MUST FIGURE-GROUND ORGANIZATION PRECEDE OBJECT RECOGNITION - AN ASSUMPTION IN PERIL

The assumption that figure-ground segmentation must precede object or shape recognition has been central to theories of visual perception. W e showed that assumption to be incorrect in an experiment in which obs ervers reported the first perceived figure-ground organization of brie fly exposed stimuli depicting two regions sharing a figure-ground bord er. We manipulated the symmetry of the two regions and their orientati on-dependent denotivity (roughly, their meaningfulness), and measured how each of these variables influenced figure-ground reports when the stimuli were exposed for 14, 28, 57, 86, or 100 ms, and followed immed iately by a mask. Influences on figure-ground organization from both s ymmetry and orientation-dependent object recognition processes were fo und; both were observed first in the 28-ms condition. Object recogniti on inputs did not dominate symmetry inputs. We suggest that object rec ognition processes may operate simultaneously on both sides of edges d etected before figure-ground relationships are determined.