Raine - What Makes a criminal

• Aim

  See if there was differences in the brain activity in areas of the brain involved with violent behaviour via PET scans of murderers
• Sample

  41 people

  39 men , 2 women who have been charged with murder or manslaughter

  Chosen because they had reasons for pleading not guilty by reason of insanity (NGRI)

  Chosen to see if they were NGRI, competent to understand the judicial process and if there was evidence of diminished mental capacity

  Matched with a control group of non murderers based on age and sex
• Research method


  Quasi

  IV was if they pleaded NGRI or normal, nonmurderer
• Procedure

  Asked to do a continuous performance task

  Had FDG a radioactive glucose tracer injected so they could trace brain function in certain areas after 30 secs of the task

  After 32 mins they scanned their brain whilst still doing CPT to determine the LEVEL OF ACTIVITY IN VARIOUS REGIONS OF THE BRAIN
• Findings

  NGRI have significant differences in the metabolism of glucose in a number of brain areas compared to non murdereds

  Reduced activity in the prefrontal cortex
• Prefrontal cortex

  Impulsivity and poor behavioural control, individuals with damage to this have less self control and are more aggressive
• Amygdala


  Responsible for emotional processiong, resulting in murderes being fearless increasing chance of acting violently
• corpus callosumm and hemispheres


  When the corpus callosum is not as active this reduces the ability of the left hemisphere to regulate the right, so murderers are unable to regulate negative mood compared to the controls so become more violent
• Conclusions

  NGRI murderers have different brain functions compared to controls

  Can't be reduced simply to a single brain mechanism that causes violence