Classic Raine 1997 Flashcards
aim of raine 1997
to study patterns in brain activity in murderers pleading not guilty by reason of insanity and whether they were similar to non-murderers
sample of raine 1997
41 NGRI murderers, 39 men and 2 women
- 6 had SZ and 23 had history of brain damage
- they were matched with non-murderer controls in matched pairs design, by age and sex, 6 also had SZ
procedure of raine 1997
- all offenders in custody and kept medication-free 2 weeks prior, no significant differences between the behaviours of ppts of different head injuries nor races
- 10mins before injection they were given a CPT practice trial so they knew what to expect
- the actual CPT task began 30 seconds before fluorodeoxyglucose tracer was injected
- CPT performed for 32 minutes then PET scan taken immediately after, brains scanned 10 times at 10mm intervals
results of raine 1997
murderers had:
- asymmetrical glucose metabolism in the hippocampus and amygdala, higher in the right/lower in the left
- murderers had lower glucose metabolism in the PFC and corpus callosum than controls
conclusions of raine 1997
- murders pleading NGRI have statistically significant differences in glucose metabolism in selected brain regions than normal
- reduced activity in these areas may be a predisposition towards violence
generalisability of raine 1997
High (for NGRI murderers)
- large sample of 41 NGRIs matched to controls
Low (for other aggressive people)
- not all aggressive people are NGRI or have murdered people
reliability of raine 1997
High
- followed a standardised procedure, for example they carried out the CPT task practise trial for 10 minutes, then began the actual CPT task 30 seconds before the FDG was injected and the CPT carried out for 32 mins
- This allows the study to be replicated to be tested for similar results and consistency of findings in biopsychology
validity of raine 1997
High
- used PET scans which took scanned the brain 10 times at 10mm intervals
- highly scientific, and gathers objective, quantitative data, which increases credibility
- took place in a highly controlled lab experiment, where the IV (NGRI or not) and DV were isolated to determine a correlation
- however correlations cannot determine cause and effect, lowering credibility
- however, the use of brain scanning to determine psychopathy is deterministic, and brain structure may not always cause psychopathy e.g. neuroscientist Jim Fallon found he matched the profile for a psychopath’s brain yet he never murdered anyone
ethics of raine 1997
- Approved by the ethics committee at the university of California, this increases how ethical the study was
- however participants had various psychiatric disorders which may have reduced their ability to give full consent, some lawyers may have given presumptive consent
- PET scans are also invasive due to the injection of the FDG tracer
applications of raine 1997
impacts judicial system, if we can understand the impact of brain structure on a person’s aggression and free will, we may be able to use brain scans as objective evidence for or against them in court
