BOUNDARY EXTENSION AS A NEW GESTALT PRINCIPLE
Gestalt principles of perceptual grouping have been suggested to reflect dynamic aspects of mental representation. Boundary extension, in which stimuli likely to have been present just beyond the boundaries of a previously viewed scene are remembered as having been included within that viewed scene, has also been suggested to reflect dynamic aspects of mental representation. Other similarities of Gestalt principles of perceptual grouping and boundary extension include (a) displacement in remembered location, (b) reflection of environmental regularities, (c) a basis in isomorphism, (d) decreases in amount of information processed, (e) dependence on surrounding context, (f) interpretation as a laboratory-based illusion or as a successful adaptation, (g) reflection of general rather than domain-specific principles, and (h) automatic application even in observers instructed about the phenomenon and asked to guard against it. It is suggested that boundary extension might be an example of a new class of Gestalt principle related to properties of scenes rather than to properties of objects.