Visual structure and the integration of form and color information

Recent evidence challenges the view that attention acts on the outputs of early filters dedicated to processing motion, color, and orientation. Instead, "proto-objects" specified by shading, depth, direction of lighting, and surface information are thought to provide input to attentional processing. These findings are extended here to the parsing of occlusion-based contours. Multicolored occlusion structures were briefly presented and illusory conjunctions measured. More illusory conjunctions were made to structures in which color was inconsistent with form information, a result that can be explained by a property of the visual system that biases the integration of color to be consistent with form. Results show that this constraint was based on global structural descriptions rather than the local information provided by T-junctions and collinearity. Together, these results offer a new tool for the study of the binding problem in vision.