Alvarez-Hidalgo Laura, Franklin David W, Howard Ian S
School of Computing, Engineering and Mathematics, University of Plymouth, Plymouth, United Kingdom.
Neuromuscular Diagnostics, TUM School of Medicine and Health, Technical University of Munich, Munich, Germany.
J Neurophysiol. 2025 May 1;133(5):1520-1537. doi: 10.1152/jn.00501.2024. Epub 2025 Apr 18.
Contextual cues arising from distinct movements are crucial in shaping control strategies for human movement. Here, we examine the impact of visual and passive lead-in movement cues on unimanual motor learning, focusing on the influence of "dwell time," where two-part movements are separated by the interval between the end of the first movement and the start of the second. We used a robotic manipulandum to implement a point-to-point interference task with switching opposing viscous curl fields in male and female human participants. Consistent with prior research, in both visual and passive lead-in conditions, participants showed significant adaptation to opposing dynamics with short dwell times. As dwell time increased for both visual and passive signals, past movement information had less contextual influence. However, the efficacy of visual movement cues declined more rapidly as dwell times increased. At dwell times greater than 800 ms, the contextual influence of prior visual movement was small, whereas the effectiveness of passive lead-in movement was found to be significantly greater. This indicates that the effectiveness of sensory movement cues in motor learning is modality dependent. We hypothesize that such differences may arise because proprioceptive signals directly relate to arm movements, whereas visual inputs exhibit longer latency and, in addition, can relate to many aspects of movement in the environment and not just to our own arm movements. Therefore, the motor system may not always find visual movement cues as relevant for predictive control of dynamics. This research uncovers, for the first time, how visual and proprioceptive sensory cues affect motor learning as a function of the pause or "dwell time" in two-part movements. The study has shown that visual lead-in movement cues lose their effectiveness sooner than passive lead-in movement cues as dwell time increases. By revealing the modality-dependent nature of sensory information, this study enhances our understanding of motor control and opens new possibilities for improving therapeutic interventions.
由不同运动产生的情境线索对于塑造人类运动的控制策略至关重要。在此，我们研究视觉和被动导入运动线索对单手运动学习的影响，重点关注“停留时间”的影响，即两部分运动由第一个运动结束与第二个运动开始之间的间隔分开。我们使用机器人操作器对男性和女性人类参与者实施了一个点对点干扰任务，其中切换相反的粘性卷曲场。与先前的研究一致，在视觉和被动导入条件下，参与者在短停留时间内都表现出对相反动力学的显著适应。随着视觉和被动信号的停留时间增加，过去的运动信息具有的情境影响变小。然而，随着停留时间增加，视觉运动线索的效果下降得更快。在停留时间大于800毫秒时，先前视觉运动的情境影响很小，而发现被动导入运动的效果显著更大。这表明感觉运动线索在运动学习中的有效性取决于模态。我们假设这种差异可能是因为本体感觉信号直接与手臂运动相关，而视觉输入具有更长的潜伏期，此外，视觉输入还可以与环境中运动的许多方面相关，而不仅仅与我们自己的手臂运动相关。因此，运动系统可能并不总是认为视觉运动线索与动力学的预测控制相关。这项研究首次揭示了视觉和本体感觉线索如何作为两部分运动中的停顿或“停留时间”的函数影响运动学习。研究表明，随着停留时间增加，视觉导入运动线索比被动导入运动线索更快失去其有效性。通过揭示感觉信息的模态依赖性本质，本研究增进了我们对运动控制的理解，并为改进治疗干预开辟了新的可能性。
