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Exposure to Backlit Displays Reduces Melatonin Production

Posted by Unknown on from the hack-all-night dept.

alphadogg writes "Researchers have discovered that relatively little exposure to tablets and other electronics with backlit displays can keep people up at night by messing with their circadian rhythms. The study from the Lighting Research Center at Rensselaer Polytechnic Institute showed that a 2-hour exposure to electronic devices with such displays causes suppression of the melatonin hormone and could make it especially tough for teens to fall asleep. The study, funded by Sharp Laboratories of America, simulated usage of such devices among 13 people using special glasses/goggles and light meters"

46 of 192 comments (clear)

  1. Orly? by Anonymous Coward · · Score: 2, Funny

    My eyes! The goggles, they do nothing!

  2. Sample size too small? by Anonymous Coward · · Score: 5, Interesting

    Surely 13 people is too few to draw meaningful conclusions?

    1. Re:Sample size too small? by cyclopropene · · Score: 5, Informative

      Surely 13 people is too few to draw meaningful conclusions?

      Yes. Especially if not compared to people reading a book under a 60 watt incandescent light bulb.

      --
      Shouldn't you be doing something useful?
    2. Re:Sample size too small? by Cato · · Score: 2, Informative

      Yes, this is really junk science, but I believe there are other studies that show similar results - see http://stereopsis.com/flux/research.html for a list, including links to the full papers (the site is for F.Lux which I really recommend to adjust colour temperature to get more sleep, for Windows, Mac and Linux, and jailbroken iOS).

  3. N = 13? by schitso · · Score: 5, Insightful

    Should this even be considered relevant?

    1. Re:N = 13? by anom · · Score: 4, Insightful

      Furthermore, why didn't they just use actual backlit displays instead of some approximation? It's not like there is a shortage of them.

    2. Re:N = 13? by MagusSlurpy · · Score: 3, Informative

      Because they wanted to control the exposure. People use tablets differently. Different distances, different brightnesses, different sized font (larger black letters means less light emitted), different tablets=different displays=different wavelengths emitted.

      Too small of a group, but an interesting start.

      --
      My sister opened a computer store in Hawaii. She sells C shells by the seashore.
    3. Re:N = 13? by cultiv8 · · Score: 2

      OK so they did a couple t-test and apparently, based on my limited understanding of how they calculated degrees of freedom, one or two people were dropped from the sample for each test, most likely because they were outliers (I would RTFA but the site appears to be slashdotted). And this is supposed to prove what?

      --
      sysadmins and parents of newborns get the same amount of sleep.
    4. Re:N = 13? by bgeezus · · Score: 3, Funny
      Nice one... you should have been a coauthor of this paper: Ten ironic rules for non-statistical reviewers by Karl Friston.

      As an expert reviewer, it is sometimes necessary to ensure a paper is rejected. This can sometimes be achieved by highlighting improper statistical practice. This technical note provides guidance on how to critique the statistical analysis of neuroimaging studies to maximise the chance that the paper will be declined. We will review a series of critiques that can be applied universally to any neuroimaging paper and consider responses to potential rebuttals that reviewers might encounter from authors or editors.

    5. Re:N = 13? by artor3 · · Score: 2

      So, if I were to give thirteen people a pill, and ten of them grew wings and flew away, you would complain that my study hasn't proven that my pills can make people grow wings?

      I don't know or particularly care whether or not the study in the article is significant, but it's ridiculous to hold up sample size as the end-all-be-all of what determines significance.

    6. Re:N = 13? by tlhIngan · · Score: 2

      Should this even be considered relevant?

      Depends what you're using the results for.

      If you're arguing that it's too small to be definitive, you're right. It's too small to generalize to the general population.

      However, if it's an initial study to see if there *might* be something worth studying (people have been arguing that exposure to screens before bed ruins sleep, after all), then a small sample might be fine to see if it's even worth studying. Rather than spend lots of money studying lots of people and controlling for all variables - try to see if a small subset even matches the hypothesis.

      This study is small to determine if the general agreement that screens-before-sleep might be an issue. If it proved otherwise, it means the hypothesis was invalid and needs to be revised, as per the scientific method (it could be you were completely unlucky and picked people who happened to disprove the hypothesis, but if it's as common as you believe, it would be unlikely).

