Ways of studying brain

• Functional magnetic resonance imaging (fMRI)

  • used to measure brain activity while person is doing a task
  • detects radio waves from changing magnetic fields
  • enables researchers to detect active areas of brain as they are rich in oxygen
• Strengths - fMRI

  1. doesn't rely on radiation - virtually risk free, straightforward, produces images with high spatial resolution, provides clear images on how brain is localised meaning fMRI produces clear images on brain activity
• Electroencephalogram (EEG)

  • measures electrical activity in brain via electrodes on patients scalp
  • represents brainwave patterns generated from action of neurones
  • used to help diagnose conditions like epilepsy, tumours, sleep conditions
• Strengths - EEG

  1. useful in sleep study - has high temporal resolution, allows it to detect random bursts of activity in brain. shows real world application of technique
• Limitations - fMRI

  1. expensive - expensive compared to other neuroimaging techniques
  2. has poor temporal resolution due to 5 second time lag between image on screen and initial neural activity, meaning fMRI may not fully represent moment to moment brain activity
• Limitations - EEG

  1. information received to generalised - EEG signal not able to pinpoint exact source of neural activity, therefore doesn't researchers to distinguish where exactly activity originates from
• Event - related potentials (ERP's)

  • types of brain waves tiggered by specific events
  • using statistical averaging techniques, all extraneous brain activity from original EEG are filtered out leaving ERP's
• Strengths - ERP'S

  1. have high temporal resolution - derived from EEG, has the same high temporal resolution compared to other techniques, means ERP frequently used to measure cognitive functions and deficits
• Limitation - ERP's

  1. lack of standardisation - differences in methodology makes it harder to confirm findings. all background noise/extraneous material must be filtered out for pure results, however this isn't always possible
• Post-mortem examinations

  • analysis of brain after person's death
  • mostly performed on people displaying unusual deficits in cognitive processing/behaviour to determine areas of damage within brain
  • often compared damaged brain with neurotypical brain to work out damage to brain
• Strengths - post mortems

  1. provided foundations for early understanding of brain - Broca and Wernicke both used post mortems to determine damage in brains linking it to the displayed behaviours in their patients. also used in HM's case to identify areas of damage. means post mortems continue to provide useful information
• Limitations - post mortems

  1. difficult to determine causation - observed damage may not be linked to deficits under review
  2. lack of informed consent - patient may not have been able to give informed consent. HM lost ability to form memories, therefore unable to give informed consent yet still had his brain studied. challenges the usefulness of post mortems in psychological research