Department of Psychiatry

Penn Behavioral Health

NASA and National Space Biomedical Research Institute

Countermeasures for Performance Deficits from Sleep Loss and Workload in Space Flight

Principal Investigator: David F. Dinges, Ph.D.

In order to be able to carry out mission-critical tasks at any time during a mission, astronauts must maintain a high level of performance in the face of demanding workloads and work-rest schedules that result in chronic sleep restriction. This research will use a laboratory-based study to acquire critically-needed information on the effects on performance of high cognitive workload and sleep restriction. We will test the hypothesis that as sleep restriction accumulates, it will potentiate the performance-impairing effects of higher cognitive workload. Another key goal of the study is to provide astronauts with an objective way to identify performance changes and the need for countermeasures for fatigue from sleep restriction and high workload. To this end, the project will complete validation of the sensitivity of the 3-minute PVT SelfTest to high workload and sleep restriction. PVT SelfTest feedback interfaces will also be evaluated, and the task will be tested in analog operations (e.g., NEEMO) to establish its technical feasibility. Tertiary goals of the project include identification of biobehavioral predictors of differential vulnerability to the cognitive effects of sleep restriction and high workload, and development of individualized biomathematical models that predict performance on the PVT SelfTest during high workload.


Optical Computer Recognition of Stress, Affect and Fatigue during Performance in Space Flight

Principal Investigator: David F. Dinges, Ph.D.

Astronauts must maintain high-level performance while experiencing demanding workload and work schedules, extreme environmental risks, and psychosocial stressors in space (e.g., isolation, confinement). Stress, negative emotions and fatigue can jeopardize their cognitive performance and neurobehavioral status. This research will deliver an objective, unobtrusive,

computational model-based tracker of the human face that validly and reliably identifies when astronauts are experiencing stress, emotion and fatigue at levels that compromise performance in space. This optical computer recognition (OCR) system will provide feedback to them for autonomous selection of countermeasures for stress, depression and fatigue. The project will be accomplished through collaborative efforts of Dr. David Dinges (Unit for Experimental Psychiatry) at the University of Pennsylvania School of Medicine, and Dr. Dimitris Metaxas (Computational Biomedicine Imaging and Modeling Center) at Rutgers University.

The project has four specific aims: (1) Create an OCR system capable of monitoring facial displays of  specific emotions (i.e. angry, happy and sad). (2) Improve our current OCR system’s ability to detect facial expressions of high versus low performance-induced stress. (3) Develop OCR algorithms to identify fatigue due to sleep loss based on slow eyelid closures (PERCLOS). (4) Test the technical feasibility of data acquisition and reliability of the advanced OCR system in spaceflight analogs that contain neurobehavioral stressors relevant to spaceflight (e.g., NEEMO).


PVT SelfTest on ISS

Principal Investigator: David F. Dinges, Ph.D.

This project will deploy a specially developed, zero upmass, algorithmically optimized, brief (3-minute) version of the well-validated Psychomotor Vigilance Test (PVT), referred to as the “PVT SelfTest,” on the International Space Station (ISS), to provide astronauts with objective feedback on performance changes in vigilant attention, psychomotor speed, lapses of attention, and impulsivity during ISS Increments 20 to 25 (N=24 astronauts). The overarching goal of the project is to establish the extent to which the PVT SelfTest can aid astronauts to objectively identify when their performance capability is degraded by various fatigue-related conditions that can occur as a result of ISS operations and time in space (e.g., acute and chronic sleep restriction, slam shifts, extravehicular activity (EVA), and residual sedation from sleep medications). Thus, the project addresses a number of high-priority NASA Behavioral Health and Performance (BHP) research gaps including (1) identification of the best measure for assessing decrements in cognitive function due to fatigue and other aspects of spaceflight; (2) determination of an individual astronaut’s vulnerability to sleep loss; (3) establishment of cognition decline or change during long-duration missions (LDM); and (4) facilitation of ways for crewmembers and ground support to detect and compensate for decreased cognitive readiness to perform in space.

The project builds on our previous NASA-funded work. Preliminary validation studies of the PVT SelfTest in astronauts engaged in NASA Extreme Environment mission (NEEMO) missions 9, 12, and 13 indicated that the 3-minute test was acceptable to astronauts, and provided unique astronaut norms on the test. We have used the data from astronauts engaged in NEEMO missions, and related data on the PVT SelfTest from extensive laboratory validation studies, to optimize the algorithm for astronaut PVT SelfTest performance, and to complete a feedback interface that displays their performance relative to astronaut norms.

