Classic study: Raine et al

Question 1

Aim

Answer 1

Use brain scanning technology to identify brain inpairments from criminals charged with murdered who pleaded not guilty by reason of insanity

Question 2

Method:

What was the sample size

Answer 2

41 murderes matched with 41 non-murderes

Question 3

Method:

IV and DV

Answer 3

IV - Whether the participant was a murderer or a non-murderer

DV - glucose metabolism in specific brain areas

Question 4

Method:

How were the participants matched to the control group?

Answer 4

Age, sex and ethnicity

Question 5

Method:

What brain scanning technique was used

Answer 5

PET scan

Question 6

Procedure:

How many males and females were in the experimental group

Answer 6

39 males
2 females

Question 7

Procedure:

WHat was the procedure of the study

Answer 7

participants injected with glucose tracer to light up brain activity

then had to performed a continous performance task for 32 minutes after the injection

Question 8

Pocedure:

What was the purpose of having the participants perfome the continous performance task

Answer 8

Encourage uptake of radioactive tracer in areas of the brain the researchers wished to investigate

Question 9

Findings corticol regions:

what cortical regions did murderers have lower activity in compared to the control group

Answer 9

lateral and medial prefrontal areas

left angular gyrus

Question 10

Findings cortical regions:

What cortical regions did murderers have higher activity in compared to the control group

Answer 10

occipital lobe (area not previously linked to violance)

Question 11

Findings subcortical regions:

What subcortical regions did murderes have lower glucose activity in compared to the control group

Answer 11

left amygdala

corpus callosum

hippocampus

Question 12

Findings subcortical regions:

What subcortical regions did murderes have higher glucose activity in compared to the control group

Answer 12

right amygdala

right medial temporal lobe

right thalamus

Question 13

What was the conclusion

Answer 13

Hypothesis was supported, murderes pleading NGRI had different brain activity.

Murderers had impared functioning in areas previously associated with violent offending

Question 14

Strenth of control of the study:

What is a strength of the control of the study

Answer 14

The study had a high degree of controls.

Question 15

Strenth of control of the study:

GIve an example in the study where there was a high degree of controls

Answer 15

Standarised procedures were used to control confoundings variables, for example…
- same continous performance task was used on all participants for the same length of time

Question 16

Strenth of control of the study:

What did this mean for the study

Answer 16

It had high internal validity as confounding variables were controlled for

Question 17

Competing arguement against control

What is a competing arguement for the controls of the study

Answer 17

The matching of participants was not done thorough enough

Question 18

Competing arguement against control

Give example of a variable that wasn’t matched

Answer 18

Raine acknowledged 23 murderers had a history of head injury.

Question 19

Competing arguement against control

What did the participants with head injury mean for the results

Answer 19

Affected the results, the activity difference of corpus callosum between 2 groups may have been explained.

Question 20

Weakness of PET scan:

What is a weakness of using the PET scan

Answer 20

It may have given misleading results

Question 21

Weakness of PET scan:

Evidence that it may have given misleading results

Answer 21

Technique scanned the brain in 10nm slices in a line fron the corner of the eye to middle of ear, this line is known to vary significantly from individuals

Question 22

Weakness of PET scan:

What does this limitation mean

Answer 22

Hard to locate precisely different brain areas under study so internal validity is reduces

Question 23

Strength of generalisability

What is a strength of the generalisability of the study

Answer 23

The sample size was large.

Question 24

Strength of generalisability

Why is the sample size being large a strength?

Answer 24

Anomalies such as unusual brain structure or not paying attention during the CPT wouldn’t skew data too much.

Question 25

Strength of generalisability

What did this mean for the results

Answer 25

The larger sample size means the results became more generalisable.