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. We showed that assumption to be incorrect in an experiment in which observers reported the first perceived figure-ground organization of briefly exposed stimuli depicting two regions sharing a figure-ground border. We manipulated the symmetry of the two regions and their orientation-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 immediately by a mask. Influences on figure-ground organization from both symmetry and orientation-dependent object recognition processes were found; both were observed first in the 28-ms condition. Object recognition inputs did not dominate symmetry inputs. We suggest that object recognition processes may operate simultaneously on both sides of edges detected before figure-ground relationships are determined.