Focus on Fatigue

Sleep and Decision Making

By January 10, 2018 No Comments

Welcome to Focus on Fatigue,

It’s a brand-new year and many of us will spend time this month deciding what areas of life or work we wish to focus on in the coming twelve months. There is, however, one important thing we should all do before making any important decisions: get a good night’s sleep. This month in Focus on Fatigue we’ll look at how sleep deprivation can affect the decisions we make.

The FRMS Team


InterDynamics Pty Ltd
320 Adelaide Street Brisbane Qld 4000
Tel +61 2 8404 0400 Ext 23

Views expressed in articles and links provided are those of the individual authors, and do not necessarily represent the views of InterDynamics (except where directly attributed).


Sleep and Decision Making

Many studies have attempted to explore the effects of sleep deprivation on decision making. So far researchers have found that sleep deprivation will produce the greatest detrimental effects under the following conditions:

Dull, monotonous tasks

The more basic and monotonous a task is, the more likely it is that sleep deprivation will make you perform badly. Performance can be improved if the person is motivated to do well.

Boredom or lack of motivation

Interesting tasks seem to be largely immune to sleep deprivation, as long as they are not too complex and are rule-based. However, even interesting tasks become dull and monotonous over time. Again, unless the motivation to do well is present, performance will begin to suffer.

Complex tasks with changing circumstances

The prefrontal cortex is the part of the brain that helps you to focus your attention on a given task for long periods of time. It also deals with novelty and the unexpected. During wakefulness, it is one of the hardest working parts of the brain.

This area of the brain is restored by deep sleep, which means that when you are sleep deprived, the prefrontal cortex is one of the first parts of the brain to suffer. Therefore, you could be affected in any of the following ways:

  • Impaired language skills-communication
  • Lack of innovation
  • Inflexibility of thought processes
  • Inappropriate attention to peripheral concerns or distraction
  • Over-reliance on previous strategies
  • Unwillingness to try out novel strategies
  • Unreliable memory for when events occurred
  • Change in mood including loss of empathy with colleagues
  • Inability to deal with surprise and the unexpected

The consequences of impaired decision making in the presence of sleep deprivation have been seen time and again throughout history. As summarised by Harrison and colleagues (2000):

“It is perhaps just a coincidence that some of the most renowned man-made disasters or near disasters concerning nuclear power plants, such as Chernobyl, Three Mile Island … all occurred in the early morning and involved human error in failing to contain otherwise controllable but unexpected and unusual mechanical or control room malfunctions. With all four, experienced control room managers misdiagnosed and failed to appreciate the extent of the fault and then embarked on courses of action that were inappropriate and continued to persevere in this way in spite of clear indications that their original assessment was wrong.” (p. 247)

Will coffee help?

When a person is in a position where they are sleep deprived and forced to make complex decisions, it is understandable that they will reach for a cup of coffee to help them cope with the demands that are being placed upon them. While the effects of coffee in such a situation have not been well researched, one study did find that a moderate dose of caffeine did nothing to reverse the effects of sleep deprivation in this sort of situation. In other words, drinking coffee may make you feel more alert, but it may not do anything to help you think more clearly.

What if I take a nap?

A nap does have the benefit of improving alertness, performance and mood. However, the nap will always be followed by a period of sleep inertia. How long this inertia lasts depends on the severity of the sleep deprivation, the length of the nap, and the sleep stage the person was in right before they woke up.

If a worker’s scheduled nap is interrupted by an emergency requiring a quick response with a high level of performance, that person may end up responding to the emergency while suffering the effects of sleep inertia. In this case, their job performance may be worse than if they had not napped at all.

Therefore, if this possibility exists, it will be necessary to weigh up the benefits of improved alertness and performance during regular work, with the potential likelihood of an emergency occurring during the period when sleep inertia is an issue.


  • Harrison, Y. and Horne, J. A. (2000) The impact of sleep deprivation on decision making: A review. Journal of Experimental Psychology: Applied, 6(3), 236-249.
  • Killgore, W. D. S., Balkin, W. J. and Wesensten, N. J. (2006) Impaired decision making following 49 h of sleep deprivation. Journal of Sleep Research, 15, 7-13.
  • Killgore, W. D. S., Lipizzi, E. L., Kamimori, G. H. and Balkin, T. J. (2007) Caffeine effects on risky decision making after 75 hours of sleep deprivation. Aviation, Space and Environmental Medicine, 78, 957-962.
  • Whitney, P., Hinson, J. M., Jackson, M. L. and Van Dongen, H. P. A. (2015) Feedback blunting: Total sleep deprivation impairs decision making that requires updating based on feedback. SLEEP, 38(5), 745-754.


In the News

Provided below are a selection of articles from around the web on the issues associated with fatigue. We hope you find them useful and interesting.

Article: Research shows sleep loss impedes decision making in crisis

Will Ferguson (7 May 2015) Washington State University

WSU researchers created a laboratory experiment that simulates how sleep loss affects critical aspects of decision making in high-stakes, real-world situations. Their results provide a new understanding of how going without sleep for long periods can lead doctors, first responders, military personnel and others in a crisis situation to make catastrophic decisions.

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