Methodology and Procedure

• Methodology:

  • Data gathered by carrying out PET scams, show areas of high activity and low activity.
  • IV- NGRI vs Control Group
  • DV-Differences in brain activity
  • Iv was based on pre-existing differences, they weren’t manipulated or controlled by Raine.
• Sample:

  • Gathered by opportunity sampling
  • 41 murders (39 males and 2 females)
  • all charged with manslaughter or murder and had some sort of mental impairment
  • all referred to Uni of California to undergo scans to prove of dismissed responsibility due to insanity
  • all had pleaded guilty by reason of insanity
• Control Group:

  • 41 non murderers- no history of mental illnesses for them or close relatives, no physical illness or medication
  • matched pairs design used - based on age and sex 6 non schizophrenics matched with 6 schizophrenics from hospitals
  • instructed to be medication free when the urine test was took.
• Procedure:

  • 10 mins before FDG injection was given to pots they were given practice trials on a continuous performance task.
  • 30 seconds before injection- task was started so that initial task novelty would not effect the results of the PET scan
  • FDG tracer injected into each ppt
  • FDG taken up by brain for 32 minutes during which pots completed CPT
  • Ppt then transferred to a PET scanner where the brain was scanned in 10mm horizontal slices.