Raine et al (1997)

• Raine et al (1997) - Brain abnormalities in murders indicated by PET scarns
• Raine et al (1997) - Hypothesized that participants pleading NGRI would show brain dysfunction in areas of the brain associated with violence
• Raine et al (1997) procedure - Participants were given a continuous performance task to start ten mins before being injected with FDG. After 30 mins on the continuous performance task a PET scan was completed to measure the metabolic rate in different areas of the brain to see activity levels.
• The participants in the study were two groups of 41 people with 39 males and 2 females in each group.
• The experimental group were 41 convicted criminals for murder or manslaughter. 6 has schizophrenia and 23 some form of brain damage. All were med free for two weeks before the PET scan.
• The control group was matched for age, gender, were screened for general health and had a physical examination. Their medical history was reviewed and a psychiatric interview was conducted. They were excluded if they has a history of substance misuse, seizures or head trauma.
• They found brain disfunction in the brain areas associated with aggression for the NGRI group
• The brain differences found have been associated with many behavioral changes that could be linked to violent behaviour. For example disfunction in thee prefrontal cortex has been linked to impulsivity, lack of self control and an inability to learn from consequences.
• The abnormal brain differences could be a result in the criminals being unable to modify their behaviour by learning from consequences.
• This study was the largest sample of severely violent offenders to be studied in this way and compared to a control group. This increases the validity of the study.
• Pet scans give a reliable comparison as all the participants has the same procedure allowing objective measures of the difference in brain activity.
• The sample only represents a small number of violent offenders making the conclusions not a representative explanation of violence
• The results cannot be generalized to all types of violent offending
• It is impossible to tell if the violence is due to biology or environmental influences.
• This study suggests that offenders are not in controll of their behaviour and not criminally responsible as criminality is biologically determind. This suggests that offenders are not in control of their behaviour and not criminally responsible.
• It is unknown if the brain abnormality is the cause of the offence or the result of it.
• The research suggests that violent offenders could be predicted using brain scans so future offending can be predicted and intervened.
• In comparison to the control group the NGRI group showed:


  • Lower activity in the prefrontal cortex
  • Lower activity in the parietal areas
  • Higher activity in the occipital lobe