Examination of neural control mechanism behind voluntary contraction of upper and lower limb muscles by using corticomuscular coherence analysis

为了了解我们的大脑如何控制我们的自主运动，我通过测量强直等长自主收缩过程中感觉运动皮层上的脑电图（EEG）信号与对侧肢体肌肉的肌电图（EMG）信号之间的相干性，研究了功能性皮质-肌肉耦合。结果表明：（1）EEG-EMG相干性的大小存在肌肉依赖性;下肢远端肌肉的一致性最大;（2）受过良好训练的运动员（如芭蕾舞者和举重运动员）的EEG-EMG一致性幅度小于未经训练的受试者;（3）不同肌肉之间通过增加收缩水平对EEG-EMG一致性的调制模式不同。

To know how our brain controls our voluntary movements, I have examined the functional corticomuscular coupling by measuring coherence between electroencephalogram (EEG) signals over the sensorimotor cortex and electromyogram (EMG) signals of contralateral limb muscles during tonic isometric voluntary contraction. Obtained results were that : (1) there existed muscle dependency of the magnitude of EEG-EMG coherence ; i.e., the distal lower limb muscles showed largest coherence ; (2) the magnitude of EEG-EMG coherence was smaller in well-trained athletes, such as ballet-dancers and weightlifters, than in untrained subjects ; (3) Modulation patterns of EEG-EMG coherence by increasing contraction levels were different between muscles.