Ways of Studying the Brain

• Ways of Studying the Brain: Scanning Techniques:

  > functional magnetic resonance imaging (fMRI)

  > electroencephalograph (EEG)

  > event-related potentials (ERPs)

  > post-mortems
• fMRI:

  > identifies changes in levels of oxygen in blood that occurs due to brain activity in specific areas

  > brain area is more active = more oxygen used = increase of blood flow to the area

  > produces a 3D image showing active brain area - activation map

  > used to identify active brain areas in particular mental processes (localisation)
• fMRI AO3:

  :) Safer - non-invasive and doesn't use radiation, unlike PET scans

  :)/:( High spatial resolution, but poor temporal resolution - 5 second time lag
• EEG:

  > electrodes placed on scalp using a skull cap - they detect small electrical changes from the activity of brain cells

  > the electrical changes are graphed over a period of time to see general brain activity

  > used to detect sleep patterns and states, such as sleep or arousal

  > used as a diagnostic tool for conditions such as brain tumours and epilepsy
• EEG AO3:

  :) High temporal resolution

  :( Low spatial resolution
• ERPs:

  > electrodes placed on scalp - unlike an EEG, an ERP shows specific brain activity

  > stimulus is presented to an individual many times and brain activity is measured in same way as an EEG - all extraneous activity is then filtered out, leaving only the responses that link to the presentation of the stimulus

  > ERPs remain - types of brainwaves triggered by particular events
• ERPs AO3:

  :) High temporal resolution

  :( Affected by external factors
• Post-mortems:

  > brain of a dead patient is examined and dissected to see if there are any physical abnormalities

  > the brain is compared with a brain that does not show this behaviour or mental process

  > mainly used on people with rare disorders or defects

  > example: Broca's area discovered through post-mortem
• Post-mortem AO3:

  :) Invasive = more detailed

  :( Hard to establish cause and effect due to confounding variables