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Updated: Jul 6, 2026
12:33
Corticospinal Excitability Modulation During Action Observation
Published on: December 31, 2013
Task-and phase-related changes in cortico-muscular coherence.
Yoshihisa Masakado1, Jens Bo Nielsen
1Keio University Tsukigase Rehabilitation Center, Shizuoka, Japan. masakado@sc.itc.keio.ac.jp
The Keio Journal of Medicine
|April 3, 2008
Summary
Cortico-muscular coherence in the 15-35 Hz band is task-dependent. This neural signal, measured via EEG and EMG, decreased during muscle contraction changes but reappeared during steady holds, especially during quasi-isotonic tasks.
Area of Science:
- Neuroscience
- Motor Control
- Human Physiology
Background:
- Cortico-muscular coherence (CMC) reflects the functional connectivity between the motor cortex and muscles.
- Understanding CMC dynamics during different contraction types is crucial for motor control research.
Purpose of the Study:
- To compare CMC in the 15-35 Hz band during ramp-and-hold isometric and quasi-isotonic ankle dorsiflexion.
- To investigate the phase- and task-related properties of CMC.
Main Methods:
- Electroencephalography (EEG) from the motor cortex and electromyography (EMG) from the tibialis anterior (TA) muscle were recorded.
- Subjects performed ramp-and-hold isometric and quasi-isotonic contractions of the ankle joint.
Main Results:
- CMC in the 15-35 Hz band was present during low-level tonic dorsiflexion.
- CMC disappeared during the ramp phase of both contraction types but reappeared during the hold phase.
- Higher CMC was observed during quasi-isotonic contractions compared to isometric contractions.
Conclusions:
- CMC in the 15-35 Hz band is phase- and task-dependent.
- The decrease during ramp phases may relate to event-related desynchronization.
- Increased CMC during quasi-isotonic tasks suggests higher demands for precise joint control and neural binding.
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