Olivia Priedeman, 17, woke one morning from a dream she had about making plans with a friend.
But it wasn’t a dream. Her phone showed that during the night Priedeman had punched in her passcode, unlocked her phone and read a text message from her friend.
All while she was fast asleep.
“It was really weird,” recalled Priedeman, a junior at the Blake School.
Weird, but not uncommon.
Reading and responding to text messages while asleep — called “sleep texting” — is an abnormal sleep behavior, similar to sleepwalking. It’s also a growing concern among doctors grappling with a sleep-deprived population: young people who can’t be separated from their cellphones. For teens, lack of sleep has been linked to obesity, high blood pressure and behavioral problems.
Dr. Mike Howell, with Fairview Sleep Center at the University of Minnesota Medical Center, estimates that as many as half of his young patients who report sleep problems have sleep texted. While some of those texts did little more than embarrass their senders, others were nothing to joke about.
“We’ve had concerns of people who have texted or called 911, not realizing what had just happened,” he said.
We tend to think of sleep in finite terms: You’re either fully awake or fully asleep. But it’s not that simple, said Dr. Andrew Stiehm, a sleep medicine specialist with Allina Health.
It’s possible for the part of the brain that controls motor skills to wake up, while the part of the brain that governs memory and judgment may remain asleep. That’s why some people can perform rote movements — such as walking, talking, texting or even driving — while they’re sleeping.
Dr. Gerald Rosen, medical director of the pediatric sleep disorders program at Children’s Hospitals and Clinics of Minnesota, considers sleep texting an automatic response, similar to how a mother responds to a baby crying in the middle of the night.
“If you’re a mother, you awaken to the sound of your child crying. Even if it’s not a loud noise, it will trigger an awakening,” he said. “That’s essentially what’s happening with lots of kids with their phones.”
But Rosen sees sleep texting as a symptom of a larger problem: young peoples’ overreliance on cellphones.
“For them, the cellphone is a life link,” he said, “and this is central to how they view the world.”
One in three teenagers sends more than 100 text messages a day, according to the Pew Internet & American Life Project. And at least four out of five teens said they sleep with their phone on or near their bed.
Elizabeth Dowdell, a Villanova University professor who has studied sleep texting, said that having a phone nearby all night is a big part of the problem.