Somesthetic messages from muscle and skin receptors contribute together to the perception of one’s body movement. Here we investigated whether cerebral networks are involved in the integrative processing of these two sensory inputs for movement perception. For this, we designed an amagnetic device able to generate (clockwise) hand movement illusions from separate or combined tactile and muscle proprioceptive stimulations. Stimulations were delivered through a vibrator applied to the subjects’ wrist adductors and a rotary disk set under the palm of their hand.
Results show that, whether induced by a tactile or a proprioceptive stimulation, the kinesthetic illusion was accompanied by the activation of a very similar cerebral network including cortical and subcortical sensori-motor areas classically found in passive or imagined movement tasks. Moreover, as expected, the strongest kinesthetic illusions occurred under the combined stimulation condition. They were specifically associated to brain area activations in the inferior parietal lobule, the superior temporal sulcus, the insula-claustrum region, and the cerebellum.
These findings support the hypothesis that heteromodal areas may subserve multisensory integrative mechanisms and suggest that the detection of the spatial coherence and of the temporal coincidence between these two kinesthetic messages might involve different cortical and subcortical brain zones.