Department of Precision Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
Faculty of Information Science and Electrical Engineering, Kyushu University, Fukuoka, Japan.
Sci Rep. 2021 Jan 28;11(1):2553. doi: 10.1038/s41598-021-82154-y.
The sense of agency refers to the feeling of control over one's own actions, and through them, the external events. This study examined the effect of modified visual feedback on the sense of agency over one's body movements using virtual reality in healthy individuals whose motor control was disturbed. Participants moved a virtual object using their right hand to trace a trajectory (Experiment 1) or a leading target (Experiment 2). Their motor control was disturbed by a delay in visual feedback (Experiment 1) or a 1-kg weight attached to their wrist (Experiment 2). In the offset conditions, the virtual object was presented at the median point between the desired position and the participants' actual hand position. In both experiments, participants reported improved sense of agency in the offset condition compared to the aligned condition where the visual feedback reflected their actual body movements, despite their motion being less precise in the offset condition. The results show that sense of agency can be enhanced by modifying feedback to motor tasks according to the goal of the task, even when visual feedback is discrepant from the actual body movements. The present study sheds light on the possibility of artificially enhancing body agency to improve voluntary motor control.
主体感是指对自身行为以及通过行为对外在事件的控制感。本研究使用虚拟现实技术，在运动控制受到干扰的健康个体中，考察了对身体运动的视觉反馈进行修正对主体感的影响。参与者使用右手移动虚拟物体，以追踪轨迹（实验 1）或引导目标（实验 2）。他们的运动控制受到视觉反馈延迟（实验 1）或手腕上附加 1 公斤重物（实验 2）的干扰。在偏移条件下，虚拟物体出现在期望位置和参与者实际手部位置的中点。在两个实验中，与视觉反馈反映实际身体运动的对齐条件相比，参与者在偏移条件下报告主体感增强，尽管在偏移条件下运动精度较低。结果表明，即使视觉反馈与实际身体运动不符，根据任务目标对运动任务的反馈进行修正也可以增强主体感。本研究揭示了通过人工增强身体主体感来改善自愿运动控制的可能性。
