Biological Classical Evidence Flashcards
Who researched into the biological evidence?
Raine et al (1997)
What is the aim of Raine’s study?
To investigate the direct measures of both the cortical and subcortial brain function using PET scans (difference in brain activity in murderers vs non murderers)
What type of experiment was this?
Quasi experiment
What experimental design was used?
Matched pairs
What sampling method was used?
Opportunity
How many participants were involved?
82 - 41 murderers (39 men and 2 women) , 41 normal adults with other mental health issues e.g. schizophrenia
What were the steps to the procedure?
- All participants injected with radioactive tracer that binds to glucose.
- All asked to take part in a continuous performance task (CPT)
- Practiced the CPT before brain scan
- Began CPT 30 seconds before being injected
- After 32 mins, 10 brain images produced, 8 subcortical and 6 cortical
- PET scans of the murderers compared to the control group scans
What nine areas of the brain were studied?
Prefrontal Cortex, Parietal Lobe, Temporal Lobe, Occipital Lobe, Amygdala, Medial Temporal Lobe, Thalamus, Cingulate and Cerebellum
What does glucose metabolism mean?
Brain activity
In which parts of the brain were there lower activity levels in?
Prefrontal cortex ( decision making )
Parietal Lobe ( pain )
What part of the brain were there more activity in?
Occipital Lobe
Right side of Amygdala
Right side of Medial temporal lobe (linked with aggression)
Thalamus
What part of the brain were there less activity in?
Prefrontal cortex (decisions)
Parietal lobe (pain)
Left side of amygdala and media temporal lobe
What part of the brain were there the same activity in?
Temporal lobe
Cingulate
What were the conclusions of the study?
Reduced activity in areas of brain associated with violence
Biology should not be used alone to explain violent predispositions
Findings are specific to NGRI murders only
