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

Abstract

Pilots in long-duration flight missions in single-seat aircraft may be affected by fatigue. This study determined associations between cognitive performance, emotions and physiological activation and deactivation - measured by heart rate variability (HRV) - in a simulated 11-h flight mission in the 39 Gripen aircraft. Twelve participants volunteered for the study. Perceived fatigue was measured by the Samn-Perelli Fatigue Index (SPFI). Cognitive performance was measured by non-executive and executive tasks. Emotions were assessed by the Circumplex Affect Space instrument. HRV was considered in relation to the cognitive tasks in four time points - Hours 3, 5, 7, 9 - and their associations with emotional ratings. Results indicated a decrease in performance in the non-executive task after approximately 7 h. This result was correlated with self-reported measures of fatigue. HRV, assessed by indices of parasympathetic modulation, remained unchanged for both non-executive and executive tasks over time (p > .05 for all). Significant correlations were observed between emotions and HRV; with increased boredom, increased passiveness, decreased stimulation, and decreased activeness, HRV indicators increased (p < .05). This suggests that a low self-regulatory effort for maintaining performance in these conditions was prevalent and that pilots could adapt to some degree to the demands and fatigue of long-duration missions.

Keywords: Fatigue; cognitive performance; emotions; heart rate variability; long-duration missions.

Figure 1.

The gondola depicting a participant strapped in the 39Gripen seat simulator. Mask and helmet were used uninterruptedly for 11 consecutive hours. Cognitive tests were presented on the center screen head-down display. Emotional rating scale and self-reported measure scale of fatigue was affixed in the upper right corner from the central display (not visible).

Figure 2.

The circumplex affect space depicting the two-dimensional structure of pleasure-displeasure (horizontal axis) and high-low levels of perceived activity (vertical axis). It has eight affective states with two adjectives each. Plus and minus signs indicate positive or negative affect, respectively. Adapted from Knez (2014).