Methods of studying the brain

• Post-mortem examinations


  Involves cutting away the skin and going inside the brain to look for evidence of brain abnormalities. This can then be linked back to any abnormal behaviours the patient displayed when they were alive.

  
  

  Strength)Can observe the brain in good detail and allows you to pinpoint abnormalities.

  Limitation)Difficult to establish cause & effect relationship because we don't know when the abnormality occurred and its hard to control confounding variables like medication which could have caused the changes in the brain
• fmRI


  Uses MRI to generate pictures but it also measures brain activity by measuring the changes in blood flow.

  
  

  Strength) Researchers can look at brain activity while people are behaving. However, it's difficult to establish cause and effect relationship because behaviour and brain activity may be associated but not directly caused by each other.

  Limitation) Blood flow is an indirect measure of neural activity. This assumes that blood flow is directly related to changes in neural activity however, blood flow is much slower than neural activity.
• MRI


  Generates images of the inside of a brain however not the brain activity.
• EEG + ERP

  Measures neural activity via electrodes attached to the scalp.

  -> Can be used to measure ERPS which are small electrical signals the brain produces in response to a stimulus. They are measured by presenting the same stimulus across hundreds of trials and collecting EEGs for each of them. They are then averaged.
• EEG + ERP A03


  Strength) Can directly measure neural activity generated by neurons in the cortex rather than using indirect measures.

  Limitation) Don't know which neurons are generating the activity and it only detects activity in the cortex.

  This activity is usually very small and hard to interpret.
• Spatial Resolution (level of detail at which our methods allow us to examine the brain)


  1. Post-mortem examinations.
  2. FMRI
  3. EEG+ERP
• temporal resolution (precision of measurements in respect to time)


  1. EEG+ERP
  2. FMRI
  3. Post Mortem