Have you ever had trouble sleeping in a new place?
你在陌生环境中是否会难以入睡？
Lots of people do. And now researchers from Brown University in Rhode Island think they know why.
很多人都会。而现在罗得岛州布朗大学的研究人员认为他们知道了原因。
They found that one-half of the brain "remains more awake" than the other half when people are trying to sleep in a new place.
他们发现当人们试图在一个陌生环境中睡觉时，大脑的一半比另一半更加清醒。
This appears a case of the brain keeping people ready for trouble in a new place, the researchers said.
研究人员表示，这似乎是因为大脑让人们在陌生环境中随时准备应付麻烦。
The sleep findings were reported in Current Biology and by Brown University.
这一睡眠研究结果由布朗大学发表在《当代生物学》杂志上。
In their report, the researchers said many people report they have a harder time sleeping the first night at a hotel or other places outside their home.
研究人员在研究报告中表示，许多人都声称自己在酒店或家庭以外的地方的第一晚难以入睡。
They call it, "first-night effect."
他们称之为“首晚效应”。
"In Japan they say, ‘if you change your pillow, you can't sleep,''' said Yuka Sasaki, one of the report's authors. "You don't sleep very well in a new place. We all know about it."
该研究报告的作者之一佐佐木优香（Yuka Sasaki）表示，“在日本，人们常说，‘如果你换了枕头就会睡不着。’”她说，“人们在新环境中睡不好，我们大家都知道这点。”
The researchers measured brain waves for 35 volunteers over two nights in a laboratory. The two nights were a week apart.
研究人员在实验室中对35位志愿者的脑电波进行了两晚的测量。这两晚相距一个星期。
They found during the first night the left hemisphere of the brain was more active than the right hemisphere. This was during the first deep-sleep period, the researchers said.
他们发现，在第一个晚上，大脑左半球比右半球更为活跃。研究人员表示，这发生在第一次深睡眠阶段。
Sasaki said a lot of questions remain.
佐佐木优香表示还有很多问题尚待发掘。
Researchers did not keep measuring brain waves all night long. So, they don't know if the left hemisphere keeps "watch" all night. Or whether it "works in shifts" with the right hemisphere later in the night.
研究人员并没有整晚测量脑电波。所以他们不知道是左脑整晚保持“警觉”，还是随后与右脑进行轮班。
They also do not know why the extra brain activity, at least during the first phase of deep sleep, is always on the left hemisphere.
他们也不知道为什么这额外的大脑活动总是发生在大脑左半球，至少第一晚的深睡眠阶段是如此。
For some, this research may be calming. It is good to know that our brain is "looking out for us," in a new place.
对一些人来说，这项研究可能会比较平静。很高兴知道我们的大脑在新环境中“在为我们放哨”。
But it may not help with sleep. That extra brain activity, at least according to this new research, makes it harder to get the sleep people need to wake up well rested in the morning.
但是这可能无助于睡眠。至少根据这项新的研究，这一额外的大脑活动让人们难以获得充足睡眠。
I'm Bruce Alpert.
我是布鲁斯·阿尔伯特。(51VOA.COM对本文翻译保留全部权利，未经授权请勿转载，违者必究！)