Perception of ambiguous stimuli by individuals with autism

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					Children’s Understanding and
Perception of Ambiguous Figures?
What are ambiguous figures?
Content   Perspective   Figure-ground
Why do ambiguous figures
reverse?
   Neural Satiation- Fatiguing of the neural
    process responsible for one perception leads
    to its end, and then the process for the
    alternative representation occurs.

   Top-down knowledge-The person’s
    knowledge of the two alternative percepts
    and their knowledge of the reversibility of the
    figure cause reversals.
Support for Bottom-up theories

 Studies using selective–adaptation
  paradigm
 Number of reversals reported increases
  over a time period of continuous viewing
Selective–adaptation paradigm
(Long, Toppino, Mondin, 1992)
Relationship between time and
reversals reported
(Toppino & Long, 1987)
 Support for Top-down theories

 Number of reversals reported are
  affected by the instructions given
 Uninformed subjects fail to reverse
  ambiguous figures
Instructions affect perception
(Seth & Reddy,1979; Liebert & Burk,
1985)
Failure to reverse ambiguous figures
by uninformed subjects.
(Rock and Mitchener, 1992)
Do young children reverse
ambiguous figures?
Procedure
-Report on initial perceptions
-Informing children of alternative perception
-Report on perception once informed
Summary of findings

Rock, Gopnik, & Hall 1994
1.) Found 3-4 year olds had difficulty
    reversing ambiguous figures even
    when informed
2.) The number of spontaneous reversals
    tends to increase with age.
Follow-up study
(Gopnik and Rosati, 2001)
1.) When does the ability to perceive
  reversals develop?
2.) How does the ability to perceive
  reversals relate to more abstract
  knowledge about multiple
  representations?
Gopnik and Rosati (2001) argue:

 Ambiguous figures involve multiple
  perceptual representations of the same
  object .
 Research has demonstrated that
  understanding multiple representations
  is quite difficult for young children.
Unexpected transfer test

   Children under age 5
    fail the Maxi task.
(Wimmer & Perner ,1983)
    Deceptive box test
   Between ages 3-5 children begin to
    understand different people hold different
    beliefs, and that their own beliefs may
    change. (Gopnik and Astington, 1988)
Droodle task
   By age 6 children appreciate that someone
    who shares their same visual perspective
    may interpret information differently (Taylor,
    1988).
What is the relationship between perceiving
ambiguous figures and understanding
multiple representations?

Gopnik and Rosati (2001)
1.) The ability to experience reversals might
    develop earlier than an abstract
    understanding of multiple representations

2.) The ability to perceive reversals might first
    require a more general understanding of
    multiple representations
    (Top-down explanation)
Method
 Tested 29 (3-5 year olds)
 Tasks
  - false belief task
  - droodle task
  - ambiguous figures
Findings

 Children only report reversals at about 5
  years of age.
 Children only reported reversals if they
  had passed false belief tasks.
 Children’s performance on the droodle
  task was correlated with their
  experiencing reversals.
Conclusion

Supports Top-down explanation
 The immediate experience of perceptual
  reversals may rely on a broader
  understanding of multiple
  representations (ambiguity).
Implications of Gopnik and
Rosati’s findings for Autism
   Triad of Impairments (Wing and Gould, 1979)
    Socialisation, communication, and
    imagination.

TOM Hypothesis of Autism
 Baron-Cohen, Leslie and Frith (1985)

- Individuals with autism fail False-belief
Ropar, Mitchell, Ackroyd (2003)
Rationale:
If individuals with autism have difficulties passing False-
    belief and Droodle tasks (TOM tasks)
And TOM tasks and AF tasks rely on understanding
    same underlying concept
Then individuals with autism who fail TOM tasks with
    have difficulty on AF task

Aim: Present individuals with autism with False-belief,
     Droodle, & AF tasks
Criticisms of Gopnik and
Rosati’s Method
  Unreliability of verbal reports of perceptions
-failure to report when see reversal
-reporting they see reversal when they don’t

 15 of 21 in Gopnik & Rosati’s needed
  prompting by experimenter pointing to
  features
- leads us to focus on ability to identify
  alternative rather than report reversals
Ropar, Mitchell, & Ackroyd (in press)

   Stimuli - simple, less familiar, head and tail at
    opposite ends




Subjects-   22 Autism, 25 MLD, 18 Typ. 7-8 yr olds
                         FB=false belief
 Results                 AF = Ambiguous figures

Group       All FB q’s       Correct on    Saw both Alternatives
            correct          Droodle       on both AF
Autistic    4                5             16
MLD         17               18            16
            Sig (<.01)       Sig (<.01)    n.s.




Provides  evidence against Gopnik and Rosati’s claim
that both TOM tests and reversing AF draw on the same
underlying concept.
Discussion
   Why then is AF easier for those with autism?
    Perhaps the difficulty is not with switching to other
    representation but acknowledging their earlier
    interpretation (like Appearance-reality task)
   However, AF differs as it requires one to interpret the
    same information in a different way, rather than
    revise their beliefs (like with App. Reality & TOM)

   Conclusion: Handling revision of beliefs is difficult for
    children with autism, while forming multiple
    representations of a single stimulus is relatively easy.
    Discussion questions
 1.) Which theory of perceiving AF do you agree with
  more and why? (List and explain your reasons.)
 2.) Do you agree or disagree with the following
  statement:
   If a child can successfully reverse one type of AF
  they should be able to reverse other types? (Explain
  your reasons for your stance); What would a
  Piagetian or rather a Domain general account of child
  development think? (List and explain your reasons.)
 3.) Are reporting reversals and being able to
  acknowledge two representations the same thing?

				
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posted:9/15/2012
language:English
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