Raine

• What was the aim of Raine’s study?

  To see if the brain activity of murderers (pleading NGRI) was different to brain activity of non-murderers
• What type of scan did Raine use?

  PET scans
• What was the sample size of murderers?

  41 murderers pleading NGRI (39 male and 2 female) - average age 34.3 years old
• What was the sample size of the control group?

  41 control ppts (39 male and 2 female) - average age 31.7 years old
• What were the reasons the NGRIs were referred?

  Schizophrenia, head injury, and personality disorders
• What were the ppts matched on with the control group?

  Age and sex

  ppts with schizophrenia were matched with people with same diagnosis but no history of murder
• How long were all ppts kept medication free for before the brain scans?

  2 weeks
• What were the ppts injected with?

  A glucose tracker
• What were the ppts required to do after the injection?

  a continuous performance task based around target recognition for 32 minutes
• What were the NGRI’s and the control group compared on?

  the glucose metabolism (level of activity) in the right and left hemispheres of the brain
• Did murderers have more or less activity in the prefrontal cortex compared to NGRIs?

  Less
• Where was there an imbalance of activity in the brains of murderers?

  Between the 2 hemispheres and in 3 other subcortical structures
• Did NGRI’s have more or less activity in the left amygdala and hippocampus compared to their right side?

  less
• Were there any ethnic differences?

  No
• Were there any differences found in right-handed and left-handed murderers?

  Very small differences but not enough for it to be significant
• What did Raine conclude?

  the brains of murderers were significantly different from the brains of non-murderers.

  The areas of abnormal activity were associated with lower self-control and increased aggression
• Give 2 strengths of Raine’s study

  1.Objectivity- using PET scans can be interpreted objectively which increases to reliability as Raine was able to see exactly how much glucose metabolism was being used up

  2.Generalisability- large sample size as he needed a specialist sample of NGRI’s so 41 is large for this category.
• Give 2 weaknesses of Raine’s study

  1.Generalisability- the results can only be generalised to NGRI’s which means the results cannot represented all violent offenders

  2.Cause and Effect-we do not know if the differences in brain activity were due to the violent murder or if the murder was due to differences there since birth, or if there were environmental influences that caused the differences.