Classic Study Flashcards
Raine et al (1997)- Classic study Murderers pleading (NGRI)
A01- Aim
Aim-
1) To show the BRAINS of MURDERERS pleading (NGRI) were DIFFERENT from brains of NON MURDERERS- thought that murdersbrains have localized impairments, it no previous brain imaging research into this had been done
2) Raine investigated his hypothesis that seriously violent individuals should have relatively localized brain dysfunction eg in PFC, amygdala and thalamus (Limbic system); linked to aggression
Raine et al (1997)- Classic study Murderers pleading (NGRI)
A01- Sample
Sample
- 41 murderers pleading (NGRI): 39 MEN, 2 WOMEN charged with either murder or manslaughter- referred to UNIVERSITY OF CALIFORNIA IRVINE IMAGING CENTRE, had history of BRAIN DAMAGE and SZ as well as other issues. 14 non- white, 27 white
- 41 matched (in sex, age and other similarities) controls: 6 SZ controls, rest thoroughly screened= no history of psychiatric illness, none committed murder
Raine et al (1997)- Classic study Murderers pleading (NGRI)
A01- Controls
Controls
- All offenders= in custody, kept MEDICATION FREE 2 weeks, didn’t have any psychoactive medication at scans and 2 week period after- confirmed by UNRINE SAMPLES at PET scans
- Controls matched murderers in great detail= SZ murders matched with SZ controls from larger psychiatric sample
- The 14 non white murderers compared with white murderers on PET measure= no sig difference
- Tests done to make sure being left or right handed had no effect on behavior
Raine et al (1997)- Classic study Murderers pleading (NGRI)
A01- Procedure
Procedure-
- 10mins before FDG injection= given practice trials on CPT, knew what to expect
- 30 seconds before injection, real task started= enabled initial task novelty not recorded
- Once injected, monitored for 32 mins, scanned in PET scanners, heads held still in head holders
- Brains scanned 10TIMES, at 10MM INTERVALS to pick up differences in GLUCOSE METABOLISM in CEREBRAL CORTEX + SUB CORTICAL LAYERS
- High levels would show up as RED
- Brain regions= identified using 2 techniques; CORTICAL PEEL TECHNIQUE (lateral areas), BOX TECHNIQUE (medial layers)
(Glucose metabolism= brain using up glucose- high levels indicate high levels of activity)
Raine et al (1997)- Classic study Murderers pleading (NGRI)
A01- Results Quantitative: Cortical Regions
Results- Left H: Right H:
Cortical Regions: M C. M. C
Lateral PF lobes: 1.09. 1.12. 1.11. 1.14
Medical PF lobes: 1.20. 1.25. 1.17. 1.22
Parietal Lobes: 1.10. 1.15. 1.13. 1.17
Raine et al (1997)- Classic study Murderers pleading (NGRI)
A01- Results Quantitative: Sub- Cortical
Results- Left H. Right H
Sub-Cortical regions: M. C. M C
Corpus Callosum: 0.56. 0.68. 0.56. 0.67
Amygdala: 0.94. 0.97. 0.88. 0.83
Medial Temporal Lobe: 0.91. 0.95. 0.96. 0.93
Thalamus: 1.09. 1.09. 1.15. 1.09
Raine et al (1997)- Classic study Murderers pleading (NGRI)
A01- Results Qualitative
Results-
- FRONTAL LOBES had REDUCED glucose metabolism relative to controls in both the LATERAL(left+right) and MEDIAL (middle) PF cortical areas
- PARIETAL LOBES had LOWER glucose metabolism than controls
- CORPUS CALLOSUM bilaterally, LOWER glucose metabolism than controls
- LIMBIC SYSTEM (AMYGDALA) abnormalities= REDUCED in LEFT and GREATER in RIGHT
Raine et al (1997)- Classic study Murderers pleading (NGRI)
A01- Conclusions
Conclusions
- Confirm brains of murderers pleading NGRI are different to non murderers, data also confirms deficits in PFC may be linked to AGGRESSIVE BEHAVIOUR
- PFC deficit= relevant as damage can lead to impulsivity, lack of self control, immaturity, inability to modify behavior, altered emotionality leading to AGGRESSIVE BEHAVIOUR
- Found abnormalities in amygdala= repeatedly linked with aggressive behaviour in both animals and humans. Destruction resulting in lack of autonomic arousal, relevant to fearlessness theory of violence based on findings of reduced autonomic arousal in offenders.
- Reduction in GM in PARIETAL LOBES= correlated with reduced verbal ability + deficits in maths ability + reading. Could pre disperse educational+ occupational failure- predispose crime + violence
- Findings can’t be taken to demonstrate that violence is determined by biology alone; clearly social, psychological, cultural and situational factors play an important role.
- But can conclude that violent behaviour is controlled by areas of the brain, despite not being certain that abnormalities are also a causation for this behaviour
Raine et al (1997)- Classic study Murderers pleading (NGRI)
A03- Generalisability
Weakness- Generalisability
Raine studied a sample 41 killers, convicted for either murder or manslaughter and pleading not guilty by reason of insanity. It involved 39 male offenders and 2 women offenders. Generalisability may be criticised as Raine only focused on offenders pleading NGRI, the findings found may not be true of violent offenders pleading just not guilty, or guilty. Furthermore, a very small sample of women offenders was considered,with only two women studied. This means it would be very difficult to apply Raine’s results to the all violent criminals as there is limited representation, reducing the usefulness of Raine’s study.
Raine et al (1997)- Classic study Murderers pleading (NGRI)
A03- Controls
Strength- Controls
Raine’s study followed strict controls to reduce participant variables; such as the detailed matching of the offenders and the controls in terms of age, sex and involving 6 Scizophrenic controls to match those offenders with schizophrenia or other mental illnesses. This improves the validity of the study as it ensures that the comparisons between the controls and murderers brains were more meaningful and reduces the impact of individual differences playing a part in the comparisons. Suggesting the conclusions on brain abnormalities impacting aggression to be accurate.
Raine et al (1997)- Classic study Murderers pleading (NGRI)
A03-Validity
Weakness-Validity
Raine carried out PET scans of offenders and controls brains 10 times at 10mm intervals to pick up differences in glucose metabolism in the cerebral cortex and sub cortical layers. However, the validity of the study can be questioned as the brains scans were carried out on the offenders after the violent acts were committed, therefore we cannot be sure that the brain abnormalities were there before the violent crimes took place. This demonstrates that Raine couldn’t establish a cause and effect relationship between brain abnormalities and violent behaviour, reducing the validity and usefulness of the findings in discovering the cause of aggressive behaviour.
Raine et al (1997)- Classic study Murderers pleading (NGRI)
A03-Application and Conclusion
Strength- Application
Raine found that the PFC and left Amygdala had reduced glucose metabolism relative to the controls. As both damage to the amygdala and PFC had previously been associated with aggressive behaviour, Raine concluded that violent behaviour is controlled by areas of brain, but can’t confirm a causal relationship. This has practical applications as it suggests that reduced brain activity in certain areas could act as a predisposition for violence, therefore having implications for the sentencing system as violent criminals may be less accountable for their actions and imprisonment wouldn’t prevent reoffending. Therefore, implying that imprisonment may not be the best way to treat violent criminals, instead maybe anger management programmes should be considered.
