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Biological explanation
OCD Biological explanation
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Create 3 questions on any of the below areas in psychopathology
Phobia explanation Phobia treatment Depression explanation Definitions of abnormality Depression treatment Characteristics
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Exam practice Rita and Holly are identical twins who were separated at birth. When they finally met each other at the age of 35, they were surprised at how different their personalities were. Rita is much more social and out-going than Holly. Use your knowledge of genotypes and phenotypes to explain this difference in their personalities (4 marks)
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Mark scheme Holly and Rita have identical genotype as they are MZ twins. They have the predisposition to develop the same personalities as each other unless another factor(s) intervenes. For them to have developed different personalities over time, this must have been influenced by being in different environments. Their phenotypes – personalities achieved – are different, presumably because Rita was encouraged to be sociable and lively and Holly was not.
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Evolution Pick out the key details
The Evolution of animals and plants is a fact. Charles Darwin argued that, over time organisms become adapted to their environment through Biological Evolution. The mechanism behind Biological Evolution is natural selection. Individuals must compete for access to resources those who survive go on to have more reproductive success than those who do not. These behaviours will be passed on to offspring and will become more widespread in the population; through the process of natural selection, successive generations will develop behaviours that are even more likely to lead to survival. For example Buss (1989) studied 37 cultures found universal similarities in human mate preferences. Women desired mates with resources (to provide for offspring)
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Evolution Natural selection (survival of the fittest) can influence human behaviour. Any behaviour that enhances survival and reproduction will be passed on to future generations. These genes are described as adaptive and give their offspring advantage.
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The theory of Evolution
Group Task Psychologists are interested in the evolution of Behaviour. How could you explain the following as a produce of evolution? Memory Social influence Attachment Mental Disorders Can you think of any other examples?
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Answers Memory- Human memory helps us predict and prevent events providing adaptive advantages (schema) Social Influence- Conformity, compliance and obedience promotes living and working in hierarchal packs which would be suggested to aid survival (e.g hunting) Attachment- Bowlby argued that care giving is adaptive as care givers aid the survival of the young and thus the species. Mental Disorders- Some are argued to have a genetic basis. Can you think of any disorders that might have some adaptive advantage e.g anxiety or ocd?
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A01 Biological quiz What can you remember?
1.List one aspect of biology that the biological approach to psychology examines 2. Explain the difference between genotype and phenotype 3. What is the term used for identical twins? 4. Explain what a concordance rate shows? 5. Research on MZ twins who are identical rarely finds a concordance rate of 100%. What does this suggest about behaviour? 6. Define Evolution 7. Darwin suggested that any genetically determined behaviour that enhances an individual’s survival (and reproduction) will continue in future generations. This is a theory of….
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Answers 1. Genetics, evolution, The central nervous system, which comprises the brain and spinal cord. The chemistry of the body 2. Genotype- individuals genetic make up which dictates characteristics. Phenotype- The way a gene is expressed through physical, behavioural and environmental factors 3. Monozygotic twins 4. The likelihood that certain traits have a genetic basis. It compares the extent to which both twins share the same characteristic. 5. It seems behaviour could be a mix of both genetics and the environment 6. The changes in inherited characteristics in a biological population over successive generations. 7. Natural Selection
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Task: In your group discuss the evaluation point you have been given.
Strengths The importance of the Scientific Approach Real Life Application Limitations Biological Reductionism Drawing causal conclusions We cannot separate Nature from Nurture
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Strengths The importance of the Scientific Approach The Biological Approach uses the Scientific method particularly the use of the Experiment method, as its main method of investigation. Experimental studies take place in highly controlled environments so that other researchers are able to replicate studies under the same conditions thus improving the reliability and validity of the original findings. Real Life Application A strength of the Biological Approach is that is provides clear predictions about the effects of biology on behaviour. This has led to significant applications in the real world for example research into the neurochemical imbalance in depression has led to the development of drug treatments which can lessen symptoms. Similarly research into circadian rhythms and their effect on Psychological wellbeing has led to improvements in working conditions.
