key research (part A)

• aim


  gibson and walk aimed to investigate the age at which young children start to show the ability to use visual stimuli to be able to discriminate depth and the recording of receding distance. wanted to find support that depth perception is innate.
• research method


  laboratory experiment

  repeated measures design
• independent variable


  whether the young child was called by its mother from the cliff side or the shallow side of the visual cliff apparatus
• dependent variable


  whether or not the child would crawl to its mother
• participants


  36 children ages 6-14 months + mothers

  parental consent was given

  chicks, turtles, rats, lambs, kids, pigs, kittens, dogs
• procedure


  visual cliff apparatus to test depth perception

  child was placed on the center of the board and their mother would call from either the cliff or the shallow side. similar procedure with the animals
• gibson and walk were trying to determine which of two visual cues plays a decisive role in depth perception:

  1. distance cue- distance decreases the size and spacing of pattern elements projected onto the retina
  2. motion parallax- which causes the pattern elements on the shallow side to move more rapidly across the field of vision when the animal moves in position on the board or moves its head.
• results- human


  75% move towards shallow edge, exhibiting desire to reach mother but reluctance to move towards cliff side
• results- chicks


  always move towards the shallow side
• results- lambs and kids


  never step onto the cliff side; become immobile (freeze or go limp) when pushed off onto the cliff side
• results- rats


  move freely over both the shallow and the cliff side, provided whiskers are in contact with the glass
• results- kittens


  almost always choose the shallow sidee, freezing or circling when placed onto the cliff side
• results- aquatic turtles


  whilst more move to the shallow side, 24% crawl towards the cliff side
• conclusions


  able to conclude that children have depth perception from when they are able to crawl, and develops before locomotor abilities. whereas depth perception in animals is evident from an earlier age as their locomotion is required earlier, maybe even evident at birth, and that depth perception in chicks, kids, goats and kittens appear rapidly.