Abstract: A frame (1) with driving members (9-11) for translating and/or rotating an assembly (4) movably mounted in said frame along one of the three planes defining the space. A unit for mechanically controlling said driving members is arranged to enable the stationary patient on the movable assembly (4) to be exposed to a moving elementary stimulation having monotonic space-time characteristics with a speed- and/or acceleration-adjustable profile, by translation and/or rotation thereof along at least one of said three planes of the space. The device further includes a processing unit for digitising waves sensed by at least some of the electrodes of an electrophysiological helmet on the patient's skull, and for finding therein evoked potentials that match the profile of the elementary stimulation. Real-time data on the functioning of at least one part of the vestibular system may thus be obtained.