Autism Flashcards
True or false? Explain your answer if necessary. (1)
Epidemiological studies suggest that ASD aetiology is entirely environmental, and does not have a genetic component.
False - Epidemiological studies suggest that ASD aetiology has a strong genetic component
What is the concordance rate for autism amongst monozygotic twins? (1)
60-70%
What is the concordance rate for autism amongst siblings? (1)
18-33%
Give the two core diagnostic criteria for ASD. (2)
- Persistent deficits in social communication and interactions
- Perseverative behaviours and interests
Fill the gaps relating to ASD. (4)
In addition to the core diagnostic criteria, most affected individuals also show aberrant reactivity to …………………… or ‘unusual interest’ in …………………… aspects of the environment.
They may also display deficits in ………………….., or general clumsiness, which may exacerbate ……………………….
sensory input
sensory
motor skills
social exclusion
Give three examples of specific sensory behaviours which may be seen in ASD. (3)
- Adverse responses to sounds or textures
- Excessive smelling or touching of objects
- Visual fascination with lights or movement
True or false? Explain your answer if necessary. (1)
25% of people on the autistic spectrum cannot drive due to difficulties interacting with dynamic objects.
False - it is actually more than 75%
Describe how difficulties interacting with dynamic objects in autistic people may manifest in childhood. (1)
Individuals with autism often describe the difficulties they had as children engaging in athletic games or team sports on the playground.
Fill the gaps relating to ASD. (6)
People with ASD often have difficulties interacting with ………………….. objects.
Several studies have shown that basic ……………………. and …………………… thresholds are largely unimpaired in autism.
However, to interact with a dynamic object, there is a crucial step beyond simple detection - ………………….. of where the moving object is likely to be at a given moment in the future.
Accurate anticipation skills help us to plan our ………………………… appropriately to intercept or avoid objects.
Even the seemingly simple task of keeping track of a moving object requires such ……………………
dynamic
object motion detection
direction perception
anticipation
motor movements
anticipation
Briefly describe the rubber hand illusion. (4)
- Patient has their hand in a box but cannot see it
- They can see a rubber hand placed near their own hand
- Give tactile stimuli to rubber hand and/or own hand and see reaction (i.e. does person retract hand)
- Then give a subsequent task involving reaching and grasping movements
How do people with ASD react to the perceptual effects of the rubber hand illusion? (1)
They react typically - no difference between ASD and non-ASD individuals
How do people with ASD react to the subsequent motor task following the rubber hand illusion? (2)
The influence of the illusion was reduced compared to controls
People with ASD perform better on the reaching and grasping movements
Give a possible explanation as to why individuals with ASD perform better on a motor task after the rubber hand illusion (the influence of the illusion is reduced in ASD). (1)
They may assign stronger weighting (precision) to proprioceptive sensory input relative to prior contextual information.
Fill the gaps relating to ASD. (9)
The Rubber Hand illusion study highlights the relatively lower weighting assigned by people with ASD to …………………………… versus ………………………….
Sensory information can be noisy and ambiguous, and so integrating ……………………… and ……………………………. into motor movements is necessary to optimally ………………………….. and predict the …………………….. of objects in the external world.
Motor incoordination in ASD can be explained by the increased weighting of ………………………. in perceptual inference.
Relying too heavily on incoming sensory information at the expense of prior information usually leads to a less accurate sense of ……………………….., which may contribute to clinical symptoms of ……………………… (and the reduced smoothness of movement observed for the clinical group in this study).
prior or contextual information
sensory feedback
prior beliefs
contextual information
interact with
motion
sensory information
body position
motor incoordination
The rubber hand illusion can mislead performance in neurotypical subjects.
Suggest why this might be. (1)
What is the advantage of this? (1)
They have an increased weighting of higher-order contextual information versus sensory input.
This increased weighting of higher-order contextual information to guide movement will usually be of benefit when engaged in skilled motor performance tasks (e.g., when performing movement without visual feedback).
True or false? Explain your answer if necessary. (1)
Sensory hypersensitivities in ASD can be explained by abnormal enhancements in sensory organs and in the lower-level processing of sensory information.
False - sensory hypersensitivities CANNOT necessarily be explained by these concepts
Complete the sentence. (1)
Sensory hypersensitivities in ASD may arise due to a reduced ability to ……………………………..
*Hint: it is a phrase
habituate to novel environmental stimuli.
