Two Assumptions: Assumption 1: (4 marks)
1st assumption: Behaviour can be explained in terms of different areas of the brain:
- Different areas of the human brain have been identified as being speciallised for certain functions:
- Cerebral cortex covers the surface of the brain and this region of the brain is responsible for higher cognitive functions such as language and perception.
- The cerebral cortex is divided up into four lobes: frontal, occipital, parietal and temporal lobe.
- Most important is the frontol cortex/lobe and is responsible for fine motory movement and thinking.
- Occipital lobe is associated with vision.
- Underneath the cortex are sub-cortical structures e.g. hypothalamus which integrates the ANS, this is important in stress and emotion.
Different components of the brain are important to understand emotions, thoughts and behaviours; different parts of the brain are linked to different behaviours. Therefore, if there is damage to a specific part of the brain, this can have an impact on behaviour. Example: A case study that looked at a man called Phineas Gage who suffered damage to the occipital lobe which can affect sight and damage to the frontol lobe which can affect personality.
Two Assumptions: Assumption 2: (4 marks)
Assumption 2: The role of neurotransmitters:
This states that emotions, thoughts and behaviours are affected by neurons and neurotransmitters:
- The activity of our brain is mediated (controlled) by neurotransmitters so that the levels of these neurotransmitters are dopamie which is associated with rewards and schizophrenia and serotonin associated with sleep and arousal.
- Examples of important neurotransmitters include serotonin, dopamine, GABA etc.
- Imbalances of dopamine are implicated in schizophrenia while imbalances in serotonin are implicated in depression.
- Neurons are electrically excitable cells that form the basis of the nervous system.
- One neuron communicates to another neuron at a synaspe, where the message is relayed by chemical messengers (neurotransmtters). These neurotransmitters are released from presynaptic vesicles in one neuron and will stimuliate or inhibit receptors in another neuron leaving a synaptic cleft.
- An example of a neuron is a motor neuron which conveys instructions to and from the brain to make our body do things; like move a muscle etc.
Describe Selye's GAS model (8 marks)
Selye's research with rats: Selye worked in a hospital and noted that patients shared common symptons e.g. aches, pains, loss of appetite etc, no matter whatever was wrong with the patient, they still shared these common symptons.
Procedure: He exposed rats to various noxious agents such as cold, surgical injury, excessive muscular exercise and production of spinal shock which involved cutting their spinal cord.
Findings and conclusions: He observed that a typical syndrome was present with symptons of which were independent of the nature of the damaging agent or the type of drug used. Syndrome developed in 3 stages:
1. Enlargement of the adrenal glands, ulcers in digestive system and shrinking of the immune system.
2. If treatment continued, appearance and function of the internal organs would return to normal.
3. Continued treatment for 1-3 months lead to animals losing their resistance and displaying symptons of the psychological triad seen in stage 1.
Describe Selye's GAS model (No.2)
Selye suggested that there is one internal mechanism for dealing with noxious agents which he called stressors.
Selye's research led him to conclude that when animals are exposed to unplesant stimuli, they display a universal response to all stressors.
General Adaptation Syndrome: Selye proposed 3 stages that lead up to illness therefore linking stress and illness, stress reuslts in a depletion of physiological resources which lower an organisms's resistance to infection:
Stage 1: Alarm stage:
- Threat or stressor is recognised and a response is made to the alarm.
- Hypothalamus in brain triggers the production of adrenaline from the adrenal glands.
- Adrenaline causes sensations (adrenaline rushes) resulting in sweaty palms, increased heart rate, increased speed of breathing etc.
- Leads to readiness for ‘fight’ or flight’ mode.
Describe Selye's GAS model (No.3)
Stage 2: Resistance:
- If stress continues then a means of coping needs to be found.
- Body is adapting to the demands of the environment but at the same time resources are slowly depleting.
- Body appears to be coping but, psychologically speaking, is deteriorating.
Stage 3: Exhaustion:
- Body’s system can no longer maintain normal functioning.
- Initial symptoms may reappear (sweating, faster breathing).
- Adrenal glands may be damaged from previous over-activity and the immune system may not be able to cope as production of important proteins has slowed down.
- Results may be seen in stress-related illness such as ulcers, depression and other mental or physical illnesses.
Applied to Chemotherapy (12 marks)
The biological approach believes all behaviour is psychological and therefore is with us from when we are born. Link to assumption: One assumption states that our behaviour can be explained in terms of neurotransitters that are sending different messages around the brain, this assumption is linked to chemotherapy as it aims to treat mental disorders through the use of psychoactive drugs and altering neurotransmitter activity in the brain.
There are 3 types of psychoactive drugs:
1. Antipsyhotics: These treat psychotic disorders such as schizophrenia where the patient has little insight into their condition and can no longer properly connect with reality. Conventional antipsychotics are used to combat the positie symptons of schizophrenia by blocking the action of the neurotransmitter dopamine in the brain by binding to the receptors but not stimulating them. It is believed dopamine increased symptons of schizophrenia.
2. Antidepressants: Insufficient amounts of serotonin being produced in the synaspe are believed to lead to depression. SSRI is a commonly prescribed antidepressant as it works by blocking the transported mechanism that reabsorbs serotonin into the presynaptic cell after it has fired. This results in serotonin being left in the synaspe so prolonging its activity and making transmission of the next impulse easier.
Chemotherapy (12 marks)
3. Antianxiety: These are not commonly used to treat anxiety and stress and the key drug used in benzodiazepines. They slow down the activity in the nervous system by enhancing the actvity of GABA that is the body's natural form of anxiety relief. GABA locks into receptors causing an increase of cloride ions into the neuro which maes it harder for the neuron to be stimulated by other transmitter therefore slowing down its activity making the person feel more relaxed.
