Overview
Cognitive Performance and Stress in a Simulated Space Environment
Principal Investigator:
David F. Dinges, Ph.D.
Organization:
University of Pennsylvania School of Medicine
During missions, crew members are frequently required to do many critical tasks with associated stress and fatigue factors. The development of embedded performance tests that can be successfully related to performance capability metrics will give the crew member and Mission Control information on the best time to perform critical events and an evaluation of the need for countermeasures.
These studies, led by Dr. David F. Dinges, will take place during NASA Extreme Environment Mission Operations (NEEMO) 14 and during a Desert Research and Technology Studies (DRATS) mission. The purpose of this study is to collect cognitive performance and stress information on astronauts and mission support personnel to identify periods of fatigue and indentify stress during analog missions and to develop normative databases on fatigue and stress in analog environments for comparison to spaceflight.
NASA Taskbook Entry
Technical Summary
This project involved neurobehavioral and physiological assessments in two NASA analog environments: N=8 participants in NASA Extreme Environment Mission Operations (NEEMO) 14 in May 2010, and N=6 participants in Desert Research and Technology Studies (DRATS) mission in August-September 2009. Both missions lasted 14 days. The purpose of this study was twofold: identify fatigue and stress in relation to performance during analog missions, and further develop normative databases on astronauts in analog environments.
The goals of the study were accomplished by making the following assessments in each analog mission.
- Cognitive performance was assessed with three brief validated software-based cognitive performance tests (Psychomotor Vigilance Test (PVT) Self Test, Digit Symbol Substitution Test (DSST) and the Descending Subtraction Test (DST), which collectively formed the Penn Neurobehavioral Test Battery (PennNTB).
- Behavioral ratings of fatigue and stress were assessed using visual analog scale ratings of stress and fatigue (part of the PennNTB).
- Physiological stress was assessed using salivary cortisol.
- Feasibility of optical computer recognition (OCR) using facial videos acquired during the cognitive performance testing was assessed with computer webcams that recorded facial videos, which were subsequently evaluated by human scorers for OCR feasibility.
- Sleep-wake patterns were assessed using wrist actigraphy and sleep logs (in NEEMO 14 only, as comparable data in DRATS was obtained by a different project and principal investigator).
Data acquisition in both analogs and for all measurement domains ranged from 84 percent to 89 percent (grand average was 86 percent). PennNTB cognitive performance tests were completed on 497 test bouts out of 580 planned. Visual analog scale ratings of fatigue and stress were completed for 497 assessments out of 580 planned. Salivary cortisol was assayed on 410 samples out of 476 planned. Facial videos for OCR feasibility were acquired in 414 test bouts out of 476 planned. Days of wrist actigraphy and sleep log data were acquired on 135 out of 150 days in NEEMO 14. The majority of data loss (which was 9 percent-14 percent, depending on measure), was associated with operational schedule conflicts (e.g., no time available to complete measure). Less than 2 percent of data loss was due to technical failure.
The data acquired will add to the overall normative performance database on astronauts functioning in space analogs. Thus, the data from the project contributes to the further development of norms and performance algorithms for the PVT Self Test (currently being evaluated on the International Space Station as the Reaction Self Test), and to the transition of the other two brief cognitive performance tests (DSST and DST) to spaceflight. The data also contributes to further development of OCR for monitoring astronauts’ expressions of stress, emotions and fatigue (e.g., these data acquired in the analogs provided valuable information of the technical need to ensure adequate facial lighting and screen angle).
Earth Applications
The 3-minute Psychomotor Vigilance Test Self Test used in the NASA Extreme Environment Mission Operations 14 and the Desert Research and Technology Studies analogs is being developed to help people quickly and objectively detect the extent to which fatigue is affecting their alertness and reaction times. As such, the technology has high potential for usefulness in a range of safety-sensitive environments on Earth. Potentially any occupation in which alertness and fatigue management are essential to prevent errors on critical tasks will benefit from adaptations of the PVT Self Test technology (e.g., airport security screeners, physicians on nightshifts and prolonged call, etc.).
The other two brief cognitive tests evaluated in this project—the Digit Symbol Substitution Test and Descending Subtraction Test—are well validated in the laboratory to be measures of cognitive throughput (DSST) and working memory (DST), and are being used to evaluate the carry-over effects of sleep medications on astronaut performance following abrupt (emergent) awakening (study at NASA Johnson Space Center crew quarters, Primary Investigator, S. Johnston). These tests have potential to be useful in a range of Earth-based scenarios in which cognitive capability must be rapidly assessed (e.g., sedation, mild to moderate traumatic brain injury, mild cognitive impairment with aging, etc.).
The automated optical computer recognition technology being developed for objective monitoring and management of stress, negative emotional states and fatigue in spaceflight has applications for many Earth-based safety-sensitive occupations, such as transportation workers (e.g., truck drivers, train conductors, airline pilots), operators in safety-sensitive industries (e.g., power plant control rooms), and military personnel.
This project's funding ended in 2010
