MU-RHYTHM CHANGES IN BRISK AND SLOW SELF-PACED FINGER MOVEMENTS

WE analysed whether type of movement (brisk vs slow) and active muscle force are encoded in the time course of mu-rhythm desynchronization d uring self-paced finger movements. Ten subjects performed 100 brisk an d slow extensions of the right index finger. The time course of mu-rhy thm desynchronization in the contralateral sensorimotor area before mo vement was identical for both types of movements. Brisk movements acco mpanied by a stronger extensor muscle contraction were preceded by lar ger desynchronization. The onset of mu-rhythm recovery was related to the duration of the extensor EMG burst in both types of movement. The results suggest that both amplitude and duration of the extensor muscl e contraction are encoded in the time course of mu-rhythm desynchroniz ation.