C2 - Causes of Autism

• The causes of autism are still being looked into.

• Many experts believe that there isn’t one specific ‘cause’.

• The consensus is that a combination of biological, cognitive and environmental risk factors can lead to autism.

• The common explanations include Genetics, neurological, cognitive and environmental.

What risk factors (causes) might COMBINE to cause Autism?

• Genetics, neurological, cognitive and environmental.

What is the myth regarding ‘Refrigerator mothers’?

• 'Refrigerator mothers' - autism is not caused by emotional deprivation or the way a person has been brought up by their mother.

• However, the theory had no scientific basis and led to guilt, shame and even forced separation of children from their families, causing immense harm, but has been replaced by more empirically backed research.

What is the myth regarding vaccines?

• A lot of research has looked into whether vaccines cause autism.

• The answer is very clear - vaccines don’t cause autism.

• Even though the research was fake, fewer people got the vaccine.

• This led to outbreaks of deadly disease.

• Since then, a huge amount of new research has been done to make sure the MMR vaccine is safe.

• It showed there is no link between the MMR vaccine and autism.

What is the myth regarding paracetamol?

• There is no evidence that taking paracetamol during pregnancy causes autism.

What is risk factor 1 - the Genetic link for Autism?

• Nature.

What have twin studies found?

• A01 explanation of Genetic link for Autism

• twin studies suggest that interactions between multiple genes cause autism but exposure to environmental modifiers may contribute to variable expression of autism-related traits.

• The identity and number of genes involved remains unknown.

How does Carvalheria et al’s literature review (2004) support the genetic link for Autism?

• A03 support

• It is believed that there are from 3 to more than 10 genes related to autism.

• When they looked at the complete genome, there are 354 associated genetic markers.

• Maybe that’s the reason we have a spectrum of autism because there are so many different genes that are possibly involved.

• Most of the markers/genes seem to be found on the chromosome ‘X’.

• Explains why more boys have autism - because they only have one x chromosome, means they only have one chance of having the correct/normal variant.

• However no specific gene has been found to link to autism.

How does Bailey et al (1995) support the genetic link for Autism?

• A03 support

• Report a 60% concordance rate for autism in MZ twins versus 0% in DZ twins.

• The higher MZ concordance suggests genetic inheritance as the dominant cause.

• When considering the broader spectrum of related cognitive or social abnormalities that included communication and social disorders, the concordance increased from 60% to 92% in MZ twins and from 0% to 10% In DZ pairs.

• This suggests that interactions between multiple genes cause autism but exposure to environmental modifiers may contribute to variable expression of autism related traits.

Was there 100% concordance between MZ twins? why not?

• A03 critique of genetic link for Autism

• The prevalence of autism in MZ twins if one has autism is not 100%.

• Suggests that other factors besides genetics contribute to the development of autism.

• Despite information to suggest a genetic cause for autism, as documented by the relationship between autism and MZ twins, to date no specific 'autism genes' have been identified.

What is risk factor 2 - Theory of mind?

• A01

• Nurture - cognitive.

• Nurture because you develop it based on life experiences and the development of your intellectual ability.

What is Theory of Mind according to Baron-Cohen (1985)?

• A01

• People with autism find it difficult to see things from other people’s perspectives.

• ToM is a cognitive explanation, we talk about the way someone processes info.

• ToM will start to develop in children as young as a few years old.

• This is a cognitive skill where people have the ability to understand others’ mental states and can see the world from someone else’s perspective.

• If a child has ToM, they are able to understand that each person has their own set of beliefs, morals, likes, dislikes and emotions. They understand that these are different from their own.

• Children with Autism don’t have this.

• By the age of four, most children have developed ToM.

• This is why diagnosis of Autism usually happens after this age.

• The lack of ToM means that children with Autism have difficulty relating to others which can result in difficulty with social interaction.

• Low empathising means not good at understanding the emotions and feelings of others.

• High systemising means being able to use internal rules and planning.

• People with autism are high systemisers and low empathisers.

• A child who finds it hard to work out external events would not have a theory of mind because he or she would find it difficult to look at things from the POV of someone else.

• In the Sally Anne scenario the child would not be able to work out what Sally knew or did not know.

• If you’re a low empathiser or a high systemiser it is very unlikely you'd have theory of mind.

• Environment can affect ToM as it is learnt.

• Environment can help ToM develop as as you experience more you develop more.

What is involved in the Sally Anne test for Theory of Mind (Baron-Cohen 1985), and why children who have autism cannot complete this task successfully?

How has this previously been used as a way to assess for autism?

• A03 support

• A group of autistic children, children with Down syndrome and some with no disability took part in the experiment.

• They were each tested individually to assess if they had theory of mind.

• Sally had a basket in front of her, and Anne had a box.

• Sally then takes a marble and hides it in her basket.

• She then leaves the room.

• While she is away Anne takes the marble out of Sally's basket and puts it in her own box.

• Sally returns and the child is asked the key question "Where will Sally look for her marble?'

• The correct response is to point to or name Sally's basket.

• Two control questions are also asked: 'Where is the marble really?' ('Reality Question"), and "Where was the marble in the beginning? ('Memory Question').

• Every child was tested twice.

• The 'naming', 'reality', and 'memory' questions were answered correctly by all the children.

• However, 85% of the 'normal' and children with Down syndrome gave the correct response to the belief question.

