Electrophysiologic signs of auditory competition in the human brain

The present project investigated the electrophysiologic effects of auditory competition on components of the late auditory evoked potential (LAEP), A group of 12 young female listeners attended to deviant tones interspersed a mong frequent tones in one ear while trains of deviant and frequent tones o f a different frequency were either present or absent at the opposite ear. Comparison of event-related potential (ERP) waveforms with competition- and attention-related difference waves revealed evidence that the neural effec ts of competition were not simply a moderation of the effects of selective attention (i.e. the processing negativity). The two difference waves exhibi ted amplitude peaks that were not mirror-images with respect to polarity. T his suggests the existence of a unique underlying neural process that is re sponsible for the effects of competition on the LAEP. (C) 2000 Elsevier Sci ence Ireland Ltd. All rights reserved.