Chromatic Induction in Space and Time
Institute Fellow Andy Coia, Ph.D. and Institute Member Steve Shevell, Ph.D. explore the color appearance of light
Coia, A.J., & Shevell, S.K. (2018). Chromatic induction in space and time. Journal of the Optical Society of America A, 35(4), B223-B230. doi: 10.1364/JOSAA.35.00B223. PubMed PMID: 29603978.
The color appearance of a light depends on variation in the complete visual field over both space and time. In the spatial domain, a chromatic stimulus within a patterned chromatic surround can appear a different hue than the same stimulus within a uniform surround. In the temporal domain, a stimulus presented as an element of a continuously changing chromaticity can appear a different color compared to the identical stimulus, presented simultaneously but viewed alone. This is the flash-lag effect for color, which has an analog in the domain of motion: a pulsed object seen alone can appear to lag behind an identical pulsed object that is an element of a motion sequence. Studies of the flash-lag effect for motion have considered whether it is mediated by a neural representation for the moving physical stimulus or, alternatively, for the perceived motion. The current study addresses this question for the flash-lag effect for color by testing whether the color flash lag depends on a representation of only the changing chromatic stimulus or, alternatively, its color percept, which can be altered by chromatic induction.