Sleeping in an unknown place can sometimes be complicated for some. In an attempt to understand, researchers at Brown University in the United States have used advanced neuroimaging techniques to analyze the brain as a sleep state. The study published in the journal Current Biology explains the reason: part of a hemisphere of the brain would remain awake during the sleep phase to act as watchman.

In fact, when you sleep outside your home, sleep comes more slowly and is irregular. It is usually only from the second night, when the environment becomes familiar, that sleep becomes "normal".

When we sleep, the hemispheres of the brain act unevenly

The image study - which detects sleep intensities - revealed during the first night of sleep that the two hemispheres of the brain function differently. The left hemisphere (the most rational) would sleep less than the right hemisphere (the most creative and emotional). It would also be more responsive to the sounds and the environment around. The study therefore justifies the poor quality of sleep in an unknown environment by the awakening of one of the two hemispheres which is revealed to be more on the lookout for external noises. The brain would always be on the alert, like a system of vigilance that would also have animals.

Each part of the brain sleeps at thresholds and sometimes at different times. The work never stops. External information is always analyzed, even though body reactions tend to be slower.

One could speak of "asymmetry of the depth of sleep" where the brain regions activate one by one alternately, as a network that remains connected, when the body sleeps. To reduce the feeling of discomfort or "danger" caused by the unknown environment where one falls asleep, the researchers advise to bring one's own pillow, or a reassuring object. This is probably why children always claim their stuffed toys before falling asleep ... (?)