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Gibson’s direct perception
- Claims that incoming sensory information contains everything needed for perception
- We perceive a dynamic ever-changing scene
- Contrasts with theories such as Gregory's constructivist theory that sensory information needs the addition of prior knowledge
- Example - Frog doesn't need to form perceptual hypotheses in order to perceive and catch a fly, it uses all the sensory information available
- Criticised because some illusions do seem to require stored knowledge in order to explain how they work
- Doesn't explain how it feels to perceive something.
- Importance
- May help to describe different facets of perception
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Bottleneck theories of attention
- Broadbent (1954)
- Theory of a bottleneck in the attentional system to limit the amount of information passing through
- Tested theory using auditory split-span procedures (one ear or other)
- Results suggested to Broadbent that filtering occurs early
- Importance
- Stimulated research into how attentional systems operate
- Explain why we may process incoming information in different ways
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Limited capacity attention
- Kahneman (1973)
- Suggested that human brain is only capable of analysing a limited amount of incoming data at a time and integrating it with prior knowledge.
- Some information will therefore be lost, we may not be aware of everything happening around us.
- Proposed a limited capacity central processor that allocates attentional resources, and that information processed increases when we are aroused
- Theory supported by Posner and Boies (1971)
- dual task studies and McLeod (1977) response time study
- Importance
- Explains limitations that are obvious in everyday life, such as why we sometimes fail to perceive events happening right in front of us
- Explains why we don't consciously perceive everything that we sense
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Attentional spotlight
- Posner (1980)
- Theory suggesting we can control the area that we focus our attention on, with the ability to zoom in and out like a spotlight
- Example – one instrument or an orchestra
- Stimuli outside this area may be sensed, but not perceived
- Attention is selective - we can choose where to point the spotlight, and can switch attention to where we expect something to happen
- Importance
- Important way to conceptualise how we 'pay attention' to things, and to explain how and why different levels of concentration are appropriate
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Top-down processing
- Process where information flows down from prior knowledge/experience which can influence sensory information coming in
- Emphasised by Gregory's constructivist theory of perception
- Existing knowledge used to form perceptual hypotheses that the sensory data is fitted against
- Illusions can be explained in terms of top-down processing, e.g. Muller-Lyer illusion is interpreted using our knowledge of what corners look like when near or far away.
- Bete people show little susceptibility to this illusion, and live in jungle environments with few corners
- Importance
- Provides an explanation for some aspects of perception, especially where there are obvious gaps in the sensory data available
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