studying brain

• what are the 4 ways of studying the brain?

  1. fMRI
  2. EEG
  3. ERP
  4. post-mortems
• what is functional magnetic resonance imaging (fMRI)?

  measure brain activity while person is performing a task
• what is electroencephalogram (EEG)?

  record of electrical impulses produce by brain's activity
• what is event-related potentials (ERP)?

  brain's electrophysiological response to specific event that is isolated via statistical analysis of EEG data
• what is post-mortem examinations?

  brain analysed after death
• outline the function of a fMRI

  detects change in blood oxygen and flow

  • haemodynamic response - increased blood flow means brain is more active
  • produces 3d activation maps
  • important for understanding localisation of function
• outline the function of an EEG

  measures electrical activity via electrodes in a skull cap

  • represents brainwave patterns from neurons
  • used by clinicians as a diagnostic tool
  • indicates abnormalities e.g. sleep disorders, tumours or epilepsy
• outline the function of an ERP

  • data shows neural responses associated with specific sensory, cognitive and motor event
  • extraneous activity is filtered out
  • shows event-related potentials which are brainwaves triggered by events
• outline the function of a post-mortem

  • analysis of brain following death for those with rare disorder or unusual deficits
  • establish cause of affliction the person experienced
  • compare to neurotypical brain to ascertain extent of difference
• one strength of using a fMRI

  no reliance on radiation

  • risk free and non-invasive
  • straightforward to use
• second strength of using a fMRI


  high spatial resolution

  • detail is by the millimetre
  • clear image of localisation of activity
• one weakness of using a fMRI

  expensive

  • patient has to lay perfectly still for clear images
  • time consuming
• second weakness of using a fMRI

  poor temporal resolution

  • 5 second time lag between image and initial firing
• third weakness of using a fMRI

  simplistic

  • only measures blood flow
  • difficult to see what brain activity is being represented
• one strength of using an EEG

  practical application

  • valuable in diagnosis of conditions
  • e.g. epilepsy and sleep disorders
• second strength of using an EEG

  high temporal resolution

  • detects resolution of single millisecond
  • detailed insight into activity
• one weakness of using an EEG

  generalised information

  • can't distinguish between activities from different locations
  • can't pinpoint exact source of activity
• one strength of using an ERP

  high temporal resolution

  • widespread use in measurement cognitive functions and deficits
• second strength of using an ERP

  detailed responses

  • identify different types of activity and describe precise roles
  • P300 component of maintenance of working memory
• one weakness of using an ERP

  lacks validity

  • no standardisation with different research studies
  • difficult to confirm findings
• second weakness of using an ERP

  not controlled

  • can't establish pure data
  • extraneous material can't be completely eliminated
• one strength of using a post-mortem examination

  medical knowledge

  • foundation for early understanding of key brain processes
  • helps generate hypotheses
• second strength of using a post-mortem examination

  research development

  • broca & wernicke relied on these studies
  • established link with language, brain and behaviour
• one weakness of using a post-mortem examination

  correlational

  • can't establish causation
  • shows links to deficits
• second weakness of using a post-mortem examination

  ethical issues

  • informed consent with individuals before death
  • HM - lost ability to form memories so couldn't provide consent