- Created by: GH1998
- Created on: 01-04-15 14:48
- Behaviour can be explained in terms of hormones.
- Effects of hormones are slow in comparison to the immune system but are very powerful.
- Adrenaline is released by the adrenal glands when we get stressed or scared, leading to the 'fight or flight' response
- Selye looked at the effects of stress and adrenaline on the body, which lead to the GAS theory.
- Different areas of the brain preform specialised functions.
- Psychosurgery is used to sever the neuronal connections in the prefrontal cortex, this has showed a direct affect on the moods of patients.
- This is supproted by PET and MRI scans which are used to objectively measure the changes in neuronal activity before and after psychosuregery.
- Cosgrove and Rauch reported 56% of cingulotomies were effective for OCD patients
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- Selye concluded that when animals exposed to unpleasant stimuli they display a universal response to all stressors.
- He observed human patients in hospitals and came to the same conclusion and said there was three sequential stages.
- Alam stage - when we become aware of the stressor through our senses, which sends a message to our hypothalamus which releases adrenaline from our adrenal glands.
- Adrenaline causes sensations often labelled an 'adrenaline rush' - increased heart rat and sweaty palms etc.
- Resistance stage - when the body finds some way of coping and adapting to the demands of the environment but at the same time our resources are depleating. The body seems to be coping on the outside but phisiologically the early stages of stress related illness can develop as vital organs start to wear out.
- Exhaustion stage - this is where the stressor continues for a long period of time, the initial symptoms such as sweating and raised heart rate may reappear. Eventually the body can no longer maintain normal functioning. Stomach ulcers can form from an interuption to digestion and there is a risk of a heart attack or stroke.
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- Psychosurgery links to the assumption that brain functions are localised and therefore damage to certain brain areas can have have specific effects on psychological functions. Psychosurgery is the physical treatment of a psychiatric disorder using surgical techniques.
- The aim of psychosurgery is to alleviate some of the severe symptoms of mental illness by destroying the connective brain tissue that connects the faulty part of the brain to the healthy part.
- Psychosurgery is a radical treatment and is irreversible, so now is only used as a last resort.
- Moniz heard that monkeys with aggressive tendencies were subdued after their frontal lobes were removed. He developed a similar operation for humans called the prefrontal leucotomy. It involved drilling a hole on both sides of the skull and inserting an instrument that resembled an icepick to destroy nerve fibres.
- Walter Freeman made this proceedure popular in the USA which was then known as the trans-orbital lobotomy. An icepick like device was hammered through the thin bone above the eye socket and then wriggled about to sever the neuronal connection between the prefrontal cortex and the rest of the brain.
- Today stereotactic surgery is used becuase it is more precise.
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- The biological approach has made a valuble contribution to our understanding of human behaviours and disorders.
- Selye made a major impact on our understanding of the relationship between stress and illness.This has shown the more stressed a person is th longer their recovery rate from illness.
- This has been applied in hospital settings to reduce the amount of stress that a patient is under.
- Another strength is that it is deterministic. If we know what predetermines our behaviour we would be more likely to be able to treat people with abnormal behaviour.
- The neurotransmitter dopamine has been linked to scitzophrenia. There is evidence that shows when patients are treated with antipsychotic drugs their levels of dopamine decreases.
- If we know mental illnesses are determined by biological factors we can treat mental illnesses using biological factors. Therefore this will enable us to improve peoples lives.
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- It only focuses on nature, which is a biological cause and ignores nurture such as the effect of the environment.
- This approach explains scitzophrenia in terms of abnormal levels of dopamine in the body but doesn't take into account how the patient feels about their illness.
- This approach only focuses on the symptoms, high levels of dopamine and not how the patient feels, environmental or social factors.
- This approach only studies a few individuals and assumes that everyone's biological systems behve in the same way. This is a normothetic approach that tends to ignore individual differences.
- For example when people are stressed some people may produce higher levels of adrenaline than others; people can react differently to stress. Taylor et al found that there was a gender difference where men react more agressively than women due to higher levels of adrenaline.
- This is a weakness as the picture we then have of behaviour is wrong, as according to this research it doesnt apply equally to all people.
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Methodology - Use of Scanning Equipment
- The biological approach assumes that behaviour can be explained in terms of activity of the brain and nervous system. Therefore biological psychologists look for methods that allow them to view brain activity.
- MRI scans involve the use of a magnetic field to show a detailed image of the brain. Eg. Maguire used MRI scans to demonstrate that taxi drivers have a larger hippocampi than non-taxi drivers.
- PET scans involve administering slightly radioactive glucose to the patient. The most active areas of the brain use glucose, meaning you are able to build up a picture of the activity of the brain. Eg. Raine et al used PET scans to compare brain activity of murderers and normal individuals.
- A strength of using MRI scanning equiptment is that it gives a detailed image of soft tissue in the brain without using x-rays and therefore are suited to people who need lots of scans. A strength of PET scans is that they reveal chemical information that is not availiable using other scanning equipment.
- A weakness of MRI scans is that it can take a long time and can be uncomfortable.A weakness of PET scans is that the patient is being injected with radiocative substances and so can only be used a number of times on the patient.
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Methodology Part 2 - Use of NHAs
- Research using animals has provided most of the early psychological knowledge about the structure and function of the nervous system and hormones.
- Selye studied the effects of the GAS on rats in the lab and found that they went from alarm stage to resistance stage to the exhaustion stage if the stressor was continued. They died from heart attacks and stomach ulcers. Similar finding were found when studying humans according to Selye's research.
- A strength of this method is that humans and animals have very similar anatomies and therefore it is possible to apply the findings from just a few carefully controlled NHA studies to humans, and help save the lives of many.
- A further strength is that by using animals for research this reduces the effect of demand characteristics.
- A weakness is that there are important differences between NHAs and humans, our brains are different is both size and structure. The cortex is much larger in humans relative to our size than in non human animals. So generalisation is only credible for some aspects.
- Another weakness is that these methods are seen as highly unethical as NHAs should not be used to help humans when they suffer so much psychological and physical harm and the treatments do not help NHAs themselves. Eg. the rats in Selyes research did not benefit from the research.
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