Raine et al (1997)

Question 1

Aim

Answer 1

To investigate whether participants pleading NGRI would show brain dysfunctions in areas of the brain associated with violence

Question 2

Angular gyrus

Answer 2

Memory, language, processing, attention

Question 3

Hippocampus

Answer 3

Learning, emotion and memory

Question 4

Thalamus

Answer 4

Sensory perception, consciousness

Question 5

Corpus callosum

Answer 5

Joins 2 hemispheres of brain

Question 6

Sample

Answer 6

2 groups of 41
39 males 2 females
41 criminals who were convicted of manslaughter
No medication 2 weeks prior
6 schizophrenic
(And had other mental disorders e.g. brain damage and substance abuse)

Question 7

Control group

Answer 7

Matched with experimental group on: age, gender, schizophrenia
None in control group has headtrauma, seizures, substance abuse
All screened for general health, looked at medical history and psychiatric interview

Question 8

Procedure

Answer 8

Consent given before PET scan
Gave CPT (blurred numbers and had to focus on specific numbers)
Did test 10 mins before injected with FDG
After 32 mins on CPT, PET scan completed to measure metabolic rate in different brain areas (see brain acitivty)

Question 9

Results of brain lobes in murderers (compared to control group)

Answer 9

Prefrontal cortex = lower activity
Parietal = lower
Occipital = higher
Temporal = identical

Question 10

Results of brain subcortical areas of murderers (compared to control group)

Answer 10

Corpus callosum = lower activity
Amygdala, medial, thalamus = asymmetrical (medial lower activity in left, higher in right), (Thalamus higher in right)

Question 11

Conclusion overall

Answer 11

Brain differences associated with many behavioural changes that can relate to violent behaviour

Question 12

Conclusion of brain areas

Answer 12

Disfunction in prefrontal = lack of self control
Hippocampus, amygdala, thalamus has abnormal activity = unable to learn from actions, or have self control

Question 13

Evaluation strengths

Answer 13

Large sample and compared with control group -> good validity
Get rid of any medication effects on brain activity -> 2 weeks clean prior
Ruled out confounding variables -> right/left-handed and head injuries in control group
PET scans reliable comparison between participants -> objective measure

Question 14

Evaluation weaknesses - pv

Answer 14

Only represents small number of violent offenders
Cannot explain other violent crimes (not murder)
Can’t know if it is directly related to behaviour