ways of studying the brain

• Four ways brains are studied

  1. FMRI
  2. EEG
  3. ERP
  4. post mortem examinations
• FMRI

  Functional magnetic resonance imaging (FMRI) detects changes in both blood oxygenation and flow that occur due to neural activity in specific brain areas. When a brain is more active it consumes more oxygen and blood flow is directed to the active areas. FMRI produces a 3D image showing which parts of the brain are active and therefore must be involved in particular mental processes.
• FMRI Evaluation

  One strength is that they are risk free and have high spatial resolution. Unlike other scanning techniques, FMRI does not rely on the use of radiation and is safe. It also produces images with high spatial resolution, showing detail by the millimetre. This means FMRI can safely provide a clear picture of how the brain activity is localised.
• FMRI Evaluation

  One limitation is that it is expensive and poor temporal resolution. FMRI is expensive compared to other techniques. It has poor temporal resolution because of the 5 second lag between initial neural activity and image. This means FMRI may not truly represent moment-to-moment brain activity.
• EEG

  Electroencephalogram (EEG) measure electrical activity within the brain via electrodes using a skull cap. The scan recordings represents the brainwave patterns generated from thousands of neurons. This shows overall brain activity. EEG is often used as a diagnostic tool.
• EEG evaluation

  One strength of EEGs are their practical uses abd high temporal resolution. EEG has contributed to our understanding of the stages of sleep. It has high temporal resolution as it shows brain activity in one millisecond. This shows the real world usefulness of the technique.
• EEG Evaluation

  One limitation of EEGs are information is generalised and source is not pinpointed. The EEG produces a generalised signal from thousands of neurons. It is difficult to know the exact source of neural activity. Therefore, EEG can't distinguish the activity of different but adjacent neurons.
• ERP

  Event-related potentials (ERP) are what is left when all extraneous brain activity from an EEG recording is filtered out. This is done using a statistical technique, leaving only those responses that relate to the presentation of a specific stimulus. ERPs are types of brainwaves that are triggered by particular events. Research has revealed many different forms of ERP and how these are linked to cognitive processes.
• ERP Evaluation

  One strength of ERP are specificity and good temporal resolution. Measures of neural processes are more specific with ERPs than EEGs. ERPs have excellent temporal resolution which is better than FMRIs. This means that ERPs are frequently used in cognitive research.
• ERP Evaluation

  One limitation is that ERPs lack standardisation and have backround noise. Lack of standardisation makes it difficult to confirm findings in studies involving ERPs. Background noise and extraneous material must be completely eliminated. These issues are a problem as they may not always be easy to achieve.
• Post mortem examinations

  a technique involving the analysis of a persons brain following their death. Areas of the brain are examined to establish the likely cause of a defecit or disorder that the person experiences in life. This may alsi involve comparison with a neurotypical brain in order to assess the extent of the difference
• Post mortem examinations evaluation

  One strength is localisation and mediacl research. Broca and Wernicke both relied on post mortem studies. This was used to link HM's memory defecits to damage in his brain. This means they continue to provide useful information.
• Post mortem examinations evaluation

  One limitation is knowing causation and ethics. Observed damage in the brain may not be linked to the defecits under review. Post mortem studies raise ethical issues of consent after death. This challenges their usefulness in psychological research.