Abstract
The watercolor illusion is a perceived spread of color when a thin colored line is adjacent to an outer luminance line or edge. Our prior work found an asymmetric color dependence for the watercolor illusion, with contrast matched +S stimuli producing larger effects than –S stimuli. In experiment 1 we show that the outer luminance line also shows an asymmetry that is also asymmetric with larger induction with increments than with decrements. This asymmetry is also color dependent, larger along the +S direction. To investigate the mechanism for this effect we measured the perceived contrast of increments vs. decrements as a function of color direction. In general, the luminance increment required to match a decrement was less than a decrement required to match an increment, but only for stimuli with +S input. These results are consistent with those of experiment 1 and suggest that the asymmetry may be driven by the apparent contrast of the inducing patterns. It is unclear why the apparent contrast of the luminance increments and decrements when paired with colored lines should have color dependence.
Meeting abstract presented at VSS 2014