Human event-related potentials and distraction during selective listening

Event-related brain potentials were recorded from healthy human subjects wh ile they attended to one of two auditory stimulus channels (defined by loca tion, left and right of a fixation point, and pitch) in order to detect rar e target events. The distracting properties of periodic noise (vs, continuo us noise, experiment 1) and backward speech (vs. forward speech, experiment 2) presented from a third speaker located behind the subjects were investi gated. A typical attention effect with a larger negativity for attended ton es was observed in both experiments. Backward speech led to a significantly reduced target detection rate for the first four stimuli after onset of th e distracter accompanied by a reduced event-related brain potential (ERP)-a ttention effect and a reduced fronto-central N2b component for the target s timuli. This indicates that irrelevant information leads to an attention de crement of about 1 s duration. (C) 2001 Elsevier Science Ireland Ltd. All r ights reserved.