Mismatch negativity as a characteristic of the distinguishing locating capacity of the human auditory system

Abstract

Mismatch negativity has been studied under the conditions of dichotic stimulation by deviant stimuli that either changed their azimuth from zero to 4.5°, 13.5°, and 22.5° or moved with small velocities from the head midline to one of the ears. The reference stimuli were located along the head midline. Our experiments have shown that both a discontinuous increase in the azimuth and an increase in the velocity of moving stimuli are accompanied by an increase in the amplitude of mismatch negativity. This process is more pronounced in the cases of (1) an instantaneous change in the deviant azimuth compared to its movement, (2) a longer duration of the deviant sound, (3) action of the deviant in the right hemisphere, and (4) the frontal derivation. The correlations of changes in the mismatch negativity with psychophysical data on the resolution of the human auditory system are considered.