How does a lack of sleep affect our judgment? Does it really lead to poorer choices?
Unfortunately, the answer is many times yes. In my research into the topic, I’ve found at least eight ways how a lack of sleep affects different aspects of our judgment and decision making.
Sleep deprivation affects us both physically and mentally, and decision-making is a complex process that requires the orchestration of multiple neural systems, such as emotion, memory, and logical reasoning. It is therefore not too surprising that sleep deprivation would take a toll on many fronts.
Here are eight effects of sleep deprivation on decision making:
1) What’s perhaps best known is that it impairs attention and working memory, leading to slower reaction times, reduced vigilance, and more mistakes. This is why the risks of driving while sleepy are considered at least as dangerous as the risks of driving under the influence of alcohol [1]. For example, being awake for 17 hours leads to impairments equivalent to having a BAC of 0.05%, and being awake for 24 hours to having a BAC of 0.10%.
For people with ADHD, sleep deprivation leads to even more focus-related problems, such as disproportionately more errors and slower reaction times. In addition, lack of sleep decreases the effectiveness of some ADHD medications [2]. (Unfortunately, ADHD also makes it harder stick to a good sleep routine. Here are some tips on how to deal with this problem.)
2) But it also affects long-term memory. Sleep deprivation affects the brain’s ability to learn and recall information [3]. In fact, lack of sleep seems to be a risk factor for (not only correlated with) dementia, probably for a number of reasons [4; 5; 6]. For one, during REM sleep the brain processes information and consolidates memories from the previous day. Sleep also plays a large part in regulating the availability of neurotransmitters. Lastly, sleep deprivation leads to an increase in beta-amyloid. This is the protein that occurs in abnormally high levels in brains with Alzheimer’s disease, where it clumps together to form plaques that collect between neurons and disrupt cell function.
3) Logical reasoning ability also suffers. Namely, sleep deprivation increases rigid thinking, perseveration errors, and difficulties in processing and using new information [7]. In other words, complex tasks and innovative decision-making do suffer from a lack of sleep.
4) Self-awareness is another aspect of our judgment that’s essential for making smart choices. Unfortunately, self-evaluation of cognitive performance is also impaired by sleep deprivation. In one study [8], during 36 h of sleep deprivation, research participants became more confident that their answers were correct as the wakefulness continued. Confidence was even stronger when the answer was actually wrong.
5) Lack of sleep makes us more risk prone. For example, in gambling tasks, sleep deprivation led to both higher expectations of rewards for risky choices, as well as diminished responses to their losses [9].
6) In addition, many studies show that sleep deprivation leads to more impulsive behavior and a lack of inhibition [e.g., 10; 11]. Note that impulsivity is not the same issue as the risk attitude from the previous point. These two aspects of decision making are independent – you can be deliberate about taking high risks (e.g., choosing an aggressive investment portfolio), and you can be impulsive about avoiding risks (e.g., giving into irrational fears or shying away from discomfort). But of course the combination of impulsivity and risk-proneness is a particularly dangerous cocktail that can lead to reckless behavior.
7) Sleep deprivation has negative effects on many aspects of mood, such as depression, anger, and anxiety [e.g., 12 – 15]. While some studies only show correlations over time [12]., others do show a causal effect [13; 14]. One study examined the effects of sleep deprivation in healthy adolescents, comparing depression, anger, confusion, anxiety, vigor, and fatigue across days. They found that all mood states significantly worsened following one night without sleep. Female participants showed a greater vulnerability to mood deficits following sleep loss, with greater depressed mood, anxiety, and confusion [14]. Another study examined a cohort of medical residents over their first postgraduate year and found that mood disturbances, lowered empathic capacity, and burnout increased over the year, and were associated with decreases in sleep amounts and increases in sleepiness [12].
Here, too, if we keep in mind that increased impulsivity will be added to this mix of bad mood, it won’t be surprising to learn that bad behavior follows. For example, one study looked at abusive supervisory behavior in managers across a variety of industries. They showed that daily sleep quality was negatively related to leaders’ self-control, and that those who were more sleep deprived were rated as significantly more abusive and toxic in interpersonal interactions [16].
8) Finally, sleep deprivation affects our hormones and metabolism. It leads to decreased glucose tolerance, decreased insulin sensitivity, increased evening concentrations of cortisol, increased levels of ghrelin, and decreased levels of leptin [17]. While cortisol is a biomarker of stress, ghrelin and leptin regulate our appetite. Ghrelin increases our appetive, while leptin decreases it. In other words, sleep deprivation leads to increased hunger and appetite on both the ghrelin and leptin fronts. Add to that again a lack of inhibition, and it becomes clear that our eating choices will be affected by a lack of sleep. Indeed, there is growing evidence both from epidemiological and laboratory studies showing an association between sleep loss and increased risk of obesity [18].
How can you get enough sleep in your busy life?
Most of all, make sleep a priority. This will most likely require some sacrifices, because it means giving up some of your waking hours. But if you’re taking into account how much better those waking hours will be if you’re fully rested, the trade-off will be well worth it.
For practical tips as to how to get into a better sleep routine, google “sleep hygiene” and follow all the advice you’ll find. As an example of that, a recent study at a boarding school found that a regular routine and no mobile devices at night helped teenagers get more sleep [19].
If your have troubles falling asleep despite good sleep hygiene, here are some interesting tips. Or, google “visualization falling sleep” and you’ll find cornucopias of techniques. I’d encourage you to try one after the other, until you find one that works for you.
