Ways of studying the brain

• What are the 4 ways of studying the brain?

  • Post mortem
  • fMRI
  • EEG
  • ERPs
• What is a post-mortem?

  A technique that analyses a person’s brain following their death.

  May involve the comparison with a neurotypical brain to assess the extent of the differences.
• Why are post mortem’s used?

  To establish the likely cause of a deficit or disorder that the person experienced in life.
• What are the strengths of post mortem’s?

  They are useful in localisation & medical research- identifying areas of the brain

  e.g. Wernicke and Broca’s area

  LL- Continue to provide useful information
• What are the weaknesses of post mortem’s?

  Ethical issues- consent issues

  Problems with causation- the damage seen may not be linked to the deficit
• What is an fMRI?

  A scan that makes a 3D image of the brain

  It detects changes in blood oxygenation and blood flow

  If the brain is active it consumes more oxygen so there is more blood flow
• What are the strengths of fMRI?

  High spatial resolution- shows region of brain that is active

  Risk free- no radiation
• What are the weaknesses of fMRIs?

  Expensive

  Has poor temporal resolution- 5 second lag
• What is an EEG?

  It measures electrical activity within the brain via electrodes using a skull cap.

  The scan recording represents the brainwave pattern generated from thousands of neurones- shows overall brain activity
• What is EEG often used for?

  A diagnostic tool

  e.g. unusual arrhythmic patterns of brain activity- this may indicate abnormalities like epilepsy, tumours or sleep disorders
• What is the strength of an EEG?

  High temporal resolution- what is seen on the screen is what is happening now
• What is the weakness of an EEG?

  Information is too generalised- difficult to pinpoint the exact source of neural activity
• What is an EEG?

  Typed of brainwaves that are triggered by specific events- what is left after all extraneous brain activity from an EEG recording is taken out.

  It is done by using a statistical technique- leaving only those responses that relate to the specific stimulus
• What have researchers found with ERPs?

  That there are many different forms of ERP & how these are linked to different cognitive processes

  e.g. perception and attention
• What is the strength of ERPs?

  Good temporal validity- what is seen on screen is what is happening now
• What is the weakness of ERPs?

  Elimination of all extraneous material is difficult/ nearly impossible to achieve