SHAPE-RECOGNITION INPUTS TO FIGURE GROUND ORGANIZATION IN 3-DIMENSIONAL DISPLAYS

It is generally agreed that figure and ground relationships must be determined, at least provisionally, before shape representations can be assessed. We have proposed that some shape recognition processes can operate in parallel with processes assessing other variables relevant to figure-ground organization. The influence of these shape recognition processes should be observed only when shape edges can be detected early enough in visual processing so that the critical shape recognition operations can be finished before figure-ground computations are completed. In three experiments, we tested this prediction using stereograms portraying two regions equal in area, but unequal in denotivity (roughly, meaningfulness): One region was high in denotivity, the other region was low in denotivity. Binocular disparity specified that either the high denotative region or the low denotative region was in front (i.e., was figure). For some stereograms (random dot stereograms), no edge was visible between the two regions until after stereo fusion; for other stereograms (black-and-white stereograms), a luminance edge was visible before fusion. In black-and-white stereograms, but not in random-dot stereograms, high denotative regions could appear to be in front (i.e., to be figure) and the shapes they depicted could be recognized, even when this organization was inconsistent with the disparity. These results are consistent with the hypothesis that shape recognition processes can contribute to figure-ground computations, at least when the figure-ground border is a luminance contrast edge. Implications for shape recognition and perceptual organization are discussed. © 1993 Academic Press, Inc.