Fill the gaps relating to sensory hypersensitivities in ASD. (4)
Sensory hypersensitivities may arise due to a reduced ability to ……………………… to novel environmental stimuli.
A key determinant of our ability to do this is ………………………….
The lack of predictability of our surroundings would compromise ………………………. and lead to ………………………….
habituate
stimulus predictability
habituation
hypersensitivity
Describe what is meant by ‘habituation’, and give an example. (4)
A type of learning that involves a decrease in behavioural response
to a repeated stimulus over time.
It’s a conscious or active shift in attention that can occur without much thought.
For example, if you hear a loud, sudden sound like a siren or thunderclap, you might jump or stop what you’re doing.Once you confirm that you’re not in danger, you’ll calm down and resume your activities.
Describe how loudness adaptation is affected in adults with ASD. (1)
Adults with ASD tend to display decreased loudness adaptation.
Describe why adults with ASD tend to show decreased loudness adaptation. (2)
Could be caused by a failure to update prior beliefs (predictions)
and a dampening of the ability to reduce surprise during a series of predictable stimuli.
What is ‘loudness adaptation’? (1)
A decrease in how loud a constant sound is perceived as over time.
Finish the sentence. (1)
Being immersed in a novel ambiguous (noisy) environment can feel like we are being unrelentingly bombarded by salient sensory stimuli.
Our capacity to habituate is dependent on …
**Hint: it is a phrase
our ability to suppress this sustained stimulation and prevent sensory overload.
Finish the sentence. (1)
Sensory bombardment is a known stressor and a cause of anxiety even in non-ASD subjects.
Thus, the aversion to environmental sounds that individuals with autism exhibit could arise from …
**Hint: it is a phrase
a reduced capacity to habituate.
True or false? Explain your answer if necessary. (1)
Environmental unpredictability is strongly correlated with anxiety.
True
Fill the gaps relating to ASD. (5)
Environmental unpredictability is strongly correlated with …………………..
A reduction in the ability to predict events, even non-threatening social situations, enhances ……………………..
Anxiety, especially when it is elevated chronically, is known to give rise to ………………………..
The behaviours that emerge under conditions of unpredictability serve as a …………………… response to an …………………….. These behaviours may be as benign as leg-swinging in school children who are working on a stressful math examination or more alarming stereotypies that inflict self-injury.
anxiety
anxious responses
ritualistic behaviour
calming
external stressor
How does the incidence rate of ASD change in rural settings vs cities? (1)
Higher rates in children living in cities (is this because there is more unpredictable stimuli?)
Fill the gaps relating to ASD. (6)
Sometimes referred to as ……………………, compulsive ritualistic behaviours in ASD can often be regarded as …………………………. and resemble ………………………….
They can manifest as an …………………….. response to a chaotic world and function to drown out the influx of ……………………………. through an increase in self-generated periodic and, hence, ……………………. stimuli.
self-stimulating behaviours (stimming)
socially inappropriate
involuntary motor ticks
anxiolytic-type
unpredictable environmental information
more predictable
A key feature of ASD is the ‘insistence on sameness’. Give five examples of how this trait may manifest. (5)
- Repetitive thoughts and actions
- Behavioural rigidity
- Reliance on routines
- Resistance to change
- Obsessive adherence to rituals
Fill the gaps relating to ASD. (10)
Highly functioning individuals on the autism spectrum used to be referred to as having …………………………….. These individuals usually lacked a general retardation in …………………… and did not display ……………………….
This term has been retired as a diagnostic classification and the autism spectrum has been widened to now include individuals who display …………………………………… at first sight.
However, their ability to cope with the demands of daily social situations and changing complex environmental settings can be ………………
This chronic stress can cause significant ……………………. and …………………….., and can predispose people with ASD to comorbidities, e.g., ………………….., ………………., or …………………
Asperger syndrome
language
intellectual disability
only a few classical symptoms of ASD
frail
mental exhaustion
internal suffering
depression
anxiety
substance misuse
Describe how ASD features may change over the lifespan. (2)
May remain hidden until they are unmasked by increasing social interactions and demands during childhood.
May also become less noticeable in adulthood due to the development of situational coping strategies.
Give four examples of situational coping strategies that may be used in ASD. (4)
- Repeating phrases exactly as others have said them
- Creating scripts to use in social situations
- Using behaviours learned from watching other interactions
- Practicing facial expressions and body language
Fill the gaps relating to ASD and Bayesian information processing. (6)
Autism spectrum disorder is clinically characterized by prominent disruptions to one’s ……………………., which may be explained by an impairment of …………………………
Individuals with ASD have striking difficulties in distinguishing between ……………………. details and ……………………. changes in their environment.
