Causes of differences in the input-output characteristics of simultaneously recorded auditory evoked magnetic fields and potentials.
The input-output characteristics of amplitude and latency of simultaneously recorded auditory-evoked magnetic fields (AEMF) and auditory-evoked potentials (AEP) are significantly different, although they are closely related to the same excitation process of the auditory system. As the source of both AEMF and AEP an equivalent-current dipole lying in the auditory cortex can be assumed. Differences in the input-output characteristics of AEMF and AEP can be explained by changes of one or more parameters of this dipole (depth, location in the tangential x-y plane and direction). Maps of the field distribution obtained at 60 and 80 dB HL indeed reveal a change of the location of the dipole in the x-y plane and the direction of the dipole momentum, whereas the depth of the dipole was found to be more or less constant.
D000161:Acoustic Stimulation; D000328:Adult; D001303:Auditory Cortex / Q000502:physiology*; D005072:Evoked Potentials, Auditory; D006309:Hearing / Q000502:physiology*; D006801:Humans; D008280:Magnetics; D011930:Reaction Time