This is why half of the brain stays awake when you sleep away from home

Do you know when we sleep in a new place for the first time, is half of our brain awake?

"Did you sleep well?"

I asked a lot of my friends this question after they spent a night on my couch. Turns out, most of them lie when answering: " Very good !"

The difficulty of sleeping in a new environment is quite common that neuroscientists have given it the name FNE - the first night effect (first-night effect). New research shows that, basically, FNE is the equivalent of the nervous system of sleep with one eye open.

A study published recently in Current Biology says that when you first sleep in a new environment, only half of your brain is really resting.

Researchers have conducted research on people who sleep in a new environment by measuring their brainwave activity in the third stage - the deepest phase of the sleep cycle. In the first experiment, the researchers found that the sleeping subjects experienced more activity in the left hemisphere than the right hemisphere on the first night of sleep, which meant that the left hemisphere was still similar. Stay alert to your surroundings.

When subjects continue to sleep at the same location on the second night, the asymmetry between the two hemispheres will disappear and both hemispheres will rest completely.

Many aquatic birds or mammals, including dolphins and sea lions, have the same form of sleep. Only half of their brains are completely rested so they can be alert to potential threats when they sleep. To test whether the model of asymmetric sleep of humans in unfamiliar environments serves similar functions, researchers have investigated whether FNE's specific light sleep makes Sleep subjects react more to external stimuli.

To do this, the researchers asked the subjects: during sleep, if you hear any sound, tap your finger when you wake up. Subjects slept for two evenings at the same location, and the researchers turned on the sound for two nights. The response time from sound to pat on the first day is much faster than the second day. This indicates that because of FNE, the brain is not only more alert but also wakes up faster.

The researchers are not sure why FNE caused vigilance in the left hemisphere rather than the right hemisphere, but they think that because the hemispheres are wired differently. Neural connections between parts of the brain - where deep sleep occurs, are known as "default mode networks", and the rest of the brain is stronger than in the left hemisphere. This can make left hemispherical alert much more useful than alertness in the right hemisphere, because stronger connections can produce faster reactions to cognitive stimuli during sleep. .

Even the comfort level of a bed is not important when it comes to sleeping in a new environment. "In our study, we have collected a subjective report of sadness, insecurity." - Yuka Sasaki, one of the researchers conducting the experiment said. "Nobody really shows discomfort in the first period, but everyone points out FNE."

These results show that a light, asymmetrical sleep that we experience in the first night in a new environment is actually a protective mechanism in our people. But, fortunately, we can still return to a deep sleep once we are familiar with a new place.