Evaluate Brain Scans (8 marks) Flashcards
→ Brain scanning can be seen to be valid as it does measure brain activity and that is not denied.
→ For example, there may be a lack of validity in that tasks intended to generate aggression in someone might not lead to aggression- that is an assumption. Getting someone to feel aggression in a study is not easy- it might not be ethical and tasks may not yield aggression in all individuals.
→ The results are visible and measurable and it is generally accepted that brain scanning, such as fMRI, does show actual brain activity, including the sites of activity, although whether the responses in the brain measure validly the behaviour of interest is in doubt.
→ Raine et al (1997) used PET scans to investigate differences between the brains or murderers and non-murderers
→ Using PET scans, they were able to map abnormal brain activity in the murderers’ group in areas of the brain associated with impulsivity and risk-taking behaviour, which may explain increased aggression.
→ Raine highlights the importance of the pre-frontal cortex and amygdala.
→ Betts (2009) discussed the case of Herbert Weinstein, whose defence used CAT scanning to show he had damage to the brain that might have led to his aggression (he strangled his wife).
→ The scan showed some damage, including widened sulci, and this evidence was used to persuade the jury that his actions were not thought through; he did not know sufficiently right from wrong. Betts suggests that 60-77% of people pleading NGRI (not guilty through reason of insanity) have a psychosis and 10% of those have a psychosis that is neurologically based.
→ This is evidence that aggressive behaviour might be based on someone’s brain physiology and so scanning is a useful research method when investigating human behaviour such as aggression.
→ Matthies et al. (2012) used MRI scans to measure the volume of the amygdala in 21 female volunteer participants.
→ Alongside that measure, they obtained an aggression score about lifetime aggression. The two scores were tested for a relationship and a significant correlation was found. Previous studies have suggested that the amygdala (in the limbic system) is the place for aggression in the brain. However, this study found surprising results, in that the smaller the amygdala the higher the aggression.
→ This suggests that MRI scans might be helpful in finding out where aggression might ‘be’ in the brain.
→ Weber et al., (2006) (fMRI) This study aims to advance the media effects debate concerning violent video games.
→ In a novel, event-related functional magnetic resonance imaging study, 13 male research participants were observed playing a latest-generation violent video game. Each participant’s game play was recorded and content analysed on a frame-by-frame basis. Onscreen activities were coded as either “passive/dead, no interactions”; “active/safe, no imminent danger/no violent interactions”; “active/potential danger occurs, violent interactions expected”; “active/under attack, some violent interactions”; and “active/fighting and killing, many violent interactions.”
→ The study found that virtual violence suppresses affective areas of the anterior cingulate cortex (ACC) and the amygdala subsequent to activity variations at cognitive areas of the ACC. However, no control group was used
