Data_Sheet_1_Effects of online and offline trigeminal nerve stimulation on visuomotor learning.xlsx

IntroductionA current thrust in neurology involves using exogenous neuromodulation of cranial nerves (e.g, vagus, trigeminal) to treat the signs and symptoms of various neurological disorders. These techniques also have the potential to augment cognitive and/or sensorimotor functions in healthy individuals. Although much is known about the clinical effects of trigeminal nerve stimulation (TNS), effects on sensorimotor and cognitive functions such as learning have received less attention, despite their potential impact on neurorehabilitation. Here we describe the results of experiments aimed at assessing the effects of TNS on motor learning, which was behaviorally characterized using an upper extremity visuomotor adaptation paradigm.ObjectiveAssessing the effects of TNS on motor learning.MethodsMotor learning was behaviorally characterized using an upper extremity visuomotor adaptation paradigm. In Experiment 1, effects of offline TNS using clinically tested frequencies (120 and 60 Hz) were characterized. Sixty-three healthy young adults received TNS before performing a task that involved reaching with perturbed hand visual feedback. In Experiment 2, the effects of 120 and 60 Hz online TNS were characterized with the same task. Sixty-three new participants received either TNS or sham stimulation concurrently with perturbed visual feedback.ResultsExperiment 1 results showed that 60 Hz stimulation was associated with slower rates of learning than both sham and 120 Hz stimulation, indicating frequency-dependent effects of TNS. Experiment 2 however showed no significant differences among stimulation groups. A post-hoc, cross-study comparison of the 60 Hz offline and online TNS results showed a statistically significant improvement in learning rates with online stimulation relative to offline, pointing to timing-dependent effects of TNS on visuomotor learning.DiscussionThe results indicate that both the frequency and timing of TNS can influence rates of motor learning in healthy adults. This suggests that optimization of one or both parameters could potentially increase learning rates, which would provide new avenues for enhancing performance in healthy individuals and augmenting rehabilitation in patients with sensorimotor dysfunction resulting from stroke or other neurological disorders.

当前神经学领域的研究热点之一涉及利用颅神经（例如，迷走神经、三叉神经）的外源性神经调节来治疗各种神经疾病的症状和体征。这些技术亦有可能增强健康个体的认知和/或感觉运动功能。尽管关于三叉神经刺激（TNS）的临床效应已有所了解，但对学习等感觉运动和认知功能的影响却未受到足够的关注，尽管这些影响在神经康复方面具有潜在的重要性。本研究旨在描述旨在评估TNS对运动学习影响的实验结果，该运动学习通过上肢视觉运动适应范式进行行为表征。研究目标评估TNS对运动学习的影响。研究方法使用上肢视觉运动适应范式对运动学习进行行为表征。在实验1中，通过临床测试的频率（120Hz和60Hz）对离线TNS的影响进行了表征。63名健康年轻人接受TNS刺激后执行涉及扰动手视觉反馈的任务。在实验2中，使用相同的任务对120Hz和60Hz的在线TNS进行了表征。63名新的参与者接受TNS或假刺激，同时伴随扰动视觉反馈。研究结果实验1的结果表明，60Hz的刺激与假刺激和120Hz的刺激相比，学习速率较慢，表明TNS的频率依赖性效应。然而，实验2显示刺激组之间没有显著差异。对60Hz离线和在线TNS结果的回顾性、跨研究的比较显示，与离线刺激相比，在线刺激在提高学习速率方面具有统计学上的显著改善，这表明TNS对视觉运动学习的影响依赖于时间。讨论结果表明，TNS的频率和时间均可影响健康成年人的运动学习速率。这表明优化其中一个或两个参数可能有望提高学习速率，从而为提高健康个体的表现和增强因中风或其他神经系统疾病导致的感觉运动功能障碍患者的康复提供新的途径。