Studying the brain

• fMRI

  • detects radio waves changing in magnetic fields.
  • detects which regions in the brain are rich in oxygen and therefore are active.
  • produces 3D images showing which parts of the brain are involved in particular mental processes
• fMRI strengths

  • high spatial resolution
  • Doesn't rely on radiation -> non-invasive and straightforward.
• fMRI limitations

  • expensive compared to other neuroimaging
  • Poor temporal resolution -> 5 second time lag.
• EEG

  • records tiny electrical impulses produced by the brain's activity.
  • measures characteristic wave patterns.
• EEG strengths

  • Useful in studying sleep stages and diagnosing epilepsy.
  • High temporal resolution -> single millisecond
• EEG limitations

  • poor spatial resolution
  • not useful at pinpointing source.
• ERP (event-related potentials)

  • brainwaves that are triggered by specific events which can be identified after extraneous brain activity from original EEG are filtered.
• ERP strength

  • More specific than EEG.
  • high temporal resolution.
• ERP limitations

  • Lack of standardisation between different studies.
  • 'background' noise has to be completely eliminated which is not easy to achieve.
• Post-mortem examinations

  • brain is analysed after death to observe structural abnormalities in the brain
• Post mortem strength

  • provided foundation for early understanding of key processes.
  • Wernicke and Broca.
  • HM
• Post mortem limitations

  • Causation is an issue.
  • ethical issues
  • cannot provide informed consent.