Limbs Movement and Motor Imagery: an EEG Study

In this paper, we used EEG recordings to investigate event-related desynchronization (ERD) and event-related synchronization (ERS) in 30 subjects, in order to differentiate between motor execution and motor imagery for hands and feet movement and imagination, respectively. ERD and ERS measurements were calculated by ERSP with the gain model. We analyzed Theta, Alpha and Beta bands in pre-motor, motor and sensorimotor regions. In the experimental procedure, for hand movement and imagination it was possible to identify an Alfa desynchronization during motor execution and a Beta synchronization during motor imagery. However, for feet movement, no significant ERD was observed whatsoever in any bands. On the other hand, during motor imagery of the feet, a synchronization occurred in Alfa band at centro-parietal channels (sensorimotor region) contralateral to the imagined foot movement. We believe these findings could be considered when designing a Brain Computer Interface (BCI) systems based on the motor imagery paradigm.