Getting a good night’s sleep is a challenge for many people. Whether it’s constant awakenings throughout the night or difficulty falling asleep or something else, your sleep is the foundation for your mental health. Without regular, deep sleep, you’re not functioning at your best. For most of us, that’s a problem.
We’ve previously reported on research that shows light in your bedroom can interrupt your sleep cycle. Turning off those LEDs and turning down those bright clocks can even help too (something a lot of people miss). And there may be tools to help you improve your sleep even if you use electronic devices at night.
But what about using our iPads, tablets, smartphones, laptops or Kindles before we go to bed?
Preliminary new research suggests you should look at all of your electronic devices just as you’d eye a cup of full-strength coffee an hour before bed — with extreme caution.
A recent survey of Americans found that about 90 percent of them used some type of electronics — a laptop, iPad, TV, smartphone or Kindle — within an hour of their bedtime. That’s a significant transformation of our pre-bedtime routines from just 20 years ago, when the only screen available to most of us in the bedroom would’ve been a TV.
Could exposure to these kinds of electronics before we go to sleep impact our sleep patterns or quality of our sleep?
Researchers from Brigham and Women’s Hospital, Boston (Chang et al., 2014) sought to find out in the new study of 12 young adults. In a simple randomized, crossover design, two sets of 6 subjects either read a regular book for about 4 hours before bedtime, or the same book on an iPad, for five consecutive evenings. Researchers then measured overall sleep quality by examining each subject’s time it takes to actually go to sleep, percentage of time in bed actually asleep, melatonin concentrations, EEG, and self-reported sleep quality ratings.
What did the researchers find?
We found that, compared with reading a printed book in reflected light, reading [an iPad] in the hours before bedtime decreased subjective sleepiness, decreased EEG delta/theta activity, and suppressed the late evening rise of pineal melatonin secretion during the time that the book was being read.
We also found that, compared with reading a printed book, reading an [iPad] in the hours before bedtime lengthened sleep latency; delayed the phase of the endogenous circadian pacemaker that drives the timing of daily rhythms of melatonin secretion, sleep propensity, and REM sleep propensity; and impaired morning alertness.
These results indicate that reading an [iPad] in the hours before bedtime likely has unintended biological consequences that may adversely impact performance, health, and safety.
Since the content of the books were the same, the researchers surmised that the significant difference was the light-emitting nature of an iPad (and other e-book devices like it, except Kindles without a backlight or the backlight turned off). Since smartphones and laptops use similar LED screens, it’s likely that the results are generalizable to those devices as well.
Of course, the fact that this study was conducted on only 12 subjects limits its generalizability. It must be confirmed by additional research, preferably on a larger and more diverse subject population before we can draw any definitive conclusions from it.
We think of our smartphones and tablets as helpful tools in keeping us updated and in touch with others wherever and whenever we’d like. And they work wonderfully at that.
But technologists seem to rarely consider the psychological impact of their inventions. How will this device change human interactions? Or, as in this case, how may it impact one of the foundations of good health and mental health, our sleep.
While we wait for additional research to confirm or deny these findings, why not try your own little experiment at home? If you’re one of those people who takes their phone or tablet to bed to read, give your bedtime routine an electronics vacation for a week (including backlit e-readers and even TV in the bedroom).
At the end of the week, has your sleep improved at all? If so, you may have your answer — and a clear path to better sleep in the future.
Chang, A-M., Aeschback, D., Duffy, J.F., Czeisler, C.A. (2014). Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. PNAS. doi: 10.1073/pnas.1418490112