Distraction effects in vision:: behavioral and event-related potential indices

Evidence is presented which shows that slight changes in serially presented visual input can be detected automatically and may result in behavioral distraction. In two experiments, reaction times on a two-alternative, forced-choice duration discrimination task were prolonged in trials where a task-irrelevant change in the location of the stimulus occurred. The PI and NI components of the event-related potential were enhanced in such trials. However, electrophysiological and behavioral effects were not affected when the duration discrimination was made more difficult and the NI amplitude increase and RT prolongation were confined to situations where task-irrelevant location changes were infrequent. Thus, these effects most probably reflect pre-attentive change detection and subsequent distraction in vision, whereas the PI effect is probably due to spatial eccentricity.