Everywhere we turn a screen calls for our attention. (Albert Gea/Reuters)

There was once a girl who spent a long time on her iPhone in bed, scrolling through photographs of her friends and watching funny videos on the Internet. The next day she woke up groggy and tired and unable to focus on anything. She walked into her calculus classroom with eyes barely open and yawned every five seconds. She fell into a deep microsleep and missed a valuable math lesson. The next day, she took a test on the material and when she got her test results, unsurprisingly, she had not done as well as she had wanted.

That girl was me.

Facebook, Instagram, and Twitter are just a few of my favorite things. These Web sites and apps help me keep in touch with my friends and family, find out what interesting events are going on and see and share photographs within my social circle. There couldn’t possibly be anything wrong with that, can there?

For a long time, I believed the answer to be no.

However, the more time I spent online — to socialize, not study — the less sleep I received, and the worse I felt. I was moody and tired, and focusing on classroom lectures and interactions became increasingly difficult, particularly after spending hours online on my computer or on my iPhone.

I began to wonder whether or not there could be a relationship between the hours I spent using recreational screen time and the negative effects it had the next day at school. To answer my question, I dove into neuroscience research.

I found that the brain’s prefrontal cortex isn’t fully formed until age 25, and during the period of adolescence, the brain is maturing and the prefrontal cortex is especially sensitive to environmental influences. Some of these influences – screen time particularly – are new types of influences that haven’t been studied in depth and are quite popular among adolescents like myself. With my own personal experience driving my motivation to find an answer to my pressing problem, I wanted to look at the intersection of sleep, stress, screen time, and things like academic achievement and mood.

I recruited local middle and high school students. Using surveys and questionnaires, I figured out who received more and who received fewer than eight hours of sleep per night, since eight hours is the recommended amount of sleep for adolescents. From the responses, I found that the sleep-deprived group had about 3 1/2 hours of screen time per day, whereas kids who got more than eight hours of sleep had about two hours of screen time. Next, to determine mood, memory and cognition, I tested the students’ decline in cognitive skills over the course of the school day. The high-screen-time, low-sleep group was more prone to stress, sleepiness and anxiety, performed poorly on tests of cognitive ability and showed more mood issues. Most interestingly, I found that the light emanating from electronic devices mimic daylight, shutting off the part of our brain that creates melatonin, the chemical we need in order to fall asleep. Therefore, using electronic devices right before bedtime increases the time it takes to fall asleep.

The results were striking, and I hadn’t expected the correlation to be so obvious or strong. The results definitely changed my perception of recreational screen time, as well as reshaped how and when I took advantage of that time. I have dramatically reduced the time I spend on Facebook, Instagram, and Twitter by a handful of hours. While I wouldn’t necessarily recommend against any screen time, I do believe that when teenagers start trading sleep time for screen time, it can have some serious consequences.

Electronic devices are tools, and like tools, they can be used to build or destroy. What we need to understand is that the overuse of these devices is negatively affecting adolescents’ cognition, mood, and memory. I hope teens will rethink the amount of time they spend on these devices. I know that I’d rather do well in school than watch another couple of hours of Netflix. It may be our nature to choose the short-term reward of entertainment, but now I’m more awake, more energized and happier in the morning thanks to a full night’s rest.

Rahman, 17, is a finalist in the Intel Science Talent Search 2014. She is a senior at Brookings High School in South Dakota.