Gibson Gregory Perception

Psychology: Foundations 2

Compare and contrast the direct perception theory of Gibson with the constructivist perception theory of Gregory, which provides a better account of human perception?

In order to compare and contrast the perception theory of Gibson and the constructivist perception theory of Gregory one has to first briefly explore what the perceptual processes and development is about. In seeing the world we do not have to think much about the world in order to make sense or it, we interpret our environment through our perceptual abilities. Gibson’s direct perception theory and Gregory’s constructivist perception theory both focus on the visual perception.

Visual perception is based on two kinds of processing. One of the two is the (bottom-up) processing, which is dependant on external stimuli. Second of the two is (top-down) processing, which is dependant on an individual’s knowledge and expectations.

Some theorists have taken to one of the types of processing, some emphasising on the (bottom-up), and some focusing on the (top-down).

In comparing Gibson with Gregory, Gibson (1950, 1966, 1979) concentrated on the (bottom-up) process of visual perception as his theory on the direct perception states that information transmitted from the visual environment provides the individual to interact and move around within the environment without involving internal processing.

Opposing theorist Gregory (1972, 1980) concentrated on the (top-down) process of visual perception. His constructivist theory stated that perception is very much an individually active and self constructive process seen to be influenced by hypothesis and expectations.

Looking firstly into Gibson’s theory of direct perception, he highlights the fact that environmental data is all that is necessary for visual perception and that there is n need for any other information. His approach is often identified as the ‘ecological theory’ because it’s so focused on environmental information being the explanation of perception.

As it is not possible to explore all of his many findings this part of the essay will explore some of his concepts however here are most of the areas that he studied; Optic array, Optic flow, Perception and action, Invariants, Texture gradients, Resonance, and Affordance.

Gibson’s theory started of with the notion of the optic array which is the pattern of light reaching the eye; the optic array is thought to have all the visual information obtainable at the retina. This optic array provides unambiguous information about the layout of an objects space. The information can come in the form of optic flow patterns and texture gradients. He states that perception entails retrieving the high information given by the optic array without having to process information concerned.

Perception and action is of particular importance to Gibson’s direct perception theory, perception and action is based on the supposition that there is a direct or close relationship between perception and action.

The notion of this is that an observer can collect valuable information based on the environment by moving about.

In summary all the above areas that Gibson studies are argued to have been, picked up or used for the retrieval of information solemnly from the environment.

On the other hand in summary, the constructivist’s theory was first explored by Helmholtz (1821-1894). He argued that the insufficient information provided by the senses is increased by unconscious inferences, which attach more meaning to sensory information. He believed that these inferences were unconscious because he stated that we are all usually unaware that we are making inferences while in the process of perceiving.

Helmholtz’s constructivists approach has been developed by many theorists, one of them being Gregory.

Gregory (1972) states that perceptions are constructions which com from the fragmentary scraps of data signalled by senses and taken from the brain memory banks, themselves constructions from the snippets of the past Therefore the insufficient information given to the sense organs is used as the basis for creating inferences of forming hypothesis concerning the visual environment.

Some of the concepts that Gregory explores include; the influence of expectations, the influence of motivational factors, explaining visual illusions and the misapplied size-constancy theory. In summary these concepts are all linked to the way in which information based on visual perception is very much based on the individual’s knowledge and expectations therefore making the individual constructive.

In contrast the main strength of Gibson’s theory of direct perception is that it emphasises on the notion that the visual environment provides much more information than what previous studies had assumed. It is said that he was correct in assuming that the moment-by-moment changes in the optic array taking place when we are moving provide very useful information about the layout of the visual environment.

The main strength of Gregory’s constructivist theory is that Gregory very much emphasises the importance of the bottom-up processes , and he also has performed demonstrations that show that top-down processes should be not be ruled out or ignored.

A not so strong concept in Gibson’s study is over simplification, the processes concerned with identifying invariants in the environment, in discovering affordance, and in producing resonance, are significantly more complicated than Gibson indicated.

According to Marr (1982) the major shortcomings of Gibson’s analysis is a failure to recognise to aspects, which are ‘the detection of physical invariants which is an information-processing problem and second, he vastly under-rates the sheer difficulty of such detection’.

However one major problem within Gregory’s constructivist theory is that perception will frequently be an error, however it is typically accurate. If we always use hypotheses and expectations to interpret sensory data, one has to ask how is it is possible for hypothesis and expectations to be constantly correct, the clear response is that the environment provides a lot more information than the “fragmentary scraps of data” assumed by constructivist theorists. Despite there being oppositional arguments this indicates that Gibson’s direct perceptual theory is better at providing an account of human perception.

Bibliography:

• Gibson, J.J. (1950). The perception of the visual world. Boston: Houghton Mifflin.

• Gibson, J.J. (1966). The senses considered as perceptual systems. Boston: Houghton Mifflin.

• Gibson, J.J. (1979). The ecological approach to visual perception. Boston: Houghton Mifflin.

• Gregory, R.L.(1972, June 24). Seeing as thinking. Times literary supplement

• Gregory, R.L.(1980). Perception as hypothesis. Philosophical transactions of the royal society of London, series B, 290, 181-197.

• Marr, D. (1978). Vision: A computable investigation into human representation and processing of visual information. San Francisco: W.H. Freeman.