In A New Place, You’re Only Half Asleep. Here’s Why
You’ve paid top-dollar for all the conveniences a hotel could offer—Egyptian cotton sheets, a noise-free floor, and a Regal resort range mattress (if you’re really lucky), but you still wake up groggy and cranky. You don’t remember tossing and turning, but you’re so sleepy you feel as though you’ve had just a few hours of rest. What gives?
Whether you’re at a hotel, a friend’s house, or on an airplane, sleeping in a new place is likely to bring about what sleep researchers call the first night effect (FNE). It’s long been well known among scientists and travellers that a new environment generally spells bad news for restful sleep, but until recently, no one understood why.
Now for a slight digression (stay with me here). Mallard ducks, clever little birds that they are, have evolved an ingenious adaptation that helps keep them safe while they sleep. They sleep in a row, and while the birds in the middle sleep normally, the ones on the outer ends literally sleep with one eye open to watch for predators. Here’s the really crazy part: the side of the brain controlling the open eye shows the activity levels of an awake bird.
See where I’m going with this? A group of researchers from Brown University placed a group of (human) subjects in unfamiliar environments and measured their slow-wave brain activity, which is thought to reflect how deeply someone is sleeping. Their study showed that one half of the brain—typically the left—has far less slow-wave activity than the other. About a week later, presumably when the body adjusts to its new surroundings, slow-wave activity patterns return to normal.
This means that in a new place, your left hemisphere acts as a night watchman, buzzing with activity to keep you alert to trouble. How cool is that? When the FNE is at work, you’re more receptive to external stimuli like sudden noises. This is probably an evolved protective mechanism, just as it is in mallard ducks and other animals that exhibit unihemispheric sleep, like some birds and aquatic mammals.
That’s all well and good for those of us who travel occasionally, but what’s a frequent traveller to do? Researchers don’t know whether sleeping in new environments regularly makes you less likely to experience the FNE, but as a general rule of thumb, if you have to be well-rested for an out-of-town event, try to arrive a few days early.