Perceptual organization is limited in peripheral vision: Evidence from configural superiority.

Perceptual organization refers collectively to those processes by which the three-dimensional structure and material properties of surfaces are abstracted from image information. It is a critical foundation of object perception. Examples of perceptual organization include the assignment of relative depth to different contrast regions, the representation of three-dimensional shape based on two-dimensional geometry, and the representation of completed regions of occluded surfaces behind other surfaces. Perceptual organization is typically studied with stimuli at fixation, where visual acuity is high; however, stimuli in the periphery are represented with poor fidelity and may not support those processes. We tested the hypothesis that perceptual organization is limited in peripheral vision by measuring configural superiority effects for four different perceptual organization processes with stimuli in central and peripheral locations. We found configural superiority for stimuli defined by surface completion, three-dimensional shape, transparency/surface scission, and shape from closure for stimuli at fixation, providing evidence that each of these processes occurred for those stimuli. However, when the same stimuli were presented in peripheral locations, but size-scaled to compensate for acuity differences, no configural superiority occurred. This is consistent with those processes having failed for those stimuli. These results suggest that peripheral vision, unlike central vision, is not object based and that it serves a fundamentally different function.