Raine et al (1997) (Biological) Flashcards
What were previous studies into criminals?
Lombroso (1876) linked psychological factors (facial characteristics) to criminal behaviour
> Argued it is easy to spot criminals (not fully evolved)
> Argued criminals are born not made
What was the aim of Raine et al’s study?
Wanted to investigate wether violent criminals had brain dysfunction in parts of the brain.
What was the methodolgy in this experiment?
- Quasi experiment
- IV was NGRI
- DV was brain differences
- Matched pairs design
>Each NGRI was matched with a control participant of the same age and gender
What did the experimental group consist of?
- 41 participants in California
> 39 men, 2 women (mean age 34.3 years)
> Charged with murder/manslaughter but used NGRI defence
> History of brain injury
> Medication free
How was the control group formed?
Matching each murderer with a ‘normal’ participant of the same sex and age
> Screened for health with tests/interviews
What sampling technique was used?
Opportunity
What was the first stage of procedure?
A PET scan was used to study the active brain of both groups
How did the experiment use FDG?
A PET scan uses Fluorodeoxyglucose (FDG) - mildly reactive gucose. When a part of the brain is active, it uses glucose. Radioactive detectors in the PET scan can then ‘see’ the radioactive areas
What was the second stage of the experiement?
The participants were given a chance to practice a continuous performance task - activates parts of the brain that they researchers were interested in.
What was the third stage of the experiment?
FDG was then injected into each participant after 30 seconds.
What was the fourth stage of procedure?
After 32 minutes, a PET scan was done of each patient.
What was the final stage of procedure?
10 horizontal sliced of the brain were recorder using peel and box technique
What were the strengths of the experiments methodology and procedures?
- Researchers had a lot of control over the procedure
- Use of PET scans
> Reliable
> Allows for a wide range of non intrusive studies
> Scientific
-Large sample size
What were the weaknesses of the experiments methodology and procedures?
- PET scans are still being developed
- Validity of task could be questioned (activity)
- Type of quasi experiment
> Can not randomly allocate participants to either of the conditions
> Can not draw cause and effect - Differences in brain activity could be caused by other factors
- NGRI are unusual offenders so lack generalisablity (Don’t remember, too confused)
- Only describe, don’t explain
What did Yang and Raine (2009) find?
Did a meta analysis of 43 imaging studies that considered both antisocial and violent behavior
Concuded that there is a significantly reduced prefrontal activity in antisocial and/or violent individuals