• Only 20% of the autistic children did so.

 

• 85% of normal children and children with down syndrome had ToM.

• Autism is on a spectrum and some children will do better with some cognitive processes than other children.

• Pass or fail given at the end.

• Strength - standardised procedure.

Is this a valid test though?

This is correlational research - what problem does that present?

• Baron-Cohen ToM A03 critique

• ToM can only explain some traits of autism.

• It cannot explain for example, verbalisation of words.

• Correlational research causes an issue - Is ToM a characteristic rather than a cause of Autism?  It could be that due to Autism, children don’t develop ToM.

• Sally Anne test has issues with validity as ToM isnt given a score so we don’t know the degree of ToM they had

• Sally Anne test is either a pass or fail but we know that autism is a spectrum. It also doesn’t show the level of ToM they have.

• We don’t know that maybe the young children did not have the verbal ability to explain the situation in the Sally Anne test rather than displaying autism.

• ToM isn't causing the autism - ToM is a characteristic of autism.

• ToM doesn’t explain why some children are non-verbal, it doesn’t explain the difficulty with all social interaction.

What is risk factor 3 - Extreme Male Brain?

• A01

• It is suggested that people with autism are low empathisers (struggle to understand other people’s feelings and perspectives.) and high systemisers (like to organise things, construct things and very logical in their thinking.)

• Boys are suggested to be better at tasks such as map reading and jigsaws whereas girls are better with communication and language tasks - they also use both halves of their brain more.

• As boys tend to demonstrate less empathising behaviours and more systemising behaviour, people with autism could be suggested to have an ‘extreme male brain.’

• Males are right hemisphere dominant.

• He suggested that as well as genetics, children with autism develop an extreme male brain because they are exposed to an increased level of testosterone in the womb.

• Males have a different brain to females.

• In the womb they are exposed to testosterone.

• Increased testosterone is seen in physical attributes such as longer ring finger than index finger.

• He is suggesting that if a person has more testosterone than normal in the womb they will develop a longer ring finger than index finger but also an extreme male brain.

What is a further example of behaviours that suggest girls are better empathisers?

• Extreme male brain A03 support

• Baron Cohen (2002) suggets evidence for females being better at empathising and says that statistically significant differences have been found in the following.

• Sharing and turn taking - girls show more concern for fairness than boys.

• Responding empathically to the distress of others - from 1 year old, girls show greater concern for sad looks.

What is a further example of behaviours that suggest boys are better systemisers?

• extreme male brain A03 support

• Baron Cohen suggets evidence for males being better at systemising and says that statistically significant differences have been found in the following.

• Toy preferences - boys are more interested than girls in boy vehicles, mechanical toys and building blocks - all of which can be ‘systemised.’

• Adult job choices - There are some jobs that are considered ‘male’ ones and they tend to focus on constructing systems.

Find evidence that suggests that autism is linked to the ‘extreme male brain’?

• Extreme male brain A03 support

• Baron Cohen cites Bailey (1998) in support of there being a genetic link for ASD and he also suggests the role of the amygdala being an abnormal size in people with ASD.

• Meaning they can’t regulate and understand emotional responses of their own and other people.

how is exposure to excess testosterone linked to autism (finger length)?

• Extreme male brain A03 support

• He suggested that as well as genetics, children with autism develop an extreme male brain because they are exposed to an increased level of testosterone in the womb.

• Males have a different brain to females.

• In the womb they are exposed to testosterone.

• Increased testosterone is seen in physical attributes such as longer ring finger than index finger.

• He is suggesting that if a person has more testosterone than normal in the womb they will develop a longer ring finger than index finger but also have an extreme male brain.

What does research by Falter et al (2007) conclude about the male brain?

• Extreme male brain A03 critique

• Falter found that there was no evidence of the extreme male brain in ASD children or evidence of increased testosterone or finger length.

What is risk factor 4 - Weak central coherence?

• Nurture - cognitive.

• Nurture because you develop it based on life experiences and the development of your intellectual ability.

What is Weak central coherence according to Frith?

• A01

• ‘‘Central coherence’’ was the term given to a human beings ability to derive overall meaning from a mass of details.

• A strong central coherence allows us to see the ‘whole picture.’

• A weak central coherence would allow us to see only specific details, not the complete context.

• This may be why some people with autism can only focus on specific details and become fixated with specific things.

What are the strengths of the weak central coherence theory in terms of providing evidence for ASD strengths?

• A03 support

• Provides evidence for ASD amazing strengths.

• For instance, some individuals with ASD have ‘‘savant’’ skills - a remarkable ability in areas such as music, memory, calculation.

What are the strengths of the weak central coherence theory in terms of being able to explain both deficits and strengths?

• A03 support

• The notion of ‘'weak central coherence’ could explain both deficits and strengths.

• When a task requires a person to extract global meaning from many details, to get the ‘big picture’ people with ASDs would be at a major disadvantage.

• When picking out extreme detail from surrounding masses of information, people with ASDs would be in a position to shine.

• They would be good at parts, but not at whole pictures.

• Not just a failure to extract global form and meaning, but is also ‘‘an outcome of superiority in local processing.’’

Is this really an explanation for the disorder?

• Weak central coherence A03 weakness

• Doesn’t account for other symptoms or people with autism who don’t have this as a significant characteristic.

• Again, correlational studies - is another feature of autism rather than a cause.

• Not all ASD people have savants.