Here’s how Figueiro frames the problem they are investigating:
The question we were trying to answer is, can you use light as a way to help [teenagers] go to bed earlier and feel more awake in the morning, without necessarily having to give them a pill, or give them some medicine?
The resulting study, recently published in Neuroendocrinology Letters, demonstrates that yes, indeed, there is a way to help the zombies teens curb their late-to-bed, late-to-rise habits.
The study shows that teens who don’t get a healthy dose of morning sunlight actually have a harder time falling asleep at night. The researchers have started refering to the phenomenon as “Teenage Night Owl Syndome.” The answer to Figueiro’s original question, therefore, is: light. Specifically, short-wave, or blue light – of which sunlight is an excellent souce.
Here’s what Figueiro said:
As teenagers spend more time indoors, they miss out on essential morning light needed to stimulate the body’s 24-hour biological system, which regulates the sleep/wake cycle.
These morning-light-deprived teenagers are going to bed later, getting less sleep and possibly under-performing on standardized tests. We are starting to call this the teenage night owl syndrome.
If you remove blue light in the morning, it delays the onset of melatonin, the hormone that indicates to the body when it’s nighttime. Our study shows melatonin onset was delayed by about 6 minutes each day the teens were restricted from blue light. Sleep onset typically occurs about 2 hours after melatonin onset.