The perception of color from motion

Abstract

Weintroduce and explore a color phenomenon which requires the prior perception of motion to produce a spread of color over a region defined by motion. Wecall this motion-induced spread of color dynamic color spreading. The perception of dynamic color spreading is yoked to the perception of apparent motion: As the ratings of perceived motion increase, the ratings of color spreading increase. The effect is most pronounced if the region defined by motion is near 1 0 of visual angle. As the luminance contrast between the region defined by motion and the surround changes, perceived saturation of color spreading changes while perceived hue remains roughly constant. Dynamic color spreading is sometimes, but not always, bounded by a subjective contour. We discuss these findings in terms of interactions between color and motion pathways.Neon color spreading (see, e.g., van Tuijl, 1975;Varin, 1971) shows that the colors we perceive do not always match predictions based on the spectral content of the stimulus. In instances of neon color spreading, color is seen over regions which in isolation would appear achromatic. Specific geometric, color, and brightness features are required in order to induce the neon color spreading into nearby areas. Consider the example in Figure 1: A full green disk can be seen, although only eight radial lines, part green and part red, are drawn. Another feature of the colored disk is that it appears luminous-hence the label "neon" color spreading.In this paper we introduce and explore a phenomenon of color spreading which differs from standard neon color spreading in that it requires the prior perception ofmotion to produce a spread of color over a region defined by motion. We call this motion-induced color spreading dynamic color spreading for short. Two frames from a typical display of dynamic color spreading are shown in Figure 2. Each frame consists of a white square containing 900 dots placed randomly (sampled from a uniform distribution) within the square area. The dots do not move from one frame to the next; only their colors are updated as follows: All dots are colored red except for those within a (virtual) disk, which are colored green. The center ofthe disk translates from one frame to the next, with the consequence that some red dots in one frame are green in the next, and vice versa. Again, the physical placement of dots remains unchanged from frame to frame; only the colors of a small number of dots (those at the leading and trailing edges of the virtual disk) change from one frame to the next. TheWe thank M. Albert, B. Bennett, M. Braunstein, 1. Yellott, and two anonymous reviewers for helpful comments. This research was supported by ONR Contract NOOOI4-88-K-0354 (D.D,H.), NSF Grant BNS8819874 (CM.C.), andNEI Grant IROIEY08200 (CM.C.). Correspondence should be addressed to C M. Cicerone, Department of Cognitive Sciences, University of California, Irvine, Irvine, CA 92717 (e-mail: cciceron@uci.edu), Mathematica (Version 2.03) program used for generating such frames is given in App...

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

“…For high luminance levels of the background, observers reported seeing a disk moving over the field of dots and the spread of a desaturated color throughout this disk (Cicerone et al 1995). Under a range of low-luminance backgrounds the observers reported seeing a highly saturated, solidly colored green disk moving in front of a solid red field.…”

“…Experimental evidence suggests that the receptive fields subserving the effect may be reasonably large. Cicerone et al (1995) showed that test regions near l deg (over a range of 0.3 to 2.4 deg) produce optimal color spread from motion. Although these sizes are too large to be compatible with the receptive field sizes of color-coded P ganglion cells of the primate retina, size alone does not allow us to specify where in the postretinaJ motion-processing chain the color spreading might occur.…”

“…I n our studies the effect was produced in a stimulus display of multiple frames shown in quick succession, each frame consisting of a fixed, random placement of colored dots on a high-luminance white background with color assignments of some dots, but not dot locations, changing from frame to frame. Cicerone et al (1995) found that the spread of subjective color into physically :achromatic regions is restricted to the part of the display that was seen to be moving. Such spread of subjective color was not seen in still views of single frames.…”

“…Other related phenomena include Benham's (1894) top, in which one sees subjective colors when viewing a rotating disk of black and white patterns; Bidwell's (1896) ghost, in which-with rapid sequential presentation of white light, colored light, and darkness-one perceives the complement of the colored light; Wallach's (1935) observations of enhancement of subjective colors when the pattern is seen in apparent motion; a nd the recent reports of the perception of motion accompanied by a spread of color over achromatic regions seen as moving (Cicerone and Hoffman 1992;Shipley and Kellman 1994;Cicerone et al 1995). I n our studies the effect was produced in a stimulus display of multiple frames shown in quick succession, each frame consisting of a fixed, random placement of colored dots on a high-luminance white background with color assignments of some dots, but not dot locations, changing from frame to frame.…”

“…1 cd m-2 ) . From frame to frame the location of each dot in the stimulu was held constant, while the assignment of color to dots was progressively change according to an algorithm (Cicerone and Hoffman 1992;Cicerone et al 1995) tha colored all dots within a shifting circular area green and all other dots red. In the firs frame the center of the circular region was 0.75 deg below the center of the display.…”