Comparing Eye-Gaze Metrics of Mental Workload in Monitoring Process Plants

摘要

Continuous, non-invasive workload indicators of operators is an essential component for dynamically assigning appropriate amount of tasks between automation and operators to prevent overload and out-of-the-loop problems in computer-based procedures. This article examines the monitoring task difficulty manipulated by the task type and load, and explores physiological measurements in relation to mental workload. In a within-subject design experiment, forty-five university students performed monitoring tasks in simulated nuclear power plants (NPPs) control room. The performance of monitoring tasks (accuracy), subjective mental workload (NASA Task Load Index), as well as four eye-related physiological indices were measured and analyzed. The results show that as monitoring task difficulty increased, task performance significantly decreased while NASA-TLX, number of fixations, and dwell time significantly increased. Number of fixations and dwell time could be effective, non-invasive continuous indicators of workload for enabling adaptive computer-based procedures.