5 Autism What is Autism l Prevalence of

5. Autism What is Autism l Prevalence of Autism l Autistic Spectrum Disorders l Characteristics of Autism l Diagnosing Autism l Theories l – theory-of-mind deficit theory – the executive function deficit theory – the central coherence theory l Learning Outcomes 1

What is Autism? complex developmental disability l Autism first described by Kanner (1943) l typically appears during the first three years of life l most severe childhood neuropsychiatric condition l triad of impairments l – socialisation – communication – imagination 2

Prevalence of Autism 2 -6 cases per 1, 000 l growing at a rate of 10 -17 percent per year l boy: girl 4: 1 l Usually identified before 30 months l No racial or socioeconomic differences l 3

Autistic Spectrum Disorders l 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) 4

Characteristics of Autism l 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 5

Characteristics of Autism – 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. 6

Language development l l 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' l l denial of personal identity? (psychoanalysts) l or just related to echoing Use of '-ing' – 'daddy piping', 'boy bubbling' (boy blowing bubbles) 9 yr old autistic girl (Wing 1976) 7

Social development physical and emotional distance from others l failure to develop social attachments l lack of cooperative group play l difficulties in reacting to or recognising other people's feelings l 8

Intellectual development poor on verbal ability l may perform above average on memory or spatial tasks l may be talented in music or drawing l 1/4 - 1/3 have IQ>70 l 9

Diagnosing Autism l l 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. 10

Diagnosing Autism l 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 11

Theories l Some current psychological theories of autism – theory-of-mind deficit theory – the executive function deficit theory – the central coherence theory 12

Theory of Mind l autistic children cannot engage in metarepresentations, therefore cannot develop To. M – 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. l 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) 13

Theory of Mind – 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) 14

Problems with To. M Prior et al (1990) found autistic children could succeed on Baron-Cohen et al's (1985) task l a child may fail a test for any number of uninteresting reasons such as lack of motivation, attention or task comprehension l 15

Executive Dysfunction l Executive function: – suppress incorrect response – retain relevant information in working memory l executive function involved in flexible planning – e. g. Tower of Hanoi l deficit occurs with frontal brain damage leading to perseverative behaviour l false photograph test (Leekam & Perner, 1991; Russell et al. , 1999) 16

Executive Dysfunction (2) l Not specific to autism – also occurs in schizophrenia l obsessive-compulsive disorder l Gilles de la Tourette syndrome l ADHD l Parkinson’s disease …and more. l So - by itself, executive dysfunction cannot explain autism l may co-occur with To. M deficit l 17

Problems with To. M & Executive Dysfunction Deficit accounts of autism fail to explain why people with autism show not only preserved but also superior skills in certain areas. l Savant skills l – ten times more common in people with autism than in others with mental handicap – occurring in approximately one in ten individuals with autism 18

Weak Central Coherence l 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 l l '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) 19

The Ebbinghaus Illusion (from Frith, 2003) 20

Weak Central Coherence l predicts: – relatively good performance where attention to local information (i. e. relatively piece-meal processing) is advantageous l 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 l l e. g. cannot integrate fragments to identify an object cognitive style rather than cognitive deficit. 21

Embedded figures test (from Frith, 2003) 22

Weak Central Coherence l Evidence: – Perceptual coherence. – Visuo-spatial constructional coherence – Verbal-semantic coherence weak coherence and theory of mind – independent (Happé, 1995) l savant skills l – musical talent – graphic talent 23

Wechsler Block Design Task (from Frith, 2003) 24

3 Complementary Theories? l Theory of Mind deficit – Social and communication impairments l Executive Function impairment – Stereotyped behaviour and narrow interests l Weak Central Coherence – Special talents and peaks in performance l Do these theories address three primary deficits affecting different brain systems? 25

Learning Outcomes Be able to describe autism and the characteristics of the disorder l Be able to describe and evaluate research on autism l Be able to describe and evaluate theories of autism l Be able to compare and contrast theories of autism l 26

Reading Essential Reading (on Digital Resources): l l 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: l See pdf handout 27

Questions to ask l l l What are the different theories of autism (at the cognitive level)? What does the research into autism tell us? Does the research support theories? 28