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.

Atypical Visual Motion-Prediction Abilities in Autism Spectrum Disorder

A recent theory posits that prediction deficits may underlie the core symptoms in autism spectrum disorder (ASD). However, empirical evidence for this hypothesis is minimal. Using a visual extrapolation task, we tested motion-prediction abilities in children and adolescents with and without ASD. We examined the factors known to be important for motion prediction: the central-tendency response bias and smooth-pursuit eye movements. In participants with ASD, response biases followed an atypical trajectory that was dominated by early responses. This differed from control participants, who exhibited response biases that reflected a gradual accumulation of knowledge about stimulus statistics. Moreover, although better smooth-pursuit eye movements for the moving object were linked to more accurate motion prediction in control participants, in participants with ASD, better smooth pursuit was counterintuitively linked to a more pronounced early-response bias. Together, these results demonstrate atypical visual prediction abilities in people with ASD and offer insights into possible mechanisms underlying the observed differences.