raine et al

• quasi experiment = iv is not artificially manipulated = not guilty by reason of insanity and dv was brain activity
• opportunity sampling - was done at California uni = 41 ppts = 39 men and 2 women = urine tested to medication free for last 2 weeks
• mean age of 34.3 and matched on age, gender and schizoid or not (6 in each)
• 1. practiced continuous performance task 10 mins before
  2. start CPT then 30 seconds after injected with FDG = radio active glucose
  3. 32 mins later pet scan is done
  4. pet scan produces 10mm horizontal slices of brain
• findings

  • no difference in mid brain and cerebellum
  • decreased activity in pre frontal cortex (impulse) corpus callosm (hemisphere communication) and left angular gyrus (iq)
  • left handed murderers = more asymmetry
  • performed same on cpt so no difference due to task
  • no difference with race
  • 23 NGRI had head injuries when younger but no impact
• conclusions

  • brain is complex and violence is not down to one area but how they communicate
  • NGRI have abnormal brain functioning
  • brain abnormalities don't mean aggressive just more predisposed
  • supports assumption certain areas of the brain link to violence
• quasi experiment = no control over IV = may be extraneous variables = lowers internal validity
• matched pairs = on age, sex, gender and schizoid or not = less ppt variables = higher internal validity
• standardised procedure = uses pet scans and step by step process = can be replicated to check for consistency = higher external reliability
• alternative evidence = banduras bobo dolls = environmental determinism = aggression is learnt not biological
• valid consent = APA approved as all consented = ethical (but are they vulnerable individuals)
• potential harm = stress and injection = NGRI would experience anyway but control group would not so unethical
• negative social implication = may assuume violence is out of control = used as excuses or to discriminate
• positive legal implications = look for alternative rehabilitation = help protect society