A mirror reflection of a hand modulates stimulus-induced 20-Hz activity.

Mirror therapy is one of the promising rehabilitation therapeutic interventions but the neural basis of the therapeutic effect remains unknown. It has been reported that the 20-Hz rhythmic activity is induced in the primary motor cortex after median nerve stimulation and the amount of the induced activity is decreased when the primary motor cortex is activated. In the present study, to elucidate the neural mechanisms underlying mirror therapy, we investigated whether the mirror reflection of a hand holding a pencil modulates the stimulus-induced 20-Hz activity.