Impact of Continuous Night Shifts on Crew Performance in 9-day Isolated Environment Shift Experiments

Continuous night shifts in isolated environments such as cabins, submarines, and space stations have a negative impact on the circadian and cognitive function of the crew. Therefore, 9-day simulated isolated environment experiments were conducted to reveal the negative impact of continuous night shifts on crew performance. A 6-shift-per-day schedule was established, in which there were 3-night shifts, namely a 0–4 shift, a 4–8 shift, and a 20–24 shift respectively. The operational performance was evaluated using the Multi-Attribute Task Battery II (MATB-II) platform. The subjective feelings were evaluated by NASA Task Load Index (NASA-TLX) questionnaire, Karolinska Sleepiness Scale (KSS), and job satisfaction scale. Generalized Additive Mixed Models (GAMMs) were established to test the fixed effect estimates of potential influencing factors on crew performance. The analysis results showed that subjects had the worst performance in the 4–8 shift and the later experimental periods, namely Day 7 to Day 9.