All this is easier said than done of course! If you’d like to get some help along the way–from deciding how to shift and re-balance your priorities, to developing strategies, and getting support as you’re putting your priorities into practice–I’d be excited to talk to you.
by Ursina Teuscher (PhD), at Teuscher Decision Coaching, Portland OR
Picture Credit:
Phil Konstantin. Photo released into the public domain via hhttps://commons.wikimedia.org/wiki/File:UtahSignByPhilKonstantin.jpg
References:
[1] Powell, N. B., Schechtman, K. B., Riley, R. W., Li, K., Troell, R., & Guilleminault, C. (2001). The Road to Danger: The Comparative Risks of Driving While Sleepy. The Laryngoscope, 111(5), 887–893. https://doi.org/10.1097/00005537-200105000-00024
[2] Waldon, J., Vriend, J., Davidson, F., & Corkum, P. (2018). Sleep and Attention in Children With ADHD and Typically Developing Peers. Journal of Attention Disorders, 22(10), 933–941. https://doi.org/10.1177/1087054715575064
[3] Alhola, P., & Polo-Kantola, P. (2007). Sleep deprivation: Impact on cognitive performance. Neuropsychiatric Disease and Treatment, 3(5), 553–567. https://pubmed.ncbi.nlm.nih.gov/19300585/
[4] Berglund, J. (2019). The Danger of Sleep Deprivation. IEEE Pulse, 10(4), 21–24. https://doi.org/10.1109/MPULS.2019.2922564
[5] Lack of sleep may be linked to risk factor for Alzheimer’s disease. (2018, April 13). National Institutes of Health (NIH). https://www.nih.gov/news-events/lack-sleep-may-be-linked-risk-factor-alzheimers-disease.
[6] Lack of sleep in middle age may increase dementia risk. (2021, April 27). National Institutes of Health (NIH). https://www.nih.gov/news-events/nih-research-matters/lack-sleep-middle-age-may-increase-dementia-risk.
[7] Harrison, Y., & Horne, J. A. (1999). One night of sleep loss impairs innovative thinking and flexible decision making. Organizational Behavior and Human Decision Processes, 78(2), 128–145. https://doi.org/10.1006/obhd.1999.2827
[8] Harrison, Y., & Horne, J. A. (2000). Sleep loss and temporal memory. The Quarterly Journal of Experimental Psychology. A, Human Experimental Psychology, 53(1), 271–279. https://doi.org/10.1080/713755870
[9] Venkatraman, V., Chuah, Y. L., Huettel, S. A., & Chee, M. W. (2007). Sleep Deprivation Elevates Expectation of Gains and Attenuates Response to Losses Following Risky Decisions. Sleep, 30(5), 603–609. https://doi.org/10.1093/sleep/30.5.603
[10] Anderson, C., & Platten, C. R. (2011). Sleep deprivation lowers inhibition and enhances impulsivity to negative stimuli. Behavioural Brain Research, 217(2), 463–466. https://doi.org/10.1016/j.bbr.2010.09.020
[11] Demos, K. E., Hart, C. N., Sweet, L. H., Mailloux, K. A., Trautvetter, J., Williams, S. E., Wing, R. R., & McCaffery, J. M. (2016). Partial sleep deprivation impacts impulsive action but not impulsive decision-making. Physiology & Behavior, 164, 214–219. https://doi.org/10.1016/j.physbeh.2016.06.003
[12] Rosen, I. M., Gimotty, P. A., Shea, J. A., & Bellini, L. M. (2006). Evolution of Sleep Quantity, Sleep Deprivation, Mood Disturbances, Empathy, and Burnout among Interns. Academic Medicine, 81(1), 82–85. https://doi.org/10.1097/00001888-200601000-00020
[13] Scott, J. P. R., McNaughton, L. R., & Polman, R. C. J. (2006). Effects of sleep deprivation and exercise on cognitive, motor performance and mood. Physiology & Behavior, 87(2), 396–408. https://doi.org/10.1016/j.physbeh.2005.11.009
[14] Short, M. A., & Louca, M. (2015). Sleep deprivation leads to mood deficits in healthy adolescents. Sleep Medicine, 16(8), 987–993. https://doi.org/10.1016/j.sleep.2015.03.007
[15] Pires, G. N., Bezerra, A. G., Tufik, S., & Andersen, M. L. (2016). Effects of acute sleep deprivation on state anxiety levels: A systematic review and meta-analysis. Sleep Medicine, 24, 109–118. https://doi.org/10.1016/j.sleep.2016.07.019
[16] Barnes, C. M., Lucianetti, L., Bhave, D. P., & Christian, M. S. (2015). “You wouldn’t like me when I’m sleepy”: Leader sleep, daily abusive supervision, and work unit engagement. Academy of Management Journal, 58(5), 1419–1437. https://doi.org/10.5465/amj.2013.1063
[17] Leproult, R., & Van Cauter, E. (2010). Role of Sleep and Sleep Loss in Hormonal Release and Metabolism. Endocrine Development, 17, 11–21. https://doi.org/10.1159/000262524
[18] Beccuti, G., & Pannain, S. (2011). Sleep and obesity. Current Opinion in Clinical Nutrition and Metabolic Care, 14(4), 402–412. https://doi.org/10.1097/MCO.0b013e3283479109
[19] Lushington, K., Reardon, A., & Agostini, A. (2022). O025 Boarding school students sleep better than day-student peers. The positive effects of bedtime routine and restricting technology use at night. Sleep Advances: A Journal of the Sleep Research Society, 3, A9–A11. https://doi.org/10.1093/sleepadvances/zpac029.024.
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