White's effect: removing the junctions but preserving the strength of the illusion.
White's effect (also known as the Munker White effect) is a lightness illusion in which, contrary to expectations based on simultaneous contrast and Wallach's rule, a gray rectangle predominantly surrounded by white appears lighter than an identical rectangle that is mainly surrounded by black. The illusion is often explained in terms of T-junctions that are formed by the three-way intersection of the gray rectangle, a black stripe, and a white stripe. I present a circular variant of White's effect in which all the junctions have been removed without significantly affecting the strength of the illusion, suggesting that junctions are not an important consideration in all versions of White's effect.
Harvard Medical School, 220 Longwood Avenue, WAB 232, Boston, MA 02115, USA. phowe@hms.harvard.edu
Piers D L
PD
Howe
D015350:Contrast Sensitivity / Q000502:physiology; D005863:Gestalt Theory; D006801:Humans; D009903:Optical Illusions / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation; D011601:Psychophysics; D015348:Vision, Binocular / Q000502:physiology; D014794:Visual Fields / Q000502:physiology