raine et al

Question 1

what is the hypothesis

Answer 1

seriously violent individuals would have relatively localised brain dysfunction in the pre frontal cortex, thalamus, amygdala, corpus callosum, hippocampus, and the medio temporal lobe

Question 2

what is the aim

Answer 2

to show that the brains of murderers who pleaded guilty by reason of insanity(NGRI) are different to the brains of non murderers

Question 3

what was the sample

Answer 3

41 NGRI murderers matched by sex, age and other similarities(39 men and 2 women) who had all been referred to the University of California Irvine Imaging centre

41 non murderers some with a history of brain damage or schizophrenia(6 schizophrenic people were test screened to see if they had any previous psychiatric illnesses and they didn’t)

Question 4

what were the experimental controls for the sample

Answer 4

all offenders were in custody and kept medication free for 2 weeks before, during, and 2 weeks after the experiment
14 non white murderers
tests to see that being left or right handed didn’t have an affect on behaviour

Question 5

what were the materials

Answer 5

thermoplastic head holder moulded to the patients head
PET scanner
FDG
CPT(continuous performance task)

Question 6

what was the procedure

Answer 6

10 mins before FDG injection, patients were given practice trials on CPT
30 seconds before injection, the real task started so initial task novelty wasn’t labelled/recorded
once injected they were monitored for 32 mins and were scanned in PET scanners
brains were scanned 10 times at 10 mm intervals to pick up differences in glucose metabolism in cerebral cortex and subcortical layers
brain regions identified using cortical peel technique and box technique

Question 7

what were the results

Answer 7

no significant difference in the task performance between the 2 groups but there was a significant difference in brain metabolism of glucose in a number of areas
frontal lobes has reduced glucose metabolism relative to controls
parietal lobes and corpus callosum had a lower glucose level than controls
limbic system abnormalities(reduced in the left, more so in the right)

Question 8

what was the conclusion

Answer 8

NGRI murderers brains were different to non murderers
damage to PFC can result in impulsivity, lack of self control, immaturity, emotional changes and the inability to modify behaviour
abnormalities in the amygdala could be relevant to fearlessness theory of violence
reductions in glucose metabolism in parietal lobes have bee correlated with reduced verbal ability and deficits in arithmetic and reading
uncertain that violent behaviours are caused by brain abnormalities alone