Biological

• Biological approach


  Combines psychology and biology to provide physiological explanations for human behaviour
• Biological psychology


  Tries to explain how we think, feel and behave in terms of physical factors within the body
• Assumptions of the biological approach

  • Evolutionary influences
  • Localisation of brain function
  • Neurotransmitters
• These three things all have an effect on our personality and psychology
• Darwin's theory of natural selection assumptions

  • Only a small proportion of each generation survives to reproduce
  • Offspring are not identical to their parents, and so each generation has a degree of variation, and that at least some of this variation is heritable (can be passed on through genes)
  • Some characteristics give the animal an advantage over others in the ability to survive and reproduce
• In practically every culture in the world, men prefer young rather than old women, women with wide hips and narrow waists, and women with full lips and large eyes.
• The evolutionary explanation for these preferences is that they indicate fertility - younger women can bear children more easily; wider hips mean easier childbirth; fuller lips and larger eyes suggest good health and nutrition during childhood.
• Female attractiveness is linked to reproductive success because it indicates youthfulness and fertility.
• Males who find such females attractive will pass on their preference for them to their sons, which means that future generations will also show this preference.
• In many cultures, there is also a preference for symmetrical faces, which again suggests good health and nutrition during childhood.
• Women who look as if they will make good mothers tend to attract more mates, and therefore pass on their genes more often.
• Men who find such women attractive will also pass on those genes because they will mate with them.
• Evolutionary psychologists argue that we still carry around many of the psychological adaptations from our ancestors, including those related to sexual attraction.
• Environment of evolutionary adaptiveness (EEA)

  ● A time period.

  ● To understand the functions of the brain, we must

  understand the environment in which the brain evolved.

  ● Humans began evolving around 2 million years to around

  100,000 years ago.

  ● Evolutionary psychologists argue that humans are adapted

  to the environment that our ancestors would have faced.
• Assumption 2: Localisation of brain function

  ● The cerebral cortex is divided into four areas. The most important is the frontal lobes deal with thinking and creativity.

  ● The parietal lobe receives sensory information such as temperature, touch and pain.

  ● The temporal lobes are responsible for memory processing, as well as processing auditory information.

  ● The final lobe is the occipital lobe which deals with vision and receives information directly from the eyes.
• Localisation of brain function

  There are specific areas of the brain linked to the processing of language
• French neurosurgeon Paul Broca studied eight patients with language problems


  Middle of the 19th century
• Paul Broca's findings


  • Examined brains of patients after death
  • Found damage to a specific area of their left hemispheres
  • This area has been named 'Broca's area'
  • Associated with speech production
  • Found in the posterior portion of the frontal lobe
• Carl Wernicke, a German neurologist, discovered another area of the brain that was involved in understanding language


  19th century
• Wernicke's area


  • In the posterior portion of the left temporal lobe
  • Patients could speak but were unable to understand language
• The left hemisphere controls the right side of the body and vice versa. This means that damage to one half of the brain can result in loss of control over the opposite side of the body.
• Broca’s area – located at the front of the left hemisphere
• Assumption 3: Neurotransmitters

  ● Neurons are the cells which are found in the brain and nervous system.

  ● They work by sending chemical and electrical messages to each other.
• Neurons


  • They are long thin cells that convey messages from one place to another
  • They can be smaller than 1mm, or longer than a metre
  • The brain contains billions of these neurons
• Synapse


  Small gaps between neurons (20 mm wide)
• Neurotransmitter transmission


  1. Neurotransmitters are released from presynaptic vesicles

  2. Neurotransmitters act between neurons within the brain
• Neurotransmitters


  Chemical messengers that allow the brain to process thoughts and memories
• The whole of the nervous system (including the brain) is composed of interconnected neurons
• Neurons pass messages from one neuron to the next via small gaps between the neurons called a synapse
• Antipsychotic drugs

  ● Used to treat mental disorders, e.g. schizophrenia.

  ● They will have lost touch with reality and has little insight

  into their condition.

  ● Conventional antipsychotics are used to combat the positive symptoms of schizophrenia (e.g. delusions and hallucinations)

  ● The drug blocks the action of dopamine by binding to it(but not stimulating) the dopamine receptor

  ● Atypical antipsychotic drugs temporarily occupy the dopamine receptor and then rapidly dissociating to allow normal dopamine transmission. this Leads to lower side effects.
• Antidepressant drugs

  ● Depression is thought to be because of a lack of serotonin in nerve endings (synapse).

  ● antidepressant work by reducing the rate of neurotransmitters being re absorbed into the nerve endings or by blocking the enzymes which break the neurotransmitters down.

  ● These methods Increase the amount of neurotransmitters available to excite neighbouring nerve cells

  ● The most common antidepressants are SSRIs – these block the transporters that absorbs serotonin, increasing the level in the synapse.
• Antianxiety drugs

  ● Used to treat stress and anxiety.

  ● E.g. (BZs) – these slow down the activity in the .

  ● GABA is the body’s natural calming neurotransmitter. BZs bind to the sites on GABA receptors and enhance the action of GABA.

  ● Serotonin has an arousing effect – BZs reduce the increased activity associated with anxiety
• Beta-Blockers (BBs)

  ● Beta-Blockers (BBs) the activity of which are part of the

  ● These do not enter the brain, instead BBs bind to the receptors in the heart and other parts of the body that are stimulated during arousal

  ● This the activity of the autonomic nervous system associated

  , i.e. reducing heart-rate, blood pressure and cortisol levels.

  ● There is therefore less stress on the heart and the person feels calmer and less anxious.

  ● These are sometimes used by snooker + darts players and musicians to reduce the negative effect on their performance
• Strengths of drug therapy

  ● There is considerable evidence for the effectiveness of drug treatments. Typically a randomised control trial is used to compare the effectiveness of the drug versus a placebo (a substance that has no pharmacological value but controls for the belief that the pill you are taking will affect you). Soomro et al. (2008) reviewed 17 studies of the use of SSRIs with OCD (which has a component of depression) patients and found them to be more effective than placebos in reducing the symptoms of OCD up to three months after treatment, i.e. in the Short term
• Strengths of drug therapy

  • Cheaper than other treatments
  • GP doesn't have to spend as much time with the patient
  • Efficient and easy to administer
• Drug therapy

  • Benzodiazepines (BZs) found to be superior to placebos in a study by Kahn et al. (1986) over 8 weeks
• Beta-blockers

  • More effective in reducing anxiety in a variety of stressful situations
  • E.g. among musicians and in sports where accuracy is more important than stamina (e.g. golf or snooker)
• Drugs

  • Easy to use and require little effort
  • Just have to remember to take the pill
  • Easier than the effort required for psychological treatments
• Strengths of drug therapy

  • Cheaper than other treatments
  • GP doesn't have to spend as much time with the patient
  • Efficient and easy to administer
• Drug therapy

  • Benzodiazepines (BZs) found to be superior to placebos in a study by Kahn et al. (1986) over 8 weeks