      This study has proved that there might be something to that, but it's not definitive. In other words, more comprehensive studies are required (perhaps you got lucky and picked the 13 people who were affected).

      There's nothing wrong with small sample sizes - it's just used to cheaply identify if the hypothesis is remotely correct before spending the time, effort and money studying a much larger sample that may generate inconclusive results.

      Also, if you're depending on grant money, it means you can walk to the grant committee and show them that you have results that prove interesting, but need further study to confirm. Grant committees don't like hypothesis, they like preliminary studies.

    7. Re:N = 13? by retchdog · · Score: 3, Informative

      the omitted cases were due to not generating enough saliva for a melatonin assay. probably not much worry of confounding there.

      it doesn't prove a whole lot, if anything. we already knew that blue light suppresses melatonin, and they give the predicted effect in the study along with their measurements. annoyingly, they don't give the two-hour theoretical effect, which is the regime in which they have statistical significance in their results. neither do they formally compare the tablet-only effect to high-blue-light (enforced by goggles) effect, but it's pretty obvious that the tablet isn't as bad. which, of course, isn't surprising since the lumens are lower.

      conclusion: it's an almost completely useless study, but the statistics they give seem legit enough. they don't do multiple comparisons correction, but if they did, the two-hour effect would still be significant.

      look, guys, if an experiment shows a statistically significant effect which also mostly conforms to the predicted effect (and there aren't blatant design errors), then there isn't much to complain about. i could, quite likely, have done this with n=6 (two for each treatment) and still gotten significance.

      --
      "They were pure niggers." – Noam Chomsky
    8. Re:N = 13? by Anonymous Coward · · Score: 2, Informative

      fuck the paywall. here's the table. the intervals for measured melatonin suppression are +/- one standard error.

      http://tinypic.com/view.php?pic=33bfl8o&s=6

    9. Re:N = 13? by dutchwhizzman · · Score: 4, Interesting

      Apart from my joke response, yes, N = 13 is way too small here. Not only that, but the circumstances are questionable as in to how the light was administered. No tests have been done with other light sources generating other spectrums either.

      Someone I know has done some rather ground breaking studies in the past, resulting in Philips selling light therapy lamps to cure winter depression. This was the first, or at least the first serious commercial supplier of such lamps, working with clinically proven effectiveness. I know what type of things he had to study to come up with what exactly works and what doesn't, so he would have scientific proof as well as proper clinical tests to prove that the light therapy fixtures he came up with actually worked and what was the "effective ingredient". He also had to make them in such a way that using them would not be too much of a burden to people, getting a usable balance between comfort while the light was on and duration. The higher the light intensity, the shorter exposure required.

      One of the things he found, was that below a threshold, your body simply wouldn't react when it came to winter depression treatment. For sleeping (another study he's continuously working on), however, any light source he tried, was an influence, even at very low intensities. He found that things like dream intensity, REM patterns and all that increased when people were in a totally dark room. Even with your eyelids shut, your body still reacts to the light.His most recent study found that by exposing senior citizens to a high dosage of "day light" slows and even can improve conditions like dementia and is very effective against depression.

      For all these, to get absolute proof, he had to do double blind field tests on large control groups, in their natural environments, because the plain effect of just exposing them to a test was itself an influence already. Also, as mentioned before, the spectrum and getting over a certain threshold was significant in the senior citizen experiment. He had to do tests in several elderly homes for long periods of time, using different light sources and amounts of light per center, for 6 months time and gather all the data on depression, dementia, number of complaints, amount of people taking an afternoon nap and all that, plus the comparison to the situation a year before, to get any significant data to work with. All in all, his study in senior citizens used more than a thousand subjects. Even with that number, it was hard to get to a level of clinical proof that using intense artificial daylight exposure inside elderly homes was beneficial to the health of the inhabitants.

