Multiple generators in the auditory automatic discrimination process in humans

To reveal the spatiotemporal characteristics of the auditory automatic disc rimination process, mismatch negativity (MMN) generators were assessed with a high-resolution EEG system (128ch) and scalp current density (SCD) analy sis. Ten normal volunteers participated in the study. Event-related potenti als were recorded during a selective attention task. Sequential SCD mapping s revealed that a current sink/source combination in the left temporal regi ons and a current sink in the right frontotemporal regions appeared around 200 msec irrespective of the ear of stimulation. Moreover, a parietal sink/ source combination was demonstrated on the right hemisphere around 240 ms i rrespective of the ear of stimulation. These findings demonstrate that the auditory automatic change detection process is, both spatially and temporal ly, a multiple-generated system. NeuroReport 10:2267-2271 (C) 1999 Lippinco tt Williams & Wilkins.