Abstract
When multiple elements are present in an apparent-motion display, the visual system must solve a motion correspondence problem. The proximity between matching elements is a factor determining motion correspondence. Previous studies have suggested that the proximity computation uses distances in retinal coordinates (e.g. Ullman, 1979), but we recently demonstrated that distances in environmental coordinates are also considered during smooth pursuit eye movement (Terao et al., 2008, SfN). Our finding indicates the processing stage is later than the integration of retinal inputs with extra-retinal signals of smooth pursuit eye movements. Here we report that the subjective proximity modulated by extra-retinal signals of saccade determines the motion correspondence computation, but consistent with the hypothesis that peri-saccadic space compression affects motion correspondence, this effect weakens as the saccadic amplitude decreases. Our findings suggest that the proximity computation for motion correspondence is based on the apparent distance, which is affected the extra-retinal signals of saccade.
