Electrophysiological evidence for sequential activation of multiple brain regions during the auditory selective attention process in humans

IN an attempt to examine dynamic involvement of multiple brain regions in t he auditory selective attention process, negative difference wave (Nd) gene rators were assessed using a high-resolution EEG system (128 ch) and scalp current density (SCD) analysis. Ten normal volunteers participated in the s tudy. Event-related potentials were recorded during a selective attention t ask. Sequential SCD mappings revealed that current sinks were located in th e bilateral temporal regions at 160 ms subsequent to the onset of stimuli, shifting the dipole orientation more tangentially to the scab at around 220 ms. Moreover, a current sink was demonstrated in the midfrontal region at around 320 ms. These findings confirm that different cortical regions are s equentially involved in the auditory selective attention process. (C) 1999 Lippincott Williams & Wilkins.