Abstract
We performed four experiments to investigate the relation between neon color spreading, subjective contours, and induced brightness inside the contours. Subjects rated the clarity of subjective contours and the perceived brightness of areas surrounded by the contours in Ehrenstein figures and the clarity of neon color spreading in van Tuijl figures. The Ehrenstein figure consisted of black radial lines surrounding a circular area on a gray background, and the van Tuijl figure was produced by inserting a colored cross in the circular area of the Ehrenstein figure. It was shown that the clarity of the neon color spreading did not always covary with that of the subjective contours and the perceived brightness. It was also found that when the luminance of the radial lines was higher than that of the background, the neon color spreading was not perceived, whereas the subjective contours and the induced brightness were perceived. These results are partially consistent with two theories of neon color spreading; the transparency theory and Grossberg and his colleagues' theory.
