Thinking Zs

Give someone a pill and tell them it will make their headaches go away, and it just might — even if the pill is nothing more than a sugar tablet. That’s because of something called the placebo effect — when a remedy known to be ineffective in treating a certain medical condition (the “placebo”) causes “a perceived or actual improvement in [that] condition,” as Wikipedia summarizes. The placebo effect is a testament to the power of our brains — we can think ourselves into feeling better, and sometimes, even into getting better.

And the placebo effect may also make us sleepy, too.

Let’s start with some stats. According to the National Institutes for Health, adults should get about 7 or 8 hours of sleep each night. Unfortunately, many of us (perhaps as many as 30%, but that feels on the low end) don’t hit that mark regularly. And therefore, many of us are more tired than we otherwise should be. At times, we even complain about it. Check out, for example, people on Twitter saying that “need more sleep,” that they’re “so tired,” or they “need a nap.”

That may be true. But thinking too much about our fatigue may be a bad idea, according to a recent study by professors at Colorado College. Because if you complain about being sleepy, the researchers discovered, you’re more likely to actually become more tired.

The test subjects — 50 people in the first trial, and another 114 in a subsequent one with slight modifications — were asked how they slept the night before (on a scale of 0 to 10), as the Atlantic notes. Then came the lies. Each of the participants was hooked up to a series of monitors which purportedly measured things like their heart rate, brain waves, and other biometrics. The subjects were told that these data points would be used to calculate the percentage of their previous-night’s sleep which was REM (basically, “deep” sleep), but it did no such thing. The participants were further told that in a typical night’s sleep, an average person would spend about 20% to 25% of the night in REM sleep. After the tests, the 164 participants were divided into two groups — members of the first group were told that their REM percentage was 28.7% (above average) while members of the second group were informed that they slept poorly, with only 16.2% of their night before in the REM stage. Those numbers, of course, were given out arbitrarily — the monitors didn’t actually output that data. But the study participants didn’t know this.

Then, each of the participants was given a cognitive abilities test. The end result: if you were told you didn’t sleep well, you didn’t do well on the test. On the other hand, if you were told you slept like a baby, you performed better than the rest. And this accounts for how you actually slept — according to the participants’ self-reported feelings (before receiving the made-up REM sleep results), at least.

So the bad news, as Slate notes, “dwelling on how tired you are might actually make you more tired.” But the good news? As Smithsonian sums up, “simply thinking you got better sleep makes your brain work better.”

Bonus Fact: If you’re not feeling well and have trouble falling asleep because you can’t stop sneezing, there’s good news — you probably won’t sneeze once you fall asleep. As mental_floss notes, when we hit REM sleep, the signals that typically trigger a sneeze aren’t transmitted to our brains. As a result, even the worst would-be sneezing fits don’t wake us up, because they never happen.

From the Archives: Kneedless Surgery: The placebo effect, via a knife.

Related: A $100 pillow. Even if it doesn’t actually work, the price tag may convince you into thinking it did… and that may be good enough!