Division of Physical Therapy and Rehabilitation Science, Department of Family Medicine and Community Health, University of Minnesota, Minneapolis, MN, USA.
Department of Neurology, Pennsylvania State University College of Medicine, Hershey, PA, USA.
Exp Brain Res. 2024 Oct;242(10):2329-2340. doi: 10.1007/s00221-024-06901-z. Epub 2024 Aug 7.
Proprioception plays an important role in both feedforward and feedback processes underlying movement control. This has been shown with individuals who suffered a profound proprioceptive loss and use vision to partially compensate for the sensory loss. The purpose of this study was to specifically examine the role of proprioception in feedback motor responses to visual perturbations by examining voluntary arm movements in an individual with a rare case of selective peripheral deafferentation (GL). We compared her left and right hand movements with those of age-matched female control participants (70.0 years ± 0.2 SEM) during a reaching task. Participants were asked to move their unseen hand, represented by a cursor on the screen, quickly and accurately to reach a visual target. A visual perturbation could be pseudorandomly applied, at movement onset, to either the target position (target jump) or the cursor position (cursor jump). Results showed that despite the continuous visual feedback that was provided, GL produced larger errors in final position accuracy compared to control participants, with her left nondominant hand being more erroneous after a cursor jump. We also found that the proprioceptively-deafferented individual produced less spatially efficient movements than the control group. Overall, these results provide evidence of a heavier reliance on proprioceptive feedback for movements of the nondominant hand relative to the dominant hand, supporting the view of a lateralization of the feedback processes underlying motor control.
本体感觉在运动控制的前馈和反馈过程中都起着重要作用。这在那些本体感觉严重丧失并使用视觉来部分补偿感觉丧失的个体中得到了证明。本研究的目的是通过检查个体在视觉干扰下的自愿手臂运动，专门研究本体感觉在反馈运动反应中的作用，该个体患有罕见的选择性周围感觉丧失（GL）。我们将她的左手和右手运动与年龄匹配的女性对照组参与者（70.0 岁±0.2 SEM）在伸手任务中进行了比较。参与者被要求快速准确地移动看不见的手，该手由屏幕上的光标表示，以到达视觉目标。可以在运动开始时随机施加视觉干扰，要么是目标位置（目标跳跃），要么是光标位置（光标跳跃）。结果表明，尽管提供了连续的视觉反馈，但 GL 在最终位置准确性方面产生的误差明显大于对照组参与者，并且在光标跳跃后，她的左手（非优势手）更易出错。我们还发现，本体感觉丧失的个体比对照组产生的运动空间效率更低。总体而言，这些结果提供了证据表明，相对于优势手，非优势手对本体感觉反馈的依赖更重，这支持了运动控制反馈过程的偏侧化观点。
