Birds and some aquatic mammals left and right hemispheres of the brain can sleep alternately. Until now it was thought that people at such a trick can not. However, as scientists found out, the first night in a new place hemispheres of our brain to sleep asynchronously.
“Often people with difficulty falling asleep in a new place. Scientists studying sleep in the laboratory, even discard data received on the first night of research, believing these results are atypical,” says Yuka Sasaki (Sasaki Yuka), a psychologist from brown University.
Sasaki and her team became interested in the flow of human sleep in a new place. The results of their work were published in the journal Current Biology on April 21.
As it turned out, in a slow phase neuroactivity the left hemisphere, unlike the right, to a lesser extent with the condition of sleep. Scientists suggest that the left half of the brain the first night in a new place doesn’t sleep as deeply as the right. However, starting from the second night of the imbalance disappears, and both hemispheres are equally deep sleep.
In the human brain there are so-called network for passive mode. It is a set of nerve cells that are active at a time when the brain is not busy performing any specific tasks. Just network for passive mode and was active in the left hemisphere during sleep.
The researchers reproduced the sharp sounds near the ears of sleeping volunteers. Thus it was possible to establish that network for passive mode of the left hemisphere reacted faster in the case of breaking the silence. When the sounds were reproduced near the right ear, from where signals go to the left hemisphere, the volunteers woke up significantly faster. Interestingly, this effect is most strongly manifested during the first night in a new place.
During one night several times the brain goes through a phase of slow sleep. However, the experiment Sasaki covered only the first of such cycles. Therefore, scientists do not know yet, does the left hemisphere vigilance throughout the night. To find out, Sasaki and her group are preparing new studies.
“In this sleep mode makes sense, at least in the animal world. Sleep is useful, if the risks with which he is associated, do not outweigh its benefits for the body. Safety during sleep often can be maintained, not losing focus of what is happening around. Obviously, a similar “night watch” is not only the first night in a new place. For example, a mother may sleep soundly even during a thunderstorm, but Wake up from the weak whimpering of the child,” explains Siegel, Jerome (Jerome Siegel), who studies sleep at the University of California.
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Alex Kudrin