      For the sleeping pattern tests, he is exposing people to different intensities and spectrums for months, using dozens of test subjects each year, for years in a row. People tend to have different sleeping patterns depending on how their day went, the temperature, their general health and the season already. It was common sense to assume that and he quickly found out that the deviation was such that he had to work with large groups and take a lot of samples to deal with that. In order to get any significant results, he'll have to figure out what the standard deviation is per subject, for the entire group and use that to come up with base levels in which he can find differences that can only be attributed to his light testing.Now, how do thirteen lab monkeys with apparatuses stuck to their eyeballs just before they were sent to bed compare to that again?

      --
      I was promised a flying car. Where is my flying car?
  4. I can attest... by suprcvic · · Score: 5, Interesting

    I've found that over the last year or so I've had trouble falling asleep and getting deep restful sleep. I started getting off the computer about an hour before I plan to go to bed, taking 3mg of Melatonin and reading a book. Now I'm getting the best sleep I've ever had. On that note, good night.

    1. Re:I can attest... by slackware+3.6 · · Score: 2

      Yah the melatonin helps you sleep but the zombie nightmares get much more realistic.

    2. Re:I can attest... by baker_tony · · Score: 3, Insightful

      Haha, solution is to pop a pill. I take it you're an American? No offence, but that seems to be the American way...

  5. Worry about it in the morning by ewg · · Score: 3, Funny

    I'll worry about this in the morning.

    --
    org.slashdot.post.SignatureNotFoundException: ewg
  6. Re:Explains a lot by Anonymous Coward · · Score: 5, Informative

    Now we know why geeks are so pale.

    You're thinking of Melanin, not Melatonin.

  7. And this is different from TV how? by thesupraman · · Score: 5, Insightful

    In breaking news:

    "Researchers have discovered that relatively little exposure to television and other electronics with backlit displays can keep people up at night by messing with their circadian rhythms."

    "Researchers have discovered that relatively little exposure to home lighting can keep people up at night by messing with their circadian rhythms."

    And finally:

    "Researchers have discovered tha tspending too much time reading obvious 'scientific' reports can keep people up at night by messing with their circadian rhythms."

    1. Re:And this is different from TV how? by queazocotal · · Score: 2

      You actually can see up to a few kHz.
      Admittedly, not directly, but if you sweep your eye past a fast flashing light, it becomes a dotted, not solid line.
      (The brain tries to turn off the eyes for a hundred or two ms during a saccade (rapid sweep), but this does not quite work.)

    2. Re:And this is different from TV how? by norpy · · Score: 2

      normal
      adjective
      1. conforming to the standard or the common type; usual; not abnormal; regular; natural.
      2. serving to establish a standard.

      Just because you don't like it doesn't make it not normal.
      Also, just because it has a TV resolution does not make it a TV. Televisions are defined by their built in tuners that conform to broadcast standards, any screen that does not supply it's own video signal is considered a monitor.

      I will give you the crappy resolution thing, but we are finally getting that pushed into the market thanks to apple. Although i'm skeptical about your "10 year old high resolution units" being much more than 1080p. Most of those panels that weren't stupidly expensive were still the same number of horizontal pixels as 1080p but were 16:10 instead of 16:9

  8. Re:Explains a lot by TemperedAlchemist · · Score: 5, Informative

    That's melatonin not melanin. Melatonin regulated sleep.

  9. Pretty Obvious + Plug for Awesomeness by Wrath0fb0b · · Score: 5, Interesting

    I think all /.ers have known this since about age 15. I used to go into a phase where I'd be up every night later and later until I was going to sleep at 6AM and waking up at 2PM. Eventually I'd lose a day and "reset" to a normal time only to inch back later ...

    Anyway, here's a plug for the awesomesuace that is f.lux, which removes the blue hues from your monitor (since blue light is more associated with circadian rhythm than red) when it's supposed to be night. I am not associated with the makers of f.lux in any way except being a hopeless devotee and mentioning them to anyone within earshot that mentions difficult keeping a normal sleep cycle.

    1. Re:Pretty Obvious + Plug for Awesomeness by ad1217 · · Score: 4, Informative

      I would also say that F.lux (or Redshift for Linux, which works about the same, but is less buggy) is extremely helpful, though I use it because the red tint does not hurt my eyes as much.

    2. Re:Pretty Obvious + Plug for Awesomeness by Trogre · · Score: 4, Informative

      This.

