Behaviour 2019
Animal Color Vision: the Opponency Dilemma
Carlay LaTour, Esteban Fernandez-Juricic. Purdue University, West Lafayette, Indiana, United States

A term frequently used in animal color vision is "opponency." Generally, opponency is used to describe how animals process different wavelengths of light. However, there are two types of opponency: color opponency and cone opponency. Color opponency describes the subjective experience of color, whereas cone opponency describes a physiological mechanism (i.e., signals from two or more cone classes are pre-processed and packaged together before they are transmitted to the visual cortex). The goal of this review is to explore both kinds of opponency and the experiments used to test for them. Color opponency is the appropriate framework for exploring visual perception. A priority is to first characterize color categorization and the perceptual relationships between colors. Cone opponency may be a useful framework when designing an experiment about visual detection (i.e., predators trying to find camouflaged prey). A priority is to characterize cone oppenency across many vertebrate species, which could then be incorporated into current visual models to potentially improve the accuracy of their predictions.