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随意运动，我通过测量紧张性等长自愿收缩时感觉运动皮质上的脑电(EEG)信号和对侧肢体肌肉的肌电(EMG)信号之间的连贯性，研究了皮质肌肉的功能性耦合。结果表明：(1)EEG-EMG相干性的大小存在肌肉依赖性，即小腿远端肌肉的相干性最大；(2)训练有素的运动员，如芭蕾舞、举重运动员的EEG-EMG相干性较小；(3)不同肌肉间EEG-EMG相干性的调制模式不同。

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.