Classic study - Raine et al (1997)

Question 1

What were the 2 aims ?

Answer 1

1. To use brain scanning technology to identify brain impairments with people charged with murder who had pleaded not guilty by reason of insanity
2. Hypothesised brain scans would show dysfunctions in areas linked in previous research to violence

Question 2

How many participants were there ?

Answer 2

82 = 41 offenders pleading NGRI to crime of murder & 41 controls

Question 3

How many men & women were in the NGRI group ?

Answer 3

39 men & 2 women

Question 4

How many NGRIs had different backgrounds ?

Answer 4

23 - history of brain damage
3 - history of drug abuse
6 - schizophrenia
2 - epilepsy
7 - other emotional/learning disorders

Question 5

Did controls have any history of crime or mental illness ?

Answer 5

No apart from 6 with schizophrenia

Question 6

What similarities were between NGRIs and controls ?

Answer 6

Same age & sex

Question 7

How were participants recruited ?

Answer 7

Opportunity sampling - not stated explicitly for control

Question 8

What was the IV ?

Answer 8

Whether the participant is an offender pleading NGRI or a control

Question 9

What was the DV ?

Answer 9

Relative glucose levels in the PFC & other lobes in the brain using PET scans

Question 10

What experimental design is used ?

Answer 10

Independent group design

Question 11

What was the practice test ?

Answer 11

Visual targeting task - CPT

Question 12

How long was the practice test ?

Answer 12

10 minutes

Question 13

What happened after the practice test ?

Answer 13

Injected with fluorodeoxyglucose trace was injected

Question 14

What did participants complete after the glucose tracer ?

Answer 14

CPT for 32 minutes

Question 15

What was recorded from the CPT ?

Answer 15

Target recognition

Question 16

What happened after the 32 minute period of FDG uptake ?

Answer 16

PET scan of the head

Question 17

What were the results in the right amygdala ?

Answer 17

NGRIs = 0.88
controls = 0.83

Question 18

What were the results in the amygdala ?

Answer 18

NGRIs had reduced activity in left amygdala & greater activity in right amygdala than controls

Question 19

What were the results in the PFC ?

Answer 19

NGRIs = 1.14
Controls = 1.18

Question 20

What were the results in the corpus callosum ?

Answer 20

NGRIs = 0.56
Controls = 0.68

Question 21

What did Raine conclude for prefrontal deficits ?

Answer 21

Makes someone more impulsive & emotional

Question 22

What did Raine conclude for deficits in the limbic system ?

Answer 22

May make someones aggressive & hard to learn from mistakes or understand emotions = amygdala controls urges & desires

Question 23

What did Raine conclude around deficits in the corpus callosum ?

Answer 23

Make it harder for brain’s hemispheres to communicate = harder to think through long term consequences & make decisions

Question 24

How does the study have high internal validity ?

Answer 24

• Control over 3 potentially confounding variables
• Participants matched on sex, age & ethnicity
• Results paired more accurately

Question 25

How is the study objective ?

Answer 25

- PET scans measure glucose metabolism in brain - Brain scans = highly scientific by predicting computerised images of brain activity identified by colour - Red = high , blue = low

Question 26

How is the study scientifically credible ?

Answer 26

- Use of scientific measures alongside standardised procedures - Findings can be falsified

Question 27

How is the study high in generalisability ?

Answer 27

- Large sample = 82 participants - Anomalies wouldn't overly skew data - Representative of wider target population

Question 28

How is the study not generalisable in terms of NGRIs ?

Answer 28

- NGRIs unusual offenders - Murderers who are too confused to understand trial or don't remember killing - Not representative of 'typical' murderers - Findings can't be applied to all criminal offences

Question 29

How is the study not generalisable in terms of women ?

Answer 29

- 2 women in experimental & control groups - Limits gen to female offenders pleading NGRI - Not truly representative of wider target population

Question 30

What are the applications of the study ?

Answer 30

Deficits in glucose metabolism in particular brain structures cause aggression = treated through medication

Question 31

Why may the study not be applicable ?

Answer 31

Study identifies brain structures as partial explanation for behaviour = not full case

Question 32

How is the study reliable in terms of PET scans ?

Answer 32

- Used since 1970s - Produces objective & replicable results - Can be tested & retested

Question 33

How is the study reliable in terms of CPT ?

Answer 33

- Standardised procedures - Same CPT fo 32m - PET scans followed = well established protocol - All participants concentrated on the same thing - Similar types of brain activity - Replicated to check for consistency

Question 34

How is the study low in task validity ?

Answer 34

- CPT artificial - Signal detection task - Unrelated to violence or provocation

Question 35

How is the study low in internal validity ?

Answer 35

- Cant show cause & effect - Uncertain when murders developed brain deficits - Did brain deficits develop after killing due to stress of events or did brain deficits cause aggression ?

Question 36

How is the study reductionist ?

Answer 36

- Only looks at brain activity - Simplistic view of criminal behaviour - Social & cultural influences not taken into account

Question 37

What is an ethical concern in terms of PET scans ?

Answer 37

- Invasive procedure for controls - Participants injected with radioactive tracer - Unnecessary medical procedure increases risk of research

Question 38

What is an ethical concern in terms of the study ?

Answer 38

- Suggest people driven to kill by brain structure & violence is out of control - Raine made clear not drawing conclusions themselves - Once released to public = opened up to scrutiny - Go against social responsibility of ethical research