Object Permanence and Object Concept

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Object Permanence and Object Concept

• Object Permanence
• Baillargeon (1987) habituated and tested as seen
  --gt
• Control condition was the same but without the box

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Baillargeon (1987)

• Object Permanence
• Baillargeon (1987)
• Found that 4.5-month-olds discriminate the
  impossible event relative to possible
• Even though the range of motion of the screen was
  the same as during habituation

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Baillargeon (1987)

• Object Permanence
• Baillargeon (1987)
• Found that 4.5-month-olds discriminate the
  impossible event relative to possible
• Even though the range of motion of the screen was
  the same as during habituation
• In the control, infants did not discriminate
  between the tests events

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Baillargeon (1987)

• Tested 3.5- to 4-month-olds

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Baillargeon (1987)

• Object Permanence
• Baillargeon (1987)
• Found that 3.5-month-olds did not discriminate
  the impossible event

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Baillargeon (1987)

• Object Permanence
• Baillargeon (1987)
• Found that 3.5-month-olds did not discriminate
  the impossible event
• In the control, infants also did not discriminate
  between the events

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Baillargeon (1987)

• Object Permanence
• Baillargeon (1987) found that in previous
  experiment data, there were fast and slow
  habituators
• Examined that effect on performance
• Found that fast habituators discriminated

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Baillargeon (1987)

• Object Permanence
• Baillargeon (1987) found that in previous
  experiment data, there were fast and slow
  habituators
• Examined that effect on performance
• Found that fast habituators discriminated
• Slow habituators did not
• Replicated with strictly 3.5-month-olds

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Baillargeon (1987)

• Object Permanence
• Piaget suggested that object permanence is
  attained by around 9 months, when they begin to
  search for hidden objects
• These results suggest that Piaget was wrong and
  that some form of object permanence is available
  as early as perhaps 3.5 months
• That they have object permanence before they can
  search (which was required by Piaget)
• Suggests that this ability is innate
• Spelke hypothesizes that conception of objects as
  spatially bounded entities that exist
  continuously in time and move through space,
  maintain their unity and boundaries, is innate
• Infants have expectations about the behavior of
  objects in space and time

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Object Concept Properties

• Physical aspects of objects
• Principle of inertia
• Object moves smoothly in absence of obstacles
• Principle of continuity
• Object traces one connected path in space and
  time, with no gaps and two object cannot occupy
  same place at any point in time (solidity
  constraint
• Spelke et al (1992) - 4 months of age look longer
  at the inconsistent result

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Object Concept Properties

• Physical aspects of objects
• 2.5 months of age look longer at the inconsistent
  result

Inconsistent
Consistent
Inconsistent
Consistent
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Object Concept Properties

• Physical aspects of objects
• Principle of continuity (Spelke et al, 1995)
• 4-month-olds habituated to continuous looked
  longer at 2 object, whereas habituated to
  discontinuous looked longer at single

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Object Concept Properties

• 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 and that
  this ability is innate

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Object Concept Properties

• Physical existence and identity
• Xu Carey (1996)
• One object appears from one side of occluder,
  different object from the other side
• Spatial condition - both objects simultaneously
  appear
• Property condition - objects appear only in
  sequence
• Both tested with both objects or single object
• 10-mo-olds and 12-mo-olds look longer at single
  object in spatial condition
• Only 12-mo-olds look longer at two object in
  property condition
• So property differences do not effect 10 mos but
  do at 12 mos

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Thinking Points

• Methodology
• Including data analysis
• Issue of Innateness
• On a larger scale, their interpretation of
  results
• Infants Expectations

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Object Permanence and Object Concept

• Object Permanence
• This paradigm and its results were taken as
  evidence of object permanence and object
  knowledge at ages as young as 3 months

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Schilling

• Numerous studies of the time course of
  information processing in infants (for example,
  Hunter Ames) have indicated that infants show a
  preference for a familiar stimulus after brief
  familiarization time
• Novelty preference emerges after longer exposure
  times, when the representation is more complete

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Schilling

• Novelty effects will emerge quicker if the
  stimulus is easy to process or infant is older
• In Baillargeon (1987), novelty effects were
  controlled by making the impossible screen
  rotation familiar
• If infants had been reacting as in typical
  studies, they should have looked longer to the
  120 deg rotation

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Schilling

• However, familiarity effects were not controlled
• That is, perhaps the infants did not completely
  encode the 180 deg screen movement and therefore
  showed a familiarity preference
• In fact, Baillargeons own 3 month data provides
  support for the familiarity hypothesis
• Only fast habituators looked longer at 180 deg
  impossible event
• Perhaps, they had least amount of exposure and so
  had not finished encoding 180 deg familiarization

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Schilling

• Investigated role of familiarity in explaining
  Baillargeons findings
• Condition A -- same as Baillargeon with 7
  familiarization trials to 180 with 4-month-olds
• Baillargeon predicts longer looking at 180 event
  because it was impossible
• Familiarity predicts longer looking at 180
  because it was familiar
• Condition B -- 12 familiarization trials
• Baillargeon predicts longer looking at 180 event
  because it was impossible
• Familiarity predicts longer looking at 112
  because it was novel
• Condition C -- 7 familiarization trials to 112
• Baillargeon predicts longer looking at 180
  because it was impossible
• Familiarity predicts longer looking at 112
  because it was familiar
• Condition D -- same as Condition A but with
  6-month-olds
• Baillargeon predicts longer looking at 180
  because it was impossible
• Familiarity predicts longer looking at 112
  because older are quicker information processors

