Question

5. List up to five advantages of MEG over the following modalities:

a. fMRI (measures changes in blood oxygenation levels related to neural activity)

b. EEG.

Answer 1

Magnetoencephalography (MEG) is a non-invasive neurophysiological technique that measures the magnetic fields generated by neuronal activity of the brain.

a. MEG is a direct measure of brain function, unlike the functional measures such as fMRI which is a secondary measure of brain function reflecting brain metabolism. It has a very high temporal resolution. Events with time scales on the order of milliseconds can be resolved, again differentiating MEG from fMRI which have much longer time scales. It has excellent spatial resolution; sources can be localized with millimeter precision. It is non-invasive. MEG is easy to use when compared to fMRI.

b. MEG clusters of the somatosensory μ rhythm have a very strict localization, while the corresponding EEG clusters are more widespread on the cortical surface. MEG has extremely high temporal and spatial resolution comparing to EEG, have either poor temporal or spatial resolution. Another advantage of MEG is noninvasive and EEG has the distinct disadvantage of being invasive. MEG is more accurate than EEG.