L13: Autism and Social Cognition

Neurodiversity

difference, usually defined with respect to what is considered typical

Historic Understanding of Autism

Kanner (1949): autism related to genuine lack of maternal warmth

later debunked

ASD

markedly atypical development with impairment in social interaction and communication and restricted repertoire of interests and activities

Characteristics of ASD

A: impairment of social interaction — non-verbal behavior, lack of peer relations

B: abnormal communication — delayed development of language, lack of social imitation

C: restricted interests, repetitive behaviors — inflexible routines or rituals, repetitive motions, reoccupation with parts of objects

Asperger’s

distinguished by no initial delay in language acquisition or cognitive difficulties, normal/high IQ

Prevalence of ASD

2.7% recent UK estimates

increase due to better services, broadening diagnostics

underdiagnoses in females

Genetic Basis of ASD

85% of all cases are idiopathic, 15% are due to rare genetic disorders

Neurology of ASD

cerebellum: attention shifts

amygdala: decoding emotional expression

temporal lobe: implicated in social perception and theory of mind

STS: activation found during perception of eye, face, mouth, hand, and body movement

parietal lobe: connectivity with frontal lobes

Weak Central Coherence Theory

superior processing of local structure/fine detail

inferior processing of overall/global structure OR ability to ignore global or contextual information

Savant Skills

Howlin et al (2009): 37% either have savant skills or more commonly an area of exceptional ability on Wechsler test, exceptional attention to local detail

O’Riordan et al (2001): superior performance in visual search, feature search: RT to find target is independent of number of distractors, pop-out, conjunction search: RT increases with number of distractors — serial deployment of attention, ASD score equally good on feature task, better than controls on conjunction task

Biological Motion Studies

no impairment in perception of biological motion BUT impaired perception of emotional state of actor

Blake et al (2003)

children with ASD differed in their ability to discriminate biological motion from typically developing children

no difference on global-form task — differences are not due to attention, motivation

Post Blake et al (2003)

various studies have shown un-impaired biological motion perception in ASD

main impairments evident at later stage of inferring intention, emotional state

Kiln et al (2009)

shows that very young ASD children are not sensitive to inversion of biological motion, more interested in audio-visual synchrony than forms

Riby and Hancock (2008)

14 participants with Williams syndrome showed prolonged face gaze

participants with ASD showed reduced face gaze