Opponent Process Theory, Lateral Inhibition, Simultaneous Contrast

What is opponent-process theory?

A psychological theory that posits that colour perception is controlled by the activity of two oponent systems: blue-yellow, red-green. It proposes that you cannot see red in green light or green in red light, etc. This explains why we never see certain colour ‘mixes’ (eg. have you ever seen a ‘reddish green’?)

What is lateral inhibition?

Where a neuron’s response to a stimulus is inhibited by the excitation of a neighbouring neuron

What is simultaneous contrast?

Where two stimuli of the same reflectance appear to have different brightness levels, because of the influence of their surrounding background (eg. where the same shade of grey looks darker on a white background and lighter on a dark background)

What is the relationship between lateral inhibition and simultaneous contrast?

Lateral inhibition presents a potential explaination for simultaneous contrast by suggesting that retinal cells which recieve greater stimulation can inhibit surrounding cells, impacting our colour/size perception