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 among frequent tones in one ear while trains of deviant and frequent tones of 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 effects of competition were not simply a moderation of the effects of selective attention (i.e. the processing negativity). The two difference waves exhibited amplitude peaks that were not mirror-images with respect to polarity. This suggests the existence of a unique underlying neural process that is responsible for the effects of competition on the LAEP.