Corticomuscular coherence: a review.
Corticomuscular coherence measured between electroencephalography (EEG), magnetoencephalography, or local field potentials and electromyography (EMG) should be helpful in understanding the cortical control of movement. EEG-EMG coherence and phase spectra depend on the types of EEG derivation and current source density function of EEG appears to be the most appropriate for computation of EEG-EMG coherence. A new model for the interpretation of the phase spectra ("constant phase shift plus constant time lag model") shows that cortical surface negative potentials are phase-locked to EMG firing. There are functional differences of EEG-EMG coherence among the alpha, beta, and gamma bands suggesting differences in their possible generator mechanisms. Since corticomuscular coherence is a noninvasive measure of corticomotoneuronal function in a specific frequency range, clinical application of this method might be very fruitful in tremor research.
Mima
T
T
Human Motor Control Section, Medical Neurology Branch, National Institutes of Neurological Disorders and Stroke, National Institutes of Health, Bethesda 20892-1428, Maryland, USA.
Hallett
M
M
D004569:Electroencephalography / Q000379:methods*; D004576:Electromyography / Q000379:methods; D006801:Humans; D015225:Magnetoencephalography; D009044:Motor Cortex / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology*; D010300:Parkinson Disease / Q000503:physiopathology*; D011597:Psychomotor Performance; D014202:Tremor / Q000503:physiopathology