Scientists have finally figured out exactly how much sleep humans need: “Just five more minutes!” KIDDING! We’re not here to perpetuate unhelpful sleep habits (yeah – uh – sorry, that snooze button probably isn’t doing much for you); we’re here to talk about the science behind a topic that all people can relate to: sleep.
Sleep is a huge part of our daily routines: it is a dynamic process that affects functioning, helps people encode new information, stay healthy, and re-energize. Also, research consistently suggests that quality sleep can improve brain performance, mood, and overall health in the short term. Long term, poor sleep has been associated with numerous disorders and difficulties, such as dementia, strokes, and obesity. Scientists and doctors regularly agree that quality sleep is a top priority, making it important to know exactly what quality sleep even means.
Here is a basic rundown on what’s happening in our bodies that causes us to sleep, and what happens once we’re catching some Z’s. Two systems, our circadian rhythms and sleep drive, work in tandem to get us to sleep. This is sometimes called the sleep-wake cycle. First, our sleep drive (sometimes called “sleep pressure”) is basically your body’s desire to sleep that builds throughout the day. Once we’ve been awake for long periods of time, our sleepiness builds (meaning our sleep drive builds). At the same time, the body’s 24-hour repeating circadian rhythm is at play. Your central circadian clock responds to cues throughout the 24-hour day, generating alertness to keep us awake with light exposure and producing melatonin to promote sleep at night. From the moment you wake up your body works to keep these two systems steady throughout the day, so by the time night time rolls around, your circadian clock is cued to release melatonin, your sleep drive is high, leading to… bedtime!
Once we’re asleep, our brains cycle through 4 stages of sleep, basically consisting of REM (rapid eye movement) sleep and non-REM sleep, typically four or five times. Non-REM sleep stages (stages 1, 2, and 3), all hold their own importance, and are marked by different brain waves and bodily responses (brain waves meaning electrical impulses within the brain, measured using EEG). Think of Stage 1 as when you are just starting to rest and can be awoken easily, Stage 2 as when your body starts really relaxing and falling into sleep deeper, and Stage 3 as one of the deepest and most vital sleep stages as it is restorative and allows your body to recover.
As you enter each stage, sleep grows deeper and deeper, evidenced by changes in our heart rate, muscle tone, breathing, and brain waves. REM sleep (stage 4 in the sleep cycle) is a sleep stage lots of folks have heard of, and is often associated with dreaming, emotional processing, and memory consolidation. In comparison to other stages of sleep, in which our brain waves slow down, our brain waves become highly active during REM sleep (and so do our eyes – hence the name!). All of the parts of the sleep cycle are important, and it’s worth noting that failing to get enough Stage 3 sleep and REM sleep (Stage 4), specifically, can lead to big time consequences in daytime thinking, decision making, and emotional processing. That’s one of the reasons that waking up a lot throughout the night (before you’re able to get into those later stages of sleep) makes us feel so dang sleepy throughout the day!
Okay, I know this is a lot of information. Don’t start dozing off just yet. I promise that learning about these sleep facts is important. Knowing how sleep actually happens can help us understand why sleep myths are just that – myths! In fact, a lot of perpetuated myths that people actively follow contribute to dysregulation of these sleep processes, generating a cyclical process of sleepiness that can even impact our mental health. Don’t just take my word for it, let’s see what the experts have to say about some common sleep health misconceptions.
Misunderstanding #1. Sleeping in is always a good idea. Clearly stated by one of IU’s Psychological Brain Sciences faculty and licensed sleep psychologist, Spencer Dawson PhD, DBSM, “One of the most important things about sleep is consistent timing, particularly wake time. ”As the research suggests, a consistent wake time helps regulate your circadian clock. Sleeping in after a bad night of sleep can actually lead to a lessened sleep drive, and more difficulties falling or staying asleep the next night. You heard me, keep that 8am wake time, even on the weekends.
