04. Classic Study: Raine

Question 1

State Raine’s aim.

Answer 1

To show that the brains of murdered who pleaded guilty by reason of insanity were different from the brains of non-murderers using brain scanning.

Question 2

State the independent variable.

Answer 2

Whether or not the participant is a murderer.

Question 3

State the dependent variable.

Answer 3

Measures of brain activity as found by PET scanning.

Question 4

Describe the experiment design.

Answer 4

Study could be called a matched pairs design as there is a clear attempt at matching individuals. However, researchers could not match variables in the same people, for example they could not match handedness, head injury and ethnicity in the same individuals.

Question 5

Outline the preliminary study.

Answer 5

A preliminary study of 22 murderers and 22 normal participants gave some support for prefrontal disfunction in the murderers.

Question 6

Describe the sample.

Answer 6

Experimental group: 39 men, 2 women.

-Group consisted of 23 people with a history of brain damage, 6 people with schizophrenia, 3 people with a history of substance abuse, 2 with an affective disorder, 2 with epilepsy, 3 were diagnosed as hyper active or with a learning disability and 2 had paranoid personality disorder.
-None were on medication when scanning took place.
-The control group (average age 31.7 years) matched each murderer with a normal participant of the same sex and age and were similar in other ways.

Question 7

Describe the procedure.

Answer 7

1. Each ppt carried out a practice test on the continuous performance task that would be used. It was carried out 10 minutes before the FDG tracer was injected.
2. 30 seconds before the tracer was injected, the continuous performance task started so that the brain activity was being recorded before the tracer was injected.
3. Ppt carried on with continuous performance task and target recognition was recorded. The continuous performance task chosen was one that had been shown to give an increase in glucose metabolic rates in the frontal lobes, so would help highlight brain areas of interest.
4. After 32 minutes for the FDG uptake to occur, the ppt was taken for a PET scan of the head and images of slices of the brain were produced.

Question 8

What lobes are found in the cortical region?

Answer 8

1. Prefrontal lobe
2. Parietal lobe
3. Temporal lobe
4. Occipital lobe

Question 9

What results were found on the prefrontal lobe?

Answer 9

-Murderers had lower glucose metabolism relative to the controls in prefrontal areas.
-Specific brain areas in prefrontal lobe showed different activation.

Question 10

What results were found on the parietal lobe?

Answer 10

Murderers had lower glucose metabolism than controls.

Question 11

What results were found on the temporal lobe?

Answer 11

There was no significant differences between the murders and control group.

Question 12

What results were found on the occipital lobe?

Answer 12

Murderers had higher glucose metabolism than controls.

Question 13

What is found in the sub cortical region?

Answer 13

1. Corpus callosum
2. Amygdala
3. Medial temporal lobe (hippocampus)
4. Thalamus

Question 14

What results were found on the corpus callosum?

Answer 14

Murderers had lower glucose metabolism in the corpus callosum than control group.

Question 15

What results were found on amygdala?

Answer 15

Murderers had reduced activity in the left amygdala and greater activity in the right amygdala than the controls.

Question 16

What results were found on the medial temporal lobe, including the hippocampus.

Answer 16

The murderers had reduced left activity and greater right activity than the controls.

Question 17

What results were found on thalamus?

Answer 17

The murderers had greater right thalamic activity than the controls.

Question 18

What are the results on how the groups performed on the continuous performance tasks.

Answer 18

The 2 groups did not differ in how well they did on the task.

Question 19

What were the results on left or right handedness?

Answer 19

-Six murderers were left handed.
-Concluded that handedness would not have affected results as only slight differences would found.
-Differences were that left handed murderers tend to show higher medial prefrontal activity and to show less abnormal amygdala symmetry.

Question 20

What were the results on injury?

Answer 20

-23 murderers had a history of head injury.
-They differed from the other murderers on only one measure, lower activity in the corpus callosum.

Question 21

What were the results on ethnicity?

Answer 21

-Fourteen of the murderers were non white. They were compared with white murderers and no significant differences were found.
-Ethnicity did not affect the findings.

Question 22

What did Raine et al (1997) conclude from their findings?

Answer 22

Murderers pleading not guilty by reason of insanity have:
-Reduced glucose in the bilateral prefrontal cortex, posterior parietal cortex and the corpus callosum.
-Abnormal activity with regard to symmetry in the 2 hemispheres.

Hypothesis was supported, findings showed murderers pleading NGRI have different brain activity from people who are not violent behaviours.