Color from Motion: Separate Contributions of Chromaticity and Luminance

Abstract

Abstract. 'Color from motion' describes the perception of a spread of subjective color over achromatic regions seen as moving. The effect is produced with a stimulus display consisting of colored dots, randomly placed upon a white field, with dots in the test region differing in both chromaticity and luminance from those in the surround. Evidence is presented suggesting that color from motion may be regulated by mechanisms different from those for contour formation and color contrast. (I) Results based on ratings show that, in the absence of luminance differences between the dots in the test and those in the surround regions, chromaticity differences alone are sufficient to produce color spread from motion. As the equiluminance point is approached, subjective color spread is seen despite a reduction in the strength of the subjective contour. Thus, contour formation is not likely to be a prerequisite for color from motion.(2) Color matches show that the hue and saturation of the subjective color spread are determined largely by the chromaticity and the luminance of the dots in the test region, not by those of the dots in the surround for the values explored. This suggests that color from motion may arise in sites distinct from those responsible for the regulation of color contrast.

Color from Motion: Dichoptic Activation and a Possible Role in Breaking Camouflage

“…luminosity, the observers described a veiling spread of color into achromatic regions near the green dots. The saturation of the veiling color was described to be low, in line with previous measurements under this condition (Miyahara and Cicerone 1997). For backgrounds of low luminance, the observers reported seeing one of two percepts: (i) A dark sheet inscribed with red dots was seen.…”

“…Hence, the effect was called 'color from motion'. Miyahara and Cicerone (1997) present results showing that, in the absence of luminance differences between dots in the test region and those in the surround region, chromaticity difference alone is sufficient to produce color spread from motion. In this case, color spread is perceived despite the absence of a clear subjective contour.…”

“…When apparent motion is perceived, the region defined by motion is enveloped in subjective color spreading into achromatic regions near the green dots. The color spread is uniform; although it is of low saturation (Miyahara and Cicerone 1997), grouping by color enhances the visibility of the region defined by motion. We asked whether this could be a mechanism for breaking camouflage.…”

“…Furthermore, the spread of subjective color is restricted to the area seen as moving. Finally, under some conditions for which the luminance of the test dots is lower than that of the surround dots, Miyahara and Cicerone (1997) show that apparent motion can be seen in the absence of color spread. If apparent motion must be perceived in order for the spread of subjective color to be perceived, the locus of the color spreading effect can be placed at or beyond the site regulating apparent motion.…”

“…Earlier results (Cicerone ct al 1995;Miyahara and Cicerone 1997) suggest that the perception of motion is yoked to the spread of subjective color into achromatic regions seen as moving. Certainly, unlike neon color spreading in still displays (cg Varin 1971;van Tuijl 1975), color spread is not seen if single frames of our stimulus are seen in still view.…”