Psychomotor vigilance task
|Task Performance and Analysis|
The psychomotor vigilance task (PVT) is a sustained-attention, reaction-timed task that measures the speed with which subjects respond to a visual stimulus. Research indicates increased sleep debt or sleep deficit correlates with deteriorated alertness, slower problem-solving, declined psycho-motor skills, and increased rate of false responding. The PVT was championed by David F. Dinges and popularized by its ease of scoring, simple metrics, and convergent validity. However, it was shown that motivation can counteract the detrimental effects of sleep loss for up to 36 hours.
How it works
The PVT is a simple task where the subject presses a button as soon as the light appears. The light will turn on randomly every few seconds for 5–10 minutes. The main measurement of this task is not to assess the reaction time, but to see how many times the button is not pressed when the light is on. The purpose of the PVT is to measure sustained attention, and give a numerical measure of sleepiness by counting the number of lapses in attention of the tested subject.
Where it has been used
The Psychomotor Vigilance Self Test on the International Space Station (Reaction Self Test) provides the crewmembers with feedback on neurobehavioral changes in vigilant attention, state stability, and impulsivity. It aids crewmembers 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). The test is ideal for use in space flight because unlike other cognitive tests, it is brief while being free of learning effects and aptitude difference that make interpretation of other measures difficult, as it has been successfully deployed in three NASA missions.
- Dinges, D. I, & Powell, J. W. (1985). Microcomputer analysis of performance on a portable, simple visual RT task sustained operations. Behavior Research Methods, Instrumentation, and Computers, 17, 652–655
- Loh, Sylvia; Nicole Lamond, Jill Dorrian, Gregory Roach, Drew Dawson (May 2004). "The validity of psychomotor vigilance tasks of less than 10-minute duration." . Behavior research methods, instruments, & computers : a journal of the Psychonomic Society, Inc (University of South Australia, Woodville, Australia) 36 (2): 339–346. doi:10.3758/BF03195580 . PMID 15354700 . Retrieved 2011-06-09.
- Walker, M. P. (2009, October 21). *Sleep Deprivation III: Brain consequences – Attention, concentration and real life.* Lecture given in Psychology 133 at the University of California, Berkeley, CA
- Boen, B. (n.d.). International space station. Retrieved from http://www.nasa.gov/mission_pages/station/research/experiments/Reaction_Self_Test.html
- Meditation acutely improves psychomotor vigilance, and may decrease sleep need. Prashant Kaul, Jason Passafiume, R C Sargent and Bruce F O'Hara. Behavioral and Brain Functions 2010, 6:47 doi:10.1186/1744-9081-6-47