title: Role of brightness contrast and brightness contrast-reversal in illusory contour formation.
abstract: The effects of artificial pupil size and the effects of a power lens upon the relative prominence of illusory contour were evaluated. The perception of illusory contour was facilitated by conditions associated with increased retinal blur and brightness averaging. This was true whether the blur and averaging were achieved using a large artificial pupil or a power lens. The effects of power lens and the effects of artificial pupil size upon the occurrence of brightness contrast and brightness contrast-reversal (or assimilation) were also investigated. Brightness contrast was changed to brightness contrast-reversal by using either a power lens or a large artificial pupil. The occurrence of vivid illusory contour under conditions found conductive to brightness contrast-reversal was interpreted as evidence that contrast-reversal was more crucial in illusory contour formation that brightness contrast.
mesh_terms: D004193:Discrimination Learning / Q000502:physiology; D005556:Form Perception / Q000502:physiology; D006801:Humans; D007088:Illusions / Q000502:physiology; D008027:Light; D009903:Optical Illusions / Q000502:physiology; D012025:Reflex, Pupillary; D012160:Retina / Q000502:physiology