Biological approach

• Techniques to study

  • Brain research relied on post mortem patients with musical/behavioural deviations
  • After brain imaging it was possible to study the human brain non-invasively
• Non-invasive brain imaging


  • No skin breaking with no injections
  • No exposure to radiation
• MRI (Magnetic Resonance Imaging)


  A common non-invasive neuroimaging technique that creates 3D images of the brain
• The study is quasi-experimental as the IV (being a taxi driver) was not manipulated
• It is difficult to generalise the findings as the sample was all male
• The study is ethical as MRI is a safe technique
• Localization


  The idea that specific brain regions are associated with specific behaviours or functions
• Localization


  • Speech, smell, sight
• Broca's Aphasia


  Loss of articulated speech, e.g. a man could only say "tan" instead of what he wanted to say
• Localization is not static, some functions are distributed across the brain while others are more localized
• Neuroplasticity


  The brain's ability to form and reorganize synaptic connections in response to learning
• Research shows the brain is constantly changing and reorganizing throughout the lifespan
• Cortical remapping


  The process of the brain creating new connections and traces to learn something new
• Synaptic plasticity


  The changes that occur at the synapse, the junction between neurons, that allow them to communicate
• Maguire's study found no differences in other parts of the brain, suggesting the changes were specific to the hippocampus
• Neural networks


  A set of algorithms modelled loosely on the brain that recognise patterns and interpret sensory data
• Neural networks allow us to do things like see an object and catch it
• LTP (Long Term Potentiation)


  The repetition of a task causes neuroplasticity, leading to dendritic branching and increased neural density
• Synaptic pruning


  The elimination of unused synaptic connections, strengthening neural networks
• Maguire's study suggests synaptic pruning occurred in the anterior hippocampus of taxi drivers, leading to a decrease in dendritic branching and synaptic connections
• Excitatory neurotransmitters


  Increase the likelihood of a neuron firing by depolarizing the neuron
• Inhibitory neurotransmitters


  Decrease the likelihood of a neuron firing by hyperpolarizing the neuron
• Metabotropic neurotransmitters


  Indirectly affect neuron firing
• Agonist


  A chemical or drug that binds to receptors in the brain and activates them
• Antagonist


  A chemical or drug that binds to receptors in the brain and prevents agonists from having an effect
• The reductionist approach of the Rodgers & Kesner study allows for establishing a cause-and-effect relationship, but it is unclear how generalizable the findings are to humans
• Antagonist


  A chemical or drug that binds to receptors in the brain and prevents an agonist from having a reaction
• Agonist


  A chemical or drug that binds to receptors and activates them, producing a physiological response
• All neurotransmitters have agonists for receptor sites
• Types of agonists


  • Endogenous (from the body, natural)
  • Exogenous (drugs, stimulants)
• Scopolamine (blocks acetylcholine)


  Longer time and more mistakes in maze task
• Physostigmine (breaks down acetylcholine)


  Shorter time and fewer mistakes in maze task
• Acetylcholine may play an important role in memory consolidation and retrieval
• Hormones


  Chemicals produced by the body that travel in the blood and regulate ongoing processes, they don't directly affect behaviour but change the probability that a behaviour will occur
• Oxytocin


  • Produced by the hypothalamus, secreted by the pituitary gland, acts as a neurotransmitter, plays a role in social bonding
• Trust game study


  1. Participants given oxytocin or placebo

  2. Played many rounds of trust game

  3. Feedback of betrayal

  4. Oxytocin group kept investing at similar rates, placebo group less likely to trust
• Pheromones are chemicals produced and released into the environment by an animal that affect its own species
• Pheromones lead to rapid behavioural effects in animals, but no human pheromone has been found
• MHC (major histocompatibility complex) genes are co-dominant and affect the immune system, people with more diverse MHC genes have better immune systems
• 1. shirt study


  Women rated the body odour of men with dissimilar MHC genes as more attractive