Time-of-day effects on speed and accuracy performance during simulated shiftwork

ABSTRACT

Performance on tasks involving speed and accuracy fluctuate throughout the 24-h day negatively affecting shift workers and organizations. Two simulated work shifts common in occupational settings were used to assess performance on a vigilance and math task. In study 1, 33 sleep-deprived participants completed a nightshift. In study 2, 32 partially sleep-deprived participants completed a dayshift. These studies found that performance differed between the type of task and the type of simulated shift where performance during the nightshift was worse than during the dayshift. In addition, collapsing speed and accuracy on the math task into inverse efficiency scores provided a unique measure that captured the impact of circadian rhythms during shiftwork. The current study also indicated that participants adopted cognitive strategies including speed-accuracy tradeoff and regulatory foci regarding work motivation (prevention focus and promotion focus) when completing the tasks depending on time-of-day, type of shift, circadian rhythms, and amount of sleep deprivation. This suggests that researchers and organizations should consider cognitive strategies in addition to the physiological components of sleep deprivation and circadian rhythms when investigating and documenting the impact of time-of-day due to different types of shiftwork conditions on performance and safety.

KEYWORDS:

• Sleep deprivation
• speed-accuracy tradeoff
• inverse efficiency score
• regulatory focus theory
• work motivation
• circadian rhythm
• sleep pressure

Acknowledgments

We thank Dr. James A. McCubbin for his effort in the initial formation of the research collaboration with the Center for Advanced Study of Language and the off-campus research laboratory. We also thank our research staff, graduate students, and undergraduate students at Clemson University for their assistance in data gathering and data management including Jesse Allen, J. Adam Beeco, Nicholas M. Beck, Michelle L. Burnett, Carrie Jung Clausen, Bradley J. Fawver, Nick Galan, Ben K. Jones, Tracy Lindquist, Robert S. Markle, Benjamin McDunn, Julian M. Montaquila, Laura McClelland, Tripp M. McElwee, Tyler Pierce, Philip Poole, J. Laura Posey, Matthew J. Smith, Rebekkah Wills, Brittany T. Wright, and Cassandra Wright.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available from the corresponding author, [JJP], upon reasonable request.

Additional information

Funding

The work was supported by the Center for Advanced Study of Language, University of Maryland, College Park, Maryland, USA.