EVENT-RELATED MAGNETIC-FIELDS IN THE AUDITORY-CORTEX OF MAN DURING UNILATERAL MOVEMENTS - A DISCRIMINANT FUNCTION-ANALYSIS

It is often assumed that sensorimotor coordination is a feature of the sensorimotor areas of the neocortex only. The purpose of the present study was to examine how this phenomenon is reflected in the auditory cortex of man. Ten subjects were engaged in a stimulus-reaction paradi gm, in which each of two acoustical tones was associated to either of two motor reactions. Magnetic fields recorded with a 122-channel magne tometer were modelled by current dipoles. The spatial coordinates as w ell as the amplitudes of the dipoles were analyzed from 90 to 110 ms a fter stimulus onset using discriminant analysis. The results suggest t hat the dipole trajectory in the auditory cortex of the right hemisphe re and amplitudes of the dipoles in the auditory cortex of the left he misphere already 90-110 ms after the beginning of the stimulus could b e affected not only by physical features of the stimulus, but also by the motor task required as a reaction. (C) 1998 Elsevier Science irela nd Ltd. All rights reserved.