Background sound impairs interruption recovery in dynamic task situations: procedural conflict?

 Interruptions impair performance even on simple, static, laboratory-based tasks, but little research has looked at their impact in more complex and realistic settings that involve dynamically evolving circumstances and other environmental stressors. Using a radar operator task with or without background sound, participants were unexpectedly interrupted to complete another task, which masked the radar screen as the scenario continually evolved. Task efficiency was impaired by interruption: decision-making time was slower immediately following interruption, this cost being greater and persevered longer in the presence of auditory distraction. Resumption time was also increased with distraction. Eye fixation durations were shorter following interruption, reflecting participants' attempts to rapidly re-encode and update their model of the situation. These results suggest that those processes involved in task resumption are also susceptible to background sound, and indicate a need for theories of task interruption to better specify the role of attention in interruption recovery.