WJEC AS Psychology PY1 - Biological Approach
Notes for the Biological Approach including assumptions, theory, therapy, methodology, 2 strengths and 2 weaknesses
- Created by: Zoey Jowett
- Created on: 13-12-11 19:44
Biological Approach - Assumptions
Assumption 1 - that emotion, thoughts and behaviour are affected by neurons and neurotransmitters
Neurons are electrical impulses that form the basis of the nervous system; they communicate with each other by sending information to and from the nervous system; there are gaps called synapses in between neurons and so chemicals called neurotransmitters pass the electrical impulse over the gap to the next neuron. An example of a neuron are motor neurons which convey instructions to and from the brain to make our body do things: move a muscle etc.
Neurotransmitters have been linked to parts of behaviour and emotion; for example serotonin is a neurotransmitter: linked to mood and has been suggested that low levels can may depression
Biological Approach - Assumptions
Assumption 2 - the influence of the brain
4 lobes of the brain: frontal, occipital, parietal and temporal lobe
Different components of the brain are important to understand emotions, thoughts and behavior; different parts of the brain linked to different behaviour
Therefore, if there is damage to a specific part of the brain, this can have an impact on behaviour; if there is a damage to a part of the brain, this can also damage another part of the body even if that part of the body is left undamaged
Example: damage to occipital lobe can affect sight, damage to frontal lobe (Phineas Gage) can affect personality
Biological Approach - Theory
Theory - Selye's General Adaptation Syndrome
Stress:when our body encounters stressors it doesn't think it can cope with , it experiences physiological and psychological responses to adapt to the environment
Selye (1947):did an experiment with rats where they were exposed to stressors (heat, fatigue); found they produced the same response regardless of stressor and the initial changes were increased pulse rate, blood pressure and breathing rate
Developed 3 phases in the body's response to stress if stressor persists:
- Alarm Reaction: immediate activation by body to deal with stressor
- Resistance Stage: attempt by body to return to steady state despite stressor persisting
- Exhaustion Stage: failure to return to normal physical state in ongoing presence of stressor that causes depletion of bodily resources
Biological Approach - Theory Continued
Theory Continued
Alarm Reaction:
- threat > sympathetic part of the autonomic nervous system activates endocrine system (ES) to work together > SNS stimulates adrenal glands from ES > adrenal glands produce adrenaline to make initial responses last (increased heart rate etc.) > SNS + ES/adrenal gland = SAM = short, fast response
Resistance Stage:
- stressor persists > other hormones released > hypothalamus produces CRF > CRF makes pituitary gland release ACTH > makes cortisol which makes energy more available > HPA = slow, long response
Exhaustion Stage:
- threat continues to persist > rats died > immune system weakened > increases risk of heart disease and cancer
Biological Approach - Therapy
Therapy - Psychosurgery
REMEMBER LINKING PARA - changing emotions, thoughts and behaviour by removing parts of the brain
Aims of Psychosurgery: to relieve patient of pain/anxiety + stabilise someone's personality
Early Techniques:
Prefrontal Leucotomy: Moniz (1935); narrow device called a leucotome inserted into the frontal lobe through holes drilled in the skill; wire extended out of the device to lesion the tissue; repeated to destroy areas of prefrontal cortex; hoped severing nerves would relieve patients of distressing thoughts and behaviours
Transorbital Lobotomy: Freeman (1946); ice pick instrument inserted through eye socket, moved about to destroy areas in frontal lobe; done in 10 minutes (quick, cheap and efficient); destroy connections to relieve thoughts and behaviours
Biological Approach - Therapy Continued
Therapy Continued
Positive Evaluation of Early Methods: TL became widely available, estimated 2/3 of patients improved or stayed the same; did have some effect of relieving distress and anxiety emotionally - patients more manageable; last resort so gave hope to long term patients
Modern Techniques:
Gamma Knife: uses high beams of radiation to destroy a designated area of the brain; stereotactic equipment used to direct beams accurately; destroy connections to change emotions, thoughts or behaviour
Deep Brain Stimulation: electrodes permanently positioned within brain to stimulate/inhibit certain parts; REVERSIBLE; technique used to treat OCD and Parkinson's
Positive Evaluation of Modern Methods: more safe: better aftercare, non invasive and less risk of infection; stereotactic equipment = more precise; DBS: non-permanent, easily stopped if treatment doesn't work/side effects; more ethically sound
Biological Approach - Methodology
Methodology - Lab Experiments and Twin Studies
Lab Experiments: biological IV controlled by experimenter (heat, exercise) and DV measured (size/colour of adrenal gland)
- Advantages: objective: biology relies on quantitative data from blood tests etc. - not open to misinterpretation; replicable so easy to test reliability; nomothetic; easy to generalise findings as humans similar
- Disadvantages: low ecological validity (stress = psychological) lack of mundane realism: biological processes change in artificial surroundings
Twin Studies: study done on monozygotic twins (MZ) who share 100% of genes and dizygotic twins (DZ) who share 50% genes to see if genetic element impacts on certain behaviour; traits showing greater similarity in identical than non-identical twins, indicating a shared genetic basis; known as concordance rate; Gottesman (1987): found that DZ have 17% concordance rate whereas MZ have 44.8% for schizophrenia
- Advantages: importance of genetic factors in behaviours
- Disadvantages: ignores importance of environment; sample sizes small so ability to generalise is questionable
Biological Approach - Strengths
Strengths of the Biological Approach
Strength 1: Lab Experiments
Explain, Elaborate + Example: uses highly controlled scientific methods (IV + DV is biological factor) to investigate how internal, physical processes determine behaviour; strength because 1) data has good validity; 2) cause and effect relationship established; example: Selye's study on rats = stress of physical injuries caused shrinkage of the thymus gland and not for example diet
Strength 2: Therapy - Psychosurgery
Explain, Elaborate + Example: mental disorders such as OCD and depression and illnesses like Parkinson's can be treated using modern procedures such as deep brain stimulation and gamma knife; strength because 1) therapy helps individuals to live a normal life by reducing distressing symptoms to regain mental health; example: DBS and gamma knife
Biological Approach - Weaknesses
Weaknesses of the Biological Approach
Weakness 1: Therapy - Psychosurgery
Explain, Elaborate + Example: procedures like the lobotomy only worked for 1/3 patients, performed inappropriately and were dangerous; weakness because 1) safer treatments were available but lobotomies still performed
Weakness 2: Reductionist Approach
Explain, Elaborate + Example: reduces all behaviour explanations to simplistic physiological procedures and suggests all humans respond in the same way; weakness because 1) oversimplifies complex behaviours that have no single cause because of focus on internal factors only; example: social/cognitive element of stress(individual's perception) is overlooked by biological psychologists who suggest all humans respond to stress in a similar way to rats
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