[Interhemispheric asymmetry of the auditory evoked potentials and mismatch negativities during sound source...

The long-latency auditory evoked potentials and mismatch negativities were studied in humans using dichotic stimulation. Deviant stimuli either changed their azimuth abruptly from zero to +/- 22.5 degrees or moved gradually to the left/right from the head midline at different velocities ranging from 11.25 degrees per second to 112.5 degrees per second. It was demonstrated that the amplitude of N1-P2 wave of the evoked potential was higher when recorded from the right frontal sites than from the left sites. The mismatch negativity depended significantly on the spatial location of the deviant stimulus: the right deviants elicited greater and earlier mismatch negativities than the left deviants. The involvement of the right hemisphere in the auditory spatial discrimination is discussed.