Perceptual binding occurs independently beyond early neural adaptation stages in human color cone pathways

Abstract

Abstract Color perception entails competing temporal context mechanisms such as adaptation versus memory persistence1. Perceptual dynamics in color cone pathways can be studied using the phenomenon of hysteresis, well-known in the framework of physical dynamical systems. It postulates analogous mechanisms: a) visual persistence defining positive hysteresis b) adaptation or habituation (negative hysteresis). Adaptation causes early perceptual switches to competing states. We investigated competition between these mechanisms in human color cone pathways. Color adaptation occurs within early visual pathways up to V4, involved in local scene analysis, but it is unknown if they underlie global perceptual binding of visual elements2. We tested if the neural locus of perceptual binding occurs at visual and memory stages beyond the locus of color adaptation, using a dynamic color matching task in cone contrast space, along Blue-Yellow (S-(L + M) and Green-Red processing channels (L-M). Simple vs Compound stimuli required or not holistic perceptual binding, under visual or memory-guided conditions. Adaptation (negative hysteresis) dominated for the former condition, was stored in memory, but vanished when binding was required either in vision or memory. In sum, cone pathway adaptation mechanisms dominate in early vision, while perceptual binding occurs at a second stage as predicted by the feature integration theory.