Raine et al Flashcards
What is the hypothesis?
Seriously violent individuals will have localised brain damage in a variety of regions:
Prefrontal cortex
Angular gyrus
Hippocampus
Thalamus
Corpus callosum
What is the methodology?
Quasi-experiment.
Matched pairs design.
IV – NGRI or not.
DV – brain differences.
Opportunity sampling.
What are the murderers (methodology) key points?
41 murderers.
39 men and 2 women. Mean age of 34.3.
They had all been charged with murder or manslaughter.
They all pleaded not guilty by reason of insanity (NGRI).
The participants had been referred to the University of California.
This was to obtain proof of their diminished capacity.
What are the mental disorders of murderers?
Schizophrenia - 6.
History of head injury or organic brain damage - 23.
History of psychoactive drug abuse - 3.
Affective disorder - 2.
Epilepsy - 2.
History of hyperactivity and learning disability - 3.
Personality disorder - 2.
What are the control group (methodology) key points?
Matched based on sex and age.
The 6 schizophrenics were matched with six schizophrenics from a mental hospital.
Everyone else from the control group had no history of psychiatric illness from any close relatives.
And no significant physical illness.
None were taking medication.
What are the procedures?
PET scans were used to study the active brain.
10 minutes before the injection participants were given the chance to practice the continuous performance task (CPT).
30 seconds before the injection participants started the CPT.
The radioactive tracer (fluorodeoxyglucose) was injected into the participant.
After 32 minutes participants were given a PET scan.
Ten horizontal slices (pictures) of the brain were taken.
Cortical peel and box technique.
What areas of the brain had increased activity in NGRI participants?
Increased activity in the brain of NGRI participants in areas not previously linked to violence:
Cerebellum
Right hemisphere:
Amygdala
Thalamus
Hippocampus
What areas of the brain had reduced activity in NGRI participants?
Reduced activity in the brain of NGRI participants in areas previously linked to violence:
Prefrontal cortex
Left angular gyrus
Corpus callosum
Left hemisphere:
Amygdala
Thalamus
Hippocampus
What areas of the brain had no difference between NGRI participants and normal individuals?
No difference between NGRI and control group in areas not previously linked to violence:
Caudate
Putamen
Globus pallidus
Midbrain
What is the summary of the findings?
Reduced activity:
In some areas, notably the areas previously linked to violence.
Abnormal asymmetries: Reduced activity on the left side of the brain.
Greater activity on the right.
No differences:
Notably areas associated with mental illness but not violence.
What is the left VS right-handed findings?
6 of the murderers were left-handed.
They had less amygdala asymmetry and higher medial prefrontal activity than right-handed murderers.
What is the race findings?
14 of the murderers weren’t white.
No significant difference in brain activity between them and white murderers.
What is the head injury VS no head injury findings?
23 of the murderers had a history of head injury.
They didn’t differ from murderers with no history of brain injury.
What is the performance on CPT findings?
Both groups performed similarly on the CPT.
Any observed brain differences weren’t related to task performance.
What are the conclusions?
Past research (animal and human studies) has identified links between areas of the brain and aggression.
These findings are supported by Raine et al’s study.
Combining all these findings together, there is preliminary evidence that murderers pleading NGRI have different brain functioning to normal individuals.
However, neural processes underlying violence are complex and can’t be reduced to a single brain mechanism.
Violent behaviour can best be explained by the disruption of a network of interacting brain mechanisms rather than any single structure.
Such disruption wouldn’t cause violent behaviour but would predispose an individual to violent behaviour.
What is the quasi-experiment evaluation point?
The independent variable was an existing condition of the individual – not something that was manipulated by the researcher.
Casual conclusions therefore aren’t justified.
Readers may misinterpret the findings and assume that criminal behaviour is predetermined and inescapable.
What are the main confounding variables of the study?
Head injury.
IQ.
What is the sample evaluation point?
The murderers weren’t typical of all violent individuals.
The study can only draw conclusions about this kind of violent offender.
An individual with a recognised form of mental impairment.
The crime studied is also a murder and many violent crimes don’t involve murder.
What is the research technique evaluation point?
Data was collected using PET scans.
PET scans have permitted researchers to study the brain in a way not possible until recently.
PET scans allow the brain in action to be examined. This meant that Raine et al could see how the brains of different individuals differed in the way they processed information.
What don’t the results demonstrate?
Violent behaviour is determined by biology alone.
Social, psychological, cultural and situational factors play important roles in predisposition to violence.
Murderers pleading NGRI are not responsible for their actions.
PET scans can be used as a means of diagnosing violent individuals.
Brain dysfunction causes violent.
What is the valid consent evaluation point?
Participants may not have been mentally competent to provide valid consent.
Participants may not have fully understood what they were required to do.
They may have found the performance task difficult.
This may have lowered their self-esteem – psychological harm.
They may have not understood what would be involved in a PET scan.
May have found this a distressing experience.
What is the right to withdraw evaluation point?
May not have understood their right to withdraw – especially as they were prisoners.
They may have felt they couldn’t say they no longer wanted to take part.
What is the socially sensitive research definition?
Any research that has consequences for the larger group the participants are part of.
What is the socially sensitive research evaluation point?
If the research indicates that murderers are born rather than made this may have consequences that would be disadvantageous for people with similar brain abnormalities.
They might be imprisoned without any trial or any reference to their social circumstances.
What is alternative evidence for this research?
James Fallon analysed his own genes.
He found that he had the genetics and brain characteristics of a violent offender.
He suggested that his positive experiences during childhood meant that his potentially criminal tendencies weren’t triggered.
This is a diathesis-stress explanation.
A diathesis is a genetic predisposition which is only manifested if certain stressors trigger it.
