A01 Ways of Investigating the Brain

• What do psychologists use to investigate brain localisation?S


  Psychologists use medical techniques to investigate brain localisation:

  • Techniques for investigating the brain are often used for medical purposes in the diagnosis of illness.
  • The purpose of scanning in psychological research is often to investigate localisation - to determine which parts of the brain do what.
• Techniques?

  • fMRI
  • EEG
  • ERPs
  • Post-Mortem
• fMRI stands for?


  functional Magnetic Resonance Imaging
• fMRI?


  • Detects changes in blood oxygenation & flow that occur due to neural activity in specific brain areas. (highlights active areas of brain).
  • When brain more active/neural activity = causes changes in flow & oxygenation levels of blood in brain. This coz when part of brain carrying out task = consumes more oxygen, so blood flow carrying this oxygen directed to active area, which known as = HAEMODYNAMIC RESPONSE. 
  • Output of fMRI = 3D image/activation maps shows parts of the brain that active & thus must be involved when carrying out specific tasks in particular mental processes.
• EEG stands for?


  • Electroencephalogram
• EEG


  • EEGs shows overall electrical activity in the brain by measuring electrical activity within the brain via electrodes attached to the scalp using a skull cap (like swim cap with electrodes attached) giving an overall account of brain activity.
  • The output is a scan recording which displays brainwave patterns generated from the action of millions of neurons.
  • Where an arrhythmic pattern is detected this can be used to indicate a neural malfunction.
  • EEG is often used as a diagnostic tool, e.g. unusual arrhythmic abnormalities such epilepsy, tumours or sleep disorders.
• ERPs Stand for?


  • Event-related Potentials
• ERPs


  • ERPs are types of brain waves related to/triggered by particular events.
  • ERPs are what is left when all extraneous brain activity from an EEG recording is filtered out, it isolates sensory, cognitive/motor responses down to the specific stimuli presented.
  • Allows researchers to see brain’s response to specific stimulus. 
  • This done using statistical technique, leaving only responses that relate to the presentation of a specific stimulus (for example).
  • This research revealed many different forms of ERP and how these are linked to cognitive processes (e.g. perception & attention).
• Post Mortem Examinations


  • A technique that is the analysis of a person’s brain after their death - often used when the person has suffered from a rare condition and has experienced unusual deficits. 
  • Areas of the brain are examined after death as a means of establishing the likely cause of any disorder or deficit that the person experienced in life. In most cases the brain is compared to a neurotypical brain to assess the extent of the differences.
• Overall summary of the techniqes?

  fMRI - Highlights active areas of the brain

  EEG - shows overall electrical brain activity

  ERPs - shows brainwaves related to particular events

  Post-mortem - examining brain after to death to establish cause of disorder or deficits that the person experienced in their life (to help others).