DETECTION OF CONTRARY CHROMATIC CHANGE

In visual search experiments we examined whether targets that are dist inguished from distracting items solely by a contrary change in color can be sought spatially in parallel. Targets under time-varying illumi nation pop out if they present a contrary luminance signal; targets un der space-varying illumination can be detected in parallel when they a re isoluminant. The results suggest that neurons with spatially and ch romatically opposed receptive fields are active across the central vis ual field.