Aetiology of autism Flashcards
MMR vaccine
Link? – no supporting ev
refrigerator parenting
Cold, rejecting, emotionally unavailable
Concordance rates between sibs/fraternal twins approx. 3%
Concordance rates between identical twins ranges between 3- and 80% (small samples)
foetal testosterone
Higher foetal testosterone associated with higher levels of autistic symptoms in both genders, but esp. for boys
empathising and systemising
Autism and Asperger syndrome: below-average empathy and average/above average systemising
exec functions
Children with autism perf poorly on exec function tasks – display difficulties with planning and set-shifting
ToM explanations
‘False belief’ test should be able to cover Wing and Gould’s triad: o Socialisation (difficulty with social r’ships) o Communication (literalness) o Imagination (inability to suspend disbelief)
Autists predicted to fail false belief test
structure of Baron-Cohen’s test
Two dolls called Sally and Ann
Sally has a basket and Ann has a box
Sally puts her marble in the basket and leaves
When Sally is away, Ann puts the marble in the box
Sally’s going to come back now!
Where will Sally look?
Baron-Cohen et al. (1985)
Note that the Down’s and autistic groups were matched on verbal mental age – the autistic group had a mean verbal age of 5.5 years but chronological age of 12
problems with Baron-Cohen et al (1985)
Perhaps autistic children unable to get involved in story that required them to suspend disbelief
Perhaps thought that if Sally is doll, she has no mind and Q put is meaningless
How are criticisms met?
More exps that take them into account
Leslie and Frith’s test (1988)
Leslie (L), Frith (F), and child (C) all get together and put a penny under an upturned cup
F leaves the room
L and C conspire and put the penny under another upturned cup nearby
F returns
L asks C - where will F look for the penny?
They used a group with specific language impairment instead of Down’s
Result similar to Baron-Cohen et al. (1985)
Mitchell and Isaac’s (1994) task
Small dolls used - ‘Mum’ and ‘John’. And some props!
Mum has two bags of wool. She puts one in the drawer and the other in the cupboard
Mum leaves
John comes in, plays with the wool, and puts the bags back but they are swapped around!
Mum calls through to John. “I need one of the bags of wool! It’s the bag in the drawer”
Get Mum the bag she really wants
interpreted message literally rather than correctly
able to correct once prompted
This has a certain ecological validity
what about speech production?
Know from clinical observation that autistic children ‘naively honest’
Why?
Can’t take into account lies in relation to holding false belief
o Lies can lead victim of message to believe something that is false – so understanding that lies can serve to conceal truth from another person might only be possible if one understood that people hold beliefs that can either be true or false
Sodian and Frith (1992)
A ‘treat’ was put inside one of two small treasure chests.
Enter ‘nasty thief’! He demands the treat and asks the child - where is it?
Autistic children rarely lie to the nasty thief and will tell him where the treat is
But, in another experiment, autistic children could lock the treasure chest to prevent the nasty thief getting the treasure!
So - the autistic children were able to prevent the thief getting what they wanted but couldn’t use lies to achieve their goal
To me this is a clear sign that ToM explanations are very much in the tradition of theories of deficit
if autistic children have communication problems, then how do they get what they want?
Experimenter places desired toy on high shelf
Autistic children have two strategies
Ignore experimenter and use another object e.g. chair
“The other was to try to drag the experimenter over to the shelf with force, as though the experimenter were a heavy physical object that had to be shifted” (Mitchell; p86)
is ToM the whole story?
Happé (199) – should look at the skill of autists as well as their shortcomings when constructing theory
central coherence explanation - Happé
Autism characterised by ‘weak central coherence’ (Frith, 1989)
Central coherence - “…to process incoming information in context for gist - pulling information together for higher level meaning, often at the expense of memory for details”
advantages
Skills and shortcomings are explained
Theoretically, it’s elegant as it relies on simple cog process
Predicts range of good or superior skills and inabilities or deficits
perceptual processing
Autists not susceptible to Titchener circles
Anecdotes provided by parents suggest that autistic children have problems with, for example, walking down stairs unless light and shadow provide depth cues
Autists good at embedded figures
verbal-semantic coherence
Sea tastes of salt and …
Can go hunting with knife and …
In her eye there was a big tear
In her dress there was a big tear
savant skills
Absolute pitch unusually common in autistic children
Autists find easy to cope ‘globally incoherent’ figures
How many indvs with autism have savant skills?
remarkable abilities
Mark Twain gave this description of “Blind Tom” in 1869:
“One of his most remarkable feats was the performance of three pieces of music at once. He played Fisher’s Hornpipe with one hand, Yankee Doodle Dandy with the other, and sang Dixie all at once …”
Derek Paravicini
Born 25 weeks prematurely, and lost sight soon after birth. Has learning difficulties and is autistic. Recognised as a musical genius and can play a piece of music – jazz, classical, pop, etc. – after having heard it only once.
Stephen Wiltshire MBE, the “human camera” (autistic savant)
