raine Flashcards
(13 cards)
What were the aims of raine
- to show that the brains of murderers who pleaded guilty by reason of insanity were different to those of non-murderers
- to investigate if this abnormality makes them more aggressive and so reduces accountability
Sample
- 41 murderers pleading NGRI
- 39 males, 2 females
- used a matched pairs design, matched on sex and age
- 6 non-murderers with sz to match those pleading NGRI
- 23 with brain damage, 3 with drug abuse, 2 with an affective disorder, 2 with epilepsy, 3 with learning disabilities, 6 with sz etc.
What type of method was used
Lab
Describe the procedure of the study
- All ppts were instructed to refrain from taking medication for two weeks prior to the study, urine screens at the time of the PET scan were negative
- 10 minutes before the FDG injection, subjects were given practice trials on the CPT task (to remove confounding variable of unfamiliarity)
- 30 seconds before the injection, the real CPT task started took place for 32 minutes
- CPT task involved spotting targets on a screen and pressing buttons to indicated that they had been registered
- then were given a PET scan
- used the cortical peel technique and the box technique, and 10 slices at 10 mm intervals were obtained.
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What was the IV and DV
IV= whether ppts were murderers or non-murderers
DV= level of brain activity, measured by the level of glucose metabolism in certain areas of the brain.
What were the results of the study
PFC= had lower activity in both hemispheres than controls, with a difference of 0.03 for both
Amygdala= LHS- lower activity- 0.94 compared to 0.97 in controls
RHS- higher activity- 0.88 compared to 0.83 in controls.
Describe the conclusions of the pfc
The pfc is involved in decision making, planning and personality. Lower levels in the NGRI’s suggest that damage/abnormal activity in the PFC can lead to impulsivity, the inability to modify behaviour which can facilitate aggressive acts, lack of self control and the inability to plan the consequences of violent/aggressive actions before you commit them.
Describe the conclusion of the amygdala
LHS of the amygdala is involved in fear perception- so lower activity suggests that there is a lack of fear of the consequences of violent actions such as prison- so will be free to commit them (reduced autonomic fear arousal/lack of fear in offenders)
RHS of the amygdala is involved in recognition/perception of stimuli- so high activity suggests that there is the perception of non-threatening stimuli as threats, so will act in defence of themselves aggressively.
Weakness- generalisability.
A weakness is that there is low levels of generalisability. This is because raine used an unrepresentative sample- of ….This cannot represent non-violent offenders pleading NGRI, reducing the findings usefulness.
Strength - reliability
A strength of the study is that there is high levels of reliabilty. This is because it uses a highly standardised procedure and controlled conditions- such as the PET scan and the same 32 minute CPT for everybody. This means that the study can be replicated easily to check for consistency within findings, increasing reliability of results.
Applications/implications
A strength is that there are positive applications to society, as it suggests that reduced brain activity in certain areas may act as a predisposition for violence. Therefore, violent criminals may therefore be less accountable for their actions which may have importance when their sentence is decided. However, there are possible implications of this research, as by suggesting that there is a biological predisposition to aggressive, violent behaviour which makes people criminals, it risks labelling people as aggressive criminals before they have committed an aggressive act, causing the discrimination of individuals and their isolation from society.
Strength- validity, CA
A strength is that there is high levels of control over participant variables. Raine used a matched pairs design, whereby ppts were matched on sex and age, as well as having 6 schizophrenics in the controls to match the 6 in the NGRI condition with sz. Therefore, this reduces ppt variables and so comparisons are more meaningful, increasing levels of internal validity. However, there is low levels of ecological validity. This is because the CPT task was carried out in a controlled lab environment, which may not be representative of how the brain operates in real life. Additionally, there is low task validity, as the CPT was an artificial task which may not reflect real life decision making or aggression- so lowering mundane realism.
Weakness- ethics
A weakness of the study is that it could have been unethical. Ppts may not have been mentally stable enough to fully comprehend what their were agreeing to and may have felt obliged to agree to take ppart, due to being prisoners- therefore compromising their informed consent and right to withdraw from the study.
