Monday, 18 February 2013

Gibson and Gregory

My understanding so far of Gibson and Gregory:

There are two opposing views in regards to perception - Gibson who argued humans processed information in a bottom-up method and Gregory (1970) who proposed a top-down method.

The bottom-up method (Gibson) meant that information was processed one way, where a person analyses a piece of raw data and this analysis increases as it makes its way through the visual system. Gibson argued that perception is direct and the environment provides enough information to make sense of our world.

The top-down method (Gregory) refers to the information which helps us to recognise patterns, mostly used in optical illusions. Gregory said this is because the meaning of surrounding words help to aid understanding.

Gibson claimed 'what you see is what you get' and there is no need for processing and interpretation, which Greogry says is necessary.
perception - Gibson optic array
McLeod, S. (2007) Visual Perception Theory [Online] available at: http://www.simplypsychology.org/perception-theories.html (Accessed 16 February)

Gibson's theory contained three important features:
  1. Optic flow patterns
    1. Light flow contains important information about the movement of a stimulus
  2. Invariant features
    1. A pattern or structure is available in texture gradients which is invariant, always occuring in the same way as we move around the environment and this helps cue depth.
  3. Affordances
    1. Optical Array - the patterns of light that reach the eye from the environment
    2. Relative brightness - brighter, clearer images are perceived as closer
    3. Texture gradient - grain of textures gets smaller as the objects get further away
    4. Relative size - objects with small images are seen as more distant
    5. Superimposition - if the image of one object blocks another, the first is seen as closer.
    6. Height in the visual field - objects further away are generally higher in the visual field
peception
McLeod, S. (2007) Visual Perception Theory [Online] available at: http://www.simplypsychology.org/perception-theories.html (Accessed 16 February)
So how does this relate to education?
Gibson said that people perceived what is in their direct field of vision, and that no further analysis is required to receive all the relevant information. I believe this is difficult to do, because children are not always able to gain the relevant information from a stimulus which they have not seen before.

Gregory said that information is gained from the relationship between the eye and the brain, where different factors influence the information someone receives. I have noticed through personal experience that when looking at optical illusions, when younger I have not been able to see both images in an illusion, but looking at it again at an older age, I have been able to see both images or use the stimuli to pick apart the parts I can see, to find the images or illusions which I cannot see.

Faults with Gibson's Theory of Perception
  • Gibson cannot explain why perceptions are sometimes inaccurate. He claimed optical illusions are extremely artifical and are unlikely to be encountered in the real world.
  • Gibson's theory cannot explain naturally occuring illusions, such as a train in the horizon.
References
McLeod, S. (2007) Visual Perception Theory [Online] available at: http://www.simplypsychology.org/perception-theories.html (Accessed 16 February)
Noe, A. Direct Perception, [Online] Available at: http://socrates.berkeley.edu/~noe/directperception.pdf

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