Attentional Capture by Deviant Sounds: A Noncontingent Form of Auditory Distraction?
The occurrence of an unexpected, infrequent sound in an otherwise homogeneous auditory background tends to disrupt the ongoing cognitive task. This “deviation effect” is typically explained in terms of attentional capture whereby the deviant sound draws attention away from the focal activity, regardless of the nature of this activity. Yet, there is theoretical and empirical evidence suggesting that the attention-capture mechanism underlying this form of distraction could rather be triggered in a task-contingent fashion. The present study aimed at determining whether the auditory deviation effect reflects the action of either a stimulus-driven or a task-contingent orienting mechanism. To do so, we conducted a systematic investigation whereby the impact of verbal deviants—a letter embedded in the repetition of another letter—and spatial deviants—a sound presented contralaterally to the other sounds—on verbal and spatial short-term memory (STM) was assessed. This study established that both verbal and spatial deviants can hinder both verbal and spatial order-reconstruction (Experiment 1) and missing-item tasks (Experiment 2). Such results demonstrate that the deviation effect reflects a general form of auditory distraction as interference took place both within and across domains and regardless of the processes engaged in the focal task.