Approximation of on-line mental workload index in ATC simulated multitasks

To assess the effects of workload pressures, participants interacted with a modified version of air traffic control simulated tasks requiring different levels of cognitive resources. Changes in mental workload between the levels were evaluated multidimensionally using a subjective rating, performance in a secondary task, and other behavioural indices. Saccadic movements were measured using a video-based eye tracking system. The Wickens multiple resource model is used as a theoretical reference framework. Saccadic peak velocity decreases with increasing cognitive load, in agreement with subjective test scores and performance data. That saccadic peak velocity is sensitive to variations in mental workload during ecologically valid tasks is demonstrated.