1 5. autism what is autism prevalence of autism autistic spectrum disorders characteristics of...
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5. Autism
What is AutismPrevalence of AutismAutistic Spectrum DisordersCharacteristics of AutismDiagnosing AutismTheories
– the theory-of-mind deficit theory
– the executive function deficit theory
– the central coherence theory Learning Outcomes
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What is Autism?
complex developmental disability Autism first described by Kanner (1943) typically appears during the first three
years of lifemost severe childhood neuropsychiatric
condition triad of impairments
– socialisation– communication– imagination
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Prevalence of Autism
2-6 cases per 1,000growing at a rate of 10-17 percent per
yearboy:girl 4:1Usually identified before 30 monthsNo racial or socioeconomic differences
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Autistic Spectrum Disorders
Autism is one of five disorders coming under the umbrella of Pervasive Developmental Disorders (PDD)
– Autistic Disorder
– Asperger's Disorder
– Childhood Disintegrative Disorder (CDD)
– Rett's Disorder
– PDD-Not Otherwise Specified (PDD-NOS)
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Characteristics of Autism Persons with autism may exhibit some of the
following traits.
– Insistence on sameness; resistance to change – Difficulty in expressing needs; uses gestures or
pointing instead of words – Repeating words or phrases in place of normal,
responsive language – Laughing, crying, showing distress for reasons not
apparent to others – Prefers to be alone; aloof manner – Tantrums – Difficulty in mixing with others – May not want to cuddle or be cuddled – Little or no eye contact
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– Unresponsive to normal teaching methods – Sustained odd play – Spins objects – Inappropriate attachments to objects – Apparent over-sensitivity or under-sensitivity
to pain – No real fears of danger – Noticeable physical over-activity or extreme
under-activity – Uneven gross/fine motor skills – Not responsive to verbal cues; acts as if deaf
although hearing tests in normal range.
Characteristics of Autism
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Language development
delayed and deviant peculiar use of sounds and words Echolalia Pronominal reversal - use 'i' where 'you' is
meant and vice-versa
– e.g. 'do you want a drink' instead of 'i want a drink'
denial of personal identity? (psychoanalysts)
or just related to echoing
Use of '-ing'
– 'daddy piping', 'boy bubbling' (boy blowing bubbles) - 9 yr old autistic girl (Wing 1976)
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Social development
physical and emotional distance from others
failure to develop social attachments lack of cooperative group playdifficulties in reacting to or recognising
other people's feelings
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Intellectual development
poor on verbal abilitymay perform above average on memory
or spatial tasksmay be talented in music or drawing1/4 - 1/3 have IQ>70
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Diagnosing Autism
no medical tests for diagnosing autism Early Diagnosis Diagnostic Tools The NICHD lists these five behaviors that signal
further evaluation is warranted:– Does not babble or coo by 12 months
– Does not gesture (point, wave, grasp) by 12 months
– Does not say single words by 16 months
– Does not say two-word phrases on his or her own by 24 months
– Has any loss of any language or social skill at any age.
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several tests have been developed that are now used in diagnosing autism
– CARS rating system (Childhood Autism Rating Scale)
– The Checklist for Autism in Toddlers (CHAT)
– The Autism Screening Questionnaire
– The Screening Test for Autism in Two-Year Olds
Diagnosing Autism
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Theories
Some current psychological theories of autism
– the theory-of-mind deficit theory
– the executive function deficit theory
– the central coherence theory
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Theory of Mind autistic children cannot engage in meta-
representations, therefore cannot develop ToM– autistic children don't seem to show pretend/symbolic play (Baron-
Cohen, 1987)
– Therefore predict poor performance on false belief tasks
– Baron-Cohen, Leslie & Frith (1985) found this poor performance.
Also:
– chance performance on mental-physical distinction (Baron-Cohen, 1989)
– poor understanding of functions of the mind (Baron-Cohen, 1989)
– fail appearance-reality tests (Baron-Cohen, 1989)
– don’t know that “seeing leads to knowing” (Baron-Cohen & Goodheart, 1994; Leslie & Frith, 1988)
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– chance performance on recognising mental state words (Baron-Cohen et al., 1994)
– don’t produce range of mental state words (Tager-Flusberg, 1992)
– difficulty understanding complex causes of emotion (Baron-Cohen, 1991)
– don’t know that eye region indicates thoughts/wants (Baron-Cohen & Cross, 1992)
– fail to make accidental-intentional distinction (Phillips, 1993)
– unable to deceive (Baron-Cohen, 1992)
– don’t understand intentionally non-literal statements (Happé, 1994)
– poor use of pragmatics (Baron-Cohen, 1988)
Theory of Mind
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Problems with ToM
Prior et al (1990) found autistic children could succeed on Baron-Cohen et al's (1985) task
a child may fail a test for any number of uninteresting reasons such as lack of motivation, attention or task comprehension
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Executive Dysfunction
Executive function:– suppress incorrect response– retain relevant information in working memory
executive function involved in flexible planning – e.g. Tower of Hanoi
deficit occurs with frontal brain damage leading to perseverative behaviour
false photograph test (Leekam & Perner, 1991; Russell et al., 1999)
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Not specific to autism– also occurs in
schizophreniaobsessive-compulsive disorderGilles de la Tourette syndromeADHDParkinson’s disease…and more.
So - by itself, executive dysfunction cannot explain autism
may co-occur with ToM deficit
Executive Dysfunction (2)
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Problems with ToM & Executive DysfunctionDeficit accounts of autism fail to explain
why people with autism show not only preserved but also superior skills in certain areas.
Savant skills
– ten times more common in people with autism than in others with mental handicap
– occurring in approximately one in ten individuals with autism
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Weak Central Coherence
Central coherence (Frith, 1989)– people need/desire high-level meaning
– everyday tendency to process incoming information in context for gist
– this feature of human information processing is disturbed in autism
'weak central coherence' autism biased toward local vs global info processing
– "inability to experience wholes without full attention to the constituent parts”
– do not succumb to visual illusions (Happé, 1996)
– failure to use context in reading (Happé, 1995)
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predicts:– relatively good performance where attention
to local information (i.e. relatively piece-meal processing) is advantageous
e.g. can recognise object from a single part
– poor performance on tasks requiring the recognition of global meaning or integration of stimuli in context
e.g. cannot integrate fragments to identify an object
cognitive style rather than cognitive deficit.
Weak Central Coherence
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Weak Central Coherence
Evidence:
– Perceptual coherence.
– Visuo-spatial constructional coherence
– Verbal-semantic coherenceweak coherence and theory of mind –
independent (Happé, 1995)savant skills
– musical talent
– graphic talent
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3 Complementary Theories?
Theory of Mind deficit– Social and communication impairments
Executive Function impairment– Stereotyped behaviour and narrow interests
Weak Central Coherence– Special talents and peaks in performance
Do these theories address three primary deficits affecting different brain systems?
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Learning Outcomes
Be able to describe autism and the characteristics of the disorder
Be able to describe and evaluate research on autism
Be able to describe and evaluate theories of autism
Be able to compare and contrast theories of autism
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Reading
Essential Reading (on Digital Resources): Frith, U. & Happe, F. (1994) Autism: Beyond
Theory of Mind. Cognition, 50, pp.115-132 Frith, U. & Hill, E. (2004) Autism: Mind and
brain. Oxford: Oxford University Press. Chapter 1.
Further Reading: See pdf handout