Ways of studying the brain - A01

• Advances in science and technology

  Produced more sophisticated and precise methods of studying the brain
• Techniques


  Often used for medical purposes in the diagnosis of illness
• Purpose of scanning


  Often used to investigate localisation - to determine which parts of the brain do what
• Methods


  • fMRI
  • EEGs
  • ERPs
  • Postmortem examination
• fMRI


  Studies function whereas MRI used to study brain structures
• EEGs


  Tracks and records brain wave patterns
• ERPs


  Measures brain response that is the direct result of a specific sensory, cognitive or motor effect
• Postmortem examination


  Conducted after death to look at structures of the brain
• Functional magnetic resonance imaging (fMRI)

  • Detects the changes in blood oxygenation and flow of blood as a result of neural activity in specific parts
  • When brain area is more active it consumes more oxygen to meet increased demand
  • Blood flow directed to the active area - known as haemodynamic response
  • Produces 3-dimensional images - activation maps
  • Shows what parts of the brain is involved in particular mental processes
• Importance of fMRI


  Understanding localisation
• Electroencephalogram (EEG)


  • Measure electrical activity in brain via electrodes fixed into the scalp using a skull cap
  • Scan represents brainwave patterns that are generated from the action of millions of neurons giving an overall account of brain activity
  • Used by clinicians as diagnostic tool
  • An unusual arrhythmic pattern of activity (no particular rhythm) may show neurological abnormalities
• Neurological abnormalities detected by EEG

  Epilepsy, tumours or sleep disorder
• Event-related potentials (ERPs)


  • EEG has clinical and scientific applications but it's crude and overly general when looking at brain activities
  • Within EEG data all neural responses associated with specific sensory, cognitive and motor event are contained
  • Using statistical averaging technique all brain activity from original EEG filtered out leaving only responses that relate to the presentation of a specific stimulus or performance of a specific task
  • What remains are event related potentials - types of brain waves are triggered by particular events
• ERPs


  Many different forms and how they are linked to cognitive processes such as attention and perception
• Post-mortem examinations


  • The analysis of a person's brain following their death
  • Used in those with a rare disorder and have experienced unusual deficits in mental processes or behaviour during their lifetime
  • Helps establish the likely cause of the affliction a person's experiences
  • Involve comparison with neurotypical brain to ascertain the extent of the difference