Ways of studying the brain

• Functional Magnetic Resonance Imaging (fMRI)

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

  > When a brain area is more active it leads to more oxygen being used so there is an increase of blood flow to this active area

  > fMRI produces a 3D image showing which part of the brain is active, called an activation map

  > It has been used to identify which specific parts of the brain are active in particular mental processes (showing localisation)
• fMRI AO3

  :) safer as non-invasive unlike PET scans

  :( poor temporal resolution - 5 second lag
• Electroencephalograph (EEG)

  > Electrodes being placed on the scalp using a skull cap

  > They detect small electrical changes resulting from the activity of brain cells

  > The electrical signals are graphed over a period of time to see a person’s general brain activity

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

  > It is used as a diagnostic tool to help diagnose conditions such as brain tumours and epilepsy
• EEG AO3

  :) high temporal resolution

  :( low spatial resolution
• Event related potentials (ERPs)

  > ERP shows specific brain activity

  > A stimulus is presented to an individual many times and their brain activity is measured in the same way as an EEG

  > All extraneous brain activity is filtered out
• ERP AO3

  :) high temporal resolution

  :( hard to obtain meaningful data - affected by external factors
• Post mortem

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

  > can be compared with a brain that doesnt show this particular behaviour or mental process

  > mainly used on people who have a rare disorder or defects

  > Brocas area showed speech production
• Post mortem AO3

  :) only way to study brain invasively

  :( hard to establish cause and effect as there are confounding variables