Cortical dynamics of three-dimensional figure–ground perception of two-dimensional pictures.

Abstract

This article develops the FACADE theory of 3-dimensional (3-D) vision and figure-ground separation to explain data concerning how 2-dimensional pictures give rise to 3-D percepts of occluding and occluded objects. The model describes how geometrical and contrastive properties of a picture can either cooperate or compete when fonning the boundaries and surface representations that subserve conscious percepts. Spatially long-range cooperation and spatially short-range competition work together to separate the boundaries of occluding figures from their occluded neighbors. This boundary ownership process is sensitive to image T junctions at which occluded figures contact occluding figures. These boundaries control the filling-in of color within multiple depth-sensitive surface representations. Feedback between surface and boundary representations strengthens consistent boundaries while inhibiting inconsistent ones. Both the boundary and the surface representations of occluded objects may be amodally completed, while the surface representations of unoccluded objects become visible through modal completion. Functional roles for conscious modal and amodal representations in object recognition, spatial attention, and reaching behaviors are discussed. Model interactions are interpreted in tenns of visual, temporal, and parietal cortices.

Interaction of color and geometric cues in depth perception: When does ?red? mean ?near??

“…A mechanism that computes a conditional probability function, which is the product of the likelihood functions for each given cue, predicts when a single cue will have enough weight to effectively determine the resulting percept. In this mixture model, based on cooperative weights, cue competition is, like in Grossberg's (1997) FACADE theory, the inevitable consequence of cue selection. Although all cues available in a given configuration cooperate in the first instance, cues with little relative weight may then be overridden by a cue with stronger relative weight.…”

“…The partial occlusion cue generates a local boundary advantage. Grossberg's FACADE model (Grossberg, 1997) explains how the local boundary advantage can make the partial occlusion cue win over the interposition cue in the competition with other depth cues such as luminance contrast in achromatic stimuli (Dresp et al, 2002). b The stimuli presented in Experiment 1 consisted of pairs of red squares or rectangles.…”

“…The positional cue systematically favored the right square of a given pair. Conditions with interposition cue (middle), or with cues of partial occlusion (bottom), systematically favored the horizontal rectangles in the cross configurations FACADE model are selected and integrated into a binocular form representation (Grossberg, 1997).…”

“…In the case of the relative height cue, the perceptual system would readily expect objects presented at lower locations in the visual field to be nearer to the human eye because other geometric constraints need not be taken into account. The FACADE theory predicts that expectation driven by cues of spatial location acts as a powerful director of visual attention (Grossberg, 1997). Like the partial occlusion cue, the positional cue does not lead to a relative boundary advantage in a stimulus pair.…”

The complementary brain: unifying brain dynamics and modularity

“…Even in the seemingly simple case of the Kanizsa square, one often perceives a square hovering in front of four partially occluded circular disks, which seem to be completed behind the square. FACADE theory predicts how surface filling-in is organized to help such figure-ground percepts to occur, in response to both two-dimensional pictures and three-dimensional scenes 7,18 .…”