Cat-astrophic update: What makes an interrupter more disruptive?

Top-down selective attention can be disrupted by salient interruptions, leading to decreased accuracy in recalling the contents of whatever source a listener was trying to focus on. This decrease in recall accuracy is referred to as the interruption effect. Here, we explored how the magnitude of the interruption effect varies with (1) novelty of interrupter, (2) working memory load, and (3) timing and predictability of an interrupter while listeners performed an auditory spatial attention task. Three studies, each including two to four online experiments, addressed these questions. In each experiment, listeners attended to a target stream of spoken syllables from a cued location, ignoring a similar distractor stream from the opposite hemifield. At the end of the trial, listeners reported back the attended target syllable sequence. Unpredictable interrupting sounds occurred in half of the trials, slightly before one of the target syllables. We found the following: (1) unfamiliar interrupters are equally disruptive as repeated interrupters, (2) increasing target sequence length increases the impact of the interruption on recall of the target syllable just after the interruption, and (3) unpredictable interrupters are more disruptive than predictable interrupters. These results support the hypothesis that salient interruptions disrupt both top-down attention and working memory maintenance.