These authors propose a method for staged-processing of motion information that serves to distinguish the boundaries of a moving object, and thus allow the object itself to be segregated. The model includes robust optic flow estimation along motion boundaries, detection of motion discontinuities with respect to those boundaries, and the analysis of occlusion differentials as one object passes in front of another. Representations of motion discontinuities and occlusion evidences mutually interact to improve and stabilize the results. The authors draw parallels among the several stages of processing, and what appear to be comparable functions of several brain regions. Their model achieved object segmentation in both artificial and natural scenes.