Gibson's Theory Flashcards
What does Gibson state about perception?
That it is not the result of learning or guesswork but it is a natural and automatic process
What elements does Gibson place emphasis on in his theory?
Optic flow patterns
Texture gradients
Affordances
What is the visual information we receive from the environment referred to as?
The optical array
What is the optical array?
The visual information we revived from the environment
What are optic flow patterns?
Changes in the optic array due to movement
What are changes inn the optic array referred to as?
Optic flow patterns
How do optic flow patterns occur?
Because of movement
What information do optic flow patterns provide us with?
Information about our position, direction and speed
What type of movements cause changes to the optic array?
The environment moving
The person moving
The persons eyes moving even though they are stationary
What is a texture gradient?
A sudden change in texture
What are texture gradients a good indicator of?
Distance
What types of things may texture gradients indicate?
A change in the direction of a surface e.g. A shift from wall to floor
Distance
In regards to texture gradient, how do things in the foreground appear?
Bigger and more detailed
In relation to texture gradient, how do things in the distance appear?
Smaller and less detailed
How does Gibson believe our perceptual system has evolved?
To perceive directly the potential uses of objects (affordances)
What are affordances?
The potential of uses of object
What can affordances also be described as?
Action possibilities
Give an example of an affordance
A cabbage could be used as a football, doorstop or weapon
How do we come to conclusions about potential uses of objects?
They have certain characteristics we can perceive use for
What is Gibson’s theory called?
The bottom up theory
Briefly, what are the strengths of Gibson’s bottom up theory?
Emphasises the importance of movement
Biological basis, supported by studies
Better than top-down theories because humans view much of the world the same way
There are many useful applications
Why was Gibson right to place a large emphasis on vision for action?
It has more ecological validity
What is vision for action?
The importance of movement
What is the importance of movement also known as?
Vision for action
In regards to vision for action, why do Top-Down theories lack?
Because they mainly look at two dimensional objects in static conditions
Why is Gibson’s theory having a firm biological basis a strength?
Because it is supported by studies that suggest perception is innate
What studies suggest perception is innate?
E.J. Gibson’s visual cliff study
How does E.J. Gibson’s study support Gibson’s theory?
It suggests infants have a depth perception at an early age, therefore it is most likely innate and a nature process as Gibson suggests.
How is Gibson’s theory better than Top-Down theories?
They look mainly at two dimensional objects in static conditions
They would also suggest more individual differences and errors in perception than there tend to be
What applications does Gibson’s theory have?
Recent research (new scientists 2005) has used information from the optic array and affordances to design a robot capable of movement Road markings approaching roundabouts make people aware of their speed
Briefly, what are the weaknesses of Gibson’s theory?
It doesn’t explain why visual illusions occur
The idea of affordances is questionable
Explain the weakness of Gibson’s theory which involves visual illusions…
He doesn’t explain why the occur and maintained they were not very important. Also that visual illusions lack ecological validity. However there must be a reason for them
Explain the weakness of Gibson’s theory about affordances…
It is difficult to accept the concept that a person who had never seen an object would know what to do with it. In light of this, it is very difficult to test as it would involve creating a new, unfamiliar object.
