Classic Research- Raine

What is the aim of this research?

It was to look at direct measures of both cortical and subcortical brain functioning using PET scans. He used a group of murderers who have pleaded not guilty by reason of insanity (NGRI) he believed it would show evidence of brain dysfunction in their prefrontal cortex as well as in other areas that are thought to be linked to violent behaviour

What did Raine expect?

He expected Dysfunction in prefrontal cortex, angular gurus, amygdala, hippocampus, thalamus and corpus callosum- areas linked to violence

Where did Raine expect no dysfunction?

Caudate, putamen, globus pallidus, midbrain, cerebellum, linked to other psychiatric conditions but not related to violence

Methodology of Raines research-

Research method-

Quasi experiment

PET scan- detect activity in the brain

Experimental design-

Matched pairs: control group (Non murderers) and murderers.

Age sex, & mental health matched

Sampling method:

Opportunity sampling

Sample:

82 participants age avg 34.3 years (41 murderers- 39 men 2 women) & control group avg 31.7

6 schizophrenics

23 history of head injury

3 psychoactive substance abuse

2 with affective disorder

2 epilepsy

3 hyperactivity & learning disability

2 passive aggressiveness & 2 paranoid personality disorder

Procedure

1. Continuous performance Task (CPT) practice trials given for 10 minutes

2. FDG (radioactive tracer) injected and P’s continue with the CPT for 32 minutes - delay intended to avoid a task novelty effect

3. 32 minutes after the injection a Positron Emission Tomography (PET) scan was done

4. 10 horizontal ‘slices’ were taken out of the brain. 2 different techniques were used so that they could be compared later and ensure reliability: these were the ‘cortical peel’ & ‘box’ techniques.

Findings in cortical areas of the brain-

Prefrontal Cortex- lower activity in murderers

Parietal Lobe- lower in murderers

Occipital- higher activity in murderers

Temporal- no difference

Cingulate- lower activity

Corpus callosum- lower activity

Medial temporal lobe & hippocampus- assymetry, low in left high in right

Caudate- no difference in murderers

Putamen- assymetry, no dif in left, higher activity in right

Globus pallidus- assymetry- low in left, no difference in right

Cerebellum- higher activity

Other findings

Performance on CPT task- no behavioural Dior fee, so brain differences cannot be related to task performance

Handedness

6 murderers left handed, showed hugher medial frontal activity compared to right handed murderers

Ethnicity

14 murderers- non-white no brain differences compared to white

Head injury had no effect

Conclusions

1. Reduced activity in areas of the brain associated with violence: murderers pleading NGRI have statistically significant difference in glucose metabolism compared to control (in selected regions)

2. Biology alone can’t be used to explain violent predispositions - findings shouldn’t be used to demonstrate violence not determined by biology alone. Other factors- social, psychological, cultural & situational

3. Findings are specific to NGRI murderers only can’t be generalised to other types of cases lacks population validity can’t be applied to all crimes

Evaluation- methodology and procedures

Standardised procedure- quasi. Strict procedures, experiment controlled- internal validity high controlled by same dosage of FDG & same timings & same amounts of CPT

but due to being quasi difficult to stable true cause & effect relationship, criminal behaviour not manipulated by researchers

PET scans- eliminates any researcher bias, social desirability bias or any subjective opinions. it’s an objective method of measurement

Matched pairs eliminating any individual differences however not matched of handedness or ethnicity so these participant variables may affect findings and validity of research.

Weakness- doesn’t represent people who have committed nonviolent crimes so we can’t generate findings to them. Many violent crimes arent murder a restricting sample

Ethics of research

Can be lack of valid consent- reduced capacity as claiming insanity

Right to withdraw- prisoners not know if they can withdraw data as it may not be clear to them

Protection from harm- Participants were kept off medication 2 weeks prior to the research- did they have any severe symptoms

Evidence supporting Raine

Raine & Yang (2009) meta-analysis 43 existing studies regarding antisocial and violent behaviour found a link between reduced pre frontal activity in antisocial/violent individuals. This supports Raine’s research. Finds a link in reduced prefrontal activity in antisocial/violent individuals.

Proves his study is correct

James fall on, analysed his own genes and found he had brain characteristics linked to violent behaviour but he wasn’t a criminal he also had a positive childhood. Goes against Raines beliefs