A study of the auditory evoked magnetic field of the human brain.

Small but reproducible and consistent auditory evoked magnetic fields have been obtained for 6 male subjects. These fields exhibit features with a clear spatial symmetry which can be accounted for by assuming that their source consists of two vertically oriented neuronal complexes symmetrically located deep in the temporal lobes. This assignment, which is also consistent with the available electrical data, places the sources within the auditory cortex near the sylvian fissure. Our results suggest that auditory evoked magnetic fields may provide assistance in unravelling the source structure that produces the auditory evoked response, both electrical and magnetic.