Classical Study: Rayne et al 1997 Flashcards
Classical Study: Rayne et al 1997
Aim (crinimal brains different? if so violent? if so where?)
To show if criminal’s brains were different to non criminal’s brains
To see if dysfunction of the brain causes violent behavior
To localize which areas of the brain are dysfunctional in violent murderers
Classical Study: Rayne et al 1997
- Generalisability (NGRI)
Has low generalizability due to the sample of the experemental group (control group also 41) of 41 (39M/2F) murderers/manslaughterers pleaded not guilty by reason of insanity (NGRI)
this means that they do not represent the normal criminals brains, as they have stated that they committed the crime due to dysfunction in their brain
and they may not have been aware that they committed the crime in the first place
Therefore they don’t represent the target population of all violent criminals and the results that certain areas of the brain being damaged affecting aggression
such as a greater glucose metabolism compared to the control group in the right amygdala
Cannot be generalised to the target population of all violent criminals
Classical Study: Rayne et al 1997
+ test retest reliability
This is due to the study having a standardized procedure of
participants completing a practice continuous performance task (CPT) for 10 min
And start the real CPT then 30 sec later then they are injected with the radioactive tracer FDG
and are put into the PET scanner
During which when the brain uses glucose from the FDG
The PET scan can detect these radioactive areas allowing the research to see the active parts of the brain which will be showed in red whereas the less active parts of the brain will be shown in blue
after 32 Min the scan was complete
10 horizontal slices of the brain was recorded using a peel and box technique
This is to identify regions of the brain with damage
Due to the standardise procedure it’s incredibly easy to replicate this study which gives it high test retest reliability
Classical Study: Rayne et al 1997
Unethical (stop meds - blood pressure meds stop = heart attack)
For the PET scan it was required for participants to not have taken medication for two weeks before the scan
Not taking certain medication for two weeks may cause blasting effects for example blood pressure medication which if abruptly stopped may cause a heart attack this will be a breach of the Ethical guideline protection from physical harm (BPS) as a heart attack may lead to death this therefore makes the study unethical
Classical Study: Rayne et al 1997
+ internal validity ( PET scans objective)
This study has high internal validity this is due to the procedure using a PET scan which is a highly objective way of measuring brain damage and activity in certain areas of the brain as it is very resistant to extraneous variables such as demand characteristics
This means the cause and effect is more easily established and the results of the study
which show that areas such as the right amygdala is more active in murderers the non murderers in terms of glucose metabolism levels may increase levels of aggression
this therefore gives the study high internal validity
Classical Study: Rayne et al 1997
Conclusion (prefrontal + amygdala) + aplication (test NGRI to stop liers from escaping trial pumishment)
The study concluded that criminals brains were different to non criminal brains and these dysfunction and damage of certain areas of the brain increased their violent behavior this is shown when the experimental group is compared to the control group
as it is shown that:
The right amygdala which is responsible for facial recognition of emotions and negative emotions such as aggression had higher glucose metabolism than in the control group this could have lead to greater levels off aggression leading to them becoming a crinimal
Another example is a prefrontal cortex which had lower levels of glucose metabolism relative to control group this resulted in a reduction in the inhibition of impulses which may have led to the violent act being committed in the first place
Application:
Due to now knowing that certain areas of the brain when damaged may increase aggression when acriminal pleads not guilty by reason of insanity they can be checked using a PET scan to see if they have any similar brain damage and whether or not they are telling the truth to escape punishment during the trial
Classical Study: Rayne et al 1997
evaluation order
Aim (crinimal brains different? if so violent? if so where?)
- Generalisability (NGRI)
+ test retest reliability
Unethical (stop meds - blood pressure meds stop = heart attack)
+ internal validity ( PET scans objective)
Conclusion (prefrontal + amygdala)
aplication (test NGRI to stop liers from escaping trial pumishment)
Classical study: Raine et al 1997
Low internal validity
• the study may have low internal validity due to the CPT task may not have stimulated the right areas of the brain that are active during murder
• therefore it would not show the correct data and cause an effect with not be able to be established meaning that this would have invalid results giving the study low internal validity
Classical study: raine et al 1997
Low ecological validity
• The study took place in a lab which then artificial setting
• meaning that there are many controls that would not have existed in real life
• due to having many controls and taking place in an artificial setting the study may not have shown valid results of what the brain would do in a real life situation
• therefore meaning that’s the study cannot be applied to real life giving it low ecological validity
