Cognitive performance, fatigue, emotional and physiological strains in simulated long-duration flight missions

Pilots in long-duration flight missions in single-seat aircrafts may be affected by fatigue. This study determined associations between cognitive performance, emotions and physiological activation and deactivation – measured by heart rate variability – in a simulated 11-hours flight mission in the 39 Gripen aircraft. Eleven participants volunteered for the study. Perceived fatigue was measured by the Samn-Perelli Fatigue Index (SPFI). Cognitive performance and objective fatigue were measured by non-executive and executive tasks. Emotions were assessed by the Circumplex Affect Space instrument. Heart rate variability (HRV) was considered in relation to the cognitive battery test in four time points – Hours 3, 5, 7, 9 – and their associations with emotional ratings. Results indicated decrease in performance in the non-executive task after approximately seven hours. This result was correlated with self-reported measures of fatigue. Heart rate variability, assessed by indices of parasympathetic modulation – RMSSD, pNN50 and mean RR Interval – remained unchanged for both non-executive and executive tasks over time. There were associations between increased boredom as well as passiveness and decrease in stimulation as well as activeness, and increased HRV. This suggests that a low self-regulatory effort for maintaining performance in these tasks in these environmental conditions was required. Combined results indicate that pilots may be able to adapt to environmental demands and fatigue in long-duration missions providing that low self-regulatory effort is prevalent. Keywords: fatigue, heart rate variability, cognitive performance, emotions, long-duration military missions