ways of studying the brain

• spatial resolution

  level of accuracy in identifying WHERE activity happens in the brain
• temporal resolution

  level of accuracy in identifying WHEN activity occured in the brain
• post mortem dissection

  -Brains that suffered trauma or illness are cut after death and are compared with other healthy brains

  -Brocas area was discovered in a post mortem dissection as damage in the frontal lobe was found in Tan
• AO3 of post mortem dissection

  -High spatial resolution as brains can be studies microscopically down to the neuronal level

  -It is not conducted on a living brain so isnt too reliable

  -Have been significant in historical development in understanding of the brain, eg language
• FMRI

  detects blood flow in the brain and as more active areas use more blood, they can be identified and compared to lower active areas in the brain
• AO3 of FMRI

  -good spatial resolution of almost 1mm

  -Safe technique compared to PET scans which use radiation

  -Poor temporal resolution as images are taken every few seconds and brain processes happen in milliseconds

  -expensive
• EEG


  collection of electrodes that are attached to a cap and onto the patient, from each electrode activated of the brain areas can be identified with brain waves
• AO3 of EEG

  -Historically important in brain research such as sleep activity

  -Cheaper than FMRI

  -Good temporal accuracy as brain activity is measured in milliseconds

  -Poor spatial activity as cannot detect where activity takes place
• ERP (event-related potential)

  Uses the same technique and equipment as EEG, however uses a stimulus many times to see how the brains reacts to certain stimuli
• AO3 of ERP

  -Allows researchers to isolate and study certain parts of the brain

  -Good temporal resolution and poor spatial resolution (same as EEG)

  -Not all processes can be measured with EEG
• General AO3

  as none of the forms of studying the brain have both good spatial and good temporal resolution, techniques such as FMRI and EEG can be combined by performing tasks with both
• fMRI

  strength - does not rely on radiation so is risk - free, non-invasive and straightforward to use

  also produces high spatial resolution and safely provides a clear picture of brain activity

  limitation - expensive

  has poor temporal resolution as there is a 5 minute lag

  so may not represent moment-to-moment brain activity
• EEG

  strength - useful in studying stages of sleep and diagnosis of disorders such as epilepsy

  has high temporal resolution

  can detect brain activity at a resolution of a milisecond - real-world usefulness

  limitation - generalised information

  not useful for pinpointing exact source of neural activity

  dosent allow researchers to distinguish between activities origiating in different but adjacent locations
• ERP's

  strength - specific measurement of neural processes

  good temporal resolution

  used to measure cognitive function and deficits such as maintenence of working memory

  limitation - lack of standardisation in different research studies make it difficult to confirm findings

  background noise and extraneous material must be completely eliminated - not always possible
• post-mortem examinations

  strength - broca and wernicke relied on post-mortem studies in establishing links between language, brain and behaviour

  post-mortem studies used to study HM's brain to identify areas of damage -asscoiated with his memory deficits

  limitation - damage may not be linked to deficits under review but to some other unrelated trauma and decay

  ethical issues - ppts not able to provide inormed consent e.g. HM lost memory so unable to provide consent

  challenges usefulness of post-mortem studies