Lien Yun R, Lin Yi-Cheng, Lin Shang-Hua N, Lin Ching-Po, Chang Li-Hung
Institute of Neuroscience, National Yang Ming Chiao Tung University, Taipei, Taiwan.
Taipei Municipal Gan-Dau Hospital, Taipei, Taiwan.
Front Neurosci. 2022 Mar 18;16:804027. doi: 10.3389/fnins.2022.804027. eCollection 2022.
The cerebellum plays a critical role in acquiring visuomotor skills. Visuomotor task mastery requires improving both visuomotor accuracy and stability; however, the cerebellum's contribution to these processes remains unclear. We hypothesized that repetitive transcranial magnetic stimulation (rTMS) of the cerebellum exerts frequency-dependent modulatory effects on both accuracy and stability in subjects performing a visuomotor coordination task (i.e., pursuit rotor task). We recruited 43 healthy volunteers and randomly assigned them to the high-frequency (HF), low-frequency (LF), and sham rTMS groups. We calculated changes in performance of the pursuit rotor task at the highest rotation speed and the minimum distance from target as indices of accuracy. We also calculated the intertrial variability (standard deviations) of time on target and distance from target as indices of stability. Visuomotor accuracy was significantly enhanced in the HF group and disrupted in the LF group compared to the sham group, indicating frequency-dependent effects of rTMS. In contrast, both HF and LF rTMS demonstrated no significant change in visuomotor stability. Surprisingly, our findings demonstrated that the accuracy and stability of visuomotor performance may be differentially influenced by cerebellar rTMS. This suggests that visuomotor accuracy and stability have different underlying neural mechanisms and revealed the possibility of training strategies based on cerebellar neuromodulation.
小脑在获得视觉运动技能方面起着关键作用。掌握视觉运动任务需要提高视觉运动的准确性和稳定性；然而，小脑对这些过程的贡献仍不清楚。我们假设，对小脑进行重复经颅磁刺激（rTMS）会对执行视觉运动协调任务（即追踪旋转任务）的受试者的准确性和稳定性产生频率依赖性调节作用。我们招募了43名健康志愿者，并将他们随机分为高频（HF）、低频（LF）和假rTMS组。我们将追踪旋转任务在最高转速和距目标最小距离时的表现变化计算为准确性指标。我们还将目标停留时间和距目标距离的试验间变异性（标准差）计算为稳定性指标。与假刺激组相比，高频组的视觉运动准确性显著提高，低频组则受到干扰，表明rTMS具有频率依赖性效应。相比之下，高频和低频rTMS在视觉运动稳定性方面均未显示出显著变化。令人惊讶的是，我们的研究结果表明，小脑rTMS可能会对视觉运动表现的准确性和稳定性产生不同的影响。这表明视觉运动准确性和稳定性具有不同的潜在神经机制，并揭示了基于小脑神经调节的训练策略的可能性。
