Cortical Rhythmic Activity and Neurophysiology Mechanism during Movement Observation and Motor Imagery

Abstract

Previous studies proved that movement/action observation and motor imagery are benefit for relearning of movement function after stroke and considered as a method for exploring the neurophysiology mechanism. To analyze and compare the features of activated cortical neurons between movement observation and motor imagery, 10 healthy subjects whose EEG signals were recorded during hand grasp movement observation and motor imagery were recruited. Gabor filter was introduced to analyze time-frequency spectrum power for EEG recorded at somatosensory and visual cortex, then time-frequency quantification of ERD/ERS was performed based on Gabor filter. At last, ERD index was built to distinguish between left hand and right hand and compare movement observation with motor imagery quantitatively. The results showed that movement observation also could activate somatosensory cortex, which issimilar to motor imagery,, and contralateral dominant ERD in a and b range was found during motor imagery. In addition, classification accuracy of motor imagery based on ERDI was greater than it of movement observation. Moreover, movement observation was associated with activation of visual cortex where a significant suppression was found. The present study provide neurophysiology basis and realization approach of movement observation and motor imagery for application in clinical rehabilitation and BCI system.