Methods of investigating the brain

• What does fMRI stand for?

  Functional Magnetic Resonance Imaging
• How does fMRI detect brain activity?

  By detecting changes in blood oxygenation and flow due to neural activity
• What is the haemodynamic response in fMRI?

  It is the increased blood flow to active brain areas to meet oxygen demand
• What type of images does fMRI produce?

  1. dimensional activation maps showing brain activity
• What are the strengths of fMRI?

  • Does not rely on radiation
  • Virtually risk-free and non-invasive
  • High spatial resolution depicting detail by the millimetre
• What are the weaknesses of fMRI?

  • Expensive compared to other techniques
  • Requires the subject to stay perfectly still
  • Poor temporal resolution with a 5-second time-lag
  • Cannot measure individual neuron activity
• What does EEG stand for?

  Electroencephalogram
• How does an EEG measure brain activity?

  By using electrodes fixed to the scalp to record electrical activity
• What can unusual EEG patterns indicate?

  Neurological abnormalities such as epilepsy or sleep disorders
• What are the strengths of EEG?

  • Valuable for diagnosing conditions like epilepsy
  • Contributes to understanding sleep stages
  • Extremely high temporal resolution (single millisecond)
• What are the weaknesses of EEG?

  • Low spatial resolution, cannot pinpoint exact neural activity source
  • Difficulty distinguishing activities from adjacent locations
• What are Event-related Potentials (ERPs)?

  Brainwaves triggered by specific events
• How are ERPs derived from EEG recordings?

  By filtering out extraneous brain activity to isolate specific responses
• What are the strengths of ERPs?

  • Excellent temporal resolution compared to fMRI
  • Useful for measuring cognitive functions and deficits
  • Identifies different types of ERP linked to cognitive processes
• What are the weaknesses of ERPs?

  • Lack of standardization in methodology across studies
  • Difficulty in eliminating background noise for pure data
• What are post-mortem examinations?

  Analysis of a person's brain after death
• What is the purpose of post-mortem examinations?

  To examine areas of brain damage and establish causes of afflictions
• What are the strengths of post-mortem examinations?

  • Vital for early understanding of brain processes
  • Detailed examination of anatomical and neurochemical aspects
  • Access to deeper brain regions not possible with other techniques
• What are the weaknesses of post-mortem examinations?

  • Damage may not relate to observed deficits
  • Ethical issues regarding consent from patients before death
• How do fMRI and EEG differ in terms of temporal resolution?

  fMRI has poor temporal resolution, while EEG has extremely high temporal resolution
• What is a key difference between fMRI and post-mortem examinations?

  fMRI measures brain activity in living subjects, while post-mortem examines brains after death
• What is a significant limitation of EEG compared to fMRI?

  EEG has low spatial resolution, making it hard to pinpoint exact neural activity
• How do ERPs contribute to our understanding of cognitive processes?

  They link specific brainwave patterns to cognitive functions like attention and perception