Space Sleeping: A New Study
(Ivanhoe Newswire) – A 520 day space mission to Mars, results in an out of this world study that reveals important information on the impact of prolonged operational confinement on sleep, mood, and performance in astronauts.
The findings revealed alterations of life-sustaining sleep patterns and neurobehavioral consequences for crew members that need to be addressed for adaption to prolonged space missions.
"The success of human interplanetary spaceflight, which is anticipated to be in this century, will depend on the ability of astronauts to remain confined and isolated from Earth much longer than previous missions or simulations. This is the first investigation to pinpoint the crucial role that sleep-wake cycles will play in extended space missions,” David F. Dinges, PhD, professor and chief, Division of Sleep and Chronobiology in the Department of Psychiatry at the Perelman School of Medicine, and co-lead author, was quoted as saying.
The simulated mission, which was developed by the Institute for Biomedical Problems (IBMP) of the Russian Academy of Sciences and sponsored in part by the European Space Agency (ESA), involved an international, six man team that required more than 90 experiments and realistic scenarios in order to gain medical and psychological data on the effects of a long-term deep space flight.
Researchers monitored the crew’s rest-activity patterns, performance, and psychological responses to study the sleep loss, fatigue, stress, mood changes, and conflicts that arose during the mission.
Researchers included continuous recordings of body movements using wrist actigraphy (noninvasive means of estimating sleep and movement intensity) and wrist exposure and weekly computer-based neurobehavioral assessments to identify changes in the crew’s activity levels, sleep-wake intervals, alertness performance, sleep quantity and quality, and workload throughout the 17 months of mission confinement.
The actigraph devices showed researchers that crew sedentariness increased across the mission. Also, most crew members experienced one or more disturbances of sleep quality, alertness deficits, or altered sleep-wake intervals and timing.
"Taken together, these measurements point to the need to identify markers of differential vulnerability to abnormal decrease in muscular movement and sleep– wake changes in crew members during the prolonged isolation of exploration spaceflight and the need to ensure maintenance of the Earth's natural circadian rhythm, sleep quantity and quality, and optimal activity levels during exploration missions," Mathias Basner, MD, PhD, MSc, assistant professor of Sleep and Chronobiology in Psychiatry at Penn and co-lead author, was quoted as saying.
Successful adaptation to missions will require crews to transit in spacecraft and live in surface habitats that mimic aspects of Earth’s sleep-wake activity cycles, for example timed exercise, food intake, and light exposure.
"A takeaway message from this line of research is the life-sustaining importance that healthy sleep duration and timing plays for everyone. As a global society, we need to reevaluate how we view sleep as it relates to our overall health and ability to lead productive lives. Whether it is an astronaut being challenged to reach another planet or a newborn baby just learning to walk, the human body's need for sleep is as essential as our need for food and water and integral to our ability to thrive,” Dr. Dinges concluded.
SOURCE: Proceedings of the National Academy of Sciences, January 2013