Abstract：
How cortical oscillations are involved in the coordination of functionally coupled muscles and how this is modulated by different movement contexts (static vs dynamic) remains unclear. Here, this is investigated by recording high-density electroencephalography (EEG) and electromyography (EMG) from different forearm muscles while healthy participants (n = 20) performed movement tasks (static and dynamic posture holding, and reaching) with their dominant hand. When dynamic perturbation was applied, beta band (15-35 Hz) activities in the motor cortex contralateral to the performing hand reduced during the holding phase, comparative to when there was no perturbation. During static posture holding, transient periods of increased cortical beta oscillations (beta bursts) were associated with greater corticomuscular coherence and increased phase synchrony between muscles (intermuscular coherence) in the beta frequency band compared to the no-burst period. This effect was not present when resisting dynamic perturbation. The results suggest that cortical beta bursts assist synchronisation of different muscles during static posture holding in healthy motor control, contributing to the maintenance and stabilisation of functional muscle groups. Theoretically, increased cortical beta oscillations could lead to exaggerated synchronisation in different muscles making the initialisation of movements more difficult, as observed in Parkinson\'s disease.
摘要：
皮质振荡如何参与功能耦合肌肉的协调以及如何通过不同的运动环境（静态与动态）来调节，目前尚不清楚。这里,通过记录不同前臂肌肉的高密度脑电图（EEG）和肌电图（EMG），而健康参与者（n=20）执行运动任务（静态和动态姿势保持，用他们的优势手伸手）。当应用动态扰动时，β带（15-35Hz）活动在对侧的运动皮质表演手减少在保持阶段，与没有扰动的时候相比。在静态姿势保持期间，与无爆发期相比，皮质β振荡（β爆发）增加的瞬时周期与β频带中更大的皮质肌肉相干性和肌肉之间的相位同步性（肌间相干性）增加相关。抵抗动态扰动时不存在这种影响。结果表明，在健康的运动控制中，在静态姿势保持过程中，皮质β爆发有助于不同肌肉的同步。有助于功能性肌肉群的维持和稳定。理论上,增加的皮质β振荡可能导致不同肌肉的过度同步，使运动的初始化更加困难，正如在帕金森病中观察到的那样。
