raine's study

avatar
Created by
jahnavi panchal

Cards (7)

  • Aim: to investigate whether there is a difference in brain structures of murderers (NGRIs) and non-murderers.
  • o   Sample of 41, 39 males and 2 females, 41 criminals tested to confirm NGRIs.
    o   Control group matched with experimental group on age and gender, they were screened for general health and a psychiatric interview.
  • o   Participants started with continuous performance tasks 10 minutes before injected with fluorodeoxyglucose.
    o   Spent another 32 minutes on CPT then had a PET scan done to measure metabolic rates in different areas of the brain to look at activity levels.
  • Findings:  murderers showed lower activity (as measured by glucose metabolism) in the prefrontal cortex and corpus collosum. This shows that damage to the prefrontal cortex is in fact linked to impulsivity where they are unable to learn from consequences.
  • A strength of this study is the use of a PET scan which provides reliable comparisons to be made between the groups as all participants were subject to the same procedure, allowing an objective measure of the difference in brain activity to be measured.
  • [strength] However, the PET scanning technique could have given misleading results in the 1990s, as the technique scans the brain relative to the orbitomeatal line, but this line can vary significantly between individuals which makes it hard to precisely locate the different brain areas under study. This reduces the reliability of the study and casts some doubt on the accuracy of the findings.
  • A weakness is that we cannot generalise the findings that brain damage causes more impulsive behaviours for women too as there was a very small proportion of only 2 females in the study compared to 39 males. Those two females could have had certain differences from most females making them more aggressive, but we cannot generalise it unless more females are involved in the study. However, a large sample of 82 was used, including the matched pairs, so any anomalies e.g., participants with unusual brain structures should not skew the data.