      Not that I use f.lux, but the GPL'd Redshift on my laptop. When switching it on, it feels like my eyes breathe a sigh of relief - it really is much easier to read off a red-orange-tinted surface at night.

      Now if only they'd port it to Android.

      --
      "Nine times out of ten, starting a fire is not the best way to solve the problem." - my wife
    3. Re:Pretty Obvious + Plug for Awesomeness by Cato · · Score: 2

      F.lux is great, works on Windows, Mac and (jailbroken) iOS. One of the downsides of iOS devices as e-readers is that you have to jailbreak to get f.lux installed and not change your sleep cycle.

      There's also XFlux, but I use Redshift too on Linux - http://www.ubuntu-inside.me/2009/03/flux-better-lighting-for-your-computer.html

      [[http://stereopsis.com/flux/ios.html Now on iOS]] for jailbroken devices - see [[iPhone]] for jailbreaking.

      Discussion: http://forum.koohii.com/viewtopic.php?id=5347&p=1

      Blue light in morning resets circadian cycle: http://www.sciencedaily.com/videos/2006/0201-waking_up_teens.htm

      Tie-in to SAD and phase advance or delay associated with depression: http://www.sciencedaily.com/releases/2006/05/060501113832.htm

  10. Uh, yeah. by russotto · · Score: 3, Insightful

    Exposure to light can reduce production of a hormone known to have its production reduced by exposure to light.

    1. Re:Uh, yeah. by VortexCortex · · Score: 2

      The difference is that the researchers studied the effects of back lit display light, vs indoor incandescent light, candle light, fireplaces, outdoor camp fires, or cave entrance torches...

      What I mean is that they lack control groups something fierce.

  11. Welcome to Tautology Club by deatypoo · · Score: 3

    The first rule or Tautology Club is the first rule of Tautology Club http://xkcd.com/703/

    --
    Any sufficiently advanced incompetence is indistinguishable from malice.
  12. Re:Turn the damn brightness down! by queazocotal · · Score: 4, Interesting

    I find that works.
    But.
    Almost all my devices will not dim adequately.
    Typical dim range is down to 1:128 or so.
    1:1000 is much better for use in true dark.
    I have to in addition use extra software to increase the dimming, or set dark fonts and backgrounds to get it truly comfortable in a dark room.
    This would be a free mod to do in hardware.

  13. on the hypothesis by ThorGod · · Score: 2

    Not sure about the sample size...but the Institute backing the research looks reputable enough. (Yes, that matters.)

    Anecdotally, I've been turning my TVs and monitors' backlights down after 5 pm for months now. I'm definitely able to get to sleep more easily than leaving monitors at full brightness.

    --
    PS: I don't reply to ACs.
  14. Any word? by fuzzyfuzzyfungus · · Score: 2

    So, any word on how many man-years of sleep have been pointlessly destroyed by the fact that blue LEDs are now cheap and 'cool' enough to include in assorted consumer electronics devices where low-power greens used to be used?

    Maybe I'm just turning into a cranky old guy in my old age; but the old, dim, reds, ambers, and greens in various blinkenlight panels were downright soothing. Now you plug something in(even something designed to be pointed at a movie-watcher's face, FFS) and odds are that a blinding blue point source will burn a hole in your retina. Even a boring domestic-grade pile o' networking gear can put out enough light to read by at night.

    1. Re:Any word? by dgatwood · · Score: 3, Informative

      Likewise. I have a Samsung TV with a bright red light that's on whenever the device is off (WHY?) and a Samsung with lighted buttons where the power button's light doesn't ever turn off (WHY?). Both are covered with electric tape.

      I swear, every time I think electronics manufacturers can't get dumber, they prove me wrong. The worst part of it is the realization that a simple firmware fix would make the difference between these being great devices and making me want to fly to South Korea and smack all their engineers upside the head repeatedly with a clue-by-four....

      --

      Check out my sci-fi/humor trilogy at PatriotsBooks.

  15. Re:Explains a lot by Tehrasha · · Score: 2

    I SO wanted that to work...

  16. Re:Turn the damn brightness down! by Larryish · · Score: 2

    Kpdf can be set to use a black background.

