to investigate if there is localized brain function in not guilty by reason of insanity such as in the hippocampus, corpus callosum, amygdala, thalamus and angular gyrus
method
quasi experiment (murderers or non murderers)
matched pairs design
sample
41 murderers pleading NGRI (39 males and 2 females)
23 head injury, 2 epileptic, 6 schizophrenia and mean age of 34
41 non murderers (39 males 2 females)
matched on age and gender with 6 schizophrenia
procedure
practiced continuous performance task for ten minutes before the injection as a control to reduce novelty and improve internal validity
CBT based on target recognition to simulate specific brain areas while having a PET scan done
control
medication free for two weeks prior
results
murderers have less activity in the perfrontal cortex, corpus callosum and angular gyrus
reduced activity in the left hemisphere amygdala, thalamus and hippocampus
higher activity in the right hemisphere amygdala, thalamus, hippocampus and cerebellum
conclusions
clear difference in brain function of murderers and non murderers
biological processes can make a criminal such as higher impulsivity and fearlessness
cautioned that biology alone cannot determining criminal behavior but other factors such as culture can be important
low activity in the left hemisphere amygdala
responsible for feelings of fear
less activity means less fear so more likely to be violent as there is less fear of consequences
lowprefrontalcortex activity
poor self control and decision making
can’t control criminal impulses and can’t think of consequences
high activity in the right hemisphere hippocampus
higher impulsivity
more spontaneous behavior
AO2
biological causes
heart rate - choy
low cortisol and high testosterone - raine and glenn
