3.3.1 - Classic Study Flashcards
AO1
Aim:
- To show that the brain of murderers who pleaded not guilty by reason of insanity (NGRI) were different from the brains of non-murderers
- To use PET scanning so they could study localised areas in the brain to check for dysfunction in those areas
Procedure:
- 41 murderer pp’s and 41 control pp’s who were an average age of 34, there were 39 men and 2 women who had all been referred to obtain evidence relating to NGRI defence
- The study was a matched pairs design with a control group of non-offenders matched with murderers for age, sex, 6 schizophrenics and 23 had history of brain damage
- each pp carried out a 10 minute practice test and were then injected with a radioactive tracer and carried out a 32 minute visual task stimulating aggression before a PET scan was carried out
Results:
- showed that murderers had lower levels of activity in the PFC and parts of the lymbic system than non-offenders; in areas of the brain associated with self-control and inhibition of violent behaviour
strengths
R) The study is reliable as there are well controlled procedures. For example the pp’s were given the same 10 minute practise task and 32 minute actual task. Therefore the study can be replicated with better ethics on other murderers to make sure results are accurate
A) The study has application to society. Results showed that murderers pleading NGRI have different brain functioning which can result in impulsivity and loss of self-control with abnormal behaviour in the amygdala, thalamus and hippocampus associated with aggressive behaviour. Therefore the NGRI defence could be used in court in order to reduce a prison sentence as their behaviour is arguably out of their control
weaknesses
G) The study is not generalisable because pp’s were 41 murderers, 39 men and 2 woman average aged 34 who were PET scanned at California university to gather evidence for their NGRI defence. Therefore the results are not representative of non-impulsive murderers and non-murderers
V) this study lacks task and ecological validity. The environment was unnatural as participants had a pet scan. It was also a 32 minute artificial task to stimulate aggression. Therefore results may not reflect how their brains are functioning in every day life and with normal tasks
E) The study was not ethical as the six schizophrenics in the control group had to go off the medication two weeks prior to scanning. Therefore they may have suffered psychological harm due to the paranoia they will experience without the medication modifying brain function
