Object Permanence

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Object Permanence

• Understanding that objects exist independent of
  our ability to perceive them
• At 8-12 months, infants can search for hidden
  objects
• Limitations in this ability A-not-B Task

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Object Permanence

• Understanding that objects exist independent of
  our ability to perceive them
• At 8-12 months, infants can search for hidden
  objects
• Limitations in this ability A-not-B Task

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Object Permanence

• Understanding that objects exist independent of
  our ability to perceive them
• At 8-12 months, infants can search for hidden
  objects
• Limitations in this ability A-not-B Task

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Object Permanence

• Understanding that objects exist independent of
  our ability to perceive them
• At 8-12 months, infants can search for hidden
  objects
• Limitations in this ability A-not-B Task

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12-18 months

• Trial-and-error experimentation of the world to
  find new and different ways of acting on it.
• Before this, the infant produces known actions
  that will produce mostly known outcomes

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12-18 months

• Here the infant produces new actions and observes
  the effects
• Can do the A-not-B task but only when object is
  visibly displaced
• Indicates that the spatial relation of objects
  relative to other objects is represented and is
  not related to their actions

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Factors

• Revolve around issues of information-processing
• Visual Attention
• Perception
• Memory
• Perceptual-Action Coupling

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Memory

• Diamond (1985)
• If no delay between hiding and allowing infant to
  search, then infants search correctly
• If impose a delay, then get errors of searching
  at B
• 2 sec at 7.5 months
• Increasing by approximately 2 sec each month

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Memory

• Lesions to adults prefrontal cortex, an area
  involved in working memory, results in poor
  performance on A not B task
• Butterworth (1977)
• Used transparent occluders
• Found infants still make error
• So, it is not just a memory issue

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Attention

• Maybe they just are not paying attention where it
  is hidden
• Could affect ability to remember
• Horobin Acredolo (1986)
• 3 conditions to test for how attention might
  relate to ability to search

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Horobin Acredolo

• 1) Close Pair (15.25 cm)
• 2) Far Pair (45.75 cm)
• 3) Six Hole (A and B 45.75 cm apart, with 4 holes
  in between)

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Horobin Acredolo Results
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Horobin Acredolo Results
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Horobin Acredolo Results
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Transparent Occluders

• Because infants were found to make errors with
  these, memory was ruled out as sole source of
  errors
• Yates Bremner (1988) suggest perhaps it is due
  to novelty of transparent occluders

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Yates Bremner

• Compared familiarizing infants to the occluders
  for 5-10 minutes to not familiarizing them
• Found Familiarized - 10 made errors
  Unfamiliarized - 40 made errors
• So memory, or more likely attention-induced
  memory issues, may play an important role in this
  error

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A not B Task Concerns

• There is concern that performance in A not B task
  is strongly influenced by the development of
  motor control
• Younger infants have poorer motor control,
  therefore make more errors
• So use task that does not require motor response
• Purpose of Ahmed Ruffman (2000)
• Use violation of expectation paradigm

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Other Work on Object Permanence

• Bower (1966, 1967, 1982)
• Even infants as young as 20 days old see the
  bottom left alternative (no ball) as surprising

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Object Permanence

• Baillargeon (1987)
• Found that not until 4.5 months of age (substage
  3) did infants increase attention to the
  impossible event

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Object Permanence

• Physical Events
• Spelke et al. (1992)
• Not until infants are 4 months of age do they
  look longer at the inconsistent result

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Object Permanence

• Numerical Cognition
• Wynn (1992)
• Infants as young as 3 months will look longer
  when the number of items does not match the total
  of what they had previously seen
• Concluded that infants do basic math

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Ahmed Ruffman

• 3 tasks
• 1) Classic A not B task
• 2) A not B nonsearch task (using violation of
  expectation)
• 3) one location nonsearch task

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Ahmed Ruffman
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Ahmed Ruffman

• Found that infants looked longer at the
  impossible appearance of toy at A after being
  hidden at B
• There was no affect of delay or age
• There was affect of age and delay on classic A
  not B task
• If infants did not have to search, they were
  found to remember even after 15s delay where toy
  had been hidden
• Go back to possibility that get effects due to
  attention wandering back to A