ways of studying the brain

• How are fMRIs used in psychology

  • a person enters a large scanner and completes a task that assesses a specific function
  • researcher looks at the active areas to find the location of the function
• how does fMRIs work?

  • the machine measures the increases and decrease in blood flow in different areas
  • areas that are more active need more oxygen and therefore increases blood flow
  • researchers produce maps showing areas of the brain that are more active during particular activities
• What are strengths of fMRIs?

  • high spacial resolution - can identify the brain region up to an accuracy of 1 mm which allows specific location of activity to be determined
  • longitudinal changes - its a non-invasive technique so no harmful radiation is used; a person can be scanned several times so researchers can track changes in brain function over time
• What are some limitations of fMRIs?

  • poor temporal resolution - there is a 5 second gap between the image shown on the screen and the initial neuronal activity; cannot be sure exactly when the brain reacts to a stimulus
  • understanding is generalised - looks at large group of neurons rather than individual neurones; this overlooks communication between areas which could provide a more complete understanding
• How do EEGs work?

  • measures electrical activity in the brain
  • electrodes placed on scalp detect small electrical changes that result from activity of the brain
  • electrical signals are graphed over a period of time
• Why can EEG be useful?

  • EEG data can be used to detect brain disorders e,g, epilepsy (pattern shows spikes of electrical activity)
  • can diagnose disorders that influence brin activity
  • the types of waves provide us with information about brain activity
• Outline event related potentials

  • they are closely related to EEG scans as they use the same equipment
  • measure changes in brain activity in response to a stimulus
• Outline post-mortem

  • the physical examination of the brain after a person has died
• Strengths of event-related potentials

  • good temporal resolution compared to FMRIs
  • they are frequently used to measure cognitive functions and deficits
• Limitations of event related potentials

  • lack of standardisation between different research studies makes it difficult to confirm findings
  • it is difficult to remove background noise and extraneous variables so pure data cannot be established