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Schilling
Number of infants (out of 20) who reached
habituation criterion
Condition
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Schilling
Accumulated looking times during familiarization
Condition
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Schilling
Decline in looking during familiarization
Last 3
First 3
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Schilling
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Schilling

• Results provide evidence that the length and type
  of familiarization strongly affects looking
  behavior to possible and impossible events
• Results question role of object concept in
  directing looking behavior
• If it did, then infants would always be expected
  to look longer at 180 impossible event
• But they do not

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Cashon Cohen

• In original studies, a conceptual explanation is
  compared to a perceptual one
• Done by making possible event perceptually novel
• And making impossible event perceptually familiar
  
• Also, a control condition is done in which the
  two test events are compared to see whether
  infants have an a priori preference for one or
  the other
• It has been suggested that, contrary to
  Baillargeons interpretation, infants look longer
  at 180 impossible event because they prefer a
  greater amount of screen movement
• Demonstrated that infants look longer at 180 than
  112 even when no block was present
• Another possible explanation is the familiarity
  explanation

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Cashon Cohen

• Studies 8-month-olds because other studies, like
  Schillings, have not found evidence for object
  concept in infants 6 months and younger
• Predicted that 8 to 9-month-olds will based
  performance more on conceptual processing than
  perceptual processing
• To make sure infants would show a novelty
  preference, rather than a familiarity preference,
  used 20 habituation trials
• Compared habituators to non-habituators

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Cashon Cohen

• Habituated to one of
• 180 - no block
• 180 - block
• 120 - no block
• 120 - block
• Tested with all four
• Hypothesized that if infants view 180 - block as
  impossible, it would take them longer to
  habituate
• This did not happen

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Cashon Cohen
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Cashon Cohen Test of perceptual processes
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Cashon Cohen Test of familiarity hypothesis
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Cashon Cohen

• Infants respond on the basis of perceptual
  changes relative to habituation
• Not the impossibility of events
• Familiarity versus novelty of events are also at
  play
• Suggesting that infants in Baillargeon were not
  fully familiarized and therefore prefered the
  familiar event
• Here, where they had more familiarization trials
  and they were older, if they habituated, they
  prefered the perceptually novel but possible
  event over the perceptually familiar but
  impossible event

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Baillargeon The Reply

• Critics focus on one or two studies, but there
  are dozens of studies that found similar results
• So need to show in each study that perceptual
  accounts/familiarity issues are more parsimonious
  explanations of results
• Further have to show that the same explanation
  accounts for each study
• Baillargeon herself focuses on a few studies and
  we have to start somewhere
• Get to the rest of the studies in time

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Baillargeon The Reply

• Critics focus on the issue of habituation and the
  number of trials
• Recent study indicates that habituation trials
  are not necessary to get results
• Undermines issue of familiarity versus novelty
  effects
• However, the current studies DO find an effect of
  number of habituation trials
• Further, if they are not needed then should
  respond to impossible trials during
  familiarization differently then other types of
  familiarization, but do not

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Baillargeon The Reply

• Critics suggest that controls were not done in
  original experiment
• However, controls were done in which there was no
  box behind occluder
• A familiarity account would suggest that infants
  would still look longer to 180 even with no box,
  but the controls did not bear this out
• Again, results of current experiments are very
  consistent and contrary to Baillargeon

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Baillargeon The Reply

• Schillings condition D, experiment with
  6-month-olds, predicts that an object concept
  account would result in preference for 180 test
  event
• However, do not make this prediction
• Already done this experiment, and did not find a
  preference for 180
• If decreased habituation trials to one, then
  prefer 180
• Again, results of current experiments are very
  consistent and contrary to Baillargeon
• Further, Baillargeons own comment provides
  support for familiarity because 6 months did not
  prefer 180 as predicted by familiarity/perception
  account, but did prefer familiar 180 when had
  less trials/exposure

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Baillargeon The Reply

• Confused about Cashon Cohens use of
  8-month-olds and 20 habituation trials
• The debate is about young infants, not older
• 20 trials is a lot even with 6-month-olds who
  perform poorly with more than 6 trials
• Because a four test design was used and
  significantly different that original, this
  cannot be a replication and therefore cannot be
  used as a comparison
• The task never works under these conditions
• Again, her own arguments work against her
• If the task only works under very specified
  conditions then you can the original be
  interpreted as indicating infants conceptual
  knowledge
• Further, she does not seem to have a clue as to
  the purpose of the Cashon Cohen study
• In fact, 20 trials is not unusual in habituation
  studies
• Further, Baillargeon set 14 trials for
  habituation and still 30 of infants did not
  habituated, indicating that 14 was not enough

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Baillargeon The Reply

• Cashon Cohens and Schillings results are
  inconsistent with each other
• Cashon Cohen found that habituators (who had
  fewer trials) showed a novelty preference,
  whereas non-habituators (who had more trials)
  showed a familiarity preference
• Schilling found that when give more trials (12)
  get novelty preference as compared to fewer
  trials (7) get familiarity preference
• True the actual results seem to be inconsistent,
  but interpretations are consistent
• Infants who are not fully habituated, because
  they had fewer trials or did not reach
  habituation criterion, have preference for
  familiar (impossible event)

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Conclusion

• The original findings can be and were replicated,
  but only under certain circumstances
• That is, under conditions that lead to a
  familiarity preference, original findings are
  replicated
• Under conditions that lead to a novelty
  preference, original findings are not replicated
• Thus, the suggestion that infants prefer
  impossible because it violates object knowledge
  was not supported