Fortin and Masse (2000) explored the effect of expecting an interruption on the ability to accurately produce a timing interval (e.g., producing a 2000 millisecond timing interval):
From the abstract:
The interference from nontemporal processing on concurrent time
estimation is usually attributed to disruption in timing caused by
artentional requirements of nontemporal processing. Here, we examined
interruption in timing without concurrent nontemporal processing.
Empty breaks of various durations, during time-interval production,
lengthened produced intervals. Moreover, an effect of break location
was observed: Intervals lengthened proportionally to prebreak
duration. When cued and uncued uninterrupted trials were introduced,
the lengthening was proportional to the duration for which a break was
expected. It was concluded that attentional time-sharing between time
estimation and expectation of its interruption contributed to the
interference effect in time-estimation research, independently of any
concurrent processing requirements during time estimation.
So, I suppose you could use this as evidence to support the idea that if an individual is anticipating an interruption, this might consume some attentional resources, especially if he or she is tuned into a signal that might communicate the commencement of the interruption.
References
- Fortin, C. and Masse, N. (2000). Expecting a break in time estimation: Attentional time-sharing without concurrent processing. Journal of Experimental Psychology: Human Perception and Performance, 26, 1788. PUBLISHER PAGE