Factors affecting perception

• Constructivist theory of perception


  Suggests our cognitive processes actively construct our perception using sensory information but combining it with stored knowledge, schemas and expectations
• Top-down theory of perception


  Constructivist theory of perception
• Sensory information


  Incomplete, so our brains have to make guesses or inferences about factors like distance and motion based on visual cues
• Model of reality


  What we ultimately perceive, influenced by a range of factors, different to what's really out there in the world
• Nurture approach


  Constructivist theory explains perception based on the experiences we've had with the world
• Visual illusions


  • Moll-Lyer illusion
• Direct theory of perception


  Suggests the eyes are able to detect the world accurately without the need for inferences
• Bottom-up theory


  Direct theory of perception
• Affordances


  The directly perceivable usefulness of objects
• Direct theory of perception


  • Accurate direct perception has evolved in animals to help them navigate the environment
  • Visual information from the eyes is complex and allows accurate direct perception of the world, including features like distance
• Motion parallax


  A monocular depth cue that gives information about motion and depth
• The speed of perception is better explained by the direct theory of perception as it requires less mental processing than the constructivist theory
• The direct theory struggles to explain how we are fooled by visual illusions