The Biological Approach

Selye's GAS Model
1. GAS Model
  1. General - Same response to all stressors
  2. Adaptation - Healthiest way for body to cope
  3. Syndrome - Several Symptoms
  4. Stage 1 - Alarm
    1. >Stressor is recognised >Hypothalamus triggers adrenaline >Adrenaline rush
  5. Stage 2 - Resistance
    1. >Body begins to adapt >Resources gradually deplete >Body appears to be coping, but it isn't
  6. Stage 3 - Exhaustion
    1. >Body can't maintain normal functioning >Immune system fails (cortisol slows down) >Development of stress related illnesses
2. Selye's Research with Rats
  1. Selye worked in a hospital and noticed generalised set of symptoms in the patients
    1. He then gave a rat a noxious agent, and they too showed a generalised response regardless of the stressor
    2. AIMS AND CONTEXT
  2. Rats were exposed to various noxious agents (cutting of the spinal cord, cold, doses of diverse drugs)
    1. PROCEDURES
  3. FINDINGS AND CONCLUSIONS
    1. 6-48 hours
      1. PHYSIOLOGICAL TRIAD >enlargement of the adrenal glands >ulcers in the digestive system >shrinkage of the immune system
    2. 48 hours - 1 month
      1. If treatment was continued internal organs returned to normal functioning
    3. 1-3 months
      1. Lost resistance, physiological triad demonstrated again
    4. These results support the DOCTRINE OF NON-SPECIFITY in that the body has the same stress response to all stressors
Assumptions
1. Behaviour can be explained in terms of different areas of the brain
  1. Different parts of the brain have certain specialised functions
    1. Hypothalamus integrates ANS which is important in stress and emotion
  2. Occipital lobe = vision Frontal lobe = motor movement and thinking
2. Behaviour can be explained in terms of hormones
  1. Biochemical substances produced in glands
    1. Circulate the blood and target organs
  2. High levels of testosterone could cause aggression
  3. adrenal glands = adrenaline
Strengths and Weaknesses
1. Weaknesses
  1. Nature rather than nurture
    1. Focusses on nature/ignores environmental factors
      1. Belives schizophrenia is to do with neurotransmitters rather than with how patients feel
  2. Reductionist
    1. Reduces complex behaviours to a set of simple explanations
      1. Stress is only down to adrenaline
        Lose an understanding of the thing we intend to study, may prevent us reaching a true understanding
        R.D Laing (1965) incomplete explanation as it ignores the experience
2. Strengths
  1. Scientific Approach
    1. Hormones and neurotransmitters are easily measurable, so scientists can conduct scientific research
      1. Psychosurgery - whether the parts of the brain have an effect on aggression Chemotherapy - link between drugs and production of neurotransmitters
        All of these, conduct objective, controlled research and demonstrates causal relationships
  2. Successful Applications
    1. Selye's research with rats has enabled us to gain a better understanding of stress and illness; used in hospitals today
      1. Capsulotomy - 67% recovery rates (Cosgrove and Rauch 2001)
        Bipolar - 60% reported improvement (Viguera et al 2000)
Chemotherapy
1. The use of treating mental disorders with prescriptive drugs
2. Antipsychotic Drugs
  1. Used to treat mental disorders such as schizophrenia
  2. Typical Antipsychotics
    1. Combat positive symptoms of schizophrenia by blocking dopamine, by binding to the receptors
  3. Atypical Antipsychotics
    1. Temporarily occupy dopamine receptors then rapidy detatch allowing normal transmission
    2. Less side effects
  4. If parts of the dopamine system become overactive, they seem to play a part in producing hallucinations, delusions and thought disorder.
3. Effectiveness of Chemotherapy
  1. easy to use and reduces sympstoms of mental disorders
  2. However, can have side effects
    1. Hill (1986) 30% of P's reported uncontrollable movements when using antipsychotics
    2. Ferguson (2005) P's are 20% more likely to commit suicide when taking antidepressants
  3. Placebos are used to test the effectiveness of a drug; whether it's pharmacological or psychological
    1. Kahn (1986) 250 P's over 8 weeks reported BZs were more effective than placebos
      1. However, many studies have been carried out where there hasn't been a significant difference between placebos and drugs
4. Antidepressant Drugs
  1. Depression is caused by low levels of serotonin in synapses
  2. In a normal brain, neurotransmitters are released from nerve endings. To terminate, they are reabsorbed or digested by enzymes
    1. Anti D's work by reducing the absorbtion rate, or blocking the enzyme that breaks down serotonin
      1. SSRIs such as Prozac block the mechanism that absorbs serotonin
        More serotonin = Better moods
5. Antianxiety Drugs
  1. BZs
    1. Slow down the activity of the CNS by enhancing GABA for anxiety relief
      1. 40% of neurons react to GABA. Reacts to GABA receptors which increases the flow of Chloride Ions
        Chloride Ions hog the neurotransmitters, slowing down the activity, hence creating relaxation
  2. BBs
    1. Reduce the activity of adrenaline and noradrenaline, part of the SNS' reaction to stress
      1. Less stress on the heart, blood pressure drops, more relaxed, less anxious
    2. Bind to receptors which are aroused by the SNS, so it's harder to stimulate
Methodology
1. Twin Studies
  1. Assumes that genes influence behaviour
  2. Reared Apart
    1. Some twins reared together have the same environment, so seperating them will help us distinguish between genes and environment
    2. Bouchard and McGue found 72% concordance rate for twins reared apart
  3. Reared Together
    1. Bouchard and McGue (1981) studied IQs of MZ and DZ twins
      1. MZ - 86% concordance rates
      2. DZ - 60% concordance rate
  4. Strengths
    1. MZ twins share 100% of genes, so they make perfect P's when studing the effect of genes on behaviour
      1. Comparing MZ twins reared together and apart has allowed psychologists to make assumptions about the importance of genes and environment
  5. Weaknesses
    1. MZ and DZ twins often have the exact same upbringing, therefore we cannot distinguish between genes and environment
      1. Some twins that are reared apart often grow up in similar environments
2. Brain Scanning
  1. EEG
    1. 1950's
    2. Electrodes are placed on the scalp, and activity in the brain is recorded
    3. Dement and Kleitman (1957) saw slower brain waves when Ps were aleep (REM). Ps that were woken up during REM were more likely to remember their dream
  2. CAT
    1. X-Rays produce a model of the brain. Dye is used as a contrast material
      1. High quality x-rays
        Useful at identifying tumours
      2. More radiation which could be harmful
        Pregnant women
  3. MRI
    1. Magnetic field causes brain to emit signals
      1. Maguire et al (2000) demonstrated that taxi drivers have larger hippocampi (spatial memories) than non-taxi drivers
        Detailed images
        Less harmful than CAT scans
        Time consuming and uncomfortable
    2. fMRI gives both anatomical and functional images of the brain
  4. PET
    1. Sugar, most active parts absorb sugar
      1. Raine et al (1997) used PET scans on murders and found more activity in parts of the brain linked with aggression
        Costly
        Radioactive so can only be used a few times
        Less precise than MRIs
        Only scan to reveal chemical information
        Show the brain in action
  5. Assumes that behaviour can be explained in terms of activity of the brain and nervous system

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	Criado por HeyThereIAmKyle mais de 11 anos atrás