Perception

• Sensation is processed by sense receptors and involves the five senses
• Perception is the organization and interpretation of sensory information
• Visual cues for depth perception:

  • Monocular depth cues can be detected using just one eye
  • Height in plane: Objects higher in the visual field appear further away
  • Relative size: Objects further away appear smaller
  • Linear perspective: Parallel lines appear to get closer together in the distance
  • Occlusion: Objects that cover others appear closer
  • Binocular depth cues are detected using both eyes
  • Convergence: Muscles around our eyes work harder when objects are up close, and relax when they are further away
• • Retinal disparity: Each eye gets a slightly different view of the world, with a bigger difference for closer objects
• Nature vs. Nurture:

  • Nature: Inherited characteristics from parents
  • Nurture: Characteristics learned from the environment
• Key terms:

  • Optic flow patterns: Inform our brain about our movement, helping us judge speed and direction
  • Motion parallax: Objects closer in our visual field appear to move faster than those further away
• Explaining visual illusions:

  • Size constancy: Objects appear to change size as they move closer or further away
  • Misinterpreted depth cues: Things in the distance appear smaller than they actually are
  • Ambiguity: When something can be interpreted in more than one way
• Visual cues can lead to incorrect conclusions, explaining visual illusions
• Inference: Filling in gaps to draw conclusions about what we see
• Gibson’s direct theory of perception:

  • Perception happens directly without the need for past experiences or expectations
  • Sensation and perception are considered the same
• Gregory’s constructivist theory of perception:

  • Our brains construct information from the environment to perceive the world
  • Sensation and perception are distinct
  • Does not explain everyday perception or how perception starts
• Key study on expectation:

  • Aim: To see how participants interpreted ambiguous figures affected by context
  • Method: Used independent measures, showing participants letters or numbers before ambiguous figures
  • Results: Participants tended to see the number 13 after numbers and the letter B after letters
• Key study on motivation by Gilchrist and Nesburg (1952):

  • Aim: To study how motivation affects perception
  • Method: Experimental group fasted for 20 hours, control group had normal meals, shown pictures of food with varying brightness
  • Results: Control group had consistent brightness judgments, while the experimental group perceived images as brighter
• Key study on culture by Hudson:

  • Aim: To investigate how culture influences perception
  • Method: Showed 2D drawings to people from different cultures and educational backgrounds
  • Results: Cultural differences affected perceptual set
• Key study on emotion by McGinnie:

  • Aim: To determine if anxiety-inducing stimuli are less noticed than emotionally neutral ones
  • Method: Showed words to participants, measuring galvanic skin response
  • Results: Provocative words caused larger changes in response than neutral words