Ways of studying the brain - AO3

• Functional magnetic resonance imaging (fMRI)


  A neuroimaging technique that measures brain activity by detecting changes in blood oxygenation and flow
• Strengths of fMRI


  • Does not rely on the use of radiation
  • Risk free, non-invasive and straightforward if administered correctly
  • Images of high spatial resolution - depicts detail by the millimetre and produces a clear picture of how brain activity is localised
• Weaknesses of fMRI


  • Expensive compared to other neuroimaging techniques
  • Can only capture clear image if person stays still
  • Poor temporal resolution because there is 5-second time lag between the image on screen and the initial firing of neural activity
  • Can only measure blood flow in the brain - it cannot clearly distinguish the activity of the neurons and so it's difficult to tell what kind of brain activity is represented on the screen
• Electroencephalogram (EEG)


  A neuroimaging technique that measures electrical activity in the brain
• Strengths of EEG


  • Invaluable in diagnosis of conditions such as epilepsy
  • Contributed to understanding of sleep stages
  • Extremely high temporal resolution - accurate in detecting brain activity at a resolution of a millisecond or even less
• Weaknesses of EEG


  • Generalised nature of information received from thousands of neurons
  • Not useful in pinpointing the exact source of neural activity
  • Cannot distinguish between activities originating in different but adjacent locations
• Event-related potentials (ERPs)


  Specific neural responses that are the direct result of a specific sensory, cognitive, or motor event
• Strengths of ERPs


  • Address limitations of EEGs
  • Bring more specificity to measuring neural processes
  • Excellent temporal resolution when compared to fMRIs
  • Researchers able to identify many different ERPs and describe their precise role in cognitive function
• Weaknesses of ERPs


  • Lacks standardisation in ERP methodology between research studies
  • Makes it difficult to confirm findings
  • Requires complete elimination of background noise and extraneous material to establish pure data, which is not easy to do
• Post-mortem examinations


  Examination of a body after death to determine the cause of death or to study disease processes
• Strengths of post-mortem examinations

  • Vital in providing foundation for early understanding of key processes in the brain
  • Improved medical knowledge and helped generate hypotheses for further research
• Weaknesses of post-mortem examinations

  • Causation is an issue - observed brain damage may not be linked to the deficits under review
  • Raise ethical issues of consent from individuals before death
  • May not be able to provide informed consent, as in the case of HM