Gibsons Bottom Up/Direct Theory - Perception Flashcards
What are optic flow patterns?
Changes in optic array due to movement
- gives info about our position, direction and speed
What might optic flow be due to?
Objects in the environment moving, a person moving or if they are stationary with their eyes moving
What is an example of optic flow?
When you are driving you are focusing on a spot in the distance that appears stationary. Objects start as central to visual field and then rush past, appearing to get bigger as they move closer (relative size)
Why are texture gradients useful?
Good indicator of distance
- sudden changes in texture may signal a change in direction of a surface
- things in the foreground are bigger and more detailed, things in the distance are smaller and less detailed
What are affordances?
- ability to perceive directly the potential uses of objects e.g chairs afford sitting on a buttons afford pushing
What did Gibson and Walk do?
36 infants aged 6-14 months were placed on a glass table with a ‘shallow’ side and a ‘deep’ side with a 4ft drop and were encouraged to walk over the table
What did Gibson and Walk find?
Most infants would not walk across
What did Gibson and Walk conclude?
Suggests depth perception is an innate ability that infants are born with
How does PAS relate to Gibson and Walk’s study?
These infants are quite old and therefore have had experience allowing them to develop depth perception
What did Segall do?
Showed lined illusions ma to 2000 adults and children- 14 non-EU groups and 3 EU groups
What did Segall find?
EU origin groups were more susceptible to the Muller-Lyer illusion
What did Segall conclude?
Study is against Gibson as shows cultural differences = nature
- could be that EU groups see more carparented buildings that are similar to the Muller-Lyer
How does Segall relate to N/N?
Gibson and Walk + Segall suggest opposites BUT both different areas of perception = some areas may be innate
What was Gibson’s main belief?
That perception is innate
