Illusory motion induced by the offset of stationary luminance-defined gradients.
An illusory motion induced by the offset of a stationary gradient stimulus is characterized. When a gradient stimulus, whose luminance contrast ranges gradually from white on one side to black on the other, is made to disappear all at once so that only the uniform white background remains visible, illusory motion is perceived. This motion lasts approximately 700 ms, as if the stimulus moves from the low to the high luminance contrast side. This gradient-offset induced motion does not occur for equiluminant color-defined gradient offsets, suggesting that it relies mainly on the magnocellular pathway. Our data are consistent with the hypothesis that this illusion is caused by the decay of the gradient afterimage.
Hsieh
P-J
PJ
Department of Psychological and Brain Sciences, Moore Hall, Dartmouth College, Hanover, NH 03755, USA. Po-Jang.Hsieh@dartmouth.edu
Caplovitz
G P
GP
Tse
P U
PU
D000360:Afterimage; D015350:Contrast Sensitivity; D006801:Humans; D008029:Lighting; D009039:Motion Perception; D009903:Optical Illusions; D010364:Pattern Recognition, Visual; D010775:Photic Stimulation / Q000379:methods; D011601:Psychophysics