1 5. Autism What is Autism Prevalence of Autism Autistic Spectrum Disorders Characteristics of Autism Diagnosing Autism Theories –the theory-of-mind deficit.

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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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The Ebbinghaus Illusion (from Frith, 2003)

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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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Embedded figures test (from Frith, 2003)

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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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Wechsler Block Design Task (from Frith, 2003)

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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

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Questions to ask

What are the different theories of autism (at the cognitive level)?

What does the research into autism tell us? Does the research support the theories?