Gibson's Bottom Up Theory

Front 1

Gibson's theory

Back 1

There is sufficient information in the sensory stimuli to allow us to make sense of our environment without the involvement of stored knowledge (direct perception). Primary stimulus is the optic array, the pattern of light hitting the eye; invariant information about how and where objects facilitate this process. Involved innate mechanisms forged by evolution, don't need to learn from experience.

Hint 1

Sensory stimuli, optic array

Front 2

Optic flow

Back 2

The change in the patterns of light and shade with movement gives us information about which the direction, distance and speed in which an object is moving.

Hint 2

Change in patterns of light & shade, direction, distance, speed

Front 3

Horizon ratio

Back 3

The ratio of how much of an object is below and how much is above the horizon (or other fixed horizontal line in one's vision) stays the same regardless of how close the object is to you, so we can tell how large things are from different distances.

Hint 3

How much an object is below & above the horizon

Front 4

Texture gradient

Back 4

The further away something is, the finer the texture will appear. So lines that are far away will appear to be closer together than lines that are nearer to us.

Hint 4

Far away, finer texture, lines far away appear closer together

Front 5

Affordances

Back 5

The possible uses of objects, which can be directly grasped from the sensory information. What we do with an object depends on the circumstances in which it is encountered.

Hint 5

Use of objects, sensory information

Front 6

Johansson

Back 6

Found that a black-cad actor in a darkened room wearing lights on his joints was perceivable as a person when moving but not when stood still, supporting the existence of the optic flow as it was the movement that enabled direct perception.

Hint 6

Black-cad actor, lights on joints, perceived as moving, but not when stood still, supports optic flow

Front 7

Frichtel

Back 7

Presented participants with a film of a car driving through scenery. Infants as young as 4 months old could perceive by using texture gradient, implying this to be an innate ability.

Hint 7

Supports texture gradient, infants, car, innate ability

Front 8

Creem

Back 8

Found that restricting participants' viewing conditions did not significantly affect their ability to judge distances using horizon ratio information, suggesting this element of the optic array to be powerful in allowing direct perception.

Hint 8

Supports horizon ratio, restricted view, still judged distance accurately

Front 9

Evaluation

Back 9

It is difficult to explain Affordances - it seems much more probable that we learn objects' uses as young infants, from seeing others using them.

Hint 9

Affordances, learnt ability

Front 10

Evaluation

Back 10

If experience isn't involved, the theory cannot explain why we are fooled by visual illusions.

Hint 10

Visual illusions, experience involved

Front 11

Nature & reductionist

Back 11

Ignores the role of learning in our perceptual abilities, reductionist.

Hint 11

Role of learning

Front 12

Nomothetic

Back 12

Provides one explanation for all, so cannot account for individual differences in perceptual abilities, which may come from experience.

Hint 12

Individual differences, experience

Front 13

Gibson & Walk

Back 13

Experiment 6-14 month old infants were put on a glass table where one half had another surface directly beneath the glass, the other half had an apparent drop where there other surface dropped to the floor. The babies were put on the first half of the table with their mothers beckoning from the other end. The majority were too scared to crawl across, as they could perceive a drop, supporting depth perception to be innate. Still could have been learnt.

Hint 13

Supports, experiment, cliff drop, innate ability, infants

Front 14

Practical applications

Back 14

Such as road markings where lines get closer together to make it look like you are speeding, inspired by texture gradient.

Hint 14

Road markings, texture gradient

Front 15

Evaluation

Back 15

Perception is almost instant, supporting the idea of it being direct from sensory information rather than from complex higher processing.

Hint 15

Supports, instant, direct info