Evaluate the methodology of Raine
+ The study used a matched pairs design, which accounted for individual differences. For example, ppts were matched on age, sex and mental health diagnoses, such as schizophrenia. This is a + because since it reduces the impact of ppt variables, meaning the results are more likely to reflect true differences in brain activity between murderers and non- murders, rather than other factors.
Another + is that the sample size was relatively large, particularly for neuroimaging research. For example, there were 41 murderers and 41 controls in the study. This is a + because a larger sample reduces the effect of anomalies and increases the reliability and internal validity of the findings, making the conclusions more trustworthy.
However a - is that the sample wasn’t representative of all violent offenders. For example, all ppts were from the USA and the experimental group were murderers pleading not guilty by reason of insanity (NGRI). This is a - because it means the results cannot be generalised to other types of criminals or to people in different cultures, reducing the population validity of the study.
Another - is that there is low ecological validity due to the artificiality of the task. For example, ppts performed a continuous performance task (CPT) while inside a PET scanner. This is a - because it is an artificial task that doesn’t reflect real life situations in which violent behaviour occurs, decreasing the ecological validity since the findings might not apply to real-world decision making or aggression
Evaluate the procedure of Raine
+ Raine used a highly standardised procedure is that Raine used a highly standardised procedure for all participants. For example, all ppts completed a continuous performance task (CPT) for 32 minutes and were injected with a glucose tracer before undergoing a PET brain scan. This is a + because this standardisation ensures all ppts were tested under the same under the same conditions, improving the internal reliability of the study. Future researchers can also replicate the study more easily.
Another + is that the procedure included the use of objective brain imaging technology. For example, Raine used PET scans to measure glucose metabolism in different areas of the brain. This is a + because it provides scientific qualitative data about brain function, reducing the risk of researcher bias and increasing the credibility and accuracy of the findings
However a - of the study is that brain scans were taken at a single time point. For example, the PET scan was done just after the CPT task and only measured brain activity once. This is a - provides only a snapshot of brain activity and may not reflect stable , long term patterns. This limits the temporal validity of the procedure, as the brain can function differently under different emotional or physical states.
Another - is that the procedure didn’t account for certain inidvidual differences that may have influenced brain activity. For example, factor such as medication use, substance abuse history or varying levels of stress were not fully controlled across the ppts. This is a - because these uncontrolled variables could have affected brain metabolism during the scan, potentially confounding the results. This reduces the internal validity of the procedure as its unclear whther differences in brain activity were due to being a murderer or other unmeasured factors.
Evaluate the ethics of Raine’s study
+ The study did seek informed consent from the ppts before proceeding. For example, all ppts agreed to take part in the study and were made aware of the procedures including the PET scan. This is a + because it shows respect for their autonomy and a consideration for ethical guidelines which helps to make the study more ethical and trustworthy.
However a - is that some ppts had mental health disorders which may make them vulnerable. For example, all the NGRI ppts had a diagnosed mental disorder, predominantly schizophrenia. This is a - because it could raise ethical issues related to consent, since these individuals may not fully appreciate or understand or understand the procedures or the potential stress involved, reducing their ability to provide informed consent.
