The absence of light is often a good cue for sleep. Of course, what exactly the effects of light are on sleep patterns still remains a mystery, but NASA scientists, in a new research, will be putting the effects of light on sleep to the test in a study that will be conducted on the International Space Station (ISS).
The new research, though quite simple in its basis, will apparently have profound effects, as researchers will be testing the effects of different colored lights on astronauts on the ISS to see what effects it may have and furthermore, see what effects the lights have on insomnia.
The equipment that NASA will be using will be Boeing-manufactured solid-state lighting modules (SSLMs), which have rows of Light Emitting Diodes (LEDs) that will produce a range of colors, namely blue, red or white light. The use of the different lights is to closely mimic that of natural day and night cycles on earth – which, of course, does not happen on the ISS. And possibly because of this, sleep, say besides oxygen, is one of the main concerns on the ISS, as, according to the US space agency, nearly half of the medication taken by astronauts is to induce sleep, with some 50 percent astronauts having difficulty to sleep, thus using sleeping pills and the like.
The space agency also added that “space travelers average about two hours sleep less each night in space than they do on the ground" and as stints on the ISS tend to last for months, insomnia or sleep deprivation is a very real possibility.
For this, the NASA SSLM test is being conducted, scheduled to start in 2016, with a reported budget of $11.2 million. The experiment will try to replicate what occurs naturally on earth in space, and seeing if such means can be used to treat sleep issues even on earth.
It has been noted in past researches that the different hours of the day have an effect on the body’s production of hormones and cell regeneration etc., as the hypothalamus, a part of the brain, reacts to the stimulus of light. Blue light, as will be produced by the SSLM panel, is known to arouse wakefulness and attention and the researchers behind the experiment feel that by using it in the visible light aboard the station, it can promote alertness while slowly transitioning to red via white light can potentially promote drowsiness and thus sleep.
Speaking about the experiment, professor of sleep and physiology at the University of Surrey, Derk-Jan Dijk said, "It hasn't been until recently that we started to realise that artificial light, as we see it or are exposed to it in the evening, will have an effect on our alertness and subsequent sleep. It turns out there are receptors in the eye which are tuned toward blue light. Adding blue light to artificial lights visible during the day can actually help us to be alert, but if there is too much blue light in the artificial lights at night that may disrupt sleep. So, varying the spectral composition of light does make sense from a circadian perspective, and better regulating artificial sleep-wake cycles may indeed benefit astronauts' sleep in space."