The Biological Approach

The Biological Approach

1. Selye's GAS Model

   • GAS Model
     • General - Same response to all stressors
     • Adaptation - Healthiest way for body to cope
     • Syndrome - Several Symptoms
     • Stage 1 - Alarm
       • >Stressor is recognised >Hypothalamus triggers adrenaline >Adrenaline rush
     • Stage 2 - Resistance
       • >Body begins to adapt >Resources gradually deplete >Body appears to be coping, but it isn't
     • Stage 3 - Exhaustion
       • >Body can't maintain normal functioning >Immune system fails (cortisol slows down) >Development of stress related illnesses
   • Selye's Research with Rats
     • Selye worked in a hospital and noticed generalised set of symptoms in the patients
       • He then gave a rat a noxious agent, and they too showed a generalised response regardless of the stressor
       • AIMS AND CONTEXT
     • Rats were exposed to various noxious agents (cutting of the spinal cord, cold, doses of diverse drugs)
       • PROCEDURES
     • FINDINGS AND CONCLUSIONS
       • 6-48 hours
         • PHYSIOLOGICAL TRIAD >enlargement of the adrenal glands >ulcers in the digestive system >shrinkage of the immune system
       • 48 hours - 1 month
         • If treatment was continued internal organs returned to normal functioning
       • 1-3 months
         • Lost resistance, physiological triad demonstrated again
       • These results support the DOCTRINE OF NON-SPECIFITY in that the body has the same stress response to all stressors

2. Assumptions

   • Behaviour can be explained in terms of different areas of the brain
     • Different parts of the brain have certain specialised functions
       • Hypothalamus integrates ANS which is important in stress and emotion
     • Occipital lobe = vision Frontal lobe = motor movement and thinking
   • Behaviour can be explained in terms of hormones
     • Biochemical substances produced in glands
       • Circulate the blood and target organs
     • High levels of testosterone could cause aggression
     • adrenal glands = adrenaline

3. Strengths and Weaknesses

   • Weaknesses
     • Nature rather than nurture
       • Focusses on nature/ignores environmental factors
         • Belives schizophrenia is to do with neurotransmitters rather than with how patients feel
     • Reductionist
       • Reduces complex behaviours to a set of simple explanations
         • 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
   • Strengths
     • Scientific Approach
       • Hormones and neurotransmitters are easily measurable, so scientists can conduct scientific research
         • 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
     • Successful Applications
       • Selye's research with rats has enabled us to gain a better understanding of stress and illness; used in hospitals today
         • Capsulotomy - 67% recovery rates (Cosgrove and Rauch 2001)
           • Bipolar - 60% reported improvement (Viguera et al 2000)

4. Chemotherapy

   • The use of treating mental disorders with prescriptive drugs
   • Antipsychotic Drugs
     • Used to treat mental disorders such as schizophrenia
     • Typical Antipsychotics
       • Combat positive symptoms of schizophrenia by blocking dopamine, by binding to the receptors
     • Atypical Antipsychotics
       • Temporarily occupy dopamine receptors then rapidy detatch allowing normal transmission
       • Less side effects
     • If parts of the dopamine system become overactive, they seem to play a part in producing hallucinations, delusions and thought disorder.
   • Effectiveness of Chemotherapy
     • easy to use and reduces sympstoms of mental disorders
     • However, can have side effects
       • Hill (1986) 30% of P's reported uncontrollable movements when using antipsychotics
       • Ferguson (2005) P's are 20% more likely to commit suicide when taking antidepressants
     • Placebos are used to test the effectiveness of a drug; whether it's pharmacological or psychological
       • Kahn (1986) 250 P's over 8 weeks reported BZs were more effective than placebos
         • However, many studies have been carried out where there hasn't been a significant difference between placebos and drugs
   • Antidepressant Drugs
     • Depression is caused by low levels of serotonin in synapses
     • In a normal brain, neurotransmitters are released from nerve endings. To terminate, they are reabsorbed or digested by enzymes
       • Anti D's work by reducing the absorbtion rate, or blocking the enzyme that breaks down serotonin
         • SSRIs such as Prozac block the mechanism that absorbs serotonin
           • More serotonin = Better moods
   • Antianxiety Drugs
     • BZs
       • Slow down the activity of the CNS by enhancing GABA for anxiety relief
         • 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
     • BBs
       • Reduce the activity of adrenaline and noradrenaline, part of the SNS' reaction to stress
         • Less stress on the heart, blood pressure drops, more relaxed, less anxious
       • Bind to receptors which are aroused by the SNS, so it's harder to stimulate

5. Methodology

   • Twin Studies
     • Assumes that genes influence behaviour
     • Reared Apart
       • Some twins reared together have the same environment, so seperating them will help us distinguish between genes and environment
       • Bouchard and McGue found 72% concordance rate for twins reared apart
     • Reared Together
       • Bouchard and McGue (1981) studied IQs of MZ and DZ twins
         • MZ - 86% concordance rates
         • DZ - 60% concordance rate
     • Strengths
       • MZ twins share 100% of genes, so they make perfect P's when studing the effect of genes on behaviour
         • Comparing MZ twins reared together and apart has allowed psychologists to make assumptions about the importance of genes and environment
     • Weaknesses
       • MZ and DZ twins often have the exact same upbringing, therefore we cannot distinguish between genes and environment
         • Some twins that are reared apart often grow up in similar environments
   • Brain Scanning
     • EEG
       • 1950's
       • Electrodes are placed on the scalp, and activity in the brain is recorded
       • 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
     • CAT
       • X-Rays produce a model of the brain. Dye is used as a contrast material
         • High quality x-rays
           • Useful at identifying tumours
         • More radiation which could be harmful
           • Pregnant women
     • MRI
       • Magnetic field causes brain to emit signals
         • 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
       • fMRI gives both anatomical and functional images of the brain
     • PET
       • Sugar, most active parts absorb sugar
         • 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
     • Assumes that behaviour can be explained in terms of activity of the brain and nervous system