## 2 Materials and Methods
### Bed Rest Study  
We used a 6\({}^{\circ}\) head-down tilt bed rest (HDBR) study performed at the German Aerospace Center (DLR) in Cologne, Germany to investigate how the AMS score for short-duration (AMS-SD) and long-duration (AMS-LD) missions was affected by HDBR (some of the descriptions below are replicated from [PERSON] et al. [16]). HDBR is considered a space-analog environment as it mimics the reduced mobility and head-ward fluid shifts encountered by astronauts in microgravity. The study was titled Artificial Gravity Bed Rest--European Space Agency (AGBRESA). Participants were randomly assigned to one of three groups of eight participants each, all of them undergoing 60 days of strict 6\({}^{0}\) HDBR: (1) Control group: no artificial gravity intervention; (2) continuous artificial gravity (cAG) group: one continuous 30 min bout of centrifugation daily; and (3) intermittent artificial gravity (iAG) group: six 5 min bouts of centrifugation with 3 min rest between bouts daily. Participants were pseudo-randomly assigned to groups. The age of the 24 participants averaged 33.3 \(\pm\)9.2 years (range 23-54 years) and 14 (66.7%) were male. Study design and protocol details can be found in [PERSON] at al. [16]. Participants performed the full Cognition battery including AMS twice for task familiarization 13 and 11 days before the start for the HDBR period. Cognition was performed three more times on days 9, 7 and 6 before HDBR (baseline bouts). Furthermore, Cognition was then administered on days 1, 3, 5, 14, 28, 42, and 57 after the initiation of the HDBR period. Finally, participants performed Cognition on days 1, 5 and 12 during the recovery period following HDBR. Cognition laptops were mounted vertically on an adjustable swivel arm and positioned at chest height in front of the participants for testing in the head-down tilt position. Statistical Analysis of Bed Rest Data  
Consistent with analyses reported in [PERSON] et al. [16], linear mixed-effect models with random intercepts were used to account for the fact that test data were clustered within participants (SAS version 9.4, SAS Institute, Carey, NC, USA). Survey data were treated as continuous for analysis purposes [17]. Item #17 (crew conflicts) was not used \begin{table}
\begin{tabular}{c c c} \hline \hline
**Item \#** & **Item Description** & **Item Anchors** \\ \hline
1 & Sleep Quality & Good–Poor \\
2 & Workload & Very low–Very high \\
3 & Sleepiness & Not sleepy at all–Very sleepy \\
4 & Happiness & Happy–Unhappy \\
5 & Health & Healthy–Sick \\
6 & Energy Level & Energetic–Physically exhausted \\
7 & Mental Status & Mentally sharp–Mentally fatigued \\
8 & Stress Level & Not stressed at all–Very stressed \\
9 & Tiredness & Fresh, ready to go–Tired \\
10 & Depression & Not depressed at all–Very depressed \\
11 & Boredom & Not bored at all–Very bored \\
12 & Loneliness & Not lonely at all–Very lonely \\
13 & Monotony & Not monotonous at all–Very monotonous \\
14 & Crew Conflicts & No (0)–Yes (10) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Item description and item anchors for the paired comparison. for calculating AMS-SD and AMS-LD, as participants had private rooms throughout the HDBR period. As explained above, AMS-SD and AMS-LD reflect weighted averages of the survey responses with PC proportions used as weights. Higher AMS scores reflect greater alertness and mood disturbance (i.e., are worse and less desirable). AMS scores range from 0 (minimal alertness and mood disturbance) to 10 (maximal alertness and mood disturbance). All models were adjusted for sex and age (continuous variable). \(p\)-values were adjusted for multiple testing according to the false discovery rate method [18] for the 15 subjective outcomes (13 individual items plus AMS-SD and AMS-LD). We provide unadjusted confidence intervals as well as the alpha level that survived adjustment (i.e., \(p<0.05\), \(p<0.01\), \(p<0.001\), \(p<0.0001\)).