Research has shown that different types of interruptions can affect their disruptiveness. However, it is unclear how different features of the interrupting task determine its disruptive effects. Specifically, some theories predict that the difficulty of an interruption does not contribute to the disruptive effects of that interruption alone. Disruptive effects can be mediated by the extent to which the interrupting task interferes with the ability to rehearse during the interruption. In this experiment participants performed a single primary task with three interruptions of different difficulty. We found that interruptions were more disruptive when the task minimized the participant's ability to rehearse (as measured by the number of mental operators required to perform the task) and not just when they were more difficult. These results suggest that the ability to rehearse during an interruption is critical in facilitating resumption of a primary task.

It is generally accepted that, with practice, people improve on most tasks. However, when tasks have multiple parts, it is not always clear what aspects of the tasks practice or training should focus on. This research explores the features that allow training to improve the ability to resume a task after an interruption, specifically focusing on task-specific versus general interruption/resumption-process mechanisms that could account for improved performance. Three experiments using multiple combinations of primary tasks and interruptions were conducted with undergraduate psychology students. The first experiment showed that for one primary and interruption task-pair, people were able to resume the primary task faster when they had previous practice with the interruption. The second experiment replicated this finding for two other sets of primary and interruption task-pairs. Finally, the third experiment showed that people were able to resume a primary task faster only when they had previous practice with that specific primary and interruption task-pair. Experience with other primary and interruption task-pairs, or practice on the primary task alone, did not facilitate resumption. This suggests that a critical component in resuming after an interruption is the relationship between two tasks. These findings are in line with a task-specific mechanism of resumption and incompatible with a general-process mechanism. These findings have practical implications for developing training programs and mitigation strategies to lessen the disruptive effects of interruptions which plague both our personal and professional environments.

Previous research has shown that there is a time cost (i.e., a resumption lag) associated with resuming a task following an interruption and that the longer the duration of the interruption, the greater the time cost (i.e., resumption lag increases as interruption duration increases). The memory-for-goals model (Altmann & Trafton, 2002) suggests that this greater time cost is a result of increased interference caused by longer duration interruptions. Therefore, the goal for this research was to determine whether individuals who can better manage interference, i.e., individuals with higher working-memory capacity (WMC), can resume tasks more quickly following interruptions than those who cannot manage interference as well (i.e., individuals with lower WMC). A procedural interruption task with 3 different interruption durations and a measure of WMC were completed by 229 students. In line with previous research, we found a strong positive relationship between interruption duration and resumption lag. We found a strong negative effect of WMC on resumption lag (i.e., increases in WMC reduced resumption lags). Notably, WMC moderated the effect of interruption duration on resumption lag (i.e., increases in WMC attenuated the positive relationship between interruption duration and resumption lag). Specifically, individuals with high WMC experienced small increases in resumption lag as interruption duration increased, whereas individuals with low WMC experienced substantial increases in resumption lag as interruption duration increased. Our data suggest that individuals with higher WMC are less susceptible to interference caused by interruptions. (PsycINFO Database Record

Past work examining the effects of interruption complexity on primary task performance has yielded quite mixed results. Some research suggests that more complex interruptions lead to greater disruption of the primary task, while other studies have shown that interruption complexity does not directly influence the amount of primary task disruption. It is our hypothesis that interruption complexity, defined by the number of mental operators required to complete a task as opposed to an intuitive sense of difficulty, does affect primary task performance, such that interruptions requiring more mental operators (more complex) lead to greater disruption than do less complex interruptions. Participants performed a single primary task in conjunction with either a simple or complex interruption. The complex interruption required more mental operators to complete than the simple interruption. Our results showed that it took longer to resume the primary task following a complex interruption than it did following a simple interruption. These results suggest that more complex interruptions, as quantified by the number of mental operations required, do indeed lead to greater primary task disruption.

Interruptions are an inescapable reality in our lives and they sometimes lead to unfortunate consequences. Most of the interruptions literature focuses on aspects of the interruption task that makes them more or less disruptive to performance. However, it is important to consider what might make a person resilient to the deleterious effects of interruptions. This research seeks to explore the individual performer and the specific cognitive aspects that might make someone better or worse at dealing with an interruption. Based on the current theory, we predicted that participants with better working memory capacity and spatial abilities would be faster at resuming an interrupted task than those who scored lower on those measures. We found that those that scored higher on the working memory capacity measure were faster at resuming from an interruption and those that scored higher on one of the spatial ability measures (mental rotation) were faster at resuming. The paper folding task measure of spatial ability did not predict interrupted task performance.