Changes in Motor Function in Response to Living in an Extreme Underwater Saturation Environment under High Stress and Increased Workload

Abstract

Understanding changes in individual motor function and how it relates to workload, personality types, and shared knowledge is vital to the success of team‐based missions. Such changes may present a challenge in long duration spaceflight and other missions in extreme environments. Therefore, we studied grip strength, dexterity, stress level, task load and the personality types of participants living in an extreme environment during the NASA Extreme Environment Mission Operation (NEEMO) 23 in June 2019. The Aquarius Reef Base is home to NEEMO missions and is located at 20 m (66 ft) with 2.6 atm (air) pressure inside the habitat, where CO2 levels are often elevated similar to the International Space Station.Motor strength was assessed using a grip dynanometer and dexterity was measured using a pegboard. The tests were performed by 6 subjects (2 males, 4 females) 1 day pre‐mission, during the mission (grip test twice) and 1 day post‐mission. Dexterity test was also performed at the beginning and at end of Extravehicular Activities (EVAs). NASA TLX tests measuring mental, physical, temporal effort, performance, general effort and frustration, were assessed immediately after returning from EVAs. To monitor changes in stress level, Short Stress State Questionnaire (SSSQ) and Generalized Anxiety Disorder (GAD7) scores were collected. Measures of social cognition, including Reading the Mind in Eyes and Big 5 personality tests, were performed once before the mission.There was a trend of decreased grip strength at the end of mission and post‐mission, compared to baseline and beginning of mission. The dexterity scores at the beginning of EVAs were significantly higher, compared to before and during mission. This suggests that tasks with fine motor function can be affected by context such as in‐water performance. At the end of the EVAs, the dexterity score was significantly higher compared to before mission and during mission as well. There was a trend of worse performance on the dexterity test at the end of EVA, compared to the beginning of EVA. A trend of increasing GAD7 scores at half time of the mission and post‐mission could be observed. There were several differences in NASA TLX scores between different subjects.These results indicate that strength and dexterity was influenced during EVAs. This may have been due to both physical and psychological stress during the extreme underwater mission in a saturation environment. Further examination of these trends is recommended.Support or Funding InformationKetone Technologies LLC provided partial funding for the study. SIFT provided partial salary for CA.