Dynamic ensemble prediction of cognitive performance in spaceflight

Abstract

During spaceflight, astronauts face a unique set of stressors, including microgravity, isolation, and confinement, as well as environmental and operational hazards. These factors can negatively impact sleep, alertness, and neurobehavioral performance, all of which are critical to mission success. In this paper, we predict neurobehavioral performance over the course of a 6-month mission aboard the International Space Station (ISS), using ISS environmental data as well as self-reported and cognitive data collected longitudinally from 24 astronauts. Neurobehavioral performance was repeatedly assessed via a 3-min Psychomotor Vigilance Test (PVT-B) that is highly sensitive to the effects of sleep deprivation. To relate PVT-B performance to time-varying and discordantly-measured environmental, operational, and psychological covariates, we propose an ensemble prediction model comprising of linear mixed effects, random forest, and functional concurrent models. An extensive cross-validation procedure reveals that this ensemble outperforms any one of its components alone. We also identify the most important predictors of PVT-B performance, which include an individual's previous PVT-B performance, reported fatigue and stress, and temperature and radiation dose. This method is broadly applicable to settings where the main goal is accurate, individualized prediction of human behavior involving a mixture of person-level traits and irregularly measured time series.

A second space age spanning omics, platforms and medicine across orbits

“…The I4 mission provided a vast amount of both physiological and molecular data from the four civilian astronauts, spanning the six research projects, thousands of samples, and three mission phases (Table 3) 7 . Key measurements include multi-omics and virome Although the effects of short-duration spaceflight on cardiovascular function and neurocognitive performance were modest, there were marked interindividual differences in response to spaceflight, consistent with previous research 67,68 . Significant changes in heart rate, heart rate variability, energy expenditure, and activity levels occurred across mission phases.…”

“…Significant changes in heart rate, heart rate variability, energy expenditure, and activity levels occurred across mission phases. Furthermore, the spacecraft environment can impact crew physiology and neurobehavioral functions 68 and three out of the four I4 crew exhibited positive associations between CO2 levels and heart rate variability in-flight. Moreover, cfRNA and…”

Circuits and Biomarkers of the Central Nervous System Relating to Astronaut Performance: Summary Report for a NASA-Sponsored Technical Interchange Meeting

“…Astronauts on long-duration space missions (e.g., transits to Mars) will experience the combined, potentially synergistic, impacts of simultaneous exposures to spaceflight hazards that affect the central nervous system (CNS) and operationally relevant behavior and performance [ 1 ]. While individual spaceflight hazards are often individually well quantified, in long-duration spaceflight, astronauts will experience multiple hazards simultaneously [ 2 , 3 ].…”