Auditory Evoked Fields elicited by Natural Sounds and Origin of Slow Vertex Response

Abstract

Auditory evoked fields (AEFs) were recorded in responses to vowel sounds and the A note of a violin from normal adults by means of SQUID magnetometer and the following results were obtained;
(1) AEF over specific portions of the scalp has the morphology similar to that of auditory evoked potential.
(2) Morphologies of AEFs are much sensitive to the measuring positions and AEF has rich information about the spatial distribution of generators in the brain.
(3) Remarkable activities of equivalent current dipole generated by synchronous excitations of a set of neurons are found in or near the primary auditory cortex during the latency range of N₁-P₂ complex of slow vertex response.
(4) AEF detection is much useful for the estimation of the location of generators in the brain.