Ways of Studying the Brain

• Localisation


  The theory that specific areas of the brain are associated with particular physical and psychological functions
• functional magnetic resonance imaging (fMRI)

  A non-invasive imaging technique that uses magnetic fields to map brain activity by measuring changes in the brain's blood flow and oxygen levels

  
• Electroencephalogram (EEG)

  - An amplified recording of the waves of electrical activity that sweep across the brain's surface.

  - These waves are measured by electrodes placed on the scalp.

  
• Event-related potentials (ERPs)


  A physiological measure of large electrical change in the brain produced by sensory stimulation or motor responses.

  
• Post-mortem examinations


  The brain is analysed after death to determine whether certain observed behaviours during the patient's lifetime can be linked to abnormalities in the brain.
• Strength of fMRI


  Non invasive

  - Unlike other scanning techniques (PET), fMRI does not rely on the use of radiation and it is safe.
• Limitation of fMRI


  Expensive

  & can only capture a clear image if the person stays still
• Strength of EEG

  Can detect brain activity at a resolution of a single millisecond
• Limitation of EEG

  Unable to show location of electrical activity.
• Strengths of ERPs


  Non-invasive

  Excellent temporal resolution
• Limitation of ERPs


  Only monitor electrical activity in outer layers of the brain and so cannot reveal activity in deeper brain sites.
• Strengths of post-mortem examinations

  - Provided foundation for early understanding of key processes in the brain

  - Broca and Wernicke wouldn't have found their respective areas without post-mortem examinations
• Limitations of post-mortem examinations

  - Cannot identify causation. Observed damage to the brain may not be linked to deficits observed but rather to unrelated trauma or decay.

  - There are ethical concerns of informed consent from the individual before death.