Ways of studying the brain

• 6 methods of studying the brain / localisation of function

  neuro surgery

  electrical and chemical simulation

  post mortem

  EEG

  ERP

  MRI
• ERP (Event Related Potential)

  Shows what happens before, during and after an activity
• Post Mortem

  After death, organs are removed. Psychologists are interested in the brain after death.AO3 of post Mortems* reliable/scientific* lets you study things which are unethical to do during a person's life* reduced sample (only organ donors)* cannot establish cause and effect
• MRI (magnetic resonance imaging)

  measures brain activity- when an area becomes more active there is an increased demand for oxygen.AO3 of MRIs* offers more objective measure* non-invasive* not a direct measure- looks at blood flow* focus only on localised activity
• EEG (electroencephalogram)

  small sensors which are designed to pick up electrical signals produced by brain cells when they send messages
• Hemispheric Lateralisation


  the idea that two hemispheres of the complete different task functionality

  e.g left/language and right/visual

  e.g Broca's area control is both lateralised(left hemisphere) and localised (posterior frontal cortex)
• Corpus Callosum


  the large band of neural fibers connecting the two brain hemispheres and carrying messages between them
• AO3 of ERPs

  • non-invasive
  • easy method with little risk as no radiation
  • may not pick up all impulses
  • cheap
  • helps to understand localisation of function
• Difference between ERPs and fMRIs

  • ERPs have good temporal resolution
  • fMRIs have good spatial resolution
  • fMRIs measure neural activity indirectly but ERPs directly measure neural activity
  • different methodology - fMRIs work by measuring changes in blood oxygenation as a measure of neural activity whereas ERPs measure electrical activity via electrodes to detect brainwaves triggered by certain events
  • fMRIs are more expensive than ERPs.
• Similarities between ERPs and fMRIs

  • fMRIs and ERPs are both non-invasive and do not use radiation (risk free)
  • fMRIs and ERPs both measure brain activity linked to events/tasks