ABSTRACT
One prior theory of the perception of partially occluded figures states that contours “intrinsic” to a figure of interest must be distinguished from those “extrinsic” to it and that this classification requires depth cues. In this chapter, the authors propose that the human visual system can use a variety of cues, local or global, to perform this classification and that this classification serves as the basis for perception of both partially occluded and fragmented figures. In each trial of the human psychophysical experiments, a polygonal figure was partially occluded by simple shapes—diamonds and squares. A subject’s task was to respond whether the figure was presented in its upright or rotated position. Subjects used orientation and length differences between the contours of a target figure and those of occluders, in detecting the figure. The human visual system can detect and use a variety of cues, local or global, to classify contours as either intrinsic or extrinsic to a partially visible figure.
