- Created by: ernily
- Created on: 03-05-15 16:49
- Behaviour Can Be Explained In Terms Of Brain Structures and Localisation.
- The organisation of the brain is known as localisation.
- The cerebral cortex is divided into four lobes, including the occipital lobe.
- Damage to the brain could affect a bodily function; for example, damage to the occipital lobe can cause sight problems.
- Behaviour Can Be Explained By Neurons and Neurotransmitters.
- Messages are passed across neurons via synapses.
- Then to the brain via neurotransmitters.
- For example, seretonin is implicated in the aetiology of depression.
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Selye's GAS Model
- General Adaptation Syndrome:
- General: The same response to all agents.
- Adaptive: The healthiest way to cope with extreme stress.
- Syndrome: Severel symptoms are in the stress response.
- Alarm Reaction:
- Stressor is recognised.
- The hypothalamus triggers the production of adrenaline from the adrenal glands.
- This prepares you for the fight or flight response.
- The body is adapting, but physiologically deteriorating.
- The body can't maintain normal functioning, so symptoms reappear.
- The immune system can't cope, so illness occurs.
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Selye's GAS Model
- The aim was to test his (Selye's) hypothesis:
- No matter the stressor, the reaction will always be the same.
- Rats were exposed to various stressors, such as extreme cold, extreme heat, surgical injury, production of spinal shock, etc.
- During the first stage (Alarm Reaction), all stimuli produced an enlargement of adrenal glands, ulcers in the digestive system, and the shrinkage of the immune system.
- If the treatment continued, the appearance and function of organs returned to normal.
- However, after 1-3 months the rats lost their resistance and the original symptoms returned.
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- Psychosurgery is a surgical procedure performed on the brain with the aim of relieving stress, anxiety and depression in patients who haven't responded to any other treatment.
- Links with the assumption that behaviour can be explained by brain structure and localisation.
- Developed by Moniz (1935).
- Involved a narrow device, called a leucotome, being inserted into the frontal lobe through holes in the skull.
- The leucotome blade was extended and rotated to lesion the brain tissue in order to destroy pieces of the frontal cortex.
- Transorbital Lobotomy:
- Developed by Walter Freeman (1950s).
- Involved inserting an 'ice pick' under the eyelid and into the eye socket.
- It broke through the skull, into the brain, and moved around to destroy connections to the frontal area.
- It was done bilaterally.
- Pippard (1955) reported worthwhile/good results in 50% of people with mood disorders; 95% of these had no more than slight personality changes.
- Comer (2002) found that early lobotomies had a fatality rate of 6%.
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- Bilateral Cingulotomy:
- Locating precise areas of the brain with an MRI scan.
- Exact parts of the brain that need removing are identified, so there is no need to remove large chunks of the brain.
- A stereotactic frame is used to measure the point where the brain needs to be operated on.
- Cosgrove & Rauch (2001) found that the cingulotomy was effective in 56% of OCD patients.
- Bridges et al (1994) said that this treatment is a last resort, as no controlled trial is possible.
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Evaluating The Biological Approach
- Assumption that behaviour can be explained with hormones, and also neurotransmitters.
- It has clear variables that can be measured, tracked, and examined.
- Psychologists can conduct scientific research, for example; psychosurgery.
- Assumption that all behaviour can be the result of genes, so behaviour is said to be deterministic.
- It is easier to treat people if we know what predetermines our behaviour.
- For example; the neurotransmitter dopamine is implicated in the aetiology of schizophrenia.
- For example; psychosurgery is designed to sever over-active areas of the brain to reduce the symptoms of OCD.
- So the biological approach allows us to control our world.
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Evaluating The Biological Approach
- It reduces complex behaviour to simple explanations.
- For example, it reduces stress to adrenaline.
- This means that we may lose a real understanding of what we are investigating.
- It doesn't consider a person as a whole.
- It ignores life experiences and psychological factors (such as feelings).
- It is concerned with adjusting abnormal biological systems, rather than talking to patients.
- For example; schizophrenia is explained by excess neurotransmitters, and not how patients feel about their illness.
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- Twin Studies:
- Concordance Rate: The degree to which two people are similar.
- Bouchard & McGue (1981) studied the inheritance of IQ in monozygotic (MZ) twins (identical twins) and dizygotic (DZ) twins (non-identical twins).
- In the MZ twins, they found a concordance rate of 86%.
- In the DZ twins, they found a concordance rate of 60%.
- They also used twins that are reared apart, however this was a problem as some twins grew up in the same environment.
- A concordance rate of 72% was found for MZ twins reared apart.
- This shows that there is a significant genetic contribution to intelligence.
- MZ twins share 100% of their genes, so make perfect participants for gene studies and provide useful information for the biological approach.
- The comparison between MZ twins reared together and apart has allowed psychologists to make sound assumptions about the importance of genes and the environment.
- Twins share genes, environment and are also treated similarly. So concordance rates may not be reliable as it's difficult to distinguish between genes and environment.
- Study of twins reared apart is problematic as they are usually raised in similar environments, so it's still difficult to distinguish.
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