top-down processing

top-down processing

1. use information acquired through experience to make sense of sensory information - contrasted with bottom-up processing which uses information present in the sensory stimulus

2. Gregory's constructivist theory of perception emphasises importance of top-down processing - while sensory information is the basis for perception it is not in itself sufficient

   • use existing knowledge to form perceptual hypotheses which are then checked against sensory data - supported with visual illusions e.g. Muller-Lyer - adjusted through size constancy
     • support from tests with Bete people live in jungle with no corners show little susceptibity to illusion
     • illusion explained in terms of what is in the stimulus - suggested perceptual compromise between actual line length and figure it is a part of

3. importance is challenged by Gibson's theory of direct perception

4. important because it integrates top-down and bottom-up processing in a theory of perception

5. criticized for over-estimating role of top-down processing and underestimating richness of sensory data