If you think you can get by at work with a few hours’ sleep, think again.
New research has found that being tired at work affects us even more than previously thought, and in more ways. The findings also strike a blow against the hope that downing several cups of coffee will help you make up the difference.
An experiment recently conducted at Michigan State University found that sleep deprivation is likely to hurt our short-term memory and “higher cognitive functions,” such as problem-solving abilities, as well as our ability to pay attention to the task at hand.
In other words, it makes us temporarily less intelligent as well as less attentive.
Sleep deprivation “may impair a range of higher-order cognitive processes directly, not just fundamental processes such as attention,” they write. “[O]ur results suggest that an intervention that benefits attention, such as caffeine, may not reduce costly errors in procedural performance,” they add.
That’s a significant finding, argue study authors Michelle Stepan, Erik Altman and Kimberly Fenn of the university’s psychology department. Existing research had still left open the possibility that sleep deprivation affected us mostly through its effect on attention.
The latest research is being published in the Journal of Experimental Psychology: General.
Some 138 college students took part in the experiment. They performed two hours of cognitive tests one evening, and then another 90 minutes of tests the following morning. During the intervening period, half the students went to sleep and the other half were kept awake. Those who went to sleep had their sleep monitored by Fitbits FIT, -1.56%.
There were two cognitive tests. The first was designed to see how attentive the students were. They had to watch a blank screen and click the mouse as fast as possible every time they saw a red circle. The second was more complex. It involved responding to questions while simultaneously tracking mentally where they were in a seven-step sequence. The researchers further tried to baffle them by interrupting them from time to time and making them perform an unrelated typing task.
Bottom line? Going without sleep made people less attentive. Those who had stayed awake all night performed much worse on the first, attention-related task. But, critically, they performed even worse on the complicated process-oriented task, even after accounting for their wandering attention.
“This suggests that sleep deprivation affects more than just vigilant attention and can cause deficits to a wide range of cognitive abilities,” says lead author Michelle Stepan. “Oftentimes we aren’t aware of how poor our performance is under conditions of sleep loss and we may think that we can perform just as well as when we are rested; however the sleep-deprived participants in our study performed much worse than rested participants.”
“These results also suggest that, even if you can perform some tasks normally under conditions of sleep loss, other aspects of cognition can still be impaired,” she added.
Admittedly the study has caveats. The sleep deprivation was severe — about 24 hours — and the participants were all young people, with an average age of 19. But it does not come in isolation.
Research in 2016 suggested those who went without sleep may actually have ended up earning less money, while other studies have found that a lack of sleep can be self-destructive or even dangerous. Going short of sleep raises your risk of hypertension, diabetes, obesity, heart attacks and strokes, other studies have suggested.
Lack of sleep often affects people whose jobs involve keeping the public safe and healthy: about 50% of protective-service workers including police officers, firefighters and correctional officers said they were getting too little sleep in 2018, and about 45% of health-care support workers did.
The problem isn’t limited to shift workers working for a paycheck; it also affects highly-compensated business leaders. Tesla TSLA, -0.41% CEO Elon Musk has said he was not getting much sleep during the summer of 2018 because he was working so hard. But the lack of sleep may have led to the increasingly erratic behavior that at one point had wiped a third off the company’s value, and landed him in a defamation lawsuit. (Tesla could not immediately be reached for comment)
Despite this, the U.S. Centers for Disease Control estimates that more than one-third of U.S. adults are going without enough sleep — possibly because the tasks that require us to work long hours are urgent, while getting enough sleep is merely important.