Most of us know it: In an unfamiliar bed you don’t
sleep well. At least not during the first night. From the second night on the insomnia
is over. Maybe you think that it is because you are a nervous type of person.
However, researchers of the Brown University have discovered that it’s normal
and that most people suffer from it. It’s probably a relic from prehistoric
times. They call it the “first-night effect” and they see it as a typical sleep
disturbance when you pass the first night in a novel environment.
The researchers let a number of test subjects sleep in
an unfamiliar environment and subjected them to several tests. I’ll spare you
the details, which you find in source (1) below, but they found that the
different hemispheres of the brain have different levels of activity during the
first night of sleeping at an unfamiliar place, while the activity levels are
the same during the next nights. To be exact, it was the left hemisphere that
slept lighter and was
more vigilant to external signals than the right when the first-night effect
occurred. So, a soft sound will awake you during the first night, because your
left hemisphere is watchful, while during the second night in the same bed you
will continue sleeping and not hear it. You can see the enhanced vigilance of
the left hemisphere also in an electroencephalogram of the two hemispheres: The
left hemisphere shows more abrupt and short shifts during the first night when
the effect occurs. The consequence is that during a first night in a novel bed you
have a fitful sleep that leads to faster awakening upon detection of deviant
stimuli by the left hemisphere of your brain.
Why does it
happen? The researchers speculate that the regional asymmetry between the two brain
spheres is linked with a protective mechanism that is sensitive to potential
danger in an unfamiliar sleeping environment and with the increased need for
vigilance during sleep. In other words, you never know whether there might come
a lion or murderer into your room, so stay alert. However, when nothing special
happens during the first night in a novel bed, your brain seems reassured and
it doesn’t expect any longer that a danger will show up. Actually it’s a bit
strange, for as soon as a lion or murderer has learned about this mechanism,
for example from own experience, he might get the idea that it’s best to drop
by not during the first night but later. It will give more chance of success.
But apparently, in prehistoric times it worked and we survived, or at least
those survived who got it in their genes. That’s why we are now cursed with it,
although we no longer need it and although actually it has become a bit
annoying. It belongs now to the human constitution. And not only to the human
constitution, for you find this unihemispheric sleep as a protective mechanism
also in some birds and marine mammals, so that they can monitor their
environments and detect predators when sleeping. To say it tersely: In a novel
bed you sleep like a bird.
How sad for me, for when I go on holiday, I often
travel around and stay no longer than one or two nights at the same place. When
touring about with my tent, you can say that the bed remains the same and that
only the environments change, but when moving from hotel to hotel, each night
or two nights means another bed. It involves much insomnia. However, it seems
that travellers can become accustomed to the phenomenon of the unfamiliar bed
and that the first-night effect disappears. Anyway, during a travel I gradually
sleep better. But basically there are no solutions for the first-night effect. Maybe
it helps to arrive a few days before an important appointment if you need to
spend the night in a hotel. It might also help to take familiar things from
home with you and put them next to your unfamiliar bed, or to take your own
pillow with you. They may make you feel at ease. Sleep well and good night.
Sources:
(1) Masako Tamaki et al., “Night Watch in One Brain
Hemisphere during Sleep Associated with the First-Night Effect in Humans” in Current Biology, http://www.cell.com/current-biology/fulltext/S0960-9822(16)30174-9
(2) “Scientists
reveal why we sleep poorly the first night we stay in an unfamiliar place”,
(3) “Sleeping away from home? Half your brain is
still awake”, https://www.newscientist.com/article/2085409-sleeping-away-from-home-half-your-brain-is-still-awake/
No comments:
Post a Comment