BEHAVIORAL AND ELECTROPHYSIOLOGICAL EFFECTS OF TASK-IRRELEVANT SOUND CHANGE - A NEW DISTRACTION PARADIGM

A distraction paradigm was utilized that is suited to yield reliable a uditory distraction on an individual level even with rather small freq uency deviances (7%). Distraction to these tiny deviants was achieved by embedding task-relevant aspects and task-irrelevant, distracting as pects of stimulation into the same perceptual object. Event-related po tential (ERP) and behavioral effects of this newly developed paradigm were determined. Subjects received tones that could be of short or lon g duration equiprobably. They were instructed to press a response butt on to long-duration tones (targets). In oddball blocks, tones could be of standard frequency or of low-probability (p = 0.1), deviant freque ncy. The task-irrelevant frequency deviants elicited MMN, N2b, and P3a components, and caused impoverished behavioral performance to targets . The usage of tiny distracters permits an interpretation of auditory distraction in terms of attention switching due to a particular memory -related change-detection process. On the basis of the results from an additional condition in which tones were of 10 different frequencies (involving those frequencies which served as standard and deviant in o ddball blocks), it is argued that one important prerequisite for linki ng the neural mechanisms reflected in change-related brain waves to be havioral distraction effects may be regarded as fulfilled. The robustn ess of the distraction effects to tiny deviations was confirmed in two control experiments. (C) 1998 Elsevier Science B.V. All rights reserv ed.