MAINTAINING VIGILANCE ON A SIMULATED ATC MONITORING TASK ACROSS REPEATED SESSIONS

This study assesses changes in vigilance/attention of air traffic controllers across 3 separate days as subjects performed an air traffic control (ATC) simulation task. Twenty subjects on 3 days monitored a simulated ATC task for 44 critical events over a 2-hour session. The complex monitoring task included the detection of: altitude malfunctions; aircraft conflict/ no conflicts where 2 aircraft were at the same altitude on an airway simultaneously; and triangular targets representing visual flight rules (VFR) aircraft that appeared either centrally or peripherally on the screen during the course of each session. Changes in performance on the complex monitoring task associated with either time on task or repeated sessions were dependent on nature of the task. Performance on the component involving detection and decision making (conflict/no conflict detection) evidenced a decrement associated with time on task on each of the 3 days. Improvement was evident from the first to the third day. Performance on the identification of the altitude malfunctions remained relatively immune to the effects of time on task or repeated sessions. Detection of the VFR aircraft intruders presented a mixed picture, with improvement noted in some aspects of performance but not in others, and some evidence of time on task effects. Outcomes were generally consistent with previous findings with this task and consistent with other literature with respect to the presence of performance decrements associated with time on task. The results were consistent with a view that the decrements are associated with lapses in attention, rather than a generalized fatigue effect or a general modification in overall scanning behavior. Furthermore, results suggest that there were aspects of monitoring performance that remain relatively immune to time on task effects.