Abstract
The visual system represents partly occluded objects as completed forms. Partly visible edges and surface features are integrated, and the visual interpolation is achieved when the visible edges are relatable (Kellman & Shipley, 1991). We examined in previous experiments how visual interpolation processes allow observers to derive representations of objects from spatially and temporally fragmented information (Unuma, Hasegawa, & Kellman, VSS 2006, 2007). Our experiments provided some evidence for spatiotemporal interpolation and the temporal limits of the Dynamic Visual Icon (Palmer, Kellman, & Shipley, 2006) in object perception. Here, we tested the temporal characteristics of contour and surface integration processes using a shape discrimination task with a moving occluder. Temporal thresholds in a contour-integration condition were compared with those in a contour and surface-integration condition. Illusory-contour squares and a large occluder with a small window were presented to observers. The occluder rotated in front of the illusory square and the speed of rotary motion was manipulated. The method of constant stimuli was used. Psychometric functions for discrimination of the shape wee measured as a function of presentation cycle of inducing figures. Results showed that accuracy increased with increasing presentation cycle, and that estimated temporal limits of the visual buffer in the contour-integration condition were shorter than those in the contour and surface-integration condition. These results support the notion of the Dynamic Visual Icon. Further, our study indicates that the temporal limits of surface integration processes differ from those of contour integration process.