Abstract
The human visual system integrates fragmental inputs both in spatial and temporal domain. Palmer et al. (JEP:G, 2006) proposed that spatiotemporal interpolation of moving inputs depends on a Dynamic Visual Icon (DVI) which represents visible fragments and updates their previous positions.Unuma et al. (VSS, 2010) explored the range of motions that support object interpolation with DVI, and suggested that ecologically valid transformations which represent approaching objects in 3D space play an important role for object interpolation in ordinary environment. The present study specifically aimed to compare the sensitivities for object interpolation in complex motions including ecologically valid transformations. The effect of velocity gradients in radial motion on object interpolation was compared with those in horizontal motion. Three velocity gradients were tested in each motion condition. Participants observed the shapes of interpolated objects through multiple apertures and made two-alternative forced choice of objects. The relatability or the misalignment of edges was varied using d' as a dependent measure. The results showed a consistent effect of velocity gradients only in the radial-motion conditions, although d′ in horizontal-motion conditions was higher overall than in radial-motion conditions. These results suggest higher sensitivities of human visual system for velocity gradients in ecologically valid situations, especially those in approaching and receding motion.