Why be interested in perception in autism?
- Perception is the interpretation of sensory input – what we
see, hear, smell, taste and touch. - Theory of Mind (ToM) and Executive Functions (EF) are ‘higher
order’ mental processes. - Perception is a fundamental building block of more complex
cognitive and behavioural processes.
Enhanced Perceptual functioning
(Mottron et al., 2006)
The hypothesis:
Perceptual processing is superior in autistic people as they are very sensitive to the environment. This
superiority is hard to control and disrupts the development of
other behaviours and abilities.
a theory devised specifically to help us understand autism - as general models and theories were in place before we started thinking about autism
Pitch discrimination
(Bonnel et al., 2003)
- Same/different judgement - listened to two tones and have to say if they were the same or different
- High/low categorization - had to say which beep they heard was a low one or a higher one
- Autistic individuals showed
superior performance. - 12 autistic adolescents and 12
comparison adolescents. - very few ptps - Both groups intellectually high
functioning. - overlooked those with autism who have a lower IQ - Only looked at pitch - only one domain of auditory perception
Auditory discrimination
(Jones et al., 2009)
- broadened it beyond pitch
- Intensity Discrimination task
“which dinosaur makes a louder sound?” - Duration Discrimination task
“which dinosaur makes a longer sound?” - Frequency Discrimination task
“which dinosaur makes a higher sound?”
72 autistic adolescents and 48
non-autistic adolescents
Wide range of intellectual ability - covered the full spectrum of IQ
ptps saw a circle appear around each dinosaur as it made a sound and has to identity which was either louder, longer or higher.
- at a group mean level there was no significant differences between the groups
- so looked to see if there was a subgroup among the 72 autistic ptps who had exceptionally good auditory discrimination - as theres lots of variability within autistic people
subgroups with superior performance (1.65 SD above the non-autistic mean)
- subgroup of autistic people who are really good at pitch discrimination - the subgroup also had on average a higher IQ than their peers and they also had delayed language
in autism research or other types of neurodevelopment conditions - heterogeneity is a factor thats not always accounted for
Auditory discrimination
- 1 in 5 autistic adolescents had enhanced frequency
discrimination - They were characterised by average intellectual ability and
delayed language - Possible subgroup whose language development had been
impaired due to over-focus on perceptual cues (such as pitch) - if sensitive to changes in pitch may be distracting so maybe missing out on content/ semantics - trying to generate a theory for why the entrance pitch perception would Map on to the language delay
Putting EPF theory to the test
Universal?
Jones et al. (2009) suggest this is not the case. Further, there is
evidence of impaired as well as enhanced perceptual processing
in autism (e.g. Milne et al., 2002).
Unique?
Largely untested in other developmental disorders.
Putting EPF theory to the test
Explanatory power?
Good at explaining sensory sensitivities - restrict receptive behaviours (e.g. hypersensitivity to
sound).
Relies on a developmental ‘knock on’ effect of EPF on higher-order
social and cognitive abilities to explain the majority of autistic
behaviours. More research is needed (e.g. longitudinal studies) to
establish these links.
doesn’t describe all different types of symptoms and features of autism
enhanced perceptual functioning might stop you developing language skills, might stop you paying attention your peers which would then lead to difficulties in friendships
Weak central coherence (WCC)
Central coherence: a natural tendency to process stimuli as a
whole.
Weak central coherence: a bias for processing the parts of any
stimulus at the expense of the global whole.
example
“Red wheel” - autistic children called a red tractor a red wheel
WCC in autism
(e.g. Frith, 1989; Frith & Happé, 2006)
The hypothesis:
Autistic people have a local processing bias (i.e. features) at the
expense of processing the ‘whole’ (i.e. not getting the ‘gist’;
not seeing the ‘bigger picture’).
This has been framed as a superiority for perceiving details and
features. A different ‘cognitive style’. - enhanced ability to notice details
The embedded figures test
Autistic children are better and
quicker at finding the
‘embedded figure’ than non-
autistic children
(e.g. Shah & Frith, 1983).
Autistic children are less distracted by the whole image.
child has to work out where in image is the small triangle
the embedded figures test - harder version for adults
Planning/drawing test
Autistic children draw in an
atypical, fragmented way
and focus on details - more likely to start with window etc
(Booth et al., 2003).
if you draw the walls and frame first more typically you see the whole picture
if you draw the windows, chimney, door = more piecemeal
roof first = somewhere in the middle
Putting WCC theory to the test
Explanatory power?
WCC does not explain all symptoms:
* May interfere with social interaction e.g. focusing on an item
of clothing or object in the room may disrupt recognition of
facial emotion or processing on social information. - could detail development in some way or mean your not interacting in a typical way
* May explain some restricted and repetitive behaviours e.g.
intense preoccupations and attention to parts of objects - you may see things others may not necessarily notice
Atypical social orienting
(e.g. Dawson et al., 1998)
The hypothesis: Autistic individuals show reduced orienting to
social information, particularly the face and eyes. They
therefore fail to become ‘face experts’, which leads to reduced
ability to perceive face identity and emotional expression. - not same fundamental inputs as typical children in terms of development
Atypical looking to the face
(Klin et al., 2002)
Autistic and non-autistic adolescents and young
adults were filmed watching ‘Who’s afraid of
Virginia Woolf’.
