Risa Yamagata* and Kazuho Fukuda
Department of Information Design, Faculty of Informatics, Kogakuin University, Tokyo, Japan.
*Corresponding author: Risa Yamagata, email@example.com
Keywords: glare effect, brightness perception, visual illusion, figure-ground, amodal completion
Poster presentation video: https://youtu.be/EyKgJeFnm5A
In a glare illusion, illusory brightness enhancement with self-luminous perception is observed to a pattern where a central white area is surrounded by radial darkening luminance gradients (Zavagno, 1999). Previous studies revealed that although self-luminous perception did not arise in low- luminance states of the glare stimulus, the brightness enhancement still arose (Tamura, et. al., 2016), and there were some differences in the intensity of illusory effect among different color conditions (Suzuki, et. al., 2019). Therefore, the glare illusion is considered to be a complex but robust phenomenon against a variety of stimulus conditions. Recently, we found that a grid arrangement of cross-shaped glare patterns caused perceptual figure-ground alternations associated with appearance and disappearance of glare perceptions. In this phenomenon, the strong glare perception appears when the grid of cross-shaped glare patterns is perceived as a figure. On the other hand, the glare perception disappears and amodal completion arises behind the gap when the grid pattern is perceived as a ground. We named this new illusory perception the switching glare illusion and began to study about it to reveal the mechanisms underlying the phenomenon. In this paper, we examined whether or not there were any effect of colors on the switching glare illusion. We investigated the frequency of perceptual alternation and the stability of each perception by measuring the timing of the perceptual alternation and the duration of each perception reported by observers. We tested nine patterns of the colored switching glare illusion as stimuli. There were five conditions of colors on luminance gradients (white to black, white to blue, white to red, blue to black, red to black) and four conditions where two types of the colored luminance gradient patterns were combined in different arrangement. As a result, according to the observer’s response and reported appearance, all of stimulus conditions caused perceptual alternation, and there were some differences in the states of appearance among the color conditions.