    Of course that means installing QT on an otherwise worthwhile system :/

  17. Re:Explains a lot by fuzzyfuzzyfungus · · Score: 2

    It's hard to do without ruining image quality or causing a CRT implosion; but shaving a bit of the glass off the front of the tube might help... They didn't use leaded glass in CRTs just for fun...

    Radiation burns are a form of 'tan' right?

  18. Re:Explains a lot by ignavus · · Score: 4, Funny

    That's melatonin not melanin. Melatonin regulated sleep.

    I clearly need more sleep. I first thought you wrote "Melatonin regulated sheep."

    I suppose sheep regulation could help you sleep - it would make them easier to count.

    --
    I am anarch of all I survey.
  19. Re:Explains a lot by Mista2 · · Score: 3, Interesting

    f course, I've been reading with my iPad and iPhone in bed.
    1 I find that the biggest problem of falling asleep with the iPad is that it hurts much more than my iPhone when you fall asleep and it hits you in the nose.
    iBooks and Kindle also have a night mode 8) this stops the wife complaining of the LCD glow.
    And I've started reading 2312. If this doesnt put you to sleep, nothing will.

  20. Re:Explains a lot by Samantha+Wright · · Score: 4, Funny

    And a lightin' up a fatty doesn't hurt

    --
    Man! It stinks in here

    Do you make a habit of speaking to your signature?

    --
    Bio questions? Ask me to start a Q&A journal. Computer analogies available for most topics!
  21. Re:Explains a lot by frosty_tsm · · Score: 2

    That's melatonin not melanin. Melatonin regulated sleep.

    I clearly need more sleep. I first thought you wrote "Melatonin regulated sheep."

    I suppose sheep regulation could help you sleep - it would make them easier to count.

    Baaaa. Baaaa.

  22. bad test then by dutchwhizzman · · Score: 2

    There are quite some good studies into how light triggers sleeping patterns and causes or prevents winter depression and all that. With a tablet, you usually will be exposing little more than the retina around your "yellow spot" while with using lenses and all, I think you might be exposing a lot more of the peripheral areas of your retina as well. There could be a significant difference in how that influences your melatonin levels. Yes, it's true that the amount of "blueish" light over a certain threshold that hits your retina influences your melatonin production and sleeping patterns. However, the actual amount that hits your retina when using a tablet and where it hits will be a significant factor in that. If the results of this study this were true, people looking at LCD televisions and LCD computer screen would also not be sleeping at night, nor would they be suffering from winter depression. I think there is plenty of statistic evidence that whoever conducted this study, must have done something wrong to come up with these results.

    --
    I was promised a flying car. Where is my flying car?
  23. Even better! N = 1 by dutchwhizzman · · Score: 2

    You may conclude that the pill you took yourself while doing the study is a powerful hallucinogen. Conclusive results based on just a single sample!

    --
    I was promised a flying car. Where is my flying car?
  24. Re:Explains a lot by Jane+Q.+Public · · Score: 2

    "That's melatonin not melanin. Melatonin regulated sleep."

    All sleep-regulated sheep aside, melatonin supplements are cheap and plentiful. The tablets most often come in 3mg size but a doctor said that's "almost certainly too much". Take 1 mg (or 1/2 a 3 mg), about half an hour to an hour before bedtime.

    Caution: taking melatonin (especially 3 mg) can cause you to feel groggy in the morning if you haven't gotten a full 8 hours.

  25. Maybe it does by Penurious+Penguin · · Score: 2

    Perhaps the line of logic was; that the effects of melatonin-deficiency induced circadian-dysrhythmia would have one sleeping more during the day than at night, thus reducing exposure to the sun and causing paling. That was my first thought when I read the original comment. Maybe melanin was never considered. And most geeks I know, do indeed spend their time primarily indoors and in front of melatonin-depleting monitors.

    I actually can't imagine modding that comment "offtopic". But I am not normal, at all.

    --
    Forward! -- Emperor Norton, 2012
  26. Re:f.lux can help by KozmoStevnNaut · · Score: 2

    I can't prove anything outright, but I feel that using f.lux has helped me sleep more easily. On Linux I use redshift.

    If you set it to the slow transition speed (1 hour), the change is imperceptible. Until you try turning it off, that is. The difference is amazing.

    --
    Eat the rich.