Objective Monitoring of Crew Neurobehavioral Functions (105-Day Russian Chamber Study)
Principal Investigator:
David F. Dinges, Ph.D.
Organization:
University of Pennsylvania School of Medicine
Fatigue, stress and negative emotional states can affect mission operations and crew safety during spaceflight. It is important that steps can be taken to reduce the risks that these factors can have on an astronaut???s performance.
Dr. David F. Dinges led a project to test two objective monitoring systems ??? the Optical Computer Recognition (OCR) system and the Psychomotor Vigilance Test (PVT) Self Test ??? during a 105-day isolation study in Russia. The researchers also evaluated two mood scales, the Beck Depression Inventory and the Positive and Negative Affect Schedule.
During the isolation study, which simulated a 105-day spaceflight, the researchers evaluated the feasibility of obtaining facial video to assess mood and fatigue using the cameras on the PVT computers. The researchers are also comparing the 3-minute PVT Self Test results to those from previous longer PVT tests and the Spaceflight Cognitive Assessment Tool for Windows.
Both systems have potential benefits for a number of safety-sensitive occupations on Earth.
NASA Taskbook Entry
As part of the 105-day Russian Chamber Study at the Institute for Biomedical Problems (IBMP) in Moscow, Russia, this project deployed two objective neurobehavioral monitoring techniques, Psychomotor Vigilance Test (PVT) and facial video for Optical Computer Recognition (OCR), as well as two mood scales, Beck Depression Inventory (BDI) and Positive and Negative Affect Schedule (PANAS).
The IBMP chamber consisted of interconnected sealed modules to simulate a space craft (analog) environment that included confinement, isolation, time delays, pressurization, dependence on and autonomy from mission control, and related behavioral factors. The 105-day isolation experiment in the chamber was the second of IBMP’s three chamber studies (14-day study, 105-day study and 520-day study), which collectively are referred to by IBMP as the Mars 500 project.
IBMP indicated that the 105-day chamber study focused on obtaining and analyzing scientific-technical information for optimal organization of preparation and efficient conduct of the main (third) experiment (i.e., 520-day study) simulating all the stages of a manned flight to Mars. Consequently, the 105-day chamber experiment was a pilot study for the 520-day experiment. Lessons learned in the 105-day study were used to improve experimental techniques and the completeness and validity of the data acquired in the 520-day study.
This project on Objective Monitoring of Crew Neurobehavioral Functions in the 105-day Russian Chamber Study was one of 72 separate protocols conducted in IBMP’s 105-day chamber study.
Specific Aims
1. Establish the feasibility of acquiring neurobehavioral data (facial video, cognitive performance, psychological assessments) on the six-person crew during the 105-day simulated mission, using specially programmed computers. Mission controllers were added to the data acquisition requirements after the study commenced.
2. Determine the feasibility of monitoring mood and fatigue states in crew members throughout the 105-day mission.
3. Evaluate the reliability of 3-minute PVT performance throughout the 105 days.
Acquisition of neurobehavioral data on the six crew members during the 105-day mission in the IBMP Mars 500 chamber was successfully completed using specially programmed notebook computers. During the simulated mission, crew members completed a total of 85 (94 percent) scheduled Beck Depression Inventories, 78 (87 percent) scheduled PANAS, 1,104 (88 percent) PVT and Visual Analog Scale (VAS) ratings and 19 (63 percent) WinSCAT tests. Facial videos of crew members to assess feasibility of Optical Computer Recognition (OCR) of emotional expressions and fatigue during the PVT tests yielded only 125 (11 percent) videos technically adequate for OCR evaluation, due to interference from facility lighting (i.e., face shadowed or too dark).
Data from 19 mission controllers showed lower adherence on all measures than did the crew members. Controllers completed 63 percent of the PANAS and BDI-II assessments, and only 50 percent of PVT. Across time in mission, crew members’ positive mood states tended to decline modestly, but negative moods states and depression were not evident and did not increase. Similarly, VAS ratings of stress and unhappiness did not change across the 105-day mission. In contrast, VAS mental fatigue declined and alertness improved significantly across time in the mission. PVT performance on the standard 10-minute PVT task showed increasing errors across time in mission. Increasing errors were not found in the optimized 3-minute PVT nor in measures from the WinSCAT performance battery.
Mission controllers showed no statistically significant changes in either positive or negative mood states or performance across time in mission except for total errors on the 10-minute PVT, which appeared to be due to increasing lax effort on the task. Night shift work by crew members increased subjective (VAS) ratings of sleepiness, tiredness and physical exhaustion and increased performance errors on the PVT, especially the 3-minute, optimized PVT.
The 105-day project results identified the following changes to procedures that would be needed to ensure the success of such data in longer-duration analog studies (e.g., IBMP’s 520-day Mars mission simulation).
- Adherence to the neurobehavioral procedures in the special computer used need to be adjusted to reduce the evaluation time burden on crews.
- Evaluation of data quality and quantity must occur regularly throughout the mission to reduce data loss by identifying and correcting problems.
- Acquisition of facial video for OCR from the built-in computer camera is feasible in the chamber if environmental lighting is standardized, and if special portable lighting of the face in the plane of the computer screen is used during the testing, when video is acquired.
- Acquisition of subjective reports should use brief rating scales, assess interpersonal conflicts, and include a measure of social desirability bias at pre-mission.
- Actigraphy should be used 24 hours a day, 7 days a week during the mission to provide an objective measure of crew behavioral rest-activity cycles for interpretation of performance and subjective data.
The 3-minute Psychomotor Vigilance Test (PVT) used in the 105-Day Russian Chamber Study 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 technology (e.g., airport security screeners, physicians on night shifts and prolonged call, etc.).
The 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 and airline pilots); operators in safety-sensitive industries (e.g., power plant control rooms); and military personnel.
