RAINE ET AL 1997

aim- to see if there were brain differences between murderers pleading guilty by reason of insanity and non murderers using pet scanning

procedure-

  • 41 murderers pleading NGRI and 41 controls. the NGRIs were 39 men and 2 women

  • opportunity sample

  • 6 had schizophrenia, 23 had suffered brain damage etc

  • participants tested at the uni of California

  • screened for general health and if any complications arose they were excluded form the study

  • each injected with glucose tracer and performed the cpt task for 32 mins. the PET scan was then carried out to measure metabolic rate within the areas in the brain linked to aggression, to indicate which areas were most active

  • controls- ppts all allowed to practice cpt 10 mins before to ensure that they were all equally familiar with it

  • no one on meds, all kept off meds for 2 weeks prior

results-

murderers had significantly lower glucose metabolism (less activity) than controls in these CORTICAL regions…

  1. lateral and medial prefrontal areas

  2. left angular gyrus

  3. both superior parietal areas

murderers have lower activity than non murderers in these SUBCORTICAL regions…

  1. corpus callosum

  2. left amygdala

  3. left medial temporal lobe

Conclusions-

  • murderers pleading NGRI have different brain functioning to those of non murderers which can lead to impulsivity and loss of self control

  • impaired functioning in areas such as the amygdala are associated with aggression and violent behaviour

evaluate RAINE

+generalisable to the murdering population as this is made up mostly of males

-may be ethically immoral as the NGRIs kept off meds for 2 weeks prior

+controls such as all ppts went drug free for 2 weeks prior to ensure they were giving a true representation of their brain functioning

-may lack task validity as the cpt consisted of learning a sequence of blurred numbers which lacks mundane realism. it isnt a task the murderers and non murderers would normally perform in their daily lives so may not be a truthful representation of hopw their brains really work

+can be applied to