Understanding Autism Flashcards
how did kanner and asperger (1944) observe early infantile autism?
as a childhood condition where children failed to integrate into social interactions, and had atypical communication with others
triad of impairments
- social interaction difficulties
- communication difficulties
- restricted, repetitive behaviours and interests
social interaction difficulties
unresponsive behaviour and not sharing interests
communication difficulties
repetitive and impoverished language, and not engaging in pretend play
restricted, repetitive behaviours and interests
fascination with objects and routines, seen in stimming behavioue
DSM 2013 compressed autism into…
- persistent deficits in social communication and social interaction
- restricted, repetitive behaviours, activities, or interests
what percent of the population are autistic?
1%
what does the increase in autism diagnosis suggest?
a greater understanding and broadening of symptoms, along with higher use of screening tools
prevalence of autism in males than females
3:1, and women tend to gain a later diagnosis
when is the prevalence of autism highest?
in 6-12 year-olds, as behaviour is more likely to be picked up on
when is the biggest increase in diagnosis?
between 13-18 years-old
recognition of previously missed cases
why might classic childhood symptoms not be the best marker for ASD in adults?
as adults have learnt how to engage in neurotypical social interaction
how can late diagnosis be explained?
camouflaging behaviour
camouflaging behaviour
- compensation
- masking
- assimiation
compensation
improving behavioural symptoms makes it unlikely to score in the range of autism at a diagnostic manual
masking
presenting a known or less autistic persona
assimilation
used to fit into social situations
evidence of genetic factors in the aetiology of autism
folstein and rutter (1977) found 36% of MZ and 0% of DZ twins are concordant for autism diagnosis
what did plomin (1994) find?
higher concordance for autism in MZ twins over other conditions
what does a median estimate of 76% for MZ concordance reflect?
a broadening of autistic symptoms between 1977-2011 and increased use of screening tools
tick et al (2016) found __% of the variance in autism is explained by inherited genetic factors
93%
what does heritability of autism not specify?
which genes or SNPs are involved
genome wide association studies should be used to find contributing SNPs to risk of autism
evidence of autism having a polygenic cause
49% of variance in ASD was explained by common variants
what has the potential to confer risk for later ASD?
prenatal exposures, which can impact foetus development and cause genetic changes
environmental risk factors- advancing paternal age
offspring of men over 40 years-old were 5.75x more likely to be autistic
advancing paternal age caused a higher likelihood of passing on greater gene mutations
kinney et al (2008) found a dose response relationship between…
exposure to severe storms during pregnancy and risk for developing autism after birth
how does mind-blindness explain social characteristics of autism?
through an inability to read others mind and understand behaviour in terms of belief-desire reasoning
baron-cohen (1985) observed __% of children with ASD failed the false-belief task
80%
what did autistic children struggle with the concept of?
theory of mind
examples of deficits in TOM
- joint attention
- false-belief
- deception
- emotional understanding
how did baron-cohen attempt to explain the cause of autism?
damage to innate domain-specific TOM modules
which brain abnormalities led to failures in mindreading, along with later social difficulties?
abnormalities in the superior temporal sulcus (STS) and medial prefrontal cortex (mPFC)
evidence against mind-blindess
20% of autistic children passed false-belief tasks, and TOM is not heritable in neurotypical children
challenges the belief of an innate module
what does mind-blindness fail to explain?
non-social symptoms of autism, and TOM may not be linked to social impairments
how does executive dysfunction explain autiusm?
domain-general cognitive dysfunction of autism, through the conscious control of thought and action
what tasks are used to measure mental flexibility?
pre-potent responses task and shfting task
how did autistic children perform in mental flexibility tasks?
performed poorer than controls across all executive function measures
abnormal brain activity in ______ _____ in adults with ASD
frontal lobe
what did russel et al (1991) find?
executive function and TOM correlated in ASD, but this correlation decreases in adolescence
what does the executive function account fail to explain?
islets of ability
how does weak central coherence explain autism?
explains islets of ability, through the tendency to draw together diverse information to construct higher meaning in context
what did happe (2006) hypothesise?
autistic individuals will have difficulty with global processing and prefer featural and local information
where did autistic children show superior performance?
in the embedded figures task (1983)
where did autistic children make more errors?
in the homographs test (1997) as they struggled to take in sentence context to understand the word
what does longitudinal research show for weak central coherence?
it predicts TOM, but not social communication, executive function, or RRBI
where did the fractionable triad hypothesis originate from?
happe questioned whether autism is a single disorder with a single cause, due to the weak correlations between the fractionable triad in the general population
what might core symptoms have?
distinct causes at the genetic, neural, and cognitive level
why is it difficult to identify a single gene for autism
as core symptoms are independently heritable, and have different causes and behavioural presentations
