Why It's So Hard to Fall Asleep When You're Away From Home
New research offers fresh insight on a common experience.
Posted May 01, 2016
Many people find that they don’t sleep well their first night in a new bed, or anywhere that’s new. Sleep is more fitful and difficult, rest less lasting. In the sleep lab this is known as the “first night effect.” The expectation is strong that sleep the first time one is in a new or different environment will not be as “normal” as at home.
Why is sleep in a perfectly comfortable bed in the home of a friend or relative, or in a posh hotel, so much more troublesome than in your own? Could it be that humans have some affinities with dolphins, who sleep in circles, so that the single hemisphere awake at any moment can scan the environment for sharks and other dangers? Or is the first night effect related to recent insomnia research, which shows different parts of the brain to be “awake” when most of it is asleep?
A group at Brown led by Yuka Sasaki tried to find out.
They rounded up the usual suspects, healthy young adults, to sleep consecutive nights in their lab. Participants were fitted for careful electroencephalography and magnetoencephalography, bit by brain bit, to define what happened to them. Then they were exposed to different types of beeps, some regular, some not, and their brains imaged.
The researchers were interested in deep sleep, when the human body gets as close to coma as we normally approach. Rather than look at deep sleep in turns of sleep stages, slow wave activity, the major marker of deep sleep, was assessed.
On the first night in the lab, participants' left hemispheres were considerably more asymmetric in their activity than on the second night. The part that showed the biggest difference was the default mode network (DMN). The DMN fascinates and confuses researchers: On one hand, it doesn’t seem to “do” much. Many think it’s used to simulate physical and mental activity, and is often assessed in studies of meditation, for example. But the DMN is more “on” during phases of sleep than one might surmise.
Not only was there less slow wave activity in people’s left hemispheres during the first night, they were also easier to activate. In essence, they were more alert and more prone to wake. The default mode network was looking out for changes in the environment—probably many different kinds.
What Does This Mean?
- The first night effect is related to increased vigilance throughout the night.
- Sleep is far from monolithic: There are many different regions of the brain that are more or less arousable at different phases of sleep, a particularly pertinent finding for insomnia.
- The default mode network is doing a lot of things in sleep and in wake—and we still don’t know what.
The Rituals of Travel
So here is prima facie evidence that sleeping in a different bed is harder on our sleep, in what appears to be a basic biological way. So is travel then inevitably difficult for sleep? Or are their steps that can counteract it?
We know that the brain loves novelty and learns from it. Get people out of the house and their risk of later Alzheimer’s dives. Grow new information in the brain and its capacity for resilience rises. Except to obtain those advantages, you first have to sleep. Sleep will consolidate many of those informational changes into useful, functional memory. And a novel bed environment is, at least at first, inimical to sleep, so the trick is to make that environment less novel and more comfortable. And one of the best ways to obtain that sense of security is to ritualize sleep and bring with you some of the elements of home.
Many of you know about sleep rituals even if you don’t use that term: Prior to sleep you floss and brush your teeth, turn down the bed, put out your clothes for the next day, and turn off computer monitors, TVs, and cellphones. Many of us read before they sleep; others take baths or listen to music; some have sex.
So it makes sense to take much of your home sleep ritual along with you on your travels, to make your sleep environment—wherever it may be—more homelike. You can take a small reminder of home with you—a coin, a piece of jewelry, a short poem. You can re-enact your usual ritual in a different spot: Many people perform yoga poses, including the sleep-inducing corpse pose, before they rest. You can take along a favorite sleep-inducing book, to put your mind into a different state. (Interestingly, reading about travel often helps people while traveling.)
But most of all, you can take with you a memory of the sense of wholeness and contentment you have when you possess a full night’s sleep. Sleep restores. The body regenerates its tissues, and retunes and remakes its informational core.
And that memory is even stronger when you wake the next morning.