Study shows how interruptions could screw up the prospective memory of air traffic controllers

A new study sheds light on how interruptions could impact the prospective memory of air traffic controllers. Failures in prospective memory occur when we form an intention to do something at a later point in time, but then forget to remember the task.

The research was recently published in the Journal of Experimental Psychology: Applied.

“Remembering to carry out an intention, such as posting a letter, requires us to use what is called prospective memory. Situations that require prospective memory are often referred to as deferred tasks,” said study author Michael David Wilson of the Human Factors and Applied Cognition Laboratory at the University of Western Australia.

“In complex and safety-critical jobs, such as air traffic control, operators sometimes have to rely on their prospective memory ability to support overall safety.”

“For example, an air traffic controller might need to defer issuing a flight instruction for a few minutes (while finishing another task), and then need to remember to issue the instruction at the appropriate time. However, we know that controllers are frequently interrupted and that interruptions can negatively impact prospective memory,” Wilson explained.

“My research is concerned with identifying the extent to which interruptions impact people’s ability to remember deferred tasks in complex workplace situations, and identifying the properties of deferred tasks at highest risk of human error.”

The researchers tested the impact of interruptions in two experiments, which each included 60 college students. The participants were trained to use an air traffic control simulator, then required to accept/handoff aircraft, detect aircraft conflicts, and perform two deferred tasks during a testing phase.

“Throughout the simulation, participants had to perform several deferred tasks that tested their prospective memory ability in different ways. We looked at two kinds of deferred task which controllers report occur frequently: (1) remembering to return to an intended task, and (2) remembering to deviate from a routine procedure.”

“Participants had to complete these deferred tasks while occasionally being interrupted by a range of additional tasks,” Wilson explained.

Interruptions included the ATC simulator screen going blank and the ATC simulator switching to another sector of airspace before switching back. The interruptions lasted for 27 seconds.

“We found that interruptions substantially increased the risk of forgetting to come back to finish an intended task, particularly when the primary and interrupting tasks are similar. However, interruptions had no impact on remembering to deviate from routine,” Wilson told PsyPost.

“These findings suggest that particular kinds of air traffic control tasks may be more susceptible to the negative effects of interruption than others. We hope that our findings will contribute to the design of future air traffic control automation systems by informing developers about the kinds of deferred task associated with a high risk of human error.”

The study provides new evidence about how interruptions affect prospective memory. But it is unclear just how big of an impact these interruptions would have on professional aircraft controllers.

“The use of undergraduate students with limited training does limit our ability to generalize the results to expert controllers who receive intensive training with well-defined performance standards,” Wilson explained. “Expert controllers would be far less likely to forget to perform deferred tasks as often as we observed in our experiments, so a lofty goal would be to validate these findings with real controllers.”

The study, “Remembering to Execute Deferred Tasks in Simulated Air Traffic Control: The Impact of Interruptions“, was authored by Michael David Wilson, Simon Farrell, Troy A. W. Visser, and Shayne Loft.