Electrophysiological analysis of the perception of passive movement.

The goal of the present study was to determine the electrophysiological correlate of the threshold of perception of passive motion (TPPM) in a group of healthy individuals. We expect a different pattern of activation over the frontoparietal network produced by the conscious perception of the passive movement. Ten right-handed male volunteers, between 20 and 30 years of age, were submitted to the threshold of perception of passive motion (TPPM) task in a proprioception testing device (PTD). The device was designed to passively move the arm in internal and external rotations about the shoulder joint. Participants were instructed to press a hand-held switch every time movement of the shoulder was detected. Electromyographic (EMG) and electroencephalographic (EEG) activities were acquired during the task. Passive movement of the shoulder joint was followed by a clear and prolonged decrease in the signal magnitude of the electroencephalogram. The electrophysiological correlate of the TPPM was characterized by the establishment of a frontoparietal network, during the processing of somatosensory information.