Biological Approach

• The role of evolutionary influences- behaviours that are adaptive are more likely to be passes on to offspring leading to continuous behaviour, some behaviours are adapted to make animals survive in their environment. An example is phobias
• The localisation of brain function- the brain has 2 hemispheres and 4 labels: occipital, temporal, parietal and frontal. An example is the hippocampus that is linked with long term memory.
• The role of neurotransmitters- a neuron has 2 key features the dendrites and axon. The synapse is the gap in-between the neurons. An example is that low levels of serotonin have been associated with depression.
• Romantic relationships- evolutionary influences can be linked with romantic relationships. romantic relationships form with individuals who posses certain traits. men seek youth and fertility while women seek maturity and stability.
• Prefrontal lobotomy- this is when the connections to and from the prefrontal cortex are destroyed. A hole is drilled on each side of the skull and a leucotome is inserted to cut the white matter of the brain.
• Transorbital lobotomy- this is when an orbitoclast is inserted under the eye lid into the back of the eye socket. It breaks through the skull into the brain to destroy the connections between the prefrontal cortex and other areas.
• Weaknesses of the lobotomies- severe side effects like changes in the patients personality lead patients to become lethargic or socially withdrawn. Comer (2002) stated that 6% of people undergoing lobotomies died.
• Brain scans- stereotactic psychosurgery uses brain scans to locate the exact points within the brain in order to sever connections very precisely.
• Capsulotomy- probes are inserted through the top of the skull and down into a region of the brain near the thalamus. The tips of the probes are heated in order to burn away tiny portions of the tissue.
• Deep brain stimulation- it deactivates parts of the brain related to specific psychological disorders without destroying the brain, Wires are placed in the brain to create high frequent currents that interrupt the brain circuity.
• Weakness of early therapies- Comer (2002) reported that early lobotomies had a fatality rate of up to 6% and a range of severe side effects like brain seizures and a lack of emotional responsiveness.
• Strengths of modern therapies- its seen as an effective treatment for very extreme cases of depression and anxiety disorders. Cosgrove and Raugh (2001) reported that capsulotomy was effective in 66% of OCD patients and 54% of patients with depression. Mayberg et al (2005) found that in 4 out of 6 patients with depression, they showed huge improvements after treatment.
• Weaknesses of modern therapies- its difficult to evaluate the overall effectiveness because its so new. Psychosurgery is limited in its use, an example is that its rarely used for the treatment of phobias. Soares et al (2013) have suggested that psychosurgery is not a universal solution for mental health problems.
• Valid consent in psychosurgery- early psychosurgical techniques were used in mental asylums and prisons on patients who had not necessarily given their valid consent to the operation. However, in 1983 the Mental Health Act increased the rights of consent for people with mental health illnesses.
• Psychological harm of psychosurgery- early procedures resulted in in significant changes to a patients mental capabilities like memory loss and limiting a patients emotional response. Modern psychosurgery methods have reduced the risk of severe damage but still carry the risks of long-term side effects (seizures).
• Raine et al (1997) study- brain scanning was used on a group of criminals and plead not guilty by reason of insanity and a control group of non-criminals.
• Methodology- it was a quasi-experiment with a matched pairs design. The independent variable was whether the participants had entered a plea of NGRI or not. The dependant variable was the brain differences in the brain scan.
• Sample- there were 41 murders (39 men, 2 women) with the mean age of 34.3. They had all been charged with murder and plead NGRI. 23 had history of a head injury, 6 had schizophrenia etc. The control group was 41 non-murderers. The 6 schizophrenics were matched with 6 schizophrenics from a mental hospital.
• Procedure- a PET scan was used and all participants were given an injection of a 'radioactive glucose tracer'. They were asked to do a continuous performance task for 32 minutes and had to press a button every time they heard a beep, it was used to test concentration and activate the prefrontal cortex.
• Findings- the study found reduced activity in the brain of murderers in areas where lowered activity had previously been linked to violence: prefrontal cortex, amygdala(left), thalamus(left) and hippocampus(left). There was increased activity in areas not previously linked to violence: cerebellum, amygdala(right), thalamus(right) and hippocampus(right). There was no difference in areas not linked with violence: caudate, putamen, globus pallidus and midbrain.
• Conclusions-murderers pleading NGRI have differences in glucose metabolism for certain brain regions, reduced activity in the prefrontal, parietal and corpus callosum with abnormal activity in the amygdala,thalamus and hippocampus could lead to violence. The findings don't establish a link between brain dysfunctional and violence.
• Weaknesses of the method- no cause and effect relationships can be stated because the findings do not show that violent behaviour is caused by biology alone. The injection used on the participants could influence the brain activity which lowers the internal validity of the study. The use of the PET scan could lower the ecological validity.
• Strengths of the method- the use of a quasi-experiment means researchers are able to study topics that would be unethical to manipulate directly. The use of PET scans permit researchers to study detailed regions of the living brain and also enable the brain in action to be examined.
• Reliability of the study- the procedure was fully reported in detail which means the study could be repeated to test the external reliability. However, the specific sample and use of PET scans makes replication more difficult.
• Sample of the study- 82 participants were used which is an adequate sample size for a study using a statistically rare population. However, the murderers sampled were not typical of all violent individuals which lowers the external validity.
• Validity of the study- differences between the two groups weren't controlled making them extraneous variables and lowers internal validity. The ecological validity may also be low due to the use of the PET scans.
• Ethical issues- the murderers pled NGRI which suggests that they might not have been mentally competent to provide valid consent. Participants might not have fully understood their right to withdraw due to them being prisoners.
• Social implications- the research can be seen as being socially sensitive due to consequences the results could have for people in society that share similar patterns of brain activity.