Perception of Partly Occluded Objects: A Microgenetic Analysis

The sensory information specifying objects is often optically incomplete: Objects occlude parts of themselves and other objects. However, people rarely experience difficulty in perceiving complete 3-dimensional forms. This report describes a paradigm for the objective study of completion effects and their microgenesis. A well-known priming method was extended to determine whether a partly occluded object produces priming effects more like one of its possible interpretations than like another. For prime durations > 200 ms, a partly occluded object produces priming effects equivalent to its complete interpretation. The results provide objective evidence for the perceptual completion of partly occluded objects and imply that the complete interpretation develops over time, possibly proceeding through a preliminary mosaic interpretation. The theoretical implications for visual perception and cognition are discussed.