[Effect of real and illusory movements on the human vestibulomotor reaction]

Lateral stabilographic responses to galvanic labyrinth stimulation were studied in healthy subjects in the standing posture. The responses increased during the body tilt forward performed either voluntarily or involuntarily as a result of vibration of the tibialis anterior muscles. The illusory body tilt forward induced by the vibration of the triceps surae muscles under mechanical fixation of the trunk resulted in similar increase of the vestibulomotor response. It is concluded that the enhancement of the vestibulomotor responses during voluntary movements is mediated by the spatial perception system.