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Limitations Biological Reductionism Reductionism is the belief that complex human behaviour can be explained by breaking it down into its smallest component parts, such as the action of genes, neurochemicals and hormones. The Reductionist approach is useful as it enables scientific investigation however others argue this simplistic approach means we cannot fully understand a behaviour without taking into account all potential influences. For example research into neurochemical imbalances suggests these are the main cause of psychological disorders however this ignores cognitive, cultural and emotional factors which are known to influence abnormal behaviour. Drawing causal conclusions The Biological approach offers explanations for behaviour in terms of Biological processes. This means it assumes that a specific Biological process has or will cause a behaviour. Research however often cannot prove that Biology is the true cause of that behaviour as it only discovers an association or relationship between two factors and correlation does not always mean causation. This can be particularly problematic from studies showing that a particular drug reduces symptoms of a disorder and thus assuming that the neurochemical in the drug is the cause of the disorder. A simple example of this would be assuming that because paracetamol relieves headaches then a lack of paracetamol causes headaches We cannot separate Nature from Nurture The Biological Approach has difficulty in investigating the true influence of nature on behaviour. Similarities in identical twins, non-identical twins and family members are argued to be down to genetics however there is an important confounding variable as they are also exposed to similar environmental conditions. It is therefore difficult to conclude that findings whether findings of such studies are down to nature or Nurture. This therefore challenges the validity of theory and research within the Biological approach
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Comparing the assumptions
How confident are you at comparing the Learning, Cognitive and Biological approaches at this stage? Explain two differences between the Learning and Cognitive approach (6 marks) Explain two ways in which the behaviourist and social learning theory overlap (6 marks)
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Biological explanations of OCD
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Define obsessive-compulsive disorder (OCD) 3 marks
An obsessive compulsive disorder is a recurring intrusive thought that produces anxiety. In order to reduce this and feel better many OCD sufferers feel compelled to do certain things. For example, they might wash their hands five times a day. This reduces their anxiety.
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OCD – The Biological Approach
Neural Explanations Genetic Explanations
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Neural explanations of OCD
Neurotransmitters and areas of the brain
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Neurotransmitters- research biochemical cause
1. Neurotransmitters are…. brain chemicals that relay signals from one neuron (nerve cells) to another. 2. Serotonin is thought to be associated with…. regulating mood and anxiety (OCD is an anxiety disorder) 3. Low levels of serotonin have been found to be associated with OCD as….. It is thought to be linked to obsessive thoughts. Support for the role of serotonin in OCD comes from research examining anti-depressants, which have found that drugs which increase the level of serotonin are effective in treating patients with OCD.
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Dopamine The neurotransmitter dopamine has also been implicated in OCD, with higher levels of dopamine being associated with some of the symptoms of OCD, in particular the compulsive behaviours.
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Neurophysiological cause
Two brain regions have been implicated in OCD, including the basal ganglia and orbitofrontal cortex/Thalamus. The basal ganglia is a brain structure involved in multiple processes, including the coordination of movement. Patients who suffer head injuries in this region often develop OCD-like symptoms, following their recovery. Max et al. (1994) found that when the basal ganglia is disconnected from the frontal cortex during surgery, OCD-like symptoms are reduced, providing further support for the role of the basal ganglia in OCD.
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Neurophysiological cause
brain areas believed to be involved in OCD include the orbitofrontal cortex (OFC) and the thalamus
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Brain structure The orbitofrontal cortex, is a region which converts sensory information into thoughts and actions. PET scans have found higher activity in the orbitofrontal cortex in patients with. One suggestion is that the heightened activity in the orbitofrontal cortex increases the conversion of sensory information to actions (behaviours) which results in compulsions. The increased activity also prevents patients from stopping their behaviours.
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Draw a flow diagram to illustrate the neurophysiological cause
The orbital-frontal cortex (OFC) is the part of the brain that notices when something is wrong. For example, when the OFC registers that there is dirt nearby, it sends a 'worry' signal to the thalamus. The thalamus directs signals from many parts of the brain to places that can interpret them - in this case back to the OFC. These nerve cell connections form a loop in the brain. The caudate nucleus lies between the OFC and the thalamus and regulates signals sent between them.
