1.1.4 Raine Et Al Study (Bi) Flashcards
What is Research Hypothesis 1?
Dysfunction in brain structures such as the prefrontal cortex, corpus callosum, left angular gyrus and limbic system will be found more often in murderers than a control group of non murderers
What is the purpose of the control group?
Baseline for comparison
Is Research hypothesis 1 adirectional, non directional or a null hypothesis?
Directional
What is research hypothesis 2?
Dysfunction in brain structures such as the prefrontal cortex, corpus callosum, left angular gyrus and limbic system will be found more often in murderers, than dysfunction in other areas of the brain that have been implicated in non violent psychiatric disorders
Is research hypothesis 2 directional, non directional or null?
Directional
Where is the left angular gyrus found?
In the parietal lobe
What components make up the limbic system?
Amygdala Hippocampus Thalamus
Methodology
What was Raine et al’s research method and what does this mean?
Raine et al used a quasi-experiment, this means the IV is naturally occurring
What was the IV in Raines experiment?
Not guilty by reason of insanity (NGRI) or not
What was the DV in Raines experiment?
Dysfunction in different brain areas
How was the DV operationalised?
Using PET scan results to see metabolic activity in the brain
Who were the subjects (participants) in Raines study?
A group of 41 prisoners all charged with murder but who pleaded not guilty by reason of insanity
Reasons for the 41 offendeds to prove their diminished capacity were
Their specific mental disorder
What does NGRI mean?
Not guilty by reason of insanity
Where were the participants charged with murder or manslaughter?
In California
How many offenders gave schizophrenia as a reason
6
How many offenders gave history of head injury/brain damage as a reason
23
How many offenders gave history of drug abuse as a reason
3
How many offenders gave affective disorder as a reason
2
How many offenders gave epilepsy as a reason
2
How many offenders gave history of learning disability as a reason
3
How many offenders gave personality disorder as a reason
2
What gender were the participants?
39 were male 2 were female
What was the average age of the participants?
34.3 years
What happened the two weeks before brain scanning?
No murderer was given psychoactive medication
How many patients were referred for scanning due to schizophrenia?
• 6
How many subjects were referred for scanning due to brain damage/ head injury?
23
What was each subject matched with?
A non murderer subject
How were the subjects and controlled matched?
As closely as possible for: • age • gender • schizophrenia
What did all controls undergo?
Screening for mental illness, drug taking and history of murder
What group did the non murderers make up?
The control group
Procedures
How were the pps selected
Oportunity sampling
Give a brief outline of the procedure raine used:
• injection • continuous performance task • PET scan
What were all participants injected with?
A tracer substance that was taken up by the brain to show the location of brain metabolism (fluorodeoxyglucose/FDG)
How long did it take for the FDG to be taken up by the brain
32 minuets
What was the CPT the participants underwent and when was it done?
- Detecting signals, designed to activate target areas of the brain
- Done straight after the drug was administered
When was the PET scan given?
After the 32 minuets
What does a PET scan involve
10 horizontal slices of the brain were recorded using the corticle peel and box techniques
What was the PET scan used to show activity in?
6 main areas outside the brain (cortical) 8 main area inside the brain (subcortical)
What did raine et al’s study focus on?
Brain scans of violent individuals who has committed murder and pleaded not guilty by reason of insanity
What did Raines procedure do to get its sample
Opportunity sampling - Raine selected his subjects from those referred for scanning
What did Raines findings show for the prefrontal cortex?
Lower metabolic activity in murderers than in controls Lower activity is linked to loss of self control and altered emotion
What did Raines findings show for the parietal cortex?
Murderers showed lower activity levels especially in the left angular gyrus Lower activity is linked to low verbal ability, leading to education failure and thus crime
What did Raines findings show about the temporal cortex?
No difference
What did Raines findings show about the corpus callosum?
Lower activity in murderers Lower activity was expected as it could stop the left hemisphere inhibiting the rights violence
What did Raines findings show about the amygdala?
Lower activity in the left in murderers
What did Raines findings show about the thalamus?
Higher activity in the right side
What did Raines findings show about the medial temporal?
Lower activity in the left compared to the right in murderers
Found reduced activity (lower glucose metabolism) in the brain of NGRI pps in areas previously linked to violence
- Prefrontal cortex
- Parietal lobe
- Corpus Callosum
- Left hemisphere - amygdala, thalamus, and hippocampus
Found increased activity (higher glucose metabolism) in the brain of NGRI pps in areas not previously linked to violence
- Cerebellum
- Occipital lobe
- Right hemisphere - amygdala, thalamus and hippocampus
What conclusions did Raines draw about the amygdala, medial temporal and thalamus?
These structures all for the limbic system (emotion) Problems may result in inhibition for violent behaviour, fearlessness and failure to learn the negative effects of violence
What did the cinguate, caudate, putamen, globus pallidus and cerebellum show?
No difference
Conclusions - Raines research showed differences in what?
The brains of murderers pleading NGRI
Conclusions - Raines research does not suggest violence is what?
Biologically determined
Raines research does not excuse what?
The behaviour of NGRI murderers
