The Psychology of Autistic Spectrum Disorders and Implications for Practice

Dr Fiona J ScottAutism Research Centre

University of Cambridge

Autistic Spectrum Disorders:

• Difficulties with reciprocal social interaction

• Difficulties with communication

• Restricted/repetitive interests & behaviours

• Unusual sensory responses/processing

• Uneven abilities

• Savant skills

Key Psychological Theories:

• Theory of Mind

•Systemising – Empathising model

•Weak Central Coherence

•Feature Processing

‘Canary Wharf’

drawn by

Stephen Wiltshire, from ‘Cities’ (1989) Dent & Sons,

London

‘Central Coherence’ (e.g., Frith 1989):

•The everyday tendency to process information in CONTEXT for GIST

•Pulling information together for higher level MEANING

Embedded Figures Test (Shah & Frith 1983)

Block Design (Shah & Frith 1993)

“ In her dress there was a big tear”

(Frith & Snowling 1983)

Homographs:

“The sea tastes of salt and……”

(Happe, 2000)

Sentence Completion:

Brosnan & Scott (2004):

‘Gestalt processing’

Children with autism show significantly less ability to process ‘nature relationships’ between stimuli.

‘Feature Processing’ (e.g., Plaisted, 1999):

•Enhanced discrimination & reduced generalisation in autism

• Inability to recognise similarities between stimuli or situations

‘Systemising – Empathising’ (e.g., Baron-Cohen, 2003)

• Understand according to rules & regulations

• Analysis of input-output relationships

Systemising:

Empathising:

• Understand according to socio-emotional experience

• Includes ToM

• Superior systemising depends on EXACTNESS in information processing

• Excellent detail is being detected, ALL information is considered

Baron-Cohen et al., (2003):

Systemising

AS/HFA males > AS/HFA females > controls (M>F)

Empathising

AS/HFA males < AS/HFA females < controls (M<F)

Neural Explanation?

•Increased cell density in brains of people with autism (Piven et al, 1995)

•Failure of ‘pruning’ in brain development (Murphy et al., 2002)

•Macrencephaly by 2 years of age (Bolton et al., ongoing; Courchesne et al., 2001)

Social difficulties:

•Poor processing of faces (e.g., identity – Ashwin, ongoing)

•Difficulty reading emotions

•Inability to easily see generalities

Communication difficulties:

•Language requires understanding of meaning

•Need meaning to see communicative purpose

•Language is heavily context dependent

Routines, rituals and rigidity:

Kanner (1943) “ ..a situation, a performance, a sentence is not regarded as complete if it is not made up of exactly the same elements that were present at the time the child was first confronted with it”

Sensory abnormalities (e.g., Belmonte, 2003):

• Overconnected network passes so much ‘noise’ it swamps the signal?

• Or an underconnected network passes so little signal it is lost in the noise?

• Filtering in autism is all-or-none

•Hyper sensitivity - due to detailed processing of features with equal weight?

•Hypo sensitivity - due to cognitive shut-down when stimuli are too intense?

Savant skills & uneven profiles:Feature processing would be good for:-

•Perfect/absolute pitch (Heaton et al 1998)

•Graphic/drawing skills (Mottron et al, 2000; Pring et al., 1995)

•Recall of facts, concrete information

•Upside down jigsaws, noticing details

Practical developments:

• Diagnostic/screening tools (e.g., AQ)

• Genetic & neurological detection & understanding

• Appropriate intervention & management

• Improved understanding

Conclusions:

Autism results from an “embarrassment of riches”? (Happe, 1999)

Psychological theories such as WCC, feature processing, & systemising can help to explain social & communication deficits, stereotypies & rigidity, sensory oddities, and cognitive & savant skills in autism.

Future research may help explain why in a neurological, and perhaps genetic, sense.