Ways of studying the brain

• fMRI - functional magnetic resonance imaging


  Detect changes in blood oxygenation and flow that occur due to neural activity in specific brain areas. 

  Produces a 3D image showing which parts of the brain are active and therefore must be involved in particular mental processes.
• Strength and limitation of fMRIs

  • It is non-invasive. Unlike other scanning techniques they don’t rely on the use of radiation and are safe. It also produces images with high spatial resolution, showing detail by the mm. Can provide a clear picture of how brain activity is localized.
  • fMRI is expensive and can only capture a clear image if the person stays still. Another limitation is it has poor temporal resolution because of 5-second lag between initial neural activity and image. This means fMRI may not truly represent moment-to-moment brain activity. 
• EEG - electroencephalogram


  Measure electrical activity within the brain via electrodes using a skull cap. The scan recording represents the brainwave patterns generated from millions of neurons, showing overall brain activity. 
• Strength and limitation of EEGs


  • Invaluable in diagnosing conditions like epilepsy. Also contributed to our understanding of sleep, has high temporal resolution and can detect brain activity at a resolution of a single millisecond. 
  • Produces a generalized signal from thousands of neurons. Another limitation is it’s difficult to know the exact source of neural activity. EEG can’t distinguish the activity of different but adjacent neurons. 
• ERPs - Event-related potentials 


  They are what is left when all extraneous brain activity from an EEG is filtered out. This is done using a statistical technique, leaving only those responses that relate to the presentation of a specific stimulus or performance of a certain task. 
• Strength and limitation of ERPs


  • More specific that what can be achieved using raw EEG data. Another strength is they also have excellent temporal resolution.
  • Lack of standardization in methodology between studies. This makes it difficult to confirm findings in studies involving ERPs. Another limitation is that background noise and extraneous materials must be completely eliminated. This may not always be easy to achieve. 
• Post-mortem examinations - involves the analysis of a person’s brain following their death. 


  • Areas of the brain are examined to establish the likely cause of a deficit or disorder that the person suffered in life. This may also involve comparison with a neurotypical brain in order to assess the extent of the difference.
• Strength and limitation of post-mortem examinations.

  • Broca and Wernicke both relied on post-mortem studies. Another strength is post-mortem studies improve medical knowledge. They help generate hypotheses for further study. 
  • Causation may be an issue. Observed damage in the brain may not be linked to the deficits under review but to some other related trauma or decay. Another limitation is post-mortem studies raise ethical issues of consent from the patient before death. Patients may not be able to provide informed consent.