03D-06 Expansive and contractive size perception induced by chromaticity and luminance
Miwa Nakano1, Seiji Tanabe1, Yoshiya Mori1, Bungo Ikegami2, Ichiro Fujita1
1.Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan, 2.School of Engineering Science, Osaka University, Osaka, Japan
Empirically, changing the color of an object modulates its perceived size; e.g., clothes in a particular color make you look thinner. To quantify this effect, we systematically examined the effects of object and background color on size perception. Subjects viewed a pair of solid square patches on a computer display, and were instructed to report which patch subjectively appeared larger. Larger chromatic or luminance contrasts between the patch and background resulted in larger size percepts, while smaller contrasts led to smaller size percepts. This result suggests that the chromatic and luminance contrasts between the patch and its background, rather than the chromaticity and luminance of the patch itself, determine the perceived size. The neural mechanism of size perception might involve cortical neurons that modulate their size tuning with chromatic and luminance contrast (Solomon et al. 2004; Sceniak et al. 1999).