Can XunTian Tai Chi intervention improve the level of emotional regulation of crew members in the Controlled Ecological Life Support System?

To explore the appropriate exercise methods and means for astronauts in confined and small isolation conditions, a set of XunTian Tai Chi suitable for the spaceflight workforce was created, with the aim of discovering the practical effects of XunTian Tai Chi and providing a scientific basis for the subsequent development of new astronaut health maintenance techniques with Chinese characteristics. Using the Controlled Ecological Life Support System (CELSS) as a research platform, we observed the changes in a crew member's emotion regulation-related indexes during 180 days of working and living in a confined isolation chamber through periodic interventions of the XunTian Tai Chi and conducted statistical analyses. During the 180-day cabin mission, expression suppression, cognitive reappraisal, attention index, and relaxation index were all lower than those before entering the cabin, suggesting that the crew member's emotion regulation ability decreased during the in-cabin mission. A single Tai Chi exercise could cause favorable changes in the indicators, positively affecting the crew member's emotional regulation. The attention and relaxation indices of the occupants were improved significantly by both single and periodic Tai Chi exercises. After the Tai Chi exercise cycle, the results of each index showed a certain degree of effect. The 180-day ground-based simulation of Tai Chi in the confinement of a space capsule positively affects the occupant's emotional regulation.

Effects of 15-Day Head-Down Bed Rest on Emotional Time Perception.

Accurate time perception is clearly essential for the successful implementation of space missions. To elucidate the effect of microgravity on time perception, we used three emotional picture stimuli: neutral, fear, and disgust, in combination with a temporal bisection task to measure 16 male participants' time perception in 15 days of -6° head-down bed rest, which is a reliable simulation model for most physiological effects of spaceflight. We found that: (1) participants showed temporal overestimation of the fear stimuli in the middle phase (day 8), suggesting that when participants' behavioral simulations were consistent with the action implications of the emotional stimuli, they could still elicit an overestimation of time even if the subjective arousal of the emotional stimuli was not high. (2) Participants' temporal sensitivity tends to get worse in the bed rest phase (days 8 and 15) and better in the post-bed rest phase, especially for neutral and fear stimuli, suggesting that multiple presentations of short-term emotional stimuli may also lead to a lack of affective effects. This reduced the pacemaker rate and affected temporal perceptual sensitivity. Also, this may be related to changes in physiological factors in participants in the bed rest state, such as reduced vagal excitability. These results provide new evidence to support the theory of embodied cognition in the context of time perception in head-down bed rest and suggest important perspectives for future perception science research in special environments such as microgravity.

Personalized Epigenome Remodeling Under Biochemical and Psychological Changes During Long-Term Isolation Environment.

It has been reported that several aspects of human health could be disturbed during a long-term isolated environment (for instance, the Mars-500 mission), including psychiatric disorders, circadian disruption, temporal dynamics of gut microbiota, immune responses, and physical-activity-related neuromuscular performance. Nevertheless, the mechanisms underlying these disturbances and the interactions among different aspects of human adaptation to extreme environments remain to be elucidated. Epigenetic features, like DNA methylation, might be a linking mechanism that explains the involvement of environmental factors between the human genome and the outcome of health. We conducted an exploration of personalized longitudinal DNA methylation patterns of the peripheral whole blood cells, profiling six subjects across six sampling points in the Mars-500 mission. Specifically, we developed a Personalized Epigenetic-Phenotype Synchronization Analysis (PeSa) algorithm to explore glucose- and mood-state-synchronized DNA methylation sites, focusing on finding the dynamic associations between epigenetic patterns and phenotypes in each individual, and exploring the underling epigenetic connections between glucose and mood-state disturbance. Results showed that DMPs (differentially methylated-probes) were significantly enriched in pathways related to glucose metabolism (Type II diabetes mellitus pathway), mood state (Long-term depression) and circadian rhythm (Circadian entrainment pathway) during the mission. Furthermore, our data revealed individualized glucose-synchronized and mood-state-synchronized DNA methylation sites, and PTPRN2 was found to be associated with both glucose and mood state disturbances across all six subjects. Our findings suggest that personalized phenotype-synchronized epigenetic features could reflect the effects on the human body, including the disturbances of glucose and mood-states. The association analysis of DNA methylation and phenotypes, like the PeSa analysis, could provide new possibilities in understanding the intrinsic relationship between phenotypic changes of the human body adapting to long-term isolation environmental factors.

Simulated Spaceflight Operations Under Sleep Deprivation and Confinement.

INTRODUCTION: This study investigated how operation complexity and type affect Chinese individuals' performance of simulated spaceflight operations under conditions of sleep deprivation and confinement (SDC). METHODS: There were 20 male volunteers who were randomly divided into 2 groups: the SDC group (N = 8) and the control group (N = 12). During the 72-h experimental period, the volunteers were asked to perform 11 computerized spaceflight emergency procedures, varying in operation complexity and type, three times at the 9(th), 33(rd), and 57(th) hours, respectively. Operation times and errors of each spaceflight emergency procedure were recorded. Three complexity levels (i.e., low complexity, high complexity, and combined complexity) and three operation types (i.e., two-way judgment, manual operation, and mixed operation) were identified according to an operation complexity measure and an engineering definition. RESULTS: Mixed model ANOVAs indicated that performance of the three complex operations and three operation types were negatively affected by SDC. Moreover, the results showed that the operation time of the manual operation (10.67 ± 1.706 at the 9th hour, 13.94 ± 4.261 at the 33rd hour) and mixed operation (4.88 ± 0.247 at the 9th hour, 5.15 ± 1.308 at the 57th [corrected] hour) increased significantly with the increase of waking time. It was also shown that the high complexity operation and manual operation got less variation in operation time compared with low complexity and two-way judgment, respectively. CONCLUSIONS: The result indicated that the task assignment with high complexity requiring cognition could be a useful way to counteract the effect of SDC. It was also implied that psychomotor abilities were more easily affected by SDC than perception and judgment.

