Raine et al 1997 - Classical Study Flashcards
What were the aims of Raine et al?
To see if murders who plead not guilty to murder by reasons of insanity (NGRI) will have brain dysfunction in the prefrontal cortex, amygdala, hippocampus etc
Describe the sample of Raine et al
41 ppts from California (39 male, 2 female)
Mean age - 34.3
All charged with murder or manslaughter
All NGRI
6 had schizophrenia, 23 had brain damage/injury
All had been medication free for 2 weeks, and urine tests were used to confirm this.
There was a control group of 39 males and 2 females
Matched to murders in age and gender
6 schizophrenics were matched to the 6 schizophrenic murderers
None were taking medication
So 82 in total
Describe the procedure of Raine et al
10 mins before injection, they were given practice trials of continuous performance task (CPT)
30 seconds before injection CPT started
A glucose tracer was injected and they did CPT for 32 minutes
They then had a PET scan
Took 10 slices at 10mm apart starting at 80% level of head height
Describe the results of Raine et al
Low levels of glucose metabolism in the prefrontal cortex
High glucose metabolism in the occipital lobe
Different levels of activity in the amygdala
Describe the conclusion of Raine et al
Murders do have differences in brain activity to non-murderers
A single brain mechanism can’t be said to cause violence but is probably caused by multiple
Violence is not just down to biology, other factors play a role
Evaluate the generalisability of Raine et al
Large sample size - 82 ppts
Androcentric - mainly males, but most murderers are males, so not as important
Ethnocentric - all from California
Evaluate the reliability of Raine et al
Standardised procedure - all did the same CPT, same PET scan etc
Controls - urine tests; matched on age, gender and schizophrenia
Evaluate the application of Raine et al
Can now use PET scans to reduce sentences if found to have brain abnormalities
Can sue lawyers if they didn’t get a brain scan (USA) as the defence wasn’t fully developed
Evaluate the validity of Raine et al
Ecological validity - PET scans done in labs
Task validity - CPT is not a natural task
Internal validity - They did measure brain activity
Demand characteristics - You can’t change your brain patterns
Evaluate the ethics of Raine et al
Protection from harm - no medication for 2 weeks could have caused symptoms to return (eg schizophrenia) causing them harm