Assumptions

• What are the assumptions of the biological approach?

  Behaviour can be explained by neurotransmitters.

  Behaviour can be explained by localisation of brain function.

  Behaviour can be explained by evolutionary influences.
• What are neurotransmitters?


  Neurotransmitters are chemical messengers that act between neurons within the brain, which communicate from one neuron to the next at a synapse. Neurotransmitters are released from presynaptic vesicles in one neuron, and will either stimulate or inhibit receptors in the other neuron.
• GABA


  Amino acid

  Reduces neuronal excitability by inhibiting nerve transmission.
• Noadrenaline / norepinephrine 


  Blood pressure

  Fight or flight response
• Dopamine 


  Movement

  Memory

  Addiction

  Pleasure & reward
• Serotonin


  Mood

  Sleep

  Appetite
• Oxytocin 


  Stimulated by touch

  ’Love hormone’

  Neurons connect when it flows, wiring you to trust in similar circumstances.
• Localisation of function


  Certain areas of the brain are responsible for specific functions.
• Frontal lobe 


  Logic

  Planning

  Goals

  Decisions
• Parietal lobe


  Processing senses.
• Temporal lobe 


  Processing auditory information.
• Occipital lobe 


  Processing visual information.
• Broca’s area 


  Language production
• Wenickes area 


  Understanding
• Cerebellum 


  Movement and coordination
• Localisation of brain function example

  Phineas Gage:

  Damaged his frontal lobe and had a change of personality. He became more aggressive.
• Behaviour can be explained by evolutionary influences

  Natural selection - those who survive breed and pass on their traits.
• Evolutionary influences examples:


  Buss:

  Mate selection is universal and therefore a result of evolutionary influences.

  Phobia of dark - necessary for survival.