Topic 1 - Raine et al - Brain abnormalities in murderers indicated by PET Flashcards
What did Raine investigate?
Raine investigated the difference in brain function between criminals and non-criminals
What was the sample?
41 criminals (39 males and 2 females) who had committed either murder or manslaughter - they had all been referred for brain scanning to find evidence that they were NGRIs for several reasons including Schizophrenia (6), head injury, or organic brain damage (23), epilepsy (2)
What was the sample compared to?
They were compared to 41 controls matched by age and gender. The schizophrenics were also matched individually to schizophrenic controls
What was the procedure?
10 minutes before the injections they were able to practice the CPT task so they knew what to expect. After the task (which took 32 minutes) the subject was transferred to the adjacent PET scanning room and their brain was scanned ten times at 10mm intervals to measure activity in both cortical and subcortical regions of the brain
What were the results?
Although there were no differences in the performance of the task between the two groups, there was evidence of significant differences in brain metabolism in a number of areas.
What does NGRI stand for?
Not Guilty by Reason of Insanity
What did the NGRIs have?
More activity in occipital areas, no difference in temporal areas, less activity in corpus callosum, less activity in left side, more activity in the right side in the amygdala and the hippocampus, more activity in the right side of the thalamus, though no difference in the left side.
What were the conclusions?
Cannot be taken to show that violence is caused by biology alone, do not show that NGRIs are not responsible for their actions, that PET scans cannot be used to diagnose potential murderers, cannot be generalised for NGRIs to other types of violent offenders, cannot be generalised to crime in general as the study did not contain a non-violent criminal control group
What did they conclude what the study did go and show?
The murderers pleading NGRIs had significant differences in glucose metabolism in certain areas of the brain compared to control
