Ways of studying the brain

• Functional Magnetic Resonance Imaging (fMRI)


  A method used to measure brain activity while a person is performing a task that uses MRI technology. Enables researchers to detect which regions of the brain are rich in oxygen and active
• Electroencephalogram (EEG)


  A record of tiny electrical impulses produced by the brains activity. By measuring wave patterns the EEG can help diagnose certain conditions of the brain
• Event Related Potentials (ERPs)


  Uses electrodes to measure very small voltage changes in the brain when patients are presented with stimuli which require cognitive processing
• Post Mortem


  The analysis of the brain after death
• What are the 4 ways of studying the brain

  1. Post Mortem
  2. EEGs
  3. ERPs
  4. fMRIs
• What are the 3 things fMRIs measure?

  1. Blood Flow- measure this while patient performs a task
  2. Oxygen- if an area of the brain is active the neurons use the most energy and require more oxygen
  3. Magnetic- Oxygen is released for use by these active neurons. Deoxygenated and oxygenated blood have different magnetic qualities.
• Strengths of fMRIs

  • Doesn't rely on the use of radiation
  • Risk free, non invasive and straightforward
  • Images produced have high spatial resolution
• Weaknesses of fMRIs

  • Expensive
  • Clear image only if the patient stays still
  • Poor temporal resolution ( 5 second delay)
  • Hard to see type of brain activity as it only measures blood flow
• EEGs

  • Measures electrical activity in the brain via electrodes fixed to a skull cap
  • Recording shows brain wave patterns providing an account of brain activity
• Strengths of EEGs

  • Helpful in diagnosing epilepsy due to the random bursts of activity
  • Can be used to monitor stages of sleep
  • Cheaper than fMRIs
  • High temporal resolution
• Weaknesses of EEGs

  • Low spatial resolution
  • Cannot pinpoint the exact source of neural activity
• Temporal Resolution


  How quickly the brain scan can detect changes in brain activity
• Spatial resolution


  How accurately it can show exactly what part of the brain is active
• ERPs

  1. Study the brain by measuring small voltages in the brain that are triggered by specific events
  2. To establish specific response to an event many presentations are averaged
  3. All background brain activity from the EEG recording are filtered
• Strengths of ERPs

  • Cheaper than fMRIs
  • More specific than EEGs
  • Good temporal resolution
  • Able to identify the precise role of the area involved in cognitive functioning
• Weaknesses of ERPs

  • Lack of standardisation in methodology between research studies so difficult to confirm findings
  • Background noise and extraneous materials need to be removed to get pure data
• Post Mortem

  • Firstly study behaviour when they are alive
  • Then study brain when they are dead to see damaged areas
  • May used to compare to a neurotypical brain to see the difference
• Strength of Post Mortem

  • Practical Application vital in providing understanding of processes in the brain
  • Improve medical knowledges
• Weaknesses of Post Mortem

  • Issues with causation as it is hard to determine cause of the damage
  • Raises ethical issues a due to the lack of consent