Whether or not we want to admit it, each hour we miss catching up on our dreams is another opportunity lost for cognitive growth. Kyla Wahlstrom, Ph.D., a senior research fellow who studies the influence of sleep on learning at the College of Education and Human Development at the University of Minnesota, has conducted sleep research on changes in school start times throughout three different states. Wahlstrom sat down to tell us more about her findings, and why we should care.
SOMNIA: Walk us through your research on sleep and education. What are some of the most interesting findings you’ve come across?
KYLA WAHLSTROM: Well, I got a phone call in the summer of 1996 from Dr. Ken Dragseth, who was the superintendent of the Edina school system, asking if I’d be interested in evaluating the change to Edina’s start time from 7:15 to 8:30 a.m. So I went to the school, started talking to parents, teachers, and the kids themselves. And it was phenomenal. Kids were saying they were staying awake in class, teachers were saying they didn’t have kids falling asleep at the desk. Teachers, counselors, nurses would grab me in the hall and say, “I gotta tell you, this has changed our life here.” And I was just blown away.
In 1997, just one year later, Minneapolis changed their high schools’ start time from 7:20 to 8:40 a.m. We really wanted to see if the Edina findings were a flash in the pan, so I studied the Minneapolis schools from 1997 to 2002, doing hundreds of interviews with parents, students, and so on.
What research tells us is that during adolescence only, the last synapses—the ones that are being developed, and formed, and maturing—are happening while the teenager is asleep. This is true all over the world.
How did that world-wide truth connect to your work?
It was interesting to have the contrast between Edina and Minneapolis, because in terms of socioeconomic status, you couldn’t get a more diverse comparison. But if the biology is the same for these teenagers, some things are going to be the same—and that’s exactly what we found. We found the same things, in terms of sleep patterns, preferences for when you wake up and how you sleep, how you feel more relaxed, and efficacious.
Once you’re done with adolescence, you go back to what your preferences were before you were an adolescent. And you’ll have that for the rest of your life. Those sleep times are a little more malleable. But adolescence is really, really hard.
The other things that’s really important is over 20 percent or more of all students sleep in the first hour of their class, if that class starts before 8:00. And that’s a big number. We did find a very statistically strong link that if you get less than eight hours of sleep a night, teenagers are much more likely to use cigarettes, drugs, alcohol, have premarital sex, everything. It’s all related to lack of sleep.
Do you feel like your findings are applicable to college students?
Applicable to freshmen, for sure. And probably to sophomores. It’s linked to puberty. So say puberty starts at age 12, 13—something like that. The sleep phase shift is mildly strong then, but it gets stronger, until about age 16 or 17, when it’s at its strongest. And then it starts to fade into adulthood. So, yes, college freshmen would most certainly be affected by this. But by the time they’re sophomores and juniors, their brains are developed and they’re into their adult sleeping habits, so they can take an early morning class at 8:00 and it won’t be detrimental.
Is your memory capacity better when you’re sleeping more?
Yes. When you are lacking in sleep, your brain does not remember the positive things as much as the negative. When the counselors and nurses came to talk to me and said, “I have to tell you, we have fewer people coming to us complaining about peer relationships, boyfriends or girlfriends,” it’s because all of the little things that might have made their brain feel agitated were washed away with greater chances for sleep.
Are there any specific indicators you feel people can turn to in order to know they didn’t get enough sleep at night?
I think I just find that I get irritated faster. Whether I’m driving and someone cuts me off on the freeway, or the dog doesn’t walk fast enough when I’m in a hurry. The other thing that’s coming out is research with the light that’s emitted from iPhones and iPads that signals to the brain that it’s still daylight. So right now, the suggestion for sleep hygiene—really getting your body totally ready for bed—is that you should not be looking at your iPhone or iPad much before an hour before you go to sleep.
Other than removing technology from your bedroom, are there any other ways you would recommend to curb unhealthy sleeping patterns in general?
Your body likes routine, especially when it’s falling asleep. So when you get ready for bed, this could mean how you put on your nightgown, wash your face—you might read a book. (I read a magazine.) Your brain will pretty much remember the last thing you’re reading or looking at. So I really try hard to read something light and breezy. Like a fashion magazine, or People.
Also, have your bedroom be as dark as you can handle. Some people sleep with their TVs on at night, which is just terrible. It’s really bad for your brain. And a cool room temperature— 68 degrees is considered the preferred sleeping temperature.
What is your best piece of advice for students suffering from a lack of sleep?
Listen to your body. People think that the body can be pushed, when in fact, pushing it is detrimental. That’s not to say that there aren’t going to be times when you’re having to do things that are extraordinarily hard, but I really do think that you need be aware of your own personal limits. The more you are sleep deprived, the less you are able to be aware that you’re sleep deprived. The less sleep you get, the more you’re going to be at risk for all kinds of things—car accidents, drug use, everything else.
This Q & A was edited and condensed from the original conversation.