Raine Classic Study Flashcards
What was the aim
To measure brain activity differences between murderes pleading NGRI and non murderers
What was the independent variable
If participant was pleading NGRI for murder or if they were a non murderer
What is a confounding variable
A Variable that affects other variables causing a distorted association between two variables
How many participants in total
82 in total
41 in each group (39 men, 2 women)
6 in each group had schizophrenia
Average age of the study
34.3 years old
NGRI group health conditions and numbers of each?
23 had brain damage
3 had history of drug abuse
2 had epilepsy
7 had emotional or learning disorders
Studies controls?
- same age and sex were compared
- no history of crime or mental illness
(Except 6 controls w schizophrenia)
What type of sample were NGRIs
Opportunity samples
What was the procedure
- tested at California uni
- injected w glucose tracer, then performed continuous performance task (CPT) for 32 minutes ( had 10 minute practice before)
- then PET scan was carried out
What does PET stand for
Positron emission tomography
Controls during the procedure?
- 10 minutes practice of CPT
- no participants on medication 2 weeks before the PET scan
Strengths of the study
Largest sample yet subjected to brain imagery for this purpose
Includes control group
Looks at different areas of brain associated w agression
Weaknesses of the study
Findings only apply to people pleading NGRI not all violence
Doesn’t show cause of brain deficits
Brain wasn’t scanned before prison
Pet image isn’t clear
2 main areas in NGRI group that showed less brain activity
- function of those areas
Frontal lobe- rational thinking, self restrain, memory
Parietal lobe - abstract thinking e.g. morality and justice
Where in sub cortical region did NGRIs have less activity
And what do these deficits cause
Corpus collosum - long term planning, “bridge” connects the two hemispheres of the brain
Make it harder for long term planning and so the consequences of actions
Which side of amygdala, thalamus, MTL/hippocampus had more brain activity
What do these have in common
More on right than the left side
When these have more activity on the right side, these are the sides associated w agression in animals
What do prefrontal deificts cause
- can make someone more impulsive and emotional
What can deficits in the limbic system cause
May make someone aggressive and find it hard to learn from their mistakes/ understanding emotions
What do deficits in parietal lobe, amygdala and hippocampus cause
Make it harder to judge social situations, can lead to someone overreacting
PET scans
What do they scan
How do they work
Scan brain activity by looking at levels of neurotransmission in the brain
Glucose tracer measures levels of glucose and is tagged with a radioactive tracer which enters the brain