An eye tracker monitored eye gaze.
The autistic group showed significantly less looking
to the eyes, and focussed more on mouths, bodies
and objects.
Increased looking to objects correlated with poorer
social skills.
Atypical looking at the eyes
(Kliemann et al., 2010)
Fixation cross led to first focus on face being on eyes or
mouth. - image was moved up or down so were forced to look at eyes or mouth
Subsequent eye gaze was monitored.
The non-autistic group showed significantly more shifts
towards the eyes rather than away from the eyes.
The autistic group showed significantly more shifts away
from the eyes rather than towards the eyes.
This suggests active avoidance of eye gaze, and not just a
lack of orienting.
typical looking to the eyes - Rutherford and towns 2008
they had to make an emotional judgement - this may affect what they naturally do
they measured looking to the eyes or the mouth
finding - autistic adults showed no difference in the amount of looking to the eyes and mouth when making emotion judgements
Putting atypical social orienting to the
test
Universal?
There are many studies that do not show impaired looking to the
face/eyes in autistic people (e.g. Rutherford & Towns, 2008).
Unique?
Individuals with Williams syndrome also show impaired looking
at faces, although there are condition-specific differences.
Putting atypical social orienting to the
test
Explanatory power?
Atypical social orienting aligns well with the social
communication difficulties seen in autism.
However, it does not adequately explain restricted and repetitive
behaviours.
The multiple deficit account
(Happé et al., 2006)
Single atypicality accounts make an assumption that the core
behaviours of autism occur together more often that would be
expected by chance as a result of a single underlying aetiology.
The multiple deficit account proposes that the behavioural
symptoms have distinct aetiologies.
multiple explanations will account for lots of the different behaviours of autism and if you have lots of different causes and lots of these different behaviours you will have a diagnosis of autism. if you just have one of those causes and only one behaviours you wont get a diagnosis of autism.
Towards a new explanation
Historically, researchers have focused on identifying a single
primary cognitive atypicality, which could account for the full
range of autistic behaviours.
Yet the “single-deficit” models proposed have all struggled to
provide complete explanatory accounts of autism. - with both social communication differences and restrictive and passive behaviour differences
So, where to go from here…?
multiple differences leading to an autism
genetic cause X – atypicality A:ToM – social and communicative symptoms
genetic cause Y – atypicality B:EF – restricted and receptive behaviours
genetic cause Z – atypicality C:WCC – attention to detail
Support for a multiple differences 1
- If a particular type of cognition (e.g. poor ToM) explains all
behavioural symptoms then these behaviours should be correlated. - social communication difficulties and difficulties in restricted and receptive behaviours - However, twin studies in the general population do not find this
(Ronald et al., 2006). 10% show atypicality in only one of three
areas (social impairment, communication impairment, restricted
and repetitive behaviours). - these are not correlated in the general population you can have difficulty in one area - not one single cause - Growing evidence suggests there is very limited genetic overlap
between the three areas (e.g. Ronald et al., 2006; Robinson et al.,
2012).
Support for a multiple differences 2
- Autism is heritable, but so are subclinical manifestations of
core behaviours. - The ‘broader autism phenotype’.
- Relatives often show isolated traits but may not have autism themselves (e.g. only restricted and
repetitive behaviours). - Different relatives with different behaviours indicates
independent genetic inheritance (e.g. Pickles et al., 2000).
Support for a multiple differences 3
- A single underlying cognitive/perceptual cause would predict
atypicalities at the neural level that are observed for the range
of behaviours. - However, a ‘social brain’ network has been identified (including
frontal and temporal regions - associated with ToM), which is very distinct from the
atypical subcortical activation associated with restricted and
repetitive behaviours. - not one single cause as we can distinguish these different neural pathways of these two areas
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Lecture One - Introduction To The Module And Big Questions38
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Lecture Two - Theories And History Of Cognitve Development46
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lecture three - attention39
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lecture four - social cognition50
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lecture five - expressing and understanding emotion49
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lecture six - attachment theory and research43
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lecture seven - social communication difficulties in autism38
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lecture eight - differences in perception in autism spectrum disorder32
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lecture nine - social understanding in the context of developmental conditions31
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lecture ten - child development in a social context48
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lecture eleven - parenting46
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lecture twelve - family structure and sibling relationships40
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lecture thirteen - childcare38
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lecture fourteen - peer relationships39
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lecture fifteen - gender differences65
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lecture sixteen - early communication and language development57
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lecture seventeen - moral and prosocial development66
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lecture eighteen - aggression44
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lecture nineteen - key themes in developmental psychology62
