WAYS OF INVESTIGATING THE BRAIN

• FMRI


  When the brain is more active it uses more oxygen and to compensate for this more blood is directed to the active area. FMRI detects these changes in blood oxygen and produces 3D images to show which parts of the brain is involved in particular processes. 
• Strengths of FMRI

  ✅Non-invasive – does not involve the insertion of instruments into the body nor does it expose the brain to potentially harmful radiation 

  ✅More objective and reliable measure of psychological processes 

  ✅Able to investigate cognitive mental processes that cannot be described through verbal reports. 

  ✅High spatial resolution – able to see smaller details 
• Limitations of FMRI

  ❌Expensive 

  ❌Person must be perfectly still to be able to work 

  ❌Only measures blood flow in the brain not a direct measure of neural activity in the brain – not a quantitative measure of mental activity in these areas of the brain. 

  ❌Criticised for overlooking the networked nature of brain activity – only focuses on localised activity 
• EEGs


  EEGs are used as diagnostic tools by measuring electrical activity through electrodes on the scalp. The idea of them is that information is passed in the brain as electrical activity in the form of electrical impulses (action potentials) 
• Strengths of EEGs

  ✅ High temporal resolution – provides a recording of brain activity in real time 

  ✅ Useful in clinical diagnosis e.g. recording abnormal neural activity associated with epilepsy 
• Limitations of EEGs

  ❌EEGs can only detect activity in superficial regions of the brain so cannot reveal what is going on in the deeper regions 

  ❌Electrical activity can be picked up by several neighbouring electrodes therefore the EEG is not useful in pinpointing the exact source of the activity 
• ERPs


  As opposed to EEGs, with ERPs electrodes are attached to the scalp and a stimulus is presented many times, and an average is graphed to reduce any extraneous neural activity. 
• Strengths of ERPs

  ✅ They bring more specificity to the measurement of neural processes compared to raw EEG data 

  ✅ High temporal resolution – activity is measured in real time 
• Limitations of ERPs

  ❌ Uncomfortable for participants as the electrodes are attached to their head – may affect cognitive responses 

  ❌ Hard to establish pure data – difficult to eliminate background noise and extraneous matter 
• Postmortem examination


  Researchers examine and analyse the brain after a person has died to look for abnormalities that may explain a certain behaviour. 
• Strengths of postmortems

  ✅ Postmortem studies improved medical understanding and helped generate future hypotheses 

  ✅ Enables researchers to examine deeper regions 

  ✅ Broca and Wernicke both relied on this method to establish links between language and brain behaviour 
• Limitations of postmortems

  ❌ People died in various circumstances at varying stages of disease and these factors can affect postmortems 

  ❌ Approach is limited – the person is dead so not able to follow up and cannot get informed consent