First-Night Effect: Why You Have Trouble Sleeping in New Places for the First Time

Don't worry if you don't get the rest and relaxation you wanted on your first night at a new place. It is just your brain acting up on its survival mechanism in an unfamiliar environment, new study shows.

The phenomenon known as the "first-night" effect has been long recognized by scientists for decades. National Public Radio reported that when researchers began studying people in sleep labs, they just tossed out all the data they gathered during the first night because of bad sleep.

To better understand the "first-night" effect, researches conducted a study to help explain why people have difficulty sleeping in new places. The study, published in the journal Current Biology, suggests that when people sleep in a new place for the first time, one side of their brain sleeps lighter than the other and is on a state of heightened alert.

For the study, researchers monitored two nights of sleep, a week apart, of 35 healthy volunteers. Using electroencephalography, magnetoencephelography, and magnetic resonance imaging, researchers made a high-resolution and sensitive measurement within a wide area of the brain.

The researchers then used sound stimuli to wake the sleeping volunteers.

They found out that the left hemisphere remained more active than the right hemisphere, especially during the "slow wave" sleep phase. They also discovered that the participants woke up faster when the sound stimuli is played in the right ear, which is connected in the left hemisphere.

There are no significant differences in the activeness of the left and right hemisphere during the sleep of participants in the second night. There was also no different in alertness or activity of either in the hemisphere in other sleep phases.

The researchers then concluded that heightened alert of left hemisphere only occurs on the first night and during the "slow wave" phase.

This survival mechanism of the brain must have evolved over time to protect us from predators during the time when people were still living in the dark and close to danger. Researchers say that this brain response is involuntary and there is nothing you can do to prevent it from happening.