asd bio exps

Question 1

what is the amygdala

Answer 1

• part of the limbic system
• fear and emotion processing
• memory processing
• connections to the prefrontal cortex, hippocampus

Question 2

amygdala dysfunction in children with ASD

Answer 2

nordahl et al (2012)
- children with ASD, there is a larger than normal growth in amygdala volume by 6-9%.
- in normal children, the volume increases but only when the children are older.
the unusual pattern of development may cause abnormalities in the neural organisation of the amygdala and damage its function

Question 3

how did baron-cohen apply the idea of the social brain

Answer 3

• the amygdala has neural connections with the frontal cortex, abnormal development of the amygdala in childhood is a causal factor involved in social and behavioural deficits.
• therefore, those with ASD have difficulties in understanding the expression of emotions in other people.

Question 4

baron-cohen 2000
procedures

Answer 4

• adults with asd were matched with a control group of adults without ASD.
• p’s presented with photos that only showed the eye area of people making different facial expressions and asked to identify the expression shown.
  -their brain activity was measured in an mri scanner

Question 5

baron- cohen
findings

Answer 5

• those with ASD performed significantly worse on the eyes task than controls
• mri scans showed that the left amygdala was not activated in the ASD P’s at all but was strongly activated in the controls

Question 6

baron - cohen
conclusions

Answer 6

the left amygdala is involved when we infer emotional state from facial expressions (especially eyes) and this is function is impaired in people with asd.

Question 7

critiques and strengths of baron - cohens study

Answer 7

• subjective, interpret expressions differently
• experimental and control group so can compare results
• matched pairs design, controls participant variables
• uses a scanning technique, objective and without bias

Question 8

method of modifying for amygdala dysfunction

Answer 8

• improve the function of the amygdala to help reduce behaviours
  -intranasal oxytocin has been found to enter the brain effectively and work to increase oxytocin levels in areas such as the limbic system
• some studies show that this improves scores on test of social behaviours

Question 9

family studies

Answer 9

szatamari (1991)
proportion of siblings of people diagnosed with ASD, that also meet the criteria.
rate was 2.2%
without ASD siblings was 0.11%
so 20x greater risk of developing ASD if you have a sibling with it.

Question 10

twin studies

Answer 10

bailey et al (1995)
- concordance rate for MZ twins was 60% but DZ twins was 0%
- when definition was widened, concordance rate was 92% for MZ and 10% for DZ twins.

Question 11

critiques in twin studies

Answer 11

• conducted before 2013 so it was based on old criteria for ASD so lacks temporal validity
  -disagreement in concordance rates across studies so lacks external reliability

Question 12

define simplex families

Answer 12

only one member of the family has ASD

Question 13

define multiplex families

Answer 13

more than one family member is diagnosed with ASD or multiple members have autistic traits but no diagnosis.

Question 14

what causes ASD in multiplex families

Answer 14

a genetic variation that is inherited

Question 15

what causes ASD in simplex families

Answer 15

a de novo mutation that affects genes