Figure-Ground Perception

A person's ability to separate an object from its surrounding visual field is referred to as figure-ground perception. The object that a person focuses on is called the figure; everything else is referred to as background, or simply ground.

Psychologists have created different kinds of stimuli in order to study how people separate figure from ground. In some cases, these stimuli involve simple ambiguous figures such as the famous face-vase (called the Rubin vase) figure that can be interpreted either as two faces looking at one another in profile or as a vase, depending on what aspect a person focuses on. In order to see both percepts, the visual system has to shift figure and ground; this is called a figure-ground reversal. The visual system apparently uses a variety of cues to choose between figure and ground. Often, the smaller stimulus is deemed figure, the larger background. Shape is a determinant as well, so objects that are convex tend to be interpreted as figures. Movement is another cue, as is color. A solid color is more likely to be perceived as background, while multiple colors seem to indicate figure. Edge can also be a cue, because the perception of figural edge helps to define the background. There is no single defining cue or feature; the perceptual system and the brain take in the available information and use it to make judgments differentiating figure from ground.

Figure and ground are used extensively in artistic compositions. They may also be used for non-visual stimuli, for example, to distinguish melody from harmony in a complex musical composition. Figureground relationships are subjective and determined by the perceptions and biases of the observer.

See also Binocular depth cues ; Color vision ; Depth perception ; Gestalt principles of organization .