Apparent subtle changes in environment (e.g., variations in location or timing) can be sufficient to induce feelings of ………………….. and a …………………..
perception
hierarchical Bayesian inference
relevant/informative
irrelevant/random
uncertainty
lack of control
Give 2 examples of a person with ASD being unable to distinguish between relevant and irrelevant changes in their environment or situation. (2)
During social interactions, a person with ASD may direct more attention to a bright colourful pullover rather then to the emotional expression on a friend’s face.
Meeting a friend in a pub in the evening may feel like a very alien situation compared to their usual afternoon meet-up in the university cafe.
Describe how generative/internal models of the outside world are affected in people with ASD. (2)
People with ASD struggle to establish abstract and generalisable representations that can be applied to a broad range of environmental situations.
Instead, they tend to generate overly precise models (priors) of single observations and sensory stimuli.
True or false? Explain your answer if necessary. (1)
People with ASD tend to establish overly-generalisable internal models that can be applied to many different situations.
False - people with ASD struggle to establish abstract and generalisable representations
Fill the gaps relating to ASD and Bayesian information processing. (4)
In people with ASD, the fact that they struggle to establish generalisable internal models can induce a chronic sensation of being …………………. for whatever may happen, unless they can exert …………………. (and thus avoid …………………) in a stable, well-known environment.
This feeling may underlie their desire for …………………., such as never changing the exact order of a sequence of actions in everyday life.
unprepared
control
surprise
fixed rituals
True or false? Explain your answer if necessary. (1)
Several recent articles have suggested that aberrant Bayesian inference underlies perceptual abnormalities in ASD.
True
Describe two theories regarding aberrant Bayesian inference underlying ASD (specifically relating to prior beliefs). (2)
ASD is characterized by overly flat (imprecise) priors, which lead to percepts dominated by the sensory input.
In ASD, an overly high weighting is assigned to sensory stimuli which may increase prediction errors and lead to overly precise (non-generalizable) priors.
Fill the gaps relating to ASD and Bayesian information processing. (6)
Lawson et al. suggest that the ………………… of top-down predictions need to be weighted against the ………………….. of bottom-up sensory input. They highlighted the importance of ………………………. as a potential neurobiological mechanism for precision weighting and hypothesized that neuromodulators such as ………………, ……………., or …………….. could play a central role in fine tuning prediction errors at each hierarchical level of sensory neural pathways.
precision
expected precision
postsynaptic gain control
GABA
acetylcholine
oxytocin
What is meant by ‘postsynaptic gain control’? (6)
Brain and spinal cord have many neural ensembles, which are modulated by interneurons
Higher cognitive centres send predictions down the hierarchical sensory processing pathway
Predictions regulate the postsynaptic gain (level of signals which get through each gate in the hierarchy)
Imprecise prior models = imprecise predictions = lots of prediction errors getting to brain
So higher postsynaptic gain and more precision weighting applied to sensory input
Therefore, internal models are constantly being updated using new information (prediction errors) which gets to brain
Describe the pathway that predictions (priors) take when they are generated and sent down the hierarchical information processing nodes. (4)
cortex
thalamus
midbrain
spinal cord
Fill the gaps relating to postsynaptic gain control. (5)
In terms of neuronal signals, predictions may take the form of ……………………. that function to modulate ……………………… activity in key neural ensembles of the …………………….. pathways.
Thus, any deviations between sensory inputs and prior beliefs ascend up the hierarchy and are integrated as …………………….. that serve to …………………………….
trains of action potentials
inhibitory interneurone
afferent sensory
prediction errors
update our model of the external world
Give four different ‘types’ of inhibition by interneurones, in terms of how interneurones are connected with projection neurones. (4)
Feedforward inhibition
Recurrent feedback inhibition
Lateral feedback inhibition
Disinhibition
Give four ways to classify interneurones. (4)
Why are these important when looking at postsynaptic gain control? (1)
- Morphology
- Connectivity
- Markers
- Intrinsic properties
A combination of these properties will determine how the interneurone acts to modify postsynaptic gain control.
Describe feedforward inhibition. (2)
Principle (projection) cell and interneurone both activated by same input neurone
Interneurone then inhibits principle cell.
