Sensation and perception

• Sensation


  The detection of actual information received through our senses
• Transduction


  Converting information we receive into electrical signals
• Perception


  How we make sense of the information we receive through our senses
• Sensation


  Detection of actual information
• Perception


  Interpretation of the information received
• How we perceive


  • Visual cues
• Depth cues


  Allow us to work out how far an object is from us
• The image our eyes receive is 2D but we live in a 3D world
• Monocular depth cues


  • Height in plane
  • Relative size
  • Occlusion
  • Linear perspective
• Height in plane


  Things further away are higher up
• Relative size


  Things closer to you are larger
• Occlusion


  An object covering up another object seems closer to us
• Linear perspective


  The way that straight lines seem to be pointing towards a single point on the horizon (vanishing point as the lines seem to disappear when they reach it)
• Two main ways binocular depth cues work


  • Detecting the difference in eye muscles
  • Comparing the images received by the two eyes
• Detecting the difference in eye muscles

  1. Focus eyes differently to see things closer

  2. Focus eyes differently to see things further away

  3. Brain detects differences in muscle work

  4. Uses as cue to distance
• Convergence


  Cue to distance based on detecting differences in eye muscle focus
• Comparing the images received by the two eyes

  1. Close things have quite a difference in what the two eyes see

  2. Further things have less difference between the images

  3. Difference hardly noticeable after 10 metres
• Retinal disparity

  Cue to distance based on comparing the images received by the two eyes
• Constancies


  How we use visual cues and assumptions to see the world and objects as the same (consistent) despite changes in visual angle or changes in the objects
• Binocular depth cues

  Using binocular depth cues allow us to be much more accurate in judgement for depth