During the long way to Mars: effects of 520 days of confinement (Mars500) on the assessment of affective stimuli and stage alteration in mood and plasma hormone levels.

For future interplanetary manned spaceflight, mental issues, as well as physiological problems, must inevitably be considered and solved. Mars500 is a high-fidelity ground simulation experiment that involved 520 days of confined isolation for six multinational crewmembers. This experiment provided a good opportunity to perform psycho-physiological and psycho-social researches on such missions. To investigate emotional responses and psychological adaptation over long-term confinement, the International Affective Pictures System (IAPS) was selected as the visual emotional stimuli in this study. Additional data collected and analyzed included the Profile of Mood States (POMS) questionnaire and the levels of four types of plasma hormones: cortisol, 5-hydroxy tryptamine, dopamine, and norepinephrine. The results demonstrated an obvious bias on valence rating for unpleasant stimuli with time (p<0.05), and the correlation between psychological and biochemical data was identified (p<0.05). Overall, we concluded that the confined crew tended to assign positive ratings to negative pictures with time, which might be driven by a defensive system. There was a stage-changing pattern of psychological adaptation of the Mars500 crew, which is similar to the third-quarter phenomenon.

Physiological responses of astronaut candidates to simulated +Gx orbital emergency re-entry.

INTRODUCTION: We investigated astronaut candidates' physiological and pathological responses to +Gx exposure during simulated emergency return from a running orbit to advance astronaut +Gx tolerance training and medical support in manned spaceflight. METHODS: There were 13 male astronaut candidates who were exposed to a simulated high +Gx acceleration profile in a spacecraft during an emergency return lasting for 230 s. The peak value was 8.5 G. Subjective feelings and symptoms, cardiovascular and respiratory responses, and changes in urine component before, during, and after +Gx exposure were investigated. RESULTS: Under high +Gx exposure, 15.4% of subjects exhibited arrhythmia. Heart rate (HR) increased significantly and four different types of HR response curves were distinguished. The ratio of QT to RR interval on the electrocardiograms was significantly increased. Arterial oxygen saturation (SaO2) declined with increasing G value and then returned gradually. SaO2 reached a minimum (87.7%) at 3 G during the decline phase of the +Gx curve. Respiratory rate increased significantly with increasing G value, while the amplitude and area of the respiratory waves were significantly reduced. The overshoot appeared immediately after +Gx exposure. A few subjects suffered from slight injuries, including positive urine protein (1/13), positive urinary occult blood (1/13), and a large area of petechiae on the back (1/13). CONCLUSIONS: Astronaut candidates have relatively good tolerance to the +Gx profile during a simulation of spacecraft emergent ballistic re-entry. However, a few subjects exhibited adverse physiological responses and slight reversible pathological injuries.

Guided imagery, anxiety, heart rate, and heart rate variability during centrifuge training.

BACKGROUND: Centrifuge training is an important method of improving the hypergravity tolerance of pilots, cosmonauts, and Chinese astronauts. However, the concomitants of tension or anxiety often impede training. Guided imagery (GI), a mind-body relaxation technique, provides a behavioral and cognitive means whereby individuals are able to exert control over the focus of attention. This study aims to investigate the immediate effects of GI for reducing stress in centrifuge training. METHODS: There were 12 healthy young men who were randomly assigned to a GI group or music group. We measured changes in heart rate during centrifuge training, in heart rate variability before and after centrifuge training, and also evaluated relaxation and anxiety in three phases: before intervention, after intervention, and following centrifuge training. RESULTS: The change in the pattern of anxiety was different in the two groups over the three phases. Anxiety (measured by State Anxiety Inventory) in the GI group changed from 31.7 +/- 5.9 to 26.8 +/- 2.6 and 27.8 +/- 4.1, whereas for the music group this changed from 32.2 +/- 7.6 to 31.2 +/- 8.3 and 26.8 +/- 6.8. During centrifuge training, the maximal HR for the GI group (101.2 +/- 8.8) was lower than that of the music group (123.0 +/- 19.1). In addition GI showed a decrease in low frequency (LF, 0.04-0.15 Hz) components and an increase in high frequency (HF, 0.15-0.4 Hz) components before and after centrifuge training. CONCLUSION: GI was capable of decreasing tension, anxiety, and sympathetic nervous system activity pre- or post-centrifugation.

[Study on relationship between emotional stability in flight and nerve system excitability].

OBJECTIVE: To study the related factors of emotional stability in flight. METHOD: Based on the operable definition of emotional stability in flight and the related literature review, 63 experienced pilots and flight coaches were investigated and the other-rating questionnaire of emotional stability in flight was established. To test the senior nerve system, Uchida Kraeplin (UK) test was administrated on 153 19-21 years old male student pilots of the second grade in the department of flight technique in China Civil Aviation College, who were selected through 13 h flight, 35 h solo flight, and acted as the standardization group. In the end, the correlation was explored between the testing results and their emotional behavioral characteristics in flight. RESULT: Significant positive correlation was found between emotional feature indexes of emotional stability in flight and excitability in UK test. CONCLUSION: The excitability in UK test are good predictors for emotional stability in flight.