Monocular and binocular thresholds for abruptly and gradually presented illusory contours

Classifying illusory contours: edges defined by "pacman" and monocular tokens.

Thresholds for the discrimination of orientation were measured in the human fovea for figures and borders delineated by solid lines and by "pacman" tokens as introduced by Kanizsa, as well as by contours induced by monocular tokens giving a stereoscopic depth illusion of a knife edge. Orientation discrimination of these illusory contours is poorer by a factor of approximately 2 than that of equ...

Illusory contours

Illusory contours are perceived in the absence of any real physical luminance gradients between inducers that are spatially discontinuous (Fig. 1a,b).1–3 It has been controversial whether the perception of these subjective contours arise from higher level cognitive mechanisms that depend on attention and serial search4–6 or from lower level parallel processing in the early automatic, preattenti...

Monocular and Binocular Visual Tracking

Direction discrimination thresholds in binocular, monocular, and dichoptic viewing: Motion opponency and contrast gain control.

We studied the binocular organization of motion opponency and its relationship to contrast gain control. Luminance contrast thresholds for discriminating direction of motion were measured for drifting Gabor patterns (target) presented on counterphase flickering Gabor patterns (pedestal). There were four presentation conditions: binocular, monocular, dichoptic, and half-binocular. For the half-b...

Cue interactions, border ownership and illusory contours

When two retinally adjacent image regions both claim 'ownership' of their common boundary based on different visual cues, their perceptual competition could result in: (1) cue averaging, in which the common boundary is not strongly perceived as owned by either region, or (2) perceptual bistability, in which the competing interpretations alternate in conscious perception over time. We report tha...