The PVT SelfTest software will be deployed in a computer in the ISS Human Research Facility (HRF) throughout each of six ISS missions on N=24 astronauts. The N=4 U.S. astronauts on each of six ISS increments (20-25) will complete the PVT SelfTest (and a few pre- and post-test questions about operations relevant to fatigue) for a total time of 6 minutes, once every 4 days throughout each 180-day ISS mission. Each astronaut will serve as their own control, and data will be aggregated over time for comparisons of PVT SelfTest performance relative to the presence versus absence of sleep loss and circadian disruption (e.g., slam shifts), of various work intensity conditions (e.g., EVA), of sleep medication use, and of time in mission. Astronauts will be asked to indicate the extent to which their PVT SelfTest performance feedback (via a graphical interface) was useful for assessing their performance capability and countermeasure needs. Thus the project will help astronauts objectively identify and mitigate fatigue-related performance deficits during space operations.


Objective Monitoring of Crew Neurobehavioral Functions in Mars-520

Principal Investigator: David F. Dinges, Ph.D.

This project will evaluate the extent to which two novel computer-based technologies-optical computer recognition (OCR) of facial expressions and the 3-minute PVT Self Test-both of which are well along in development and validation for NSBRI and NASA, can be used to track stress, fatigue and negative affect during the Russian Mars 520-day simulated space flight. They will be deployed in the 520-day study on notebook computers supplied to each of the 6 volunteer crewmembers. Using a specially-programmed and calibrated notebook computer, 10-minute neurobehavioral assessments that include OCR video acquisition and the PVT Self Test, as well as a number of brief valid subjective assessments of stress, fatigue, mood states, depression, and sleep-wake, caffeine, etc, will be obtained twice a day (early AM and late PM) every 7th day of the mission, as well as on the morning after a night shift. The total crewmember time requirement for our assessments is no more than 20 minutes per week throughout the mission, which is designed to optimize data validity and crew adherence to assessments, while minimizing crew burden to ensure they have time to accomplish the extensive workload of the full-scale mission simulation. The 1-in-7-days data acquisition rate will permit a sampling rate across the mission that is needed to measure the sensitivity of the OCR and PVT Self Test technologies to the effects of work shift, sleep loss, critical incidents and time in mission.

The project procedures and outcome measures are based on lessons we learned from making more extensive measurements in the Russian 105-day pilot study in the same facility. The revised measures for the Mars 520-day study will require 26.7 hours per crewmember for the entire 520-day mission, which only 1/10th of the time required of crewmembers in the 105-day pilot study, and only 0.21% of the total in mission time in the 520-day study. Crewmembers will serve as their own controls in a longitudinal design (repeated measures) in which key variables (e.g., time in mission, sleep loss from 24-hour shift every 6 days, critical incidents) will be tracked to determine the extent to which OCR and PVT Self Test technologies co-vary within each crewmember as a function of these key variables. The output from these novel technologies will also be compared across the mission to participants’ self-report data on stress, fatigue, mood, depression, and sleep (which will also be tracked using wrist Actiwatches).


Individualized Real-Time Neurocognitive Assessment Toolkit for Spaceflight Fatigue

Principal Investigator: Mathias Basner, M.D., M.Sc.

This project will deliver a comprehensive, software-based, neurocognitive toolkit. By building on state-of-the-art neuropsychological test development, the toolkit will permit evaluation of a full range of cognitive functions using brief (1-5 min), validated procedures. The tests include—but go beyond—what is currently measured by WinSCAT and the Reaction Self Test on ISS. Importantly, the toolkit will permit rapid assessment of performance in cognitive, social-emotional and sensorimotor domains. Real-time performance assessment algorithms will be individualized to each astronaut’s norm, and adjusted for learning using a data modeling approach, in order to optimize individual and team performance relative to the effects of fatigue and related cognitive impacts. The toolkit will facilitate identification of underlying neural mechanisms affected when cognitive deficits are identified, by using tests selected on the basis of published fMRI studies that identify the specific brain regions subserved by each test. Toolkit development will progress from laboratory, to space analog (NEEMO), to ISS. The resulting comprehensive, neuroscience-validated, cognitive test battery for real-time evaluation of astronauts in space will be an essential detection technology for effective fatigue countermeasure management of astronaut performance in space. The link to neuroscience will yield directions for mechanisms of cause and potential interventions.



NASA and National Space Biomedical Research Institute -

Back to Top