Sobell Department of Motor Neuroscience and Movement Disorders, UCL, London, UK.
Eur J Neurosci. 2018 Jul;48(2):1789-1802. doi: 10.1111/ejn.14050.
A recent theoretical account of motor control proposes that modulation of afferent information plays a role in affecting how readily we can move. Increasing the estimate of uncertainty surrounding the afferent input is a necessary step in being able to move. It has been proposed that an inability to modulate the gain of this sensory information underlies the cardinal symptoms of Parkinson's disease (PD). We aimed to test this theory by modulating the uncertainty of the proprioceptive signal using high-frequency peripheral vibration, to determine the subsequent effect on motor performance. We investigated if this peripheral stimulus might modulate oscillatory activity over the sensorimotor cortex in order to understand the mechanism by which peripheral vibration can change motor performance. We found that 80 Hz peripheral vibration applied to the right wrist of a total of 54 healthy human participants reproducibly improved performance across four separate randomised experiments on a number of motor control tasks (nine-hole peg task, box and block test, reaction time task and finger tapping). Improved performance on all motor tasks (except the amplitude of finger tapping) was also seen for a sample of 18PD patients ON medication. EEG data investigating the effect of vibration on oscillatory activity revealed a significant decrease in beta power (15-30 Hz) over the contralateral sensorimotor cortex at the onset and offset of 80 Hz vibration. This finding is consistent with a novel theoretical account of motor initiation, namely that modulating uncertainty of the proprioceptive afferent signal improves motor performance potentially by gating the incoming sensory signal and allowing for top-down proprioceptive predictions.
最近有理论解释了运动控制，提出传入信息的调制在影响我们运动的容易程度方面发挥了作用。增加传入输入不确定性的估计是能够运动的必要步骤。有人提出，无法调节这种感觉信息的增益是帕金森病（PD）的主要症状的基础。我们旨在通过使用高频外周振动来调节本体感觉信号的不确定性，从而测试该理论，以确定对运动表现的后续影响。我们研究了这种外周刺激是否可以调节感觉运动皮层上的振荡活动，以了解外周振动如何改变运动表现的机制。我们发现，80 Hz 的外周振动施加于总共 54 名健康人类参与者的右腕，在多个运动控制任务（九孔钉任务、箱和块测试、反应时间任务和手指敲击）的四个独立随机实验中可重复地改善了性能。在药物治疗的 18 名 PD 患者样本中，所有运动任务（除了手指敲击的幅度）的表现都得到了改善。调查振动对振荡活动影响的 EEG 数据显示，在 80 Hz 振动的起始和结束时，对侧感觉运动皮层的β功率（15-30 Hz）显着降低。这一发现与运动起始的新理论解释一致，即通过门控传入的感觉信号并允许自上而下的本体感觉预测，调节本体感觉传入信号的不确定性可改善运动表现。
