Loss of proprioception has been shown to produce deficits in intralimb coordination and in the ability to stabilize limb posture in the absence of visual feedback. However, the role of proprioceptive signals in the feedforward and feedback control of interlimb coordination remains unclear. To address this issue, we examined bimanual coordination in a deafferented participant (DP) with large-fiber sensory neuropathy, which resulted in the loss of proprioception and touch in both arms, and in age-matched control participants. The task required participants to move a single virtual bar with both hands to a rectangular target with horizontal orientation. The participants received visual feedback of the virtual bar, but not of the hand positions along the bar-axis. Although the task required symmetrical movement between the arms, there were significant differences in the trajectories of the dominant and non-dominant hands in the deafferented participant, and thus more final errors and impaired coordination compared to controls. Deafferentation was also associated with an asymmetric deficit in stabilizing the hand at the end of motion, where the dominant arm showed more drift than the non-dominant arm. While the findings with DP may reflect a unique adaptation to deafferentation, they suggest that 1) Bilateral coordination depends on proprioceptive feedback, and 2) Postural stability at the end of motion can be specified through feedforward mechanisms, in the absence of proprioceptive feedback, but this process appears to be asymmetric, with better stability in the non-dominant arm.

本体感觉的丧失已被证明会导致肢体内协调和在没有视觉反馈的情况下稳定肢体姿势的能力缺陷。然而，本体感觉信号在肢体间协调的前馈和反馈控制中的作用仍不清楚。为了解决这个问题，我们检查了患有大纤维感觉神经病变的传入神经聋参与者（DP）的双手协调性，该病导致双臂本体感觉和触觉丧失，以及年龄匹配的对照参与者。该任务要求参与者用双手将单个虚拟条移动到水平方向的矩形目标。参与者收到了虚拟杆的视觉反馈，但没有收到沿着杆轴的手部位置的视觉反馈。尽管这项任务需要手臂之间的对称运动，但传入神经聋的参与者的优势手和非优势手的轨迹存在显着差异，因此与对照组相比，最终错误更多，协调性受损。传入神经阻滞还与运动结束时手部稳定性的不对称缺陷有关，其中优势臂比非优势臂表现出更多的漂移。虽然 DP 的研究结果可能反映了对传入神经阻滞的独特适应，但他们表明：1）双边协调取决于本体感觉反馈，2）在没有本体感觉反馈的情况下，运动结束时的姿势稳定性可以通过前馈机制指定，但是这个过程似乎是不对称的，非优势臂具有更好的稳定性。