Potential Correlation Between Circadian Phase Monitored and Crash Events (in addition to sleep deprivation)

As sleepiness is an imperative safety issue in the whelm of professional driving, many studies have looked into analyzing sleep deprivation and its’ effects on driving performance. Comparing Dr. Baura’s work and Dr. Jackson’s work at Victoria University of Australia, both studies investigated how sleep deprivation manifests itself within driving-related cognitive capacities. Both looked at professional drivers however with different experimental sessions under varying conditions. As Dr. Baura’s work monitored live performance of the drivers while Dr. Jackson used a projection simulation.

Two drivers in Dr. Baura’s study each had an episode of stage one sleep while driving proving that these drivers working at long intervals were not obtaining as much sleep as is required for alertness on their job. Supporting such findings, Dr. Jackson observed that subjects reported higher levels of sleepiness following the simulation indicating that even their standard of one night without sleep is sufficient to prove a ‘significant subjective increase in sleepiness’, of which was also reflective in the subjects’ behavior performance. Amongst the multitude of indicators of sleep deprivation and its’ effects on driving, there was no significant increase in crash events amongst the two cases. Overall, both studies showed how sleep deprivation is imperative in driving performance.

Generally speaking, sleepiness and performance are claimed to be influenced by input from the circadian rhythm and homeostatic drive and is the interaction between the two that causes fluctuations within daily performance. These systems show to influence varying cognitive tasks in different ways. Knowing this information, both studies tested subjects during a seemingly favorable circadian phase being either a time the subjects were accustomed to, in the Dr. Baura’s case, or during a reasonable day-time as in Dr. Jackson’s study. Because of this, it was expected that there would be minimal impact of circadian processes on driving performance. In both cases, this potential limitation was not addressed and I think that controlling the circadian phase in which subjects are being monitored could be a key overarching element in more accurately understanding the effects sleep deprivation have on driving performance. Depending on the phase interval, significant potential increases or decreases in something like crash events, of which were not observed before, might be a result. As performance and and related cognitive processes are believed to be partially dependent on the circadian rhythm, it would be interesting to see how controlling just that variable, through altering the time of monitoring instead of focusing on sleep deprivation, might have as significant of effects manifesting in driving performance.

Works Cited

Jackson, M. L., et al. “Cognitive Components of Simulated Driving Performance: Sleep Loss

Effects and Predictors.” Accident Analysis & Prevention, www.sciencedirect.com/science/article/pii/S0001457512002059

Mitler, Merrill, et al. “The Sleep of Long-Haul Truck Drivers .” The New England Journal of

Medicine, pp. 755–761.

Filtness, et al. “Sleep-Related Crash Characteristics: Implications for Applying a Fatigue

Definitions to Crash Reports.” Accident Analysis & Prevention , vol. 99, Feb. 2017, pp.

440–444.