Color constancy improves, when an object moves: High-level motion influences color perception

Abstract

Color constancy refers to our remarkable ability to perceive the color of objects nearly constant despite considerable changes in the spectral content of the illumination. As such it is most important for object recognition. Visual motion can make object recognition harder because it limits the viewing time and increases the likelihood that an object encounters illumination changes. However, color constancy, as human color perception in general, has long been thought to be "motion blind." Here I show that, on the contrary, human color constancy is influenced by motion and improves when a color surface moves. Psychophysical experiments revealed that color constancy is influenced specifically by slow object motion and depends on the saliency of the moving figure. These surprising findings cannot be explained by low-level co-processing of color and motion signals. Instead they demonstrate a previously unknown influence of attention-driven, high-level motion processes on cortical color computation. Since motion is a frequent aspect of natural visual scenes, the synergistic integration of color and motion signals is an important mechanism for improving color identification. The new findings speak against a strict segregation of color and motion processing in the human visual cortex and suggest a network for encoding object color, which includes specialized ventral as well as dorsal visual areas.