Cortico-muscular coherence of time–frequency and spatial characteristics under movement observation, movement execution, and movement imagery

Studies show that movement observation (MO), movement imagery (MI), or movement execution (ME) based brain–computer interface systems are promising in promoting the rehabilitation and reorganization of damaged motor function. This study was aimed to explore and compare the motor function rehabilitation mechanism among MO, MI, and ME. 64-channel electroencephalogram and 4-channel electromyogram data were collected from 39 healthy participants (25 males, 14 females; 18–23 years old) during MO, ME, and MI. We analyzed and compared the inter-cortical, inter-muscular, cortico-muscular, and spatial coherence under MO, ME, and MI. Under MO, ME, and MI, cortico-muscular coherence was strongest at the beta-lh band, which means the beta frequency band for cortical signals and the lh frequency band for muscular signals. 56.25–96.88% of the coherence coefficients were significantly larger than 0.5 ( ps