Magnetoencephalography in the Study of Human Brain Functions
In magnetoencephalography (MEG), magnetic fields are measured with superconducting sensors outside the human head. The signals result mainly from intracellular currents that flow in synchronously active neurons of the fissurai cortex. Source and volume conductor models—like a current dipole within a sphere—are commonly used to determine locations of these currents. With multichannel SQUID magnetometers, field patterns can be constructed and source locations determined even with a “single shot” measurement without repositioning the instrument, opening new possibilities in clinical applications as well as studies of the neural basis of cognitive functions. Examples are given here of MEG recordings from auditory and somatosensory cortices.
KeywordsMedian Nerve Auditory Cortex Somatosensory Cortex Noise Burst Current Dipole
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