Abstract
A pitched visual inducer in the retinal periphery produces illusory changes in the perceived elevation of a small luminous target on a dark field. The inducer also affects manual behavior when subjects point at the target with the unseen hand. This manual effect depends on hand-to-body distance: When the arm is fully extended, pointing is veridical; when the arm is close to the body, gross pointing errors occur, similar to the errors in visual perception (Li & Matin, 2005; Li, E. Matin, Bertz, & L. Matin, 2008). In the present Experiment 1, subjects pointed at an eye-level target. In Experiment 2 they pointed horizontally at eye level (no visual target). In both experiments, we measured the manual behavior as a function of hand-to-body distance during the presence of the inducer and for 10 minutes after inducer offset. In both cases the hand-to-body distance effect disappeared shortly after inducer offset. We suggest that the rapid disappearance of the distance effect is a manifestation of processes in the dorsal visual stream that are involved in updating short-lived representations of the body in egocentric perception and manual behavior.
Meeting abstract presented at VSS 2012