Abstract
Evidence suggestive of holistic representation for faces often is obtained in tasks in a facial feature (e.g., a nose) is judged either in the absence or presence of a facial surround, with that surround being either consistent or inconsistent (at the level of identity) with the feature. These types of paradigms are similar to those used to reveal influences of global form on the perception of local features. The present project investigates the hypothesis that effects in facial perception and effects in object perception reflect the same characteristics of visual perception. There are two specific hypotheses that are addressed in this work: (a) Perceptual organization relies as much or more on similarity at the level of second-order characteristics than at the level of first-order physical similarity, and (b) perceptual organization reflects both perceptual and decisional factors. We tested these hypotheses using hierarchical forms in which one of the dimensions was created using illusory contours. Observers responded with judgments about each of the manipulated dimensions, allowing the data to be analyzed from the perspective of general recognition theory. In Experiment 1 the effect of consistency was examined with hierarchical illusory stimuli in the presence or absence of a to-be-ignored central element that itself could be either consistent or inconsistent with the global and local forms. In Experiment 2 the same effects were examined, but observers were instructed to identify the central as well as the global and local forms. Experiment 3 extended these comparisons to face- and object-like stimuli in which the global shape was an illusory contour. Results from all three experiments indicate that the perceptual organization of all types forms demonstrate common reliance on both perceptual and decisional components.