aqa psychology revision

• Perception


  How we interpret or make sense of the sensory information that we receive
• Perception


  • Various explanations and theories for how perception actually works including how culture can affect perception
• Visual perception


  • Seeing the outline of a dalmatian walking along in a collection of dots and blobs
• Bottom-up process


  Perception is based solely on the information received by our eyes
• Top-down process


  Our mind generates expectations of what we are looking at, and it is these expectations that then help us make sense of the information our eyes receive
• Gibson's direct theory of perception


  • The real world presents sufficient information for direct perception without inference
  • Role of motion parallax in everyday perception
• Sensation


  Information we receive through the senses
• Transduction


  The process of converting sensory information into electrical signals
• Our bodies are bombarded with lots of information, far more than we can actually cope with if we were to give it all attention
• Perception


  The process of interpreting and making sense of all the information we receive
• Monocular depth cues


  • Height in plane
  • Relative size
  • Occlusion
  • Linear perspective
• Binocular depth cues


  • Retinal disparity
  • Convergence
• Motion parallax


  The way in which our visual field changes with movement, with close objects seeming to move more than objects which are far away
• Gibson argued the real world was three-dimensional and where we stand and move about within it is as much a part of real-world perception as shape and colour
• Affordances


  The possibilities for actions which the environment offers
• Gibson's theory proposes that sensation and perception are the same processes
• Visual illusions demonstrate that perception involves making inferences about what we see when the image is ambiguous, undermining Gibson's theory
• Explanations for visual illusions


  • Ambiguity
  • Misinterpreted depth cues
  • Fiction
  • Size constancy
• Linear perspective


  Depth cue where straight lines appear to converge towards a vanishing point
• Ambiguity


  When an image could be interpreted in more than one way
• Fiction


  Creating something that isn't really there in order to complete the image
• Size constancy


  Keeping the original perception of the size of an object even when information received by the eyes changes
• Perceptual constancy


  Perceiving objects as being the same (constant) even when the visual image we receive is different
• Perceptual system


  Generates an image that fills the gap to create something plausible for us
• Shape constancy


  Applying constancy scaling which helps us make allowances for changes in the shapes we receive on the retina
• Size constancy


  Enables us to see people as the same size in reality even as they approach and the visual image changes
• Ames room illusion


  Uses size constancy to produce a visual illusion
• Gregory's constructivist theory of perception


  • Past knowledge and experience is the most important factor when making sense of the world around us
  • Perception involves cognitive processes and we do not simply perceive information that we receive
  • We rely on stored knowledge and experiences which affects our perception
• Studies supporting Gregory's theory


  • Gilchrist and Nesberg (1952) found that hunger affected how people perceived images of food
• Critics argue the Muller-Lyer illusion works because the arrowheads make the lines look like the edges of a building
• The Muller-Lyer illusion still works when the arrowheads are replaced with circles
• Perceptual set


  A state of readiness for the information we receive from the environment
• Perceptual set


  Helps us anticipate what is coming so we can act effectively
• Perceptual set


  Affects our memory, decision-making, learning and perception
• Expectation


  When we expect something, we are more likely to notice it
• Culture

  Can influence perception, e.g. children in western societies draw animals from the side while traditional tribal children draw them spread across
• Emotion


  Can influence perception, e.g. someone in a negative mood is more likely to interpret ambiguous pictures negatively
• Motivation


  Can influence perception, e.g. hungry participants perceived food images as brighter
• Gilchrist and Nesberg 1952 motivation study


  1. Recruited 26 university students, half went 20 hours without food, all viewed food images and adjusted brightness

  2. Hungry group perceived images as brighter
• The Gilchrist and Nesberg study showed motivation can affect perception