Poor sleep makes for bad decisions
Picture this: after a bad night, where you slept too few hours or were awake for long stretches, you instal yourself at your desk. You know you have to work, you may even know exactly what tasks you need to accomplish to get through the day, but you feel slow, dull and a bit numb. You may find yourself staring at the same e-mail for a 10 solid minutes. Words are at the tip of your tongue, but you can’t quite seem to get your memory working. Problems are harder to solve and when a colleague speaks to you, the meaning of their words takes a bit longer to seep into your skull.
You may instinctively know that your performance at work is impaired after a bad night, but how does that work exactly?
Scientists have been studying the effects of sleep deprivation on the brain since at least the 1970s and evidence is mounting that poor sleep affects almost every single major brain function suffers when we don’t get enough sleep. Memory, creativity, problem solving and emotional processing all take a hit after a short night.
A growing body of scientific work tells us that sleep has an effect on associations among concepts in processing and memory (1), allowing us to restructure information (2), and therefore solve both easy and complex problems (3).Researchers have even shown that we are more likely to form false memories when we sleep poorly.
The sleep group solved a greater number of difficult problems than the other two groups
A very interesting study from 2012 had participants first try to solve both complex and easy problems and then divided them into three groups. One group went to sleep, another stayed awake and the last group tried to solve the problem again without delay. The sleep group solved a greater number of difficult problems than the other two groups. (4) Sleep makes problem solving easier.
Our creativity is also hampered by poor sleep. Connecting loosely associated ideas is the core trait of creativity, and our ability to do this is strengthened by a solid night’s sleep. Studies have shown that we re-organise and restructure information in our minds during our deep, non-REM sleep. (5, 6)
This impaired decision making for those who were sleep deprived was not only seen in complex tasks or gambling experiments, but also at lunch. Research from Uppsala University shows that sleep-deprived people are more likely to go for greater portion sizes and are more likely to choose high fat and high-sugar snacks than they do after a good night’s sleep. While we all know, on some level, that these types of junk food are bad for us, we’re much less likely to resist them when we are tired. (7)
It’s no accident than so many scientific discoveries and masterpieces in art and literature were inspired by a good night’s sleep. Niels Bohr saw the structure of the atom, electrons spinning around the nucleus like planets around the sun, in a dream. After years of research, he was able to prove his theory. The inventor of the sewing machine, Elias Howe, was inspired to put a hole in the tip of the needle of his machines by a dream. And more recently, James Cameron saw an entire strange extraterrestrial world in a dream and created the Avatar films. Our REM sleep allows for greater creative thinking, and the rest of the sleep stages can help turn loose creative ideas into real-world solutions or creations during the day.
We can feel the cognitive effects of poor sleep almost immediately, we are bleary-eyed after a short night, we can feel our memory lagging and our emotional processing is sub-par. The long-term effects of sleep deprivation on the brain, however, are still being studied.
An analysis of more than 25 scientific studies found a considerably higher risk of cognitive impairment and Alzheimer’s disease for those with sleeping problems. (8) This is likely because during sleep, the brain cleans itself up. Our brain is a lot better at clearing out waste, such as the beta amyloid proteins that cluster in patient’s with Alzheimers, when we sleep.
Sleep can feel like a luxury, especially when we’re busy or stressed out; and it’s often the first thing we sacrifice in times like these. But as the research shows, sleep isn’t an indulgence, it’s a necessity. Sleep helps solidify your memories, it clears out waste and toxins, improves our attention and helps us think outside of the box. Your brain will probably refuse service in some way or another if it doesn’t get enough downtime. So it may be time to change your attitudes about sleep and give it a little more attention than it usually gets.
References:
Cai, D., Mednick, S. A., Kanady, J. C., & Mednick, S. C. (2009). REM, not incubation, improves creativity by priming associative networks. Proceedings of the National Academy of Sciences, 106, 10130–10134.)
Payne, J. D. (2011). Sleep on it: Stabilizing and transforming memories during sleep. Nature Neuroscience, 14(3), 272–274.)
Ohlsson, S. (1992). Information-processing explanations of insight and related phenomena. In M. T. Keane & K. J. Gilhooly (Eds.), Advances in the psychology of thinking (pp. 1–44). London: Harvester Wheatsheaf.
Yordanova, J., Kolev, V., Wagner, U., & Verleger, R. (2010). Differential associations of early- and late-night sleep with functional brain states promoting insight to abstract task regularity. PloS one, 5(2), e9442.
Cai, D. J., Mednick, S. A., Harrison, E. M., Kanady, J. C., & Mednick, S. C. (2009). REM, not incubation, improves creativity by priming associative networks. Proceedings of the National Academy of Sciences of the United States of America, 106(25), 10130–10134.
Hogenkamp PS et al. Acute sleep deprivation increases portion size and affects food choice in young men. Psychoneuroendocrinology, in press
Bubu, O. M., Brannick, M., Mortimer, J., Umasabor-Bubu, O., Sebastião, Y. V., Wen, Y., Schwartz, S., Borenstein, A. R., Wu, Y., Morgan, D., & Anderson, W. M. (2017). Sleep, Cognitive impairment, and Alzheimer’s disease: A Systematic Review and Meta-Analysis. Sleep, 40(1), 10.1093/sleep/zsw032.