Methodology and procedures

• Raine et al's research method


  • Quasi-experiment with a matched pair design
  • IV NGRI or not, DV brain differences
• Sample consisted of

  • 41 offenders (19 men and 22 women) charged with murder/manslaughter and pleaded not guilty
• Procedures

  1. Participants selected using opportunity sampling

  2. PET scan with FDG tracer injection, 32 minutes uptake during continuous performance task

  3. 10 minutes practice on CPT before injection, CPT started 30 seconds before injection

  4. After 32 minutes, PET scan recorded 10 horizontal brain slices using cortical peel and box techniques
• Cortical Peel- pet scans


  Measured surface cortical regions
• Box- pet scans


  Measured medial (middle) and subcortical (below the cortex) regions
• The control group were screened for health with a physical exam and psychiatric interview
• The 6 schizophrenic offenders were matched with 6 schizophrenic controls from a mental hospital, other controls had no history of psychiatric illness
• Reasons to prove diminished responsibility

  • schizophrenia:6
  • History of head injury/brain damage: 23
  • History of drug abuse: 3
  • Affective disorder: 2
  • Epilepsy: 2
  • History of learning disability: 3
  • Personality disorder:2