Studying the Brain

• Cognitive neuroscience - concerned with the study of the biological processes that underlie cognition with a specific focus around neural connections
• 4 methods of brain study:

  • fMRI
  • EEG
  • ERP
  • post-mortem
• Post-mortem examinations

  an examination of the brain once the patient has died.

  • used to understand neurological explanations for behaviour by looking for abnormalities compared to a control
  • Broca's patient (Tan) was found to have a lesion on an area now known as Broca's area
• PM Advantages:

  • detailed examination of the brain which isn't possible with other methods
  • deeper investigation into the inside structures of the brain (e.g. hypothalamus, hippocampus)
  • played a central role in understanding the origins of schizophrenia - structural abnormalities/changes in neurotransmitter systems (Harrison et al)
• PM Disadvantages:

  • the reason for a patient's death/stage of disease etc. may impact the brain
  • how long a person has been dead for also affects the brain and therefore PM results
  • retrospective approach to research which is problematic due to not being able to follow anything up/provide treatment
• fMRI

  • measuring brain activity while a person performs a task
  • looks at blood flow to identify increased neurological activity due to increased demand for oxygen
• fMRI Advantages:

  • non invasive
  • doesn't involve any harmful radiation
  • objective and reliable rather than verbal reports
• fMRI Disadvantages:

  • not a direct measurement but just for particular areas so not quite general and therefore not truly quantitative
  • it overlooks networked nature of the brain by only looking at specific areas and that it is the communication between areas that provides vital information
• EEG

  • electrodes placed on the scalp to detect small electrical charges resulting from activity of brain cells
  • can be used to detect brain disorders e.g. epilepsy or even slowing of the brain
• EEG Advantages:

  • provides a recording of brain activity in real time
  • allows for casual explanations to be made
  • a quick way of diagnosing abnormal brain activity e.g. epileptic seizures
• EEG Disadvantages:

  • only measures superficial/exterior areas of the brain and is not able to measure deeper structural activities
  • electrodes can be implanted on animals, but this is not ethically viable of humans
  • if an electrode is nearby, it may get confused about where the precise location of activity is - might identify neighbouring locations instead of actual source
• ERPs

  • presenting a person with a stimulus and measuring small voltage changes in the brain that are triggered
  • waves of sensory ERPs are sent and findings are gathered through repetition
• ERPs Advantages:

  • due to the continuous nature of the processing, it is possible to identify how manipulation of a stimulus impacts processing
  • the readings can be in a covert way, to avoid predictability/pre-planning
• ERPs Disadvantages:

  • large number of trials required to gather meaningful data
  • threshold of electrical activity picked up - ignoring internal neural activity and only detecting changes in cortex