Summary Document summarises brain imaging techniques - including advantages and disadvantages of each

Brain Imaging Techniques
Electroencephalogram (EEG):
Records electrical activity along the scalp using
electrodes and an amplifier.
 Relatively cheap
 Non-invasive
 Excellent temporal resolution
 Easy to use
 Poor spatial resolution
Functional Magnetic Resonance Imaging (fMRI):
Measures brain activity by changes in blood flow (specifically
oxygen/haemoglobin – the differences between oxygenated
and deoxygenated blood has very small magnetic differences),
when a brain area is in use, blood in that area increases.
 Detailed spatial resolution (1-6mm)
 Non-invasive
 No risks of radiation
 Has the capacity to demonstrate entire networks of brain
areas
 Poor temporal resolution (delay of 2-5 seconds between
activation of neurons and the increase in oxygen rich blood)
 Some tiny clusters of neurons may be too small to be detected (less than 3mm)
 Patient has to stay very still
 Very noisy (uncomfortable for patient)
 Expensive
 Need a magnetically isolated room
 Is an indirect measure (BOLD (blood oxygen level dependent) signal) so is susceptible
to non-neuronal changes
 Some individuals may get very stressed out in the machine
Magnetoencephalography (MEG):
Identifies brain activity through micro magnetic changes in the brain,
multiple neurons together in one area of the brain generates a measurable
magnetic field.
 Non-invasive
 A direct measure of brain function
 High temporal resolution
 Silent
 No radiation
 Expensive