Successes of chemotherapy:
- Proven very successful as a way of treating psychological orders e.g. Viguera et al reported that over 60% of patients with bipolar disorder improved when taking lithium.
- However, there are some concerns: Example: Ferguson found that patients taking SSRI's are twice as likely to commit suicide.
Link to aims of approach:
- Chemotherapy links to the assumption that neurotransmitters in the brain have control over our behaviour as it shows for example that lower levels of serotonin can lead to depression and in order to prevent this from being the case SSRI's are available to keep patients serotonins levels high.
Two strengths of the biological approach (6 marks)
- Scientific: The biological approach believes that behaviour can be controlled in the brain by neurotransmitters and hormones meaning that biological explanations have variables that can be measured, tested and proven through lab experiments. For example: Selye's rats experiment where he conducted research on rats and exposed them in noxious agents. This was carried out in a highly controlled environment where all variables are controlled and a cause and effect relationship can be found. (OPTIONAL- Another example is psychosurgery which involves functionally removing parts of the brain. Such procedures are based on earlier research that has linked areas of the brain to certain behaviours such as aggression.) All of these examples of research are scientific as they fulfil the aims of scientific research- to conduct objective, well-controlled studies and ideally to demonstrate casual relationships. This is a strength because the approach lends itself to scientific research that can then be used to support biological explanations.
- Applcations: This approach has led to many successful applications meaning that patients lives can be improved following the findings of this approach. The biological approach has also led to many forms of treatment for mental disorders, such as psychosurgery and chemotherapy, Cosgrove and Rauch (2001) reported recovery rates of 67% (reasonaly high). Also, in Vigeura's study where all patients with bipolar disorder have been successfully treated with drugs for instance, 60% of them improved after taking lithium. This is a strength because there are many empirical studies to support the theories.
Two weaknesses of the biological approach (6 marks
- Nature rather than nurture: The biological approach focuses on nature and the biology and doesn't take into account that life experiences and psychological factors have a large impact on the way people think and feel. For example, when explaining schizophrenia, the approach is concerned with abnormal levels of neurotransmitters rather than opposed to looking at factors such as living within a family unit with high levels of emotional tension as a determinant for the illness. This is a weakness because it only focuses on one aspect of the nature/nurture debate and is bias.
- Nomothetic approach: This approach is nomothetic and assumes that all people respond in a similar way therefore meaning that individual differences are ignored. For example, Taylor found that biological psychologists tend to use males more often than females as female hormones are subject to change however he also found that males deal differently to stress as they have a 'fight of flight' response whereas women have a 'tend and befriend' response, therefore meaning that everyone acts in different ways and findings cannot be generalised. This is a weakness because if findings cannot be generalised, they can rarely be applied to real life situations and just remain a theory.
The methodology (12 marks)
Brain scanning: Biological approach assumes that behaviour can be explained in terms of activity in the brain and the nervous system meaning that psychologists look for methods that allow them to view brain activity.
(OPTIONAL- ONLY NEED 2 BRAIN SCANNING)- EEG: One method available in 1950's involved placing electrodes on the scalp and electrical activity in different regions of the brain can be recorded. This method can be used to detect different stages of sleep (Research from Dement and Kleitman).
:)- Completely harmless
:(- Limited information is gained.
:(- It tells us nothing about the structure of the brain.
Methodology: Brain Scanning (No.2)
CAT scans- involves taking a series of x-rays and combing them to form a 2D or 3D picture of that part of the brain being scanned. A dye is then injected as a contrast material and then the patient is placed under a CAT scan machine to take pictures.
- :)- It reveals abnormal structures in the brain.
- :)- The quality of pictures is much higher than x-rays
- :(- The more detailed the scan, the more radiation the patient is exposed to which is dangerous.
- :(- Pregnant women cannot be scanned this way.
MRI scans- Involves the use of magnetic fields to map the structure of the brain and read signals. Maguire used MRI scans to show that taxi drivers had larger hippocampi supporting the view that, that area of the brain is important in spatial memory.
- :)- Gives more detailed images of soft tissue than CAT scans do.
- :)- Does not expose the patient to the hazards of radiation.
- :(- Takes a long time.
- :(- Uncomfortable for the patient.
Methodology: Brain Scanning (No.3)
(OPTIONAL)- PET scans:This sort of scan involves administering slightly radioactive glucose (sugar) to the patient. The most active areas of the brain use glucose, and radioaction detectors can 'see' the radioactive areas, so building up a picture of activity in the brain.
- :)- Reveals chemical information that is not available using other techniques.
- :)- Can show the brain in action which is uesful for pyschological research.
- :(- Very costly.
- :(- PET scans are less precise than MRI scans.
- :(- Involves injecting the patient with radioactive substances so can only be used a few times.
Methodology: Twin Studies:
Twin Studies: One assumption of the approach is that the influence of genes that we inherit affects our behaviour. Twin studies are used to compare the effects of genetics against experience. Monozygotic twins have a concordance rate of 100%. Bouchard & McGue looked at 30 studies and found a concordance rate of 86% which suggests a large amount of intelligence is inherited. Bouchard & McGue also looked at monozygotic twins reared apart and found that they had a 72% concordance rate which supports the idea that there is a significant genetic contribution to intelligence.
- :)- Twins can be ideal participants for studies of genes on behaviour and provide useful information about the extent to which genetics and upbringing are responsible for a characteristic.
- :)- MZ twins reared together and apart have allowed psychologists to make assumptions about the importance of genes and environment on development.
- :(- Twins not only share their genetics but also their upbringing and share the same experience which can make it difficult to seperate the effects of genetics from the effects of environment in results.
- :(- The study of twins is problematic as twins that have been seperated at birth are often raised in similar environments in terms of education, family valies and socioeconomic background.