Study shows short naps do not relieve lack of sleep – sciencedaily

“We are interested in understanding the cognitive deficits associated with sleep deprivation. In this study, we wanted to know whether a short nap during the deprivation period would alleviate these deficits,” said Kimberly Fenn, associate professor at MSU, author of the study and director of MSU Sleep and Learning Laboratory. “We found that short naps of 30 or 60 minutes showed no measurable effect.”

The study was published in the journal Sleep and is one of the first to measure the effectiveness of shorter naps, which often allow all people to adjust to their busy schedules.

“Although short naps did not show measurable effects in relieving the effects of sleep deprivation, we found that the amount of slow-wave sleep participants got during the nap was linked to a reduction in sleep deprivation. impairments associated with sleep deprivation, ”said Fenn.

Slow wave sleep, or SWS, is the deepest and most restorative phase of sleep. It is marked by high amplitude and low frequency brain waves and is the phase of sleep during which your body is most relaxed; your muscles are comfortable and your heart rate and breathing are at their lowest.

“The SWS is the most important stage of sleep,” said Fenn. “When someone doesn’t sleep for a while, even just during the day, they develop a need for sleep; in particular, it develops a need for SWS. When individuals fall asleep each night, they will soon enter SWS and spend a lot of time at this stage. “

Fenn’s research team – including his MSU colleague Erik Altmann, professor of psychology, and Michelle Stepan, a former MSU alumnus currently working at the University of Pittsburgh – recruited 275 college-aged participants for the ‘study.

Participants performed cognitive tasks upon arriving at MSU’s Sleep and Learning Lab in the evening and were then randomly assigned to three groups: the first was sent home to sleep; the second spent the night in the laboratory and had the opportunity to take a 30 or 60 minute nap; and the third did not take a nap at all in the deprivation condition.

The next morning, participants met again in the lab to rehearse cognitive tasks, which measured attention and maintaining space, or the ability to perform a series of steps in a specific order without skipping them. or repeat them, even after being interrupted.

“The group who spent the night and took short naps still suffered from the effects of sleep deprivation and made many more task errors than their counterparts who went home and got a full night’s sleep.” , Fenn said. “However, each 10-minute increase in SWS reduced post-interrupt errors by about 4%.”

These numbers may seem small, but when you consider the types of errors that could occur in sleep deprived operators – such as surgeons, police officers or truck drivers – a 4% decrease in errors could potentially save lives, Fenn said.

“Individuals who scored more SWS tended to show fewer errors on both tasks. However, they still performed worse than participants who slept,” she said.

Fenn hopes the findings underscore the importance of prioritizing sleep, and that naps – even if they include SWS – can’t replace a full night’s sleep.

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Material provided by University of Michigan. Original written by Caroline Brooks. Note: Content can be changed for style and length.