What does the term 'opponent-process' refer to in visual processing?

The term 'opponent-process' in visual processing describes a model that explains how color is perceived through the interaction of opposing pairs. This theory posits that certain colors cannot be represented simultaneously; for instance, the perception of colors such as red and green or blue and yellow are processed through opposing mechanisms in the visual system. When one color in a pair is stimulated, the other is inhibited, which helps to explain phenomena such as afterimages and color contrast. This dual processing mechanism enhances our ability to perceive and differentiate colors effectively and contributes to the complex nature of color vision.

Choosing this answer highlights the fundamental principle of how our visual system encodes and interprets color in a way that goes beyond simple additive mixing, which is the primary focus of the other options.