The Sleep Onset Latency Test Might Tell You Whether You're Sleep Deprived
As I stare into my enormous mug of coffee, there is no question in my mind that I need more sleep. But despite my heavy eyelids and caffeine cravings, am I actually sleep deprived according to science? Well, apparently the Sleep Onset Latency Test is here to help. (Sleep latency refers to the length of time it takes a person to go from complete wakefulness to the first stage of sleep). The test isn't new; it was devised by Nathaniel Kleitman of the University of Chicago, a psychologist and sleep researcher known for his 1939 book Sleep and Wakefulness (which is still used as a reference today). But it's currently making the rounds again, thanks to a recent article by British TV personality and journalist Michael Mosley published in The Daily Mail, so it's worth taking a closer look at now. Mosley wrote that the self-administered home test helped him confirm his sleep issues and build better nighttime habits — no electrodes needed. If you want more clarity on whether their sleep patterns are healthy, this is one test you should definitely make time for.
While having a bad night’s sleep here and there isn’t the end of the world, missing out on those much needed Zzzs can have a quite a few negative effects. Missing sleep consistently can lead to issues with memory, concentration, and mood swings, as well as changes in blood sugar levels and appetite. If you need a few good reasons to squeeze in a nap, long-term risks of chronic sleep deprivation include a heightened chance of type 2 diabetes, a weakened immune system, heart attack, hypertension, and stroke.
The simplicity of the Sleep Onset Latency Test may sound silly, but its principles are founded in actual science. The test examines the subject's daytime fatigue, one of the many symptoms of sleep deprivation, with just a few common objects: a metal spoon, a metal tray (a cookie sheet works perfectly), and a clock.
Here's how to take it: Set aside some time in the early afternoon to draw the shades closed and lie down in a dark and quiet room. Place the metal tray on the floor by your bed (or couch, or chair), and hold the spoon in your hand so that it rests just over the edge of the bed. Glance at the clock and make note of the time, and then close your eyes and try to relax. If the test is successful, the spoon will fall from your hand once you fall asleep and hit the metal tray. The sound of the drop should wake you up. Once awakened by the sound of the spoon, check the time, and see how long it took you to drift off.
According to Dr. Kleitman's research, those who fall asleep within five minutes of closing their eyes are severely sleep deprived. Falling asleep within 10 minutes is deemed "troublesome," but those who drift off after 15 minutes are in the clear. If you couldn't fall asleep at all — congrats! You are definitely not sleep deprived. If you are worried you won't wake up from the spoon clang, Mosley recommends setting a timer for 15 minutes. If you fall asleep before the timer goes off, you are showing signs of sleep deprivation.
While not the most convenient, the test must be performed during the day, as as sleep onset latency may be naturally lower at night. The ideal times to perform the test include 10:00 a.m., 12:30 p.m., and 3:00 p.m. So, perhaps a little after lunch nap might be in order?
Now, if you would excuse me, I have to go find a dark room to lie down in... for science.