Neuromagnetic beta oscillation changes during motor imagery and motor execution of skilled movements.

We showed the differences in brain activities during motor imagery and motor execution when performing single skilled movements using magnetoencephalography. The tasks included finger tapping and chopstick usage with the dominant or nondominant hand. Chopstick usage with the nondominant hand was an unfamiliar task and required higher skill. Neuromagnetic data were processed by fast Fourier transformation, and β band event-related synchronization was evaluated. Beta oscillation changes were observed in the right and left sensorimotor cortices during both tasks; however, the ipsilateral changes were smaller during motor imagery than during motor execution. These results suggest that motor imagery of skilled movement tasks causes a smaller neuronal burden in the sensorimotor cortex.