Wrist-Worn Psychomotor Vigilance Task Device Validation Study

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Shattuck, Nita Lewis
Matsangas, Panagiotis
Psychomotor vigilance task (PVT)
field studies
Date of Issue
January 2021
Monterey, California. Naval Postgraduate School
Collecting reliable human performance data in military operational environments is an ongoing challenge. A major issue of concern is identifying systems that can capture human performance metrics in a reliable and valid manner in the field. One task that has been used extensively in the laboratory - and more recently in field settings - is the Psychomotor Vigilance Test (PVT). Since 2008 the PVT has been included as a feature on a wrist-worn actigraph (AMI, Inc.), thereby enabling researchers to easily administer the PVT in the field. The current project has three aims, a) to validate the 3-minute PVT which is currently embedded in the AMI actigraph, b) to explore the utility of other devices for field use, and c) to provide recommendations for the collection of PVT data in the military operational environments. In our studies, we found that when the screen backlight is illuminated, the results of the 3-minute PVT on the AMI actigraph are comparable to those from the laptop PVT. These findings demonstrate that the 3-minute PVT on the AMI actigraph is a valid alternative to the 3-minute laptop-based PVT for field assessment. Given the widespread use of hand-held devices with a touch screen interface, we also tested a PVT application on a representative touch screen device. Our findings were disappointing, showing that the hand-held touch screen PVT system was not comparable to the validated PVT. In particular, the touch screen PVT introduced a large constant bias as well as a proportional bias that decreased the range of response speed. These findings raised the question of what the appropriate user interface should be for a field-grade PVT system. Herein, we present a method we have developed and refined over multiple years to prepare PVT data collected in field setting for analysis. This method reduces bias due to missing data and artifacts from external disturbances by assessing the quality of the PVT data on three levels: the raw response level, the aggregated (trial) level, and the participant level. In brief, our experience of collecting PVT data, combined with findings from this current 3 year effort, suggests that when administering the PVT in field settings, it is best if the PVT is embedded in a wearable device such as the AMI device. While other types of devices (e.g., smartphones, iPods, tablets, etc.) can be used for PVT administration, they have important constraints which should be taken into consideration.
Technical Report
Prepared for: Naval Advanced Medical Development Program; Naval Medical Research Center; 503 Robert Grant Avenue, Silver Spring, MD 20910
Series/Report No
Operations Research (OR)
Naval Postgraduate School
NPS Report Number
Naval Medical Research Center Advanced Medical Development Program
Naval Advanced Medical Development Program; Naval Medical Research Center
80 p.
Distribution Statement
Approved for public release; distribution is unlimited.
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.