Raine key research

• What was the 1988 study about?

  • classifying individuals as criminals based off of their heart rate
  • 101 boys
  • Lower galvanic skin response, EEG and heart rate = more likely to commit crime
• second study?

  • birth complications and maternal rejection were more likely to be violent offenders
  • 4269 male births in Copenhagen, Denmark
  • birth complications such as: breech, forceps, C-section, unwanted pregnancy, attempted abortion
• third study?


  • low resting heart rates at 3 years old correlated with anti-social behaviour at 13 years old
  • longitudinal study
  • participants with low resting heart rate also had lower activity in prefrontal cortex
  • low activity: increase arousal, need fro self-gratification, thrill-seeking, low-delayers
• Raine 1997 study name?

  • “ brain abnormalities in murderers, indicated by Positron Emission Tomography”
• what are PET scans?

  • look at different levels of metabolic activity in the brain
  • uses radioactive glucose tracer injection
  • the scanner detects gamma-ray emission and shows high areas of high activity
• What do brain neurones use glucose for?

  • energy
• aim?

  • to look at direct measures of brain functioning in a group of murderers who were pleading not guilty for reasons of insanity (NGRI)
• method?


  • quasi experiment
  • matched design
  • comparison of PET scans of NGRI murderers and control group of non-murderers
• Participants?


  • 41 murderers, 39 male, 2 female (prison population:95% males)
  • all pleading not guilty
  • scan taken to see whether they were competent to stand trial
  • reasons why they were insane: 6 schizophrenia, 3 drug abuse, 2 epilepsy, other mental issues, average age = 34.3 years
• control group?


  • 41 matched for age and sex
  • 6 matched for schizophrenia
  • 35 thoroughly screened and deemed to have no history of psychiatric disorder
  • average age = 31.7 years
  • all consented and procedure was proved by Human Subjects Committee of University of California
• controls?


  • all defendants kept in custody
  • medication free for 2 weeks
  • tests were conducted to show there’s was no significant difference between: handedness, head injury, black/white
• materials?

  • thermoplastic head holder
  • PET machine to generate 2D map of brain activity
  • FDG tracer
  • continuous performance tasks: spot a ’target’ on screen and press when found - required concentration for 32 minutes
• procedure?


  • 10 mins before injection, participants practiced CPT
  • started CPT and after 30 seconds were given FDG injection
  • CPT for 32 minutes - glucose going to brain
  • immediately transferred to PET scanner
  • 10 horizontal (10mm) slices which took 10 minutes
  • PET scans analysed using: critical peel technique and box technique
• what is the critical peel technique?

  • slices examined and the glucose value of each region of interest compared to those of other areas in the slice.
• what is the box technique?

  • 2cm squared of brain area were examined and linked to suggested areas for violence in the brain
• results in left hemisphere?

  • murderers had lower activity in all areas: lateral prefrontal cortex, medial prefrontal cortex, panetal cortex, corpus callosum, amygdala, temporal lobe, hippocampus and thalamus
• results in the right hemisphere?

  • murderers had low activity in all, except in hippocampus, amygdala and thalamus
• pre-frontal cortex for murderers?

  • much lower activity than control group
• conclusions?


  • pre-frontal cortex - lower activity than controls - linked to loss of self-control and altered emotion
  • Raine said his findings shouldn’t be seen as deterministic and we can’t generalise the findings to other offendors/crimes
  • findings dont say anything about the cause of brain differences
  • however, brain scans are valid and not affected by demand characteristics, but PET scans were relatively new in 1997, and CPT is general and not related to the thinking which may occur when committing a crime
• conclusions p2?

  • significant differences in metabolism of glucose in certain areas, which may explain: impulsive behaviour, loss of self control, immaturity, inability to modify behaviour, lack of fear, inability to grasp long term implication
• what does further research suggest?

  • that adolescent brains are still forming connections in the pre-frontal cortex right up to the early 20’s
  • activity in the pre-frontal cortex is lower in impulsive individuals who are also likely to be aggressive - may explain why offending peaks during adolescence.