Exposure to Backlit Displays Reduces Melatonin Production

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"

Comments

Sample size too small?

[Anonymous Coward]

Surely 13 people is too few to draw meaningful conclusions?

Re:Sample size too small?

[cyclopropene]

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.

N = 13?

[schitso]

Should this even be considered relevant?

Re:N = 13?

[anom]

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

Re:N = 13?

[MagusSlurpy]

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.

Re:N = 13?

[bgeezus]

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.

Re:N = 13?

[retchdog]

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.

Re:N = 13?

[dutchwhizzman]

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 can attest...

[suprcvic]

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.

Re:I can attest...

[baker_tony]

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

Worry about it in the morning

[ewg]

I'll worry about this in the morning.

Re:Explains a lot

[Anonymous Coward]

Now we know why geeks are so pale.

You're thinking of Melanin, not Melatonin.

And this is different from TV how?

[thesupraman]

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."

Re:Explains a lot

[TemperedAlchemist]

That's melatonin not melanin. Melatonin regulated sleep.

Pretty Obvious + Plug for Awesomeness

[Wrath0fb0b]

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.

Re:Pretty Obvious + Plug for Awesomeness

[ad1217]

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.

Re:Pretty Obvious + Plug for Awesomeness

[Trogre]

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.

Uh, yeah.

[russotto]

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

Welcome to Tautology Club

[deatypoo]

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

Re:Turn the damn brightness down!

[queazocotal]

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.

Re:Explains a lot

[ignavus]

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.

Re:Any word?

[dgatwood]

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....

Re:Explains a lot

[Mista2]

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.

Re:Explains a lot

[Samantha Wright]

And a lightin' up a fatty doesn't hurt

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