Biological Explanation AO1

Question 1

Explain the Dopemaine Hypothesis.

Answer 1

It suggests that unusual levels of dopamine can cause schizophrenia:
Schizophrenics are thought to have hyperdopaminergia in Broca’s area as they may have more D2 receptors there which is where dopamine binds
Schizophrenics are also thought to have hypodopaminergia in the pre-frontal cortex

Question 2

How does hyperdopaminergia in the Brocas area cause schizophrenia?

Answer 2

it causes overactivity of neurotransmitters in the auditory areas of the brain, resulting in auditory hallusination

Question 3

How does hypodopaminergia in the pre-frontal cortex causes Schizophrenia?

Answer 3

the prefrontal cortex is where logical thinking occurs therefore low levels of dopamine can impair their ability to form gramatical sentences and function in day to day life
therefore it can cause speech poverty and avolition (respectively)

Question 4

What are the key consepts of the biological explantion for Schizophrenia?

Answer 4

• genetics
• dopamine hypothesis
• neutral correlate

Question 5

Who believed that schizophrenia is caused by hypodopaminergia?

Answer 5

Goldman-Rakic

Question 6

Who found that Schizophrenia may be genetic?

Answer 6

Gottesman

Question 7

What did Gottesman find in his study?

on the effect of genetics on Schizophrenia

Answer 7

• he found a positive correlation between genetic similarities of family members and the likelyhood of developing schizophrenia
• he found the concordence rate of different family members as well
• he found that MZ twins have the highest concordence rate which shows that schizophrenia is genetic as MZ twins share 100% of their DNA

Question 8

What did Gottesman find the concordence rate of MZ twins to be?

Answer 8

48%

Question 9

What did Gottesman find the concordence rate of DZ twins to be?

Answer 9

17%

Question 10

What did Gottesman find the concordence rate of siblings to be?

Answer 10

9%

Question 11

What did Gottesman find the concordence rate of parents to be?

Answer 11

6%

Question 12

What is a concordence rate

Answer 12

the probability that a person will have a certain condition depending on their genetic similarity to someone else

Question 13

What are candidate genes?

Answer 13

genes rated to a specific trait

schizophrenia for example

Question 14

Who showed that some genes are related to Schizophrenia?

Answer 14

Ripke et al

Question 15

How did Ripke show the presence of canditate genes associated with Schizophrenia?

Answer 15

• he conducted a genome wide study on 5001 Swedish nationals with schizophrenia compared to 6243 controls
• through this he found 8300 candate genes that each represent a variable that increases the likelihood of developing schizophrenia
• this therefore shows that schizophrenia is polygenic disorder

Question 16

What is a polygenic disorder?

Answer 16

a disorder with muliple contributing genes

Question 17

What is neutral correlates?

Answer 17

patterns of cortical activity (activity in the cerebrum cortex) that are related to specific psychological symptoms

Question 18

How does Juckle et al think neutral correlates causes schizophrenia?

Answer 18

• he believed that low levels of activity in the ventral stiatum is associated with avolition
• this is because the ventral stiatum is in control of the evaluation of reward values
• therefore abnormalities in it can make it difficult to assess the reward of carrying out day to day tasks (resulting in avolition)

Question 19

How does Allen et al think neutral correlates causes Schizophrenia?

Answer 19

• they believes that abnormalities in the antierior cingulate and left temporal cortext is related to Schizophrenics being unable to identify their own words and auditory hallusination
• this is shown in his study where he got Schizophrenics and a control group to identify things threy have said compared to those they hadn’t while under a brain scan (fMRI)
• those with Schizophrenia made more mistakes during this task