-021-86325-9.
Humans are often required to plan/execute movements in the presence of multiple motor targets simultaneously. Under such situations, it is widely confirmed that humans frequently initiate movements towards the weighted average direction of distinct motor plans toward each potential target. However, in situations where the potential targets change in a step-by-step manner, the strategy to proceed towards the weighted average direction at each time could be sub-optimal in light of the costs of the corrective response. Herein, we tested the sensorimotor strategy followed during a step-by-step reduction of potential goals. To test the hypothesis, we compared the corrective responses when the number of targets went from three to two, and when the number of targets went from three to one at the same time. As the results, weak corrections were confirmed when the number of targets was reduced from three to two. Moreover, the corrective responses when the number of targets went from three to two was smaller than the average behavior estimated from the corrective responses when the number of targets went from three to one at the same time. This pattern of corrective responses reflects the suppression of unnecessary corrections that generate noise and cost to the control system. These results suggest that the corrective responses are flexibly modulated depending on the necessity, and cannot be explained by weighted average behavior.
人类经常需要在同时存在多个运动目标的情况下规划/执行运动。在这种情况下，广泛证实人类经常朝着每个潜在目标的不同运动计划的加权平均方向发起运动。然而，在潜在目标逐步变化的情况下，考虑到校正响应的成本，每次朝着加权平均方向前进的策略可能不是最优的。在这里，我们测试了在潜在目标逐步减少的情况下所遵循的感觉运动策略。为了验证假设，我们比较了当目标数量从三个减少到两个，以及当目标数量同时从三个减少到一个时的校正响应。结果，当目标数量从三个减少到两个时，确认了较弱的校正响应。此外，当目标数量从三个减少到两个时的校正响应小于同时从三个减少到一个时从校正响应估计的平均行为。这种校正响应模式反映了对控制系统产生噪声和成本的不必要校正的抑制。这些结果表明，校正响应根据必要性灵活调节，不能用加权平均行为来解释。
