Visual pursuit biases tactile velocity perception

During a smooth pursuit eye movement of a target stimulus, a briefly flashed stationary background appears to move in the opposite direction as the eye's motion ― an effect known as the Filehne illusion. Similar illusions occur in audition, in the vestibular system, and in touch. Recently, we found that the movement of a surface perceived from tactile slip was biased if this surface was sensed with the hand. This suggests a common process of motion perception between the eye and the hand. In the present study, we further assessed the interplay between these effectors by investigating a novel paradigm that associated an eye pursuit with a tactile motion over the skin of the fingertip. We showed that smooth pursuit eye movements can bias the perceived direction of motion in touch. Similarly to the classical report from the Filehne illusion in vision, a static tactile surface was perceived as moving rightward with a leftward pursuit eye movement, and vice versa. However, this time the direction of surface motion was perceived from touch. The biasing effects of eye pursuit on tactile motion were modulated by the reliability of the tactile and visual estimates, as predicted by a Bayesian model of motion perception. Overall, these results support a modality- and effector-independent process with common representations for motion perception.