Autism Spectrum Disorders

Eduqas GCE A-Level Psychology - Component 3 - ASD

What is ASD?

ASD is a lifelong developmental disorder that begins in childhood and impairs everyday functioning. It is characterised by a persistent impairment in reciprocal social communication and social interaction, repetitive patterns of behaviour, interests or activities. It is a spectrum disorder which means that everyone shares the same core difficulties, but they are affected to different degrees.

In 2013, the DSM-V changed the criteria for ASD to three levels, what are they?

• Level 1 - requiring support - without support social interaction is impaired.

• Level 2 - requiring substantial support - even with support, there will be impaired functioning

• Level 3 - requiring very substantial support - even with support, there will be severely impaired functioning

Define the social communication deficits of ASD.

People with ASD struggle to use both verbal and non-verbal communication in social interactions.

What is social-emotional reciprocity?

People with ASD don’t initiate conversation or find it easy to respond to others. Interactions tend to be one-sided, as people with ASD struggle to maintain the flow of conversation. Sometimes, the medium of response may be inappropriate (e.g. touching).

What deficits in non-verbal communication may a person with ASD experience?

People with ASD rarely use facial expressions, and when they do they may not match the content of the conversation. They may also use non-verbal cues inappropriately, and understanding of personal space can be an issue.

How do people with ASD struggle to develop and maintain relationships?

People with ASD struggle to see the world from another perspective; often they are unaware of the ‘social rules’ and they may struggle to pick up on non-verbal cues that suggest another person is uncomfortable making it difficult to make friends. 

Define the repetitive behaviour deficits of ASD.

People with ASD often have strict routines, behaviour patterns and fixed interests.

What repetitive behaviour patterns may a person with ASD experience?

• Unusual Usage of Language

  • e.g. Echolalia - repeating what they just heard.

  • e.g. Little Professor Syndrome - bizarrely formal or pedantic language.

• Repetitive Hand Gestures

• Spinning or Rocking

• Using Objects in the Same Way

  • e.g. Lining Up Toys

What routines, rituals and resistance to change may a person with ASD experience?

• Inflexible Rigidity regarding routines with no variation.

• Overreaction to changes in routine.

• Difficulty recognising sarcasm.

What restricted and fixed interests may a person with ASD experience?

People with ASD can be preoccupied with a very narrow interest, e.g. space.

What unusual reactions to sensory input may a person with ASD experience?

Many people with ASD dislike being touched, may become distressed at loud or unusual sounds, can have obsessive interests in the movement of objects and can appear indifferent to pain.

What is the overall sibling risk for developing ASD according to Szatamari (1991)?

2.2%.

What is the overall risk for developing ASD without siblings according to Szatamari (1991)?

0.11%

What did Bailey et al. (1995) find in their analysis of the British Twin Study?

They found that the concordance rate for MZ twins was 60%, while the concordance rate for DZ twins was 0%.

What did Bailey et al. (1995) find after widening their definition of autistic spectrum behaviours?

92% concordance rate for MZ and 10% for DZ.

What were the concordance rates found by Ritvo et al. (1985) for MZ and DZ twins?

96% for MZ twins and 23% for DZ twins.

What is a multiplex family?

Families where more than one member of the family are diagnosed with ASD, or multiple members with autistic traits, but not necessarily diagnosed. In multiplex families, ASD is likely to be caused by a genetic variation that is inherited.

What is a simplex family?

Families with only one member with ASD. In simplex families, ASD is likely caused by a ‘de novo’ mutation. This process affects multiple genes as the mutation is duplicated as the fertilised ovum divides.

What is a de novo mutation?

A genetic alteration that is present for the first time as a result of a mutation in a germ cell (egg or sperm) of one of the parents, or a variant that arises in the fertilised egg itself during early embryogenesis.

The genetic explanation of ASD is reductionist. Why is this a strength?

The genetic explanation takes a complex disorder like ASD and explains it via a single component, genes. This means that we are able to study the genetic influence on ASD in more detail, for example de novo mutations on the origination of simplex families.

• However, this means that the explanation of ASD is oversimplified, and other influences of ASD are not considered, for example, the theory of mind. As a result, despite the reductionist viewpoint providing a more in-depth understanding of the genetic influence on ASD, this perspective alone does not give us a holistic view of the potential causes of ASD.

The genetic explanation of ASD has supporting evidence. Why is this a strength?

Ritvo et al (1985) found concordance rates of 96% for MZ twins and 23% for DZ twins whereas Bailey et al. found a that the concordance rate for MZ twins was 92% and for DZ twins was 10%.

• These statistics suggest that genes play a strong role in the development of ASD because the concordance rates are higher than would be seen in most other disorders, however MZ have consistent concordance rates, but DZ are inconsistent and so the results are not externally reliable. As a result, it is evident that despite the evidence provided to support the genetic influence on ASD, the lack of reliability means that we have to question whether the studies are able to provide us with the information we need to draw causal conclusions about the development of ASD.

The genetic explanation of ASD is deterministic. Why is this a weakness?

If genes are present that lead to ASD, there is no control over developing the disorder. This lack of control can lead to feelings of guilt of a genetic predisposition, feelings of powerlessness etc. which can cause even further problems for both the patient and their families.

• However, there is potential for earlier diagnosis of ASD because it is far easier to predict, e.g. because of the presence of family studies which means that support for people with ASD can begin sooner. As a result, it is clear that despite the potential for determinism to produce problems within families with a genetic predisposition for ASD, the fact that it is able to be predicted means that support can be put in place more quickly, meaning that quality of life will be greatly improved.

What is the amygdala?

The amygdala is part of the limbic system and is essential in the processing of fear and emotions, as well as implicated in implicit memory and explicit memory processing. It has connections to the prefrontal cortex, hippocampus, hypothalamus and other areas.

Why is dysfunction of the amygdala linked to ASD?

Emotional processing is altered and so a neurodivergent person may not be able to regulate their emotional output to a change or certain stimuli like a neurotypical person would.

How does the amygdala develop in neurotypical children vs children with ASD?

The amygdala develops differently in ASD children and neurotypical children. From the age of 2, there is larger than normal amygdala volume growth by about 6 to 9% (overgrowth).

• In normal children, amygdala volume increases with age but only when children are older, meaning that by the time they reach adulthood there Is essentially no difference in amygdala volume between people with/without ASD. The key difference is that it occurs earlier in children with ASD, and this unusual pattern of development may result in abnormalities in neural organisation and therefore damage its functioning as new neural connections are not as stable.