describe methodology and procedures of raine (10)

• Methodology

  Raine, Buchsbaum and La Casse (1997) conducted a quasi-experiment using a matched pairs design to investigate brain abnormalities in murderers who pleaded not guilty by reason of insanity (NGRI). The independent variable was whether the participants was an NGRI murderer or non-murderer, and the dependent variable was brain activity as measured by PET scans. The experimental group consisted of 41 murderers (39 men and 2 women), with a mean age of 34.3 years, who had been referred for brain examination due to various mental impairments such as schizophrenia, brain injury, and drug abuse. They were all medication-free for 2 weeks before scanning, confirmed via urine tests. The control group was matched with the murderers on sex and age; the 6 schizophrenics participants were matched with 6 schizophrenic controls, while the rest were matched with mentally and physically healthy individuals with no history of illnesses.
• Procedures

  The procedure involved PET brain scanning after participants performed a continuous performance task (CPT) designed to activate specific brain areas. All participants were injected with a radioactive tracer (FDG), which is absorbed by active parts of the brain. To avoid task novelty affecting results, participants began the CPT 30 seconds before the FDG injection. After 32 minutes, a PET scan was conducted, generating 10 horizontal images of brain activity using cortical peel and box techniques. These highly controlled procedures allowed researchers to compare brain activity across the 2 groups and ensured the study could be reliably replicated. The sample was obtained using opportunity sampling.