3.3.1 Classic- Raine et al (1997)

Question 1

Aims?

Answer 1

• To show that the brains of NGRI murderers were different from the brains of non-murderers
  > To investigate if this abnormality makes them more aggressive and so reduces accountability

Question 2

Sample?

Answer 2

> Uni of California
2 groups 41 NGRI murderers(39 m 2 f) mean age-34.3
,41 non murderers
> Exp: 6 w Sz
23 w TBI
3 w drug abuse history
2 w epilepsy
7 w emotional/learning disorders
> Control: 6 w Sz
Matched pairs
No history of crime/ mental illness
Matched pairs design (Exp; age,sex,ethnicity)

Question 3

IV & DV?

Answer 3

IV
>Murderer or non murderer (2 conditions, couldn’t be assigned to conditions though)

DV
>Level of glucose metabolism/activity in specific brain areas (corpus callosum, amygdala, PFC)

Question 4

Ppt design & method?

Answer 4

Matched pairs: sex & age (6 NGRI murderers had Sz, to match 6 controls w Sz)

Lab exp (method)

Question 5

Briefly describe the procedure of this classic study.

Answer 5

• 10 mins before being given a FDG injection for the PET scan ppts were given practice trials on the continuous performance task (CPT)
• 30 secs before the injection, the real CPT task started and were monitored for 32 mins in the PET scan
• The CPT involved spotting targets on a screen and pressing a button to indicate the target had been recognised

-Their brains were scanned 10 times at 10 minute intervals to pick up differences in glucose metabolism in the cerebral cortex and sub-cortical layers

Question 6

Results?

Answer 6

• Parietal lobes of murderers had lower activity in both hemispheres than controls with a difference of 0.05 in the left and 0.04 in the right

Frontal lobes of murderers had lower activity in both hemispheres than controls with a difference of 0.03 for both

• Amygdala of murderers had lower activity in left (0.94) compared to 0.97 of non-murderers and greater activity in right (0.88) compared to 0.83 of non-murders

Question 7

Describe the conclusion based on the parietal lobes.

Answer 7

The parietal lobes are responsible for speech and so if there is low activity in this region someone wouldn’t be able to articulate their feelings such as anger and so it gets differed to aggressive acts

Question 8

Describe the conclusion based on the frontal lobes.

Answer 8

The frontal lobes are responsible for personality and self-control and so damage to the frontal lobes can result in impulsivity, lack of self control and the inability to modify behaviour which in turn can facilitate aggressive acts

Question 9

Describe the conclusion based on the amygdala.

Answer 9

The amygdala plays a role in the recognition of affective and social significant stimuli and so abnormalities could be relevant to a theory of violence based on the findings of reduced autonomic arousal (fight or flight) and lack of fear in offenders

Question 10

Conclusion?

Answer 10

Violent behaviour is controlled by areas of the brain and that abnormalities to these areas can affect behaviour, even though we can’t be certain that their violent behaviour was caused by these abnormalities.

Question 11

GRAVE-Generalisability

Answer 11

P-Low
E-Raine’s sample can only apply to one type of criminal; 41 NGRIs, with a mean age of 34.3, and 6 had sz.
E- W, offender sample is limited as their conviction of NGRI may have resulted in ppts variables of similar mental health issues affecting their aggression levels. This makes the findings for aggression limited back to a wider population of convicts.

Question 12

GRAVE-Reliability

Answer 12

P-High
E- BST(Brain scan tech)- PET scan (scanned 10 times @ 10mm intervals) and 10 mins before FDG injection, were given a cpt task, then monitored activity for 32 mins under PET
E- S, incr test-retest R for standardised proceds so control for EVs and findings can be tested again for consistency for brain activity and criminals cause of aggression

P - High inter-rater
E - PET scans are objective as they produce images
E - These can then be analysed by more than one researcher

Question 13

GRAVE-Application

Answer 13

P - Yes
E - Findings suggest that reduced brain activity in certain areas of the brain may act as a predisposition for violence
E - Violent criminals may therefore be less accountable for their actions which may have importance when their sentence is decided

Question 14

GRAVE-Validity

Answer 14

P - High
E - Matching the control group with murderers on mental illnesses, sex and age
E - Reduces ppt variables and so comparisons are more meaningful
P - High
E - Ppts stopped taking medication for 2 weeks prior
E - S, control for EV’s as nothing would’ve affected brain activity in lower/ subcortical areas, better establishes cause + effect

Question 15

GRAVE-Ethics

Answer 15

P - Unethical
E - Went medication free for 2 weeks
E - This may have had a negative impact on their mental health and so compromised protection from harm
P - Unethical
E - Ppts may not have been mentally stable enough to understand what they were agreeing to and may have felt obliged due to being prisoners
E - Compromising their informed consent and right to withdraw