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Draw a flow diagram to illustrate the neurophysiological cause
When the thalamus receives a 'worry' signal, it becomes excited and sends strong signals back through the loop to the OFC, which interprets them. Normally, the head of the caudate nucleus acts like the brake pedal on a car, suppressing the original 'worry' signals sent by the OFC to the thalamus. This prevents the thalamus from becoming hyperactive. But in OCD, the caudate nucleus is thought to be damaged, so it cannot suppress signals from the OFC, allowing the thalamus to become over-excited. If this occurs, the thalamus sends strong signals back to the OFC, which responds by increasing compulsive behaviour and anxiety. This could explain the repetitive and seemingly senseless rituals performed by obsessive-compulsives REF:
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Outline the neural explanation in explaining OCD (4 marks)
Exam practice Outline the neural explanation in explaining OCD (4 marks)
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Mz (mono) Dz (non idemtical) concordance rate (probability)
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Genetic explanations- Discuss
Predisposition to OCD is inherited. Do you agree?? How do you think Psychologists investigate genetic influences on OCD? Family studies, twin studies, adoption studies Question: Do you know any research that looks at the concordance rate for OCD? What does this suggest about the statement in the orange box?
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Genetic explanations- Discuss
What do you think ‘polygenic’ means? ‘Poly’ - many ‘genic’ – genes so NOT just 1 gene, several! Taylor (2013) found evidence that up to 230 different genes may be involved in OCD.
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What role do genes play in the development of OCD?
Genes that have been studied in relation to OCD are called ‘candidate genes’ – these are seen to create a vulnerability towards developing OCD. Some of these are associated with the action of dopamine and serotonin which are both neurotransmitters believed to be involved in regulating mood. Bullet point the key words/phrases above into your pack.
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The Diathesis- stress model
The diathesis-stress model suggests that certain genes leave some people more likely to suffer a mental disorder but some environmental stress or experience is necessary to trigger the condition. Read your pack and highlight any additional information on the role genes play in OCD
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“Outline and Evaluate the biological approach to OCD”
Exam question “Outline and Evaluate the biological approach to OCD” (16 marks) Task: Bullet point the main points you would include in the outline of this essay Extension: Can you think of potential evaluation points that you could use in the essay
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Biological explanations
Evaluation and treatments
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Evaluation
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Discuss- Evaluation of Genetic explanations and OCD
Make notes Determinism Nature vs Nurture/Diathesis stress model Reductionism
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Genetic Explanations Task: Write model paragraphs on the below statements Elaboration is key here 1. There is consistent evidence 2. Not sure exactly what genes are involved 3. Environmental factors 4. Reductionist 5. Not 100% Concordance rates
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Neural explanation evaluation – evidence
Hu (2006) compared serotonin activity in 169 OCD sufferers and 253 non-sufferers, finding serotonin levels to be lower in the OCD patients. Zohar et al (1987) gave mCPP (a drug that reduces serotonin levels) to 12 OCD patients and 20 non-OCD control participants, finding that symptoms of OCD were significantly enhanced in the OCD patients. Menzies (2007) found an association between ability to stop a repetitive task and a decrease in grey matter in the orbital frontal cortex in participants with OCD You have been asked to peer review some of the research into neural explanations. The research must be assessed for validity. You need to identify issues with this research and explain how it affects validity (link to explanation). Link these to evaluation points
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Evaluation In pairs: Thinking about other approaches to explaining mental disorders, write down an alternative explanation for OCD. Ext: Which explanation for OCD do you think is the best? Why?
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Neural Explanations Discuss the following
Make notes from the text book Cause and Effect Co-morbidity Abnormal levels of seretonin and activity with foc cause of ocd or merely effects – hasn’t been established
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Plan the following essay
“Outline and Evaluate the biological approach to OCD” (16 marks)
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Recap- Biological explanation of OCD
Groups 1,3, 5 Outline the genetic Explanation of OCD (4 marks) Groups 2,4 Outline the Neural Explanation of OCD
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