3.3 Biological studies

Question 1

What is your biological classic study? (just name it)

Answer 1

Raine, A. et al. (1997)

Brain abnormalities in murderers indicated by positron emission tomography (PET)

Question 2

What is the aim for your biological classic study?

Answer 2

To investigate whether Pps pleading NGRI (not guilty by reason of insanity) would show brain dysfunctions in areas of the brain associated with violence.

(prefrontal cortex,
angular gyrus,
amygdala,
hippocampus,
thalamus,
corpus callosum)

Question 3

What is the procedure for your biological classic study?

Answer 3

Pps:

• 2 groups of 41
• 39 males + 2 females in each group
• Experimental group, 41 criminals with convictions for murder or manslaughter.
• Of these, 6 had Sz, 23 organic brain damage/head injury, 3 substance abusers, 2 effective disorder, 2 epilepsy, 3 hyperactivity/learning disability, 2 passive-aggressive/paranoid personality disorder.
• Pps were medication-free for 2 weeks prior PET scan.
• Control group matched with experimental + all screened for general health, access to their medical history, psychiatric interview. (excluded if they had history of seizures, head trauma or substance misuse.
• Consent obtained from all Pps before PET scan.

All Pps given continuous performance task (CPT) to complete,
Consisted of sequence of blurred numbers to focus on.

Started CPT as practice trial 10 mins before injected with fluorodeoxyglucose (FDG).

After further 32 mins on CPT a PET scan was completed to measure metabolic rate in different areas of brain in order to look at activity levels in those areas.

Question 4

What is the results for your biological classic study?

Answer 4

Brain dysfunction in the NGRI group was in areas previously implicated in violent behaviour.

MURDERERS SHOWED:

Lower activity in:

• Prefrontal cortex
• Parietal areas
• Corpus callosum

Higher activity in:
- Occipital lobe

Identical activity in:
- Temporal lobe