ways of investigating the brain

• Functional Magnetic Resonance Imaging (fMRI) uses radio waves to form changing magnetic fields. Detects changes in blood oxygenation. More active areas of the brain use more oxygen and show up on the scans when in use
• Strengths of fMRI:

  • doesn’t rely on the use of radiation
  • If administered correctly it is virtually risk-free
  • non-invasive and straightforward to use
  • produces images that have very high spatial resolution, providing a clear picture of how brain activity is localised
• Limitations of fMRI:

  • expensive compared to other techniques
  • can only capture a clear image if the person stays perfectly still
  • has poor temporal resolution due to a 5-second-time lag behind the image on screen and the initial firing of neural activity
  • can only measure blood flow, not the activity of individual neurons
• Electroencephalogram (EEG) records general brain wave activity by recording tiny electrical impulses produced by the brain
• EEG's are used to diagnose epilepsy, tumours and sleep disorders
• Strengths of EEG:

  •  important for diagnosis of conditions because random activity bursts are easy to identify
  • Contributed to our understanding of sleep
  • high temporal resolution
• Limitations of EEG:

  • signal not useful for pinpointing exact source of neural activity
  • Doesn’t allow researchers to distinguish between activity originating in different but adjacent locations
• Event-Related Potentials (ERPs) measure the brain's response to specific sensory, cognitive or motor stimuli. These measure brain waves triggered by specific events
• Strengths of ERPs:

  • high temporal resolution
  • Bring more specificity to measurement of neural processes
  • Led to widespread use of ERPs in the measurement of cognitive functions and deficits
• Limitations of ERPs:

  • lack of standardisation in ERP methodology between different research studies makes it difficult to confirm findings
  • all background noise and extraneous material needs to be eliminated
• Post-Mortem examination is analysis of the brain after death
• post-mortems are usually carried out on individuals who have a rare disorder or have experienced unusual deficits in mental processing or behaviours during their lifetime
• Strengths of post-mortems:

  • Broca and Wernicke’s research relied on post mortems
  • Vital to foundation research
  • Improve medical knowledge and generate hypotheses
• Limitations of post-mortems:

  • issues with causation. Observed damage may not be linked to deficits but other unrelated damage
  • Raises ethical issues - informed consent e.g HM case (lost his ability to form memories so was not able to give consent yet a post mortem happened anyway)