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Biomedical subjects

Natsuhiko Inoue

Publications and source records attributed to Natsuhiko Inoue.

8 recordsLinked to original sources
PubMed2004

Group interactions in SFINCSS-99: lessons for improving behavioral support programs.

Human factors can significantly influence successful mission completion of prolonged space missions such as ISS expeditions or future Mars missions. This paper describes group dynamics and group interactions during SFINCSS-99, a very unique international long-term confinement study in a space mission analog environment. Many interpersonal or inter-group conflicts occurred, and these caused the early retirement of a Japanese subject. This paper cites examples of these conflicts, and analyzes their causes with our results. The international cooperation to extract lessons learned, which could be used to refine behavioral support programs for the ISS or similar international studies, is also introduced.

Adult↗
PubMed2003

Exercise load index and changes in body weight during long-duration confinement in an isolated environment.

PURPOSE: The objectives of this project were to investigate exercise load and body weight related to long-duration confinement in a closed environment simulating ISS flight conditions, and to evaluate subjects' motivation to continue the experiment and their adaptation to isolation. METHODS: Four Russian male subjects participated in a 240-d experiment (Group I), and four subjects (three male subjects and one female subject) from Austria, Canada, Japan, and Russia participated in a 110-d experiment (Group II). Exercise load was estimated during confinement using a modified Rating of Perceived Exertion scale. Free reports were used to determine subjects' motivation. Body weight was measured before, during, and after confinement. RESULTS: Group I achieved their lowest exercise loads during their first month of isolation; problems with adaptation to the isolation environment were also reported during this first month. Group II exercise load was significantly lower in the second month due to crewmember problems; loss of motivation could be noted from their free reports. The subject with the lowest exercise load retired from the isolation experiment earlier than scheduled. Exercise load was not correlated with prior exercise habits. Significant differences in body weight was observed between group I and II and between Russian and non-Russian subjects. One subject in Group I experienced a significant increase in his body weight. CONCLUSION: Exercise load may be a good indicator for adaptation problems and motivation changes in closed environments. Immobility, lack of space, and smoking cessation in general did not induce significant body weight changes.

Adaptation, Physiological↗
PubMed2002

Psychological changes and group dynamics during confinement in an isolated environment.

PURPOSE: Cultural and personal traits will become important as the number of short-duration spaceflights of international crews supporting the International Space Station (ISS) increases and more people begin staying aboard ISS for longer durations. This project investigated the interpersonal and personal changes of Japanese subjects during a 1-wk stay in the Japanese Experiment Module. The Giebetaen Test (GT) was used to determine if the cultural background and personality traits of the subjects become more explicit and stronger during isolation. METHODS: Six males and two females aged 22-28 yr participated in the study. They stayed 7 d in the isolation chamber at the National Space Development Agency of Japan (NASDA). The GT was chosen as an individual and group diagnostic instrument; it was administrated four times during, and one time after, isolation. RESULTS: According to the GT-self-picture, subjects exhibited a change toward negative social resonance and social withdrawal. Subgroups formed but caused no isolation or tension. The GT-foreign-pictures showed that the judgment of other subjects changed toward hedonic and permeability directions. The common interpersonal relationships of the Japanese subjects influenced the group dynamics. These relationships tend to be integrative and tend to support the network and value systems, emphasizing connectedness and minimizing differences. CONCLUSION: The cultural background became more explicit and stronger during isolation. Based on this, isolation studies with international crews and intercultural training will be necessary for international crews performing both short- and long-duration missions.

Adaptation, Psychological↗
PubMed2002

Physiological changes, sleep, and morning mood in an isolated environment.

BACKGROUND: Previous isolation studies have shown increased 24-h urine volumes and body weight gains in subjects. This project examined those and other physiological variables in relationship to sleep motor activity, subjective sleep quality, mood, and complaints during confinement. METHODS: Six male and two female subjects lived for 7 d in the National Space Development Agency of Japan's isolation chamber, which simulates the interior of the Japanese Experiment Module. Each 24-h period included 6 h of sleep, 3 meals, and 20 min of exercise. Each morning, subjects completed Sleep Sensation and Complaint Index questionnaires. Catecholamine and creatinine excretion, urine volume, and body weight were measured on the 2 d before and 2 d after confinement, and sleep motor activity was measured during confinement. RESULTS: Confinement produced no significant change in body weight, urine volume, or questionnaire results. In contrast, epinephrine, norepinephrine, and sleep motor activity exhibited significant differences during confinement (p < 0.05). Higher nocturnal norepinephrine excretion correlated with higher sleep motor activity. CONCLUSION: The 24-h epinephrine values were slightly higher than normal throughout the experiment, but lower than for subjects working under time-stress. High sympathetic activity (as indicated by norepinephrine) may have interfered with sleep.

Adult↗