Psya3 Perception

Front 1

Gibson's Direct Theory of Perception
AO1 Key Feature 1

Back 1

‘Bottom-up’ or ‘data driven’ view proposes that all of the data necessary for perception comes from being able to detect information from the environment.

Front 2

Gibson's Direct Theory of Perception
AO1 Key Feature 2
Optic Array and Movement

Back 2

The optic array is the light rays that are perceived by the observer after hitting various objects and surfaces. This bundle of light, according to Gibson, is sufficient to provide us with the necessary information to perceive.
The optic array changes as the observer moves in their environment, therefore movement is essential if the observer needs additional information.

Front 3

Gibson's Direct Theory of Perception
AO1 Key Feature 3
Invariants and Texture Gradient

Back 3

Invariant means that the information received in the optic array does not change, regardless of the movement of the observer, as the information is continuously being given out, it does not change.

An example of this is Texture Gradient, where information received from surfaces vary in their degree of detail, which indicates their distance (depth) and orientation from the observer. Objects close to the observer are more detailed than objects farther away.

Front 4

Gibson's Direct Theory of Perception
AO1 Key Feature 4
Affordances

Back 4

Each object affords us a behavioural significance by the way that it is shaped, helping us to understand how to respond to the object, for example, a flat raised surface suggests we can sit on it.

The affordance of the object, however depends on the particular circumstances we are in, the same raised flat surface we saw initially as a chair may also become a step for us if we needed to reach something.

Front 5

Gibson's Direct Theory of Perception
AO1 Key Feature 5
Flow Patterns

Back 5

Flow patterns are created as objects in the visual environment move past the observer. The nature of the flow, provides information to the observer about the position and distance of the object. A motorway sign, first seen is a distant spot will eventually pass on your left hand side as you move forward towards it.

Front 6

Gibson's Direct Theory of Perception
AO2 Criticism 1
Importance of movement

Back 6

A key component of Gibson’s theory are his ideas about the importance of movement. Support for the visual systems innate ability to detect information comes from the findings of Johannsons’ (1973) research. He found that participants were able to detect motion simply from a changing array of dots. Even young infants and non-human animals were able to respond appropriately when shown the sequences, suggesting that this is indeed an innate ability.

Front 7

Gibson's Direct Theory of Perception
AO2 Criticism 2
Affordance only important to insects?

Back 7

A weakness of Gibson’s theory is his concept of affordance. Bruce & Green (1990) suggested that affordance may be able to account for the visually guided behaviour of insects, which have no need for a conceptual representation of the environment, however humans function in an environment where our knowledge about objects and their uses to us are influenced by cultural expectations and values. For example how would an individual from the African bush know that a red pillar box ‘affords’ posting a letter?

Front 8

Gibson's Direct Theory of Perception
AO2 Criticism 3
Problems explaining illusions?

Back 8

Illusions are situations where an observer’s perception can sometimes be inaccurate. e.g. Ames Room situation. Illusions can more easily be explained in terms of top-down processing, the opposite of Gibson. However, Gibson did not believe in researching in highly artificial laboratory conditions, and studies based on the illusions were conducted under these conditions; Gibson believed that illusions have little relevance to perception of real-life situations.

Front 9

Gibson's Direct Theory of Perception
IDA Criticism 1
Valuable real-world application

Back 9

One strength of Gibson’s theory is his principles have been applied to real life situations. Airports are constructed with the best possible lighting and markings to enhance optical flow patterns for incoming pilots. Also traffic control techniques change perception by changing the structure of the perceived world. Gibson's view of perception has undoubtedly benefited our day to day life and has even potentially saved lives.

Front 10

Gibson's Direct Theory of Perception
IDA Criticism 2
Nature vs Nurture

Back 10

Gibson proposes that an appropriate physiology is all that is needed in order to perceive. As we are born with a visual system and a brain we should be able to perceive from birth, meaning Gibson is a supporter of the Nature side of the Nature/Nurture debate.