Visual Motion Information Influences the Perceived Position of Touch

This study investigated the influence of visual motion information on perceived tactile position. In Experiment 1, tactile stimuli were presented on participants’ left and right index fingers together with visual motion stimuli projected onto a semi-silvered mirror, which allowed participants to view their hands. Participants were asked to discriminate the positional relationships of tactile stimuli. Discrimination performance differed depending on the relationship between the positions of the tactile stimuli and direction of the visual stimuli. In Experiment 2, a normal mirror was used which eliminated the view of the hands and the effects observed in Experiment 1 disappeared. These results suggest that the perceived spatial position of touch is displaced in the direction of visual motion, but this effect is dependent on vision of the stimulated body part.