Specific or general? The nature of attention set changes triggered by distracting auditory events.

Distraction is a disruption of a selective attention set triggered by infrequent, unpredictable events. In the present study, two hypotheses on the nature of this attention change were contrasted in the auditory domain: (1) distraction is a specific attention-switch: attention is diverted from the task-relevant to the distracting information or (2) distraction is a general attention resetting, that is, a transition to a general attention set in which the organism is more capable of facing any event. The general attention resetting hypothesis predicts that any infrequent, unpredictable stimulus would trigger distraction, whereas the specific attention-switch hypothesis predicts that such a stimulus triggers distraction only if it deviates in a task-irrelevant stimulus aspect. To test this, a sequence of tone-pairs was presented. The participants' task was to respond according to the direction of within-pair pitch-change. Deviant trials were presented occasionally (10%). In the Relevant Deviance condition, the deviation concerned the task-relevant stimulus aspect (larger within-pair pitch-difference); in the Irrelevant Deviance condition the deviance occurred in a task-irrelevant stimulus aspect (spectral width of the second tone of the pair). In the Double Deviance condition, deviants featured both a larger pitch-difference and a spectral width difference. The elicitation pattern of the N2b/MMN, P3a and late negative components favors the specific attention-switch hypothesis, that is, distraction comprises an involuntary attention shift from the task-relevant information to the distracting one. The presence of deviance-related response time delay in the Relevant Deviance condition suggests that other effects unrelated to distraction also occurred.