Search

Past studies show that novel auditory stimuli, presented in the context of an otherwise repeated sound, capture participants' attention away from a focal task, resulting in measurable behavioral distraction. Novel sounds are traditionally defined as rare and unexpected but past studies have not sought to disentangle these concepts directly. Using a cross-modal oddball task, we contrasted these aspects orthogonally by manipulating the base rate and conditional probabilities of sound events. We report for the first time that behavioral distraction does not result from a sound's novelty "per se" but from the violation of the cognitive system's expectation based on the learning of conditional probabilities and, to some extent, the occurrence of a perceptual change from one sound to another.

Unexpected events often distract us. In the laboratory, novel auditory stimuli have been shown to capture attention away from a focal visual task and yield specific electrophysiological responses as well as a behavioral cost to performance. Distraction is thought to follow ineluctably from the sound's low probability of occurrence or, put more simply, its unexpected occurrence. Our study challenges this view with respect to behavioral distraction and argues that past research failed to identify the informational value of sound as a mediator of novelty distraction. We report an experiment showing that (1) behavioral novelty distraction is only observed when the sound announces the occurrence and timing of an upcoming visual target (as is the case in all past research); (2) that no such distraction is observed for deviant sounds conveying no such information; and that (3) deviant sounds can actually facilitate performance when these, but not the standards, convey information. We conclude that behavioral novelty distraction, as observed in oddball tasks, is observed in the presence of novel sounds but only when the cognitive system can take advantage of the auditory distracters to optimize performance. (Contains 2 tables and 2 figures.)

Unexpected auditory stimuli are potent distractors, able to break through selective attention and disrupt performance in an unrelated visual task. This study examined the processing fate of novel sounds by examining the extent to which their semantic content is analyzed and whether the outcome of this processing can impact on subsequent behavior. This issue was investigated across five laboratory experiments in which participants categorized visual left and right arrows while instructed to ignore irrelevant sounds. The results showed that auditory novels that were incongruent with the visual target (e.g., word "left" presented before a right arrow) disrupted performance over and above congruent novels (semantic effect) while both types of novels delayed responses in the visual task compared to a standard sound (novelty effect). No semantic effect was observed for congruent and incongruent standards, suggesting that novelty detection is necessary for involuntary semantic processing to unravel. While the novelty effect augmented as the difference between novels and the standard increased, the semantic effect was immune to this variation. Furthermore, the novelty effect decreased across the task while the semantic effect did not. A general cognitive framework is proposed encompassing these new findings and previous work in an attempt to account for the behavioral impact of irrelevant auditory novels on primary task performance. (Contains 1 table and 5 figures.)

Unexpected stimuli are often able to distract us away from a task at hand. The present study seeks to explore some of the mechanisms underpinning this phenomenon. Studies of involuntary attention capture using the oddball task have repeatedly shown that infrequent auditory changes in a series of otherwise repeating sounds trigger an automatic response to the novel or deviant stimulus. This attention capture has been shown to disrupt participants' behavioral performance in a primary task, even when distractors and targets are asynchronous and presented in distinct sensory modalities. This distraction effect is generally considered as a by-product of the capture of attention by the novel or deviant stimulus, but the exact cognitive locus of this effect and the interplay between attention capture and target processing has remained relatively ignored. The present study reports three behavioral experiments using a cross-modal oddball task to examine whether the distraction triggered by auditory novelty affects the processing of the target stimuli. Our results showed that variations in the demands placed on the visual analysis (Experiment 1) or categorical processing of the target (Experiment 2) did not impact on distraction. Instead, the cancellation of distraction by the presentation of an irrelevant visual stimulus presented immediately before the visual target (Experiment 3) suggested that distraction originated in the shifts of attention occurring between attention capture and the onset of the target processing. Possible accounts of these shifts are discussed.