Misunderstanding #2. Alcohol = ticket to quality sleep. Unfortunately, this isn’t the case at all (van Schrojenstein et al., 2017). Even low amounts of alcohol can decrease sleep quality by almost 10% while high amounts of alcohol can decrease your sleep quality by almost 40%! Have you ever had a drink or two, or six, and felt like you were going to sleep so well, but then woke up feeling so tired? Well, you’ve fallen prey to two things: (1) alcohol is a depressant, making you fall asleep quickly; and (2), alcohol is still circulating in your system once you’re asleep, decreasing sleep quality by messing with the sleep cycles. Essentially the alcohol increases the suppression of REM sleep during your initial sleep cycles, causing serious sleep disruptions (Ebrahim et al., 2013).
Misunderstanding #3. Screens are the villain of good sleep. Screens at night can definitely impact circadian rhythms and sleep quality, but it’s only a small part of the picture, according to Dr. Dawson and the evidence to back him up (Orben & Przybylski, 2019). Actually, what you’re doing with the screen is just as important. Let’s put it this way: do you think it’s the screen itself keeping you awake, or is it the high-speed car chase in Breaking Bad that you just watched that’s stressing you out? If what you’re engaging in is exciting, thrilling, or anything of the sort, it might be tricky to fall asleep. Sure, decreasing brightness or turning on “night mode” is helpful, too, but the stimuli on the screen plays just as important a role in influencing your quality of sleep. Bonus tip: get more exposure to sunlight during the day – apparently, this can decrease sensitivity to light at night. Cool, huh?!
Misunderstanding #4. Snoring isn’t harmful. So, this isn’t 100% true. Many Americans believe snoring can signal deep sleep, which one might think “Nice! I’m a deep sleeper!”. While snoring isn’t always harmful (if it is light and infrequent), it can also be a problem. Snoring may be a sign of breathing difficulties at night and can signal sleep apnea, which can turn into excessive daytime sleepiness, depression, and daytime problems such as motor vehicle accidents. If you’re a snore-er, don’t fret. Check out some evidence-based resources.
Misunderstanding #5. You can “catch up” on sleep with naps. There are several things at play here. Many things impact our sleep cycles, like jet lag, busy schedules, and alcohol to name a few. In general, research has shown that the things that might make common sense following a single poor night of sleep, such as taking a nap, may be counterproductive. This is particularly true in people with chronic insomnia, as naps aren’t natural for our circadian rhythms and messes with our sleep drive. At the end of the day, while naps aren’t always bad, if you’re using naps to catch up on insufficient sleep, you might just end up making it harder to fall asleep at bedtime, further causing disruptions to your sleep routine.
The fun thing we’re learning during this series is that many health topics hold mysteries and nuances, and sleep is no exception. Fortunately, we have science and research on our side. Keep that wake time consistent, be smart about alcohol intake, consider whether your Tik Tok “For You” page is causing too much excitement, take note if you’re snoring, and “catch up” on your sleep at bedtime. If you’re experiencing symptoms of insomnia or other sleep disorders, always remember, help and resources are available. What other topics can Miss Understanding clear up?! Comment below!
Thank you to Dr. Spencer Dawson for his insights and comments on this article.
Edited by J Wolny and Jonah Wirt
Cited References:
Ebrahim, I. O., Shapiro, C. M., Williams, A. J., & Fenwick, P. B. (2013). Alcohol and sleep I: effects on normal sleep. Alcoholism: Clinical and Experimental Research, 37(4), 539-549.
Orben, A., & Przybylski, A. K. (2019). Screens, teens, and psychological well-being: Evidence from three time-use-diary studies. Psychological science, 30(5), 682-696.
van Schrojenstein Lantman, M., Roth, T., Roehrs, T., & Verster, J. C. (2017). Alcohol hangover, sleep quality, and daytime sleepiness. Sleep and Vigilance, 1, 37-41.
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