Perception in brief

Page 1

Key people /theories

'The whole is greater than its parts'

It focuses on the organisation of the elements of an image rather than the elements themselves.

Perceptual organisation includes:

Closure

Good continuation

Proximity

Similarity

Similarity seems to be stronger than proximity

Criticism: The stimuli used by Gestalt researchers tended to be quite simple 2Dgeometric patterns in lab settings

Gibson 1947

Gibson developed an ecological approach to perception;Interaction with the environment is the key aspect of this theory: action is seen as the 'goal' of perception. The emphasis is on the way in which real objects and surfaces structure Invariant information (such as texture gradient) could be 'picked up' from the optic array to provide cues to the position, orientation and shape of surfaces. Invariant information also revealed by motion which could produce flow patterns in the optic array.The importance of real surfaces and motion suggest that perception could not be studied by using artificial stimuli in a lab setting. Believed cognitive analysis is not necessary but that objects could 'afford' their use directly.

Bottom-up theory.

Positive:

Criticism : lack of explanation HOW info is picked up., Affordance theory: no cognitive processing or prior knowledge needed?

Marr 1982

Based on bottom-up processing of information using a computational model which simulated the human visual system Perception composed of a series of stages, each stage generating an increasingly sophisticated description:

Grey level-Primal sketch-2 1/2 D sketch- 3D sketch. end stage of perceptual process as object recognition rather than action.

Criticisms: based on hypothetical assumptions, not always ecological valid.Does not account for cognitive processes involved with perception. Cannot be adequately reconciled with the separation of visual pathways into action (dorsal stream) and object recognition (ventral stream)

Constructivist approach / Gregory 1980

The way you perceive a stimulus depends on previous knowledge-> top-down processing.

Sensory data are often incomplete thus description need previous knowledge to be constructed. Gregory: people generate perceptual hypotheses based on stored knowledge and accept the one that fits best

Perception

New Page