Depiction - Dual Invariants

Dual Invariants

A more frankly behaviouristic view is taken by the perceptual psychologist James J. Gibson (1978), partly in response to Gombrich. Gibson treats visual perception as the eye registering necessary information for behaviour in a given environment. The information is filtered from light rays that meet the retina. The light is called the stimulus energy or sensation. The information consists of underlying patterns or ‘invariants’ for vital features to the environment.

Gibson’s view of depiction concerns the re-presentation of these invariants. In the case of illusions or trompe l’oeil, the picture also conveys the stimulus energy, but generally the experience is of perceiving two sets of invariants, one for the picture surface, another for the object pictured. He pointedly rejects any seeds of illusion or substitution and allows that a picture represents when two sets of invariants are displayed. But invariants tell us little more than that the resemblance is visible, dual invariants only that the terms of reference are the same as those for resemblance