C1-Biological Approach-Classic study Flashcards
What are the weaknesses in the findings of Raine et al’s study in terms of ethical issues?(3)
- may not be capable of providing valid consent due to mental competency
- may not be understood even though they were prisoners that hold right to withdraw
- possible psychological harm as they may not have fully understood what to do, causing distress
What are the strengths in the findings of Raine et al’s study in terms of ethical issues?(2)
+useful applications- pet scans can be used as part of a defence in court of law when pleading NGRI - offers objective evidence to support legal rpocess
+neurosurgery or drug therapy- reduces liklihood of violent crimes
Who is Tiihonen et al 2015 as alternative evidence?(3)
- findings from studies like Yang and Raine are further supported by genetic studies that indicate a ‘criminal gene’
- one candidate for this is MAOA gene causes abnormally high levels of dopamine
- recent study analysed the genes of 895 finnish prisoners and found an association between this gene and an increase liklihood of commiting a violent crime
Who is Yang and Raine 2009 as alternative evidence?(3)
- meta analysis of 43 imaging studies
- considered both anti social and violent behaviour
- concluded that there is significantly reduced prefrontal activity and/or violent behaviour
What are the weaknesses in the methodology and procedure of Raine et al’s study?(3)
- quasi experiment method: cant show casual relationship, unclear if brain abnormalities cause violent actions or other way round
- generalisability of sample: studied only murderers, unique group of people and dont necessarily represent all violent criminals
- other variables? individual circumstances of murderers not taken into account
What is the alternative evidence in findings of Raine et al’s study?(2)
- Yang and Raine 2009
- Tiihonen et al 2015
What are the strengths in the methodology and procedure?(2)
+research equipment used- objective measure, allows them to see detailed regions of the brain and how they process information
+control variables- match controlled group means researchers can be quite confident that the characteristics they matched for were not the cause of different brain activity between two groups, can assume the difference in brain activity seen in two groups was likely to be the cause of difference in violent behaviour
What are the conclusions drawn from the study?(4)
- prefrontal deficits might make someone more impulsive and emotional
- deficits in limbic system might make someone more aggressive
- neural processes underlying violence are complex and cant be reduced by single mechanism
- study doesnt mean murderers arent responsible for their actions
What is the procedure in this study?(4)
- california university
- continuous performance task for 32 minutes, injected with radioglucose tracer also called fluroxyglucose after 30 seconds
- given PET scan which picked up brain activity, NGRI were compared with controls on glucose metabolism on right and left hemispheres of brain in 14 areas( 6 cortical and 8 subcortcal)
- 10 horizontal slices of brain were recorded using cortical peel and box technique
What are the findings of the study?(5)
- both groups performed same on CPT
- murderers had sig. lower glucose metabolism in prefrontal cortexes in both hemispheres
- reduced activity in left angular gyrus and corpus callosum, reduced activity in amydala, thalamus and hippocampus but only in left hemipshere
- increased activity in cerebellum, occipital lobe as did amygdala, thalamus and hippocampus in right hemisphere
- no difference in glucose uptake in midbrain and caudate
What is the aim of the study?(2)
- to find out if there is a difference in the structure of the brain activity between those pleading NGRI and those who didnt
- the researchers were interested in parts already known to link to aggression eg amygdala and prefrontal cortex
What is the methodology in this study?(4)
- quasi experiment, matched pairs design where matched for age and gender
- opportunity sampling: 41 murderers and 41 non murderers
- mean age of NGRI was 34.3 and control was 31.4, 39 males and 2 females
- 23/41 had past head injury or organic damage
What is the context in this study?(1)
-brain scanning technology allowed to search for brain differences in criminals and non criminals and other studies associated with brain injury is Phineas Gage
