Integrating Modafinil Effects Into a Biomathematical Model of Fatigue

Long duration missions exacerbate cognitive fatigue. For effective dosage practices, advanced modeling capabilities must be developed to accurately simulate effects of countermeasures on cognition. This paper focuses on modulating the Sleep, Activity, Fatigue, and Task Effectiveness (SAFTE) biomathematical fatigue model based on a new modafinil physiocognitive model to enhance predictive performance. Model predictions were compared to an archival sleep deprivation dataset where subjects received either 200 mg of modafinil or a placebo across two sessions (counterbalanced) and completed the Psychomotor Vigilance Test (PVT) every hour. Based on high versus low performance on the PVT, the modafinil SAFTE model fit high performer data well and low performer data marginally, but rank ordering of predictions was accurate. Compared against the baseline SAFTE model, the modafinil SAFTE model generally performed better, especially for high performers. This effort advances predictive accuracy of fatigue risk management tools where modafinil is used to combat cognitive fatigue.