Showing papers by "Stuart Anstis published in 2017"
TL;DR: A random-dot background was expanded and contracted, and rotated, or expanded in one dimension while contracting on the other, or skewed back and forth horizontally.
Abstract: A random-dot background was expanded and contracted, and rotated, or expanded in one dimension while contracting on the other, or skewed back and forth horizontally. Squares that were flashed at the reversal points of these affine pattern distortions, aligned to edges in the texture, showed massive changes in size and shape.
7 citations
TL;DR: A patch that alternates between two hues such as dark green and light blue looks greenish on a light gray surround and bluish on a dark gray surround (“flicker-augmented contrast”) but the afterimage is the same pink, driven by the time integral of the physical, not the perceptual, adapting hues and regardless of the surround luminance.
Abstract: A patch that alternates between two hues such as dark green and light blue looks greenish on a light gray surround and bluish on a dark gray surround ("flicker-augmented contrast"). Thus, when an edge alternates between two hues in the same location, the visual system selects the more salient hue-the one with the higher Michelson contrast. However, the afterimage is the same pink, driven by the time integral of the physical, not the perceptual, adapting hues and regardless of the surround luminance. So the process of edge biasing does not transfer to the mechanism that creates afterimages.
3 citations
TL;DR: The results support the idea that human speed perception is biased by temporal frequency, which physically goes up as SF increases when the speed is held constant, and the more dots or lines, the greater the perceived speed when they are moving coherently in a defined area.
Abstract: The perceived speed of a ring of equally spaced dots moving around a circular path appears faster as the number of dots increases (Ho & Anstis, 2013, Best Illusion of the Year contest). We measured...
1 citations
TL;DR: It is found that when the inducer was made to flicker, its SF appeared to be higher and consequently, the test’s SF appeared lower than before, suggesting that simultaneous contrast of spatial frequency exists further downstream than the flicker-induced increase in perceived SF.
Abstract: In simultaneous contrast of spatial frequency (SF), a test grating surrounded by a coarser inducing grating looks apparently finer. We combined this effect with another visual illusion; the fact that flickering the inducing grating raises its apparent SF. We found that the inducer's apparent, not physical spatial frequency, drove the simultaneous contrast that it induced into a test grating. Thus, when the inducer was made to flicker, its SF appeared to be higher and consequently, the test's SF appeared lower than before. This suggests that simultaneous contrast of spatial frequency exists further downstream than the flicker-induced increase in perceived SF.