Disorders, Explanations

Question 0

What method did Murray et al use?

Answer 0

A lab experiment with an independent measures design. A behavioural measure of cued reinforcement reaction time task.

Question 1

What is the aim of Murray et al’s study?

Answer 1

To use behavioural measures to investigate whether schizophrenics have disrupted reward and motivational processing.

Question 2

What are the details of the sample in Murray et al’s study?

Answer 2

18 people with first episode psychosis, recruited from CAMEO. 9 males, 9 females w/ a mean age of 23. The controls were 19 healthy volunteers chosen through an advert.

Question 3

In Murray (2008) why were people w/ first episode psychosis chosen?

Answer 3

Because they were less likely to be suffering from global cognitive impairment.

Question 4

What task did the participants have to complete in Murray et al (2008) and what were their instructions?

Answer 4

They had to choose the odd one out from 3 shapes. This had to be done as quickly as possible over 96 trials. They were instructed to gain as many points as possible.

Question 5

How did the reward system work in Murray et al (2008)?

Answer 5

A cue before each trial that signalled the likelihood of a reward, the cue was a coloured rectangle, one colour indicating 10% chance of reward, one colour indicating 50% and one 90% probability. A fast response gained 100 points, a slow correct choice 1 point and an incorrect choice 0 points.

Question 6

How was the ethical issue debriefing handled in Murray et al (2008)?

Answer 6

The participants were given a debrief questionnaire that measured how aware they were of the reinforcement contingencies.

Question 7

What was the point of the practice session in Murray et al (2008)?

Answer 7

So reward levels could be adjusted for a participants psychomotor speed. Another test was done that measured general cognitive ability (attention and memory)

Question 8

In what areas was no significant difference found in Murrary (2008)?

Answer 8

Attention function, response bias or target detection.

Question 9

In what area was a significant difference found in Murray et al (2008)?

Answer 9

The time it took for the participants to complete the trials. The control group’s reactions were quicker the bigger the reward. This did not appear for people with schizophrenia, but they could correctly report what each card meant.

Question 10

When did the difference hold in Murray et al (2008)?

Answer 10

When medication was accounted for.

Question 11

What conclusion can be drawn from Murray et al (2008)?

Answer 11

There appears to be an abnormality in a schizophrenics ability to recognise rewards. Therefore learning theory can explain the behaviour of schizophrenics as being due to maladaptive thought. This may ultimately be due to physiological reasons.

Question 12

What is the aim of Gottesman and Shields (1976) study?

Answer 12

To review research on genetic transmission of schizophrenia

Question 13

What method was used by Gottesman and Shields (1976)?

Answer 13

A review of 3 adoption studies and 5 twin studies into schizophrenia between 1967 and 1976.

Question 14

What are the details of the sample in Gottesman and Shields (1976)?

Answer 14

711 participants in the adoption studies. In the twin studies a total of 210 monozygotic twins and 319 dizygotic twins.

Question 15

How was the data used in Gottesman and Shields (1976)?

Answer 15

The incidence of schizophrenia in adopted children and monozygotic twins was taken from the research. This was done by comparing biological parents and siblings and adoptive parents and siblings in the adoption studies. In the twin studies the concordance rates for mono and di twins was compared.

Question 16

What would indicate a genetic basis for schizophrenia, Gottesman and Shields (1976)?

Answer 16

If there was an increased incidence of schizophrenia in biological relatives and higher concordance rates between mono twins.

Question 17

What did all three adoption studies find in Gottesman and Shields (1976)?

Answer 17

All three adoption studies found an increased incidence of schizophrenia in adopted children with a schizophrenic biological parent. Whereas normal children fostered to schizophrenic parents and adoptive parents of schizophrenic children showed little evidence of schizophrenia.

Question 18

What did one of the reviewed studies find, Gottesman and Shields (1976)?

Answer 18

One of the reviewed studies showed that biological siblings of those with schizophrenia showed a higher percentage (19.2%) of schizophrenia than adopted siblings (6.3%).

Question 19

What did all five twin studies find, Gottesman and Shields (1976)?

Answer 19

A higher concordance rate for schizophrenia in mono twins than di twins.

Question 20

What conclusions can be drawn from Gottesman and Shields (1976)?

Answer 20

There is clearly a genetic input into the onset of schizophrenia, but with concordance rates less than 100% interaction with the environment must have some input. There is also confusion as to whether it is one or more genes are responsible for predisposing someone to schizophrenia.