Operations in space are anything but restful for astronauts, as there are both physical and psychological stressors. One known stressor is the lack of sufficient sleep in space which can...Show moreOperations in space are anything but restful for astronauts, as there are both physical and psychological stressors. One known stressor is the lack of sufficient sleep in space which can drastically impact astronauts’ performance. Successful docking is highly important during space missions since small mistakes can lead to disastrous consequences. The docking process can be trained with the 6df task, a simulation in which six degrees of freedom must be controlled. This experimental study aimed to investigate the effect of susceptibility to sleep deprivation (SSD) on 6df docking performance impairment due to sleep deprivation (SD). A total of 62 participants (28 female; 18-39 years, Mage = 24.84; SDage = 4.69) completed a balanced-repeated-measures-cross-over-total-SD design. Test variables were calculated by subjects’ performance differences between “well-rested-“ and “SD measurements”. The dependent variable docking performance impairment due to SD was operationalised by 6df outcomes(“top-level achieved” and “mean docking accuracy”). SSD was defined as 1/reaction time (RT) from the Psychomotor Vigilance Test. A background analysis showed that participants’ RT slows significantly when SD (p < .001). Multinomial regressions (“top-level achieved”) showed no significant relations between SSD and docking performance impairment, whereas multiple regressions (“mean docking accuracy”) showed significant relations (p < .001). Post-hoc analysis showed that testing order is noteworthy because participants assessed in the order “well-rested-“ followed by “SD measurements” have lower docking performance impairment due to SD than the group with reversed order. Further, a posthoc analysis showed when participants split in “least SSD” and “most SSD”, the effect of SSD on 6df docking performance impairment due to SD was affected by testing order. The importance of testing order suggests the presence of a learning effect, meaning that docking performance impairment due to SD could be reduced by exhaustive training in well-rested conditions. In conclusion, this study can help construct guidelines for determining whether an individual can still perform the operationally relevant task safely under SD. This could also be interesting for other professions such as submarines, pilots, and surgeons, in which six degrees of freedom have to be controlled under SD.Show less
