The principle that two stimuli must differ by a constant proportion for their difference to be perceived is known as

A) the opponent-process theory.
B) Weber's law.
C) feature detection.
D) prosopagnosia.

Weber's Law

A principle in psychology that states the smallest change in a stimulus that can be detected is a constant proportion of the original stimulus.

Opponent-Process Theory

The theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision. For example, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green.

Feature Detection

The process by which the brain identifies specific components of visuals, such as lines, edges, or movements, to interpret what is seen.