Citation: Vision Research, 36, 149-173
Abstract: How does the visual system generate percepts of moving forms ? How does this happen when the forms are emergent percepts, such as illusory contours or segregated textures, and the motion percept is apparent motion between the emergent forms? We develop a neural model of form-motion interactions to explain and simulate parametric properties of psychophysical motion data and to make predictions about how the parallel cortical processing streams V1→MT and V1→V2→MT control form-motion interactions. The model explains how an illusory contour can move in apparent motion to another illusory contour or to a luminance-derived contour ; how illusory contour persistence relates to the upper interstimulus interval (ISI) threshold for apparent motion ; and how upper and lower ISI thresholds for seeing apparent motion between two flashes decrease with stimulus duration and narrow with spatial separation (Korte s laws). The model accounts for these data by suggesting how the persistence of a boundary segmentation in the V1→V2 processing stream influences the quality of apparent motion in the V1→MT stream through V2→MT interactions. These data may all be explained by an analysis of how orientationally tuned form perception mechanisms and directionally tuned motion perception mechanisms interact.