Biomathematical Modeling of Fatigue and Cognitive Performance

Cognitive fatigue is a prevalent factor in military communities, resulting in performance degradations and contributing to costly mishaps. It is critical that organizations can predict fatigue effects of cognitive processes in order to implement countermeasures to allay fatigue. Biomathematical models are one means to objectively predict fatigue effects. This effort focuses on examining the relationship between biomathematical model predictions and performance on different cognitive tasks during an operationally relevant 24-hr simulated mobility mission. Thirty-nine mobility pilots wore an actigraph watch while self-reporting sleep, and completed several bouts of psychomotor vigilance, working memory, and executive functioning tasks throughout the mission simulation. Pilots’ sleep data was processed through the Sleep, Activity, Fatigue, and Task Effectiveness (SAFTE) biomathematical fatigue model and corresponding performance effectiveness values were extracted for each bout and each task. We examined the percentage of pilots who had significant correlations between their performance effectiveness values and the corresponding task dependent measures. We found that for certain participants, biomathematical predictions of fatigue were highly correlated with performance on the psychomotor vigilance task, particularly if the range of effectiveness values varied for that participant. Correlations with other tasks were not as profound, suggesting psychomotor vigilance performance is more sensitive to fatigue.