Ways of Studying the Brain

• fMRI

  
  

  • Detects blood oxygenation and flow changes 
  • Procedure: active brain area consumes more oxygen by blood flowing to that area (haemodynamic response)
  • Results: active maps show which areas involved in mental processes
• strengths of fMRI

  
  

  • Important implication for localisation
  • Not rely on radiation – virtually risk free and non-invasive = patients are more willing to participate and limits long term impairments
  • High spatial resolution – detailed images by the millimetre = clear data on localised brain areas
• weakness of fMRI

  
  

  • low temporal resolution & expensive therefore restricts expansion of sample sizes - reduces validity, low generalisability
• EEG

  electroencephalogram
• fMRI

  functional magnetic resonance imaging
• ERP

  event related potentials
• EEGs

  
  

  • Measures electrical activity via electrodes on scalp
  • Procedure: electrodes to scalp to detect neuronal activity in response to researcher’s stimulus; scan recordings show brainwave patterns 
• strengths of EEGs

  
  

  • Practical application – used by clinicians as a diagnostic tool = can indicate neurological abnormalities such as epilepsy, tumours, sleep disorders
  • High temporal resolution than fMRI – accurately detects brain activity at a resolution of a single millisecond = real world usefulness [efficient]
• ERPs

  
  

  • Isolates EEG data by studying responses to sensory, cognitive or motor events
  • Procedure:  filters out extraneous brain activity from the original EEG recording
• strengths of ERPs

  
  

  • Cheaper than fMRI – enables larger sample sizes = can increase validity of data obtained [high generalisability]
  • Isolates EEG data – excellent temporal resolution = more specificity to measurement of neural processes 
• weaknesses of ERPs

  
  

  • Lack of standardisation – difficult to confirm findings = low internal validity therefore cannot be relied upon to study brain
  • Background noise and extraneous material – must be controlled and eliminated = not easy to achieve therefore 
• post-mortem

  
  

  • Analyse brain after death
  • Establishes likely cause of affliction
  • Compares it with a neurotypical to ascertain the extent of difference
• strength of post-mortem

  
  

  Provides useful information – HM identify areas associated with memory deficits = allow people of similar conditions to diagnose and get treatment and resources earlier to help them
• weaknesses of post-mortem

  
  

  • Not a neuroimaging technique – cannot investigate brain’s activeness in specific tasks = assumptions are more likely to be made
  • Post death changes – neural structure could be due to processes after death = incorrect causation and effect connections being made
  • Ethics – informed consent must be given prior to death from the P whose brain it belongs to = undermines integrity of psychological research which may prevent others from wanting to be involved in such research therefore limiting sample sizes
• temporal resolution

  how quickly scanner detects changes in brain activity
• spatial resolution

  how clearly scanner can detect features in brain