* the mechanism behind/underlying/for this都可以。
Those among us who grew up with the popular cartoon "Dexter's Laboratory" might remember the famous episode wherein Dexter's trying to learn French overnight.
He creates a device that helps him to learn in his sleep by playing French phrases to him.
Of course, since the show is a comedy, Dexter's record gets stuck on the phrase "Omelette du fromage" and the next day he's incapable of saying anything else.
This is, of course, a problem that puts him through a series of hilarious situations.
结果，第二天起床之后这个可怜的孩子只会说Omelette du fromage这一个单词了。
在睡眠中学习的想法吸引（captivate）了众多艺术家和科学家，也许有一天我们都可以通过在睡眠中学习来极大的提高效率，这非常吸引人。不过这样的情景真的能够实现（become a reality）吗？
New research seems to suggest so, and scientists in general are moving closer to understanding precisely what goes on in the brain when we sleep and how therestful state affects learning and memory formation.
新的研究似乎支持这一点，对于睡眠时大脑里在发生什么，以及这种静息状态如何影响学习和记忆形成，科学家们有了越来越清晰的认识（moving closer to understanding precisely）。
For instance, previous studies have shown that non-rapid eye movement (non-REM) sleep — or dreamless sleep — is crucial for consolidating memories.
* 两个破折号（em dash）相当于两个逗号。 更多标点符号使用请参考：中国留学生英文论文写作常见标点符号错误及案例解析
It has also been shown that sleep spindles, or sudden spikes in oscillatory brain activity that can be seen on an electroencephalogram (EEG) during the second stage of non-REM sleep, are key for this memory consolidation.
However, the mechanism behind such achievements remained mysterious until now. Researchers were also unaware if such mechanisms would help with memorizing new information.
* help with sth/doing sth或者help (to) do sth.
Therefore, a team of researchers set out to investigate. Scott Cairney, from the University of York in the United Kingdom, co-led the research with Bernhard Staresina, who works at the University of Birmingham, also in the U.K.
Their findings were published in the journal Current Biology.
因此，两位英国科学家Scott Cairney和Bernhard Staresina共同主持了一项研究来探讨在睡眠中巩固记忆的机制，研究成果发表在了Current Biology上。
Sleep spindles key for memory consolidation
Cairney explains the motivation for the research, saying, "We are quite certain that memories are reactivated in the brain during sleep, but we don't know the neural processes that underpin this phenomenon."
* 这里的processes相当于mechanisms；underpin相当于underlie、behind，也可以表达成the neural processes/mechanisms underpinning/underlying/behind this phenomenon.
"Sleep spindles," he continues, "have been linked to the benefits of sleep for memory in previous research, so we wanted to investigate whether these brain waves mediate reactivation."
"If they support memory reactivation, we further reasoned that it could be possible to decipher memory signals at the time that these spindles took place."
* these brain waves mediate reactivation和they support memory reactivation是一回事，英文里不喜欢重复，同样的事情换着法的说。
To test their hypotheses, Cairney and his colleagues asked 46 participants "to learn associations between words and pictures of objects or scenes before a nap."
Afterward, some of the participants took a 90-minute nap, whereas others stayed awake. To those who napped, "Half of the words were [...] replayed during the nap to trigger the reactivation of the newly learned picture memories," explains Cairney.
试验者醒来后，再次把单词给他们看（present them with sth/present sth to sb），并让他们回忆物体和情景的图片。
"We found that their memory was better for the pictures that were connected to the words that were presented in sleep, compared to those words that weren't," Cairney reports.
* 如果说...their memory of the pictures that were connected to the words that were presented in sleep was better ....，主语就太长了，所以可以把冗长的结构甩到后面，使用... was better for ....这样的句型。
Using an EEG machine, the researchers were also able to see that playing the associated words to reactivate memories triggered sleep spindles in the participants' brains.
More specifically, the EEG sleep spindle patterns "told" the researchers whether the participants were processing memories related to objects or memories related to scenes.
How to boost memory while we sleep
"Our data suggest that spindles facilitate processing of relevant memory features during sleep and that this process boosts memory consolidation," says Staresina.
"While it has been shown previously," he continues, "that targeted memory reactivation (delivery of auditory cues) can boost memory consolidation during sleep, we now show that sleep spindles might represent the key underlying mechanism."
Cairney adds, "When you are awake you learn new things, but when you are asleep you refine them, making it easier to retrieve them and apply them correctly when you need them the most. This is important for how we learn but also for how we might help retain healthy brain functions."
Staresina suggests that this newly gained knowledge could lead to effective strategies for boosting memory while sleeping.
Direct induction of sleep spindles — for example, by stimulating the brain with electrodes — perhaps combined with targeted memory reactivation, may enable us to further improve memory performance while we sleep."
- Bernhard Staresina
原论文：Memory Consolidation Is Linked to Spindle-Mediated Information Processing during Sleep（Cairney et al., 2018, Current Biology 28, 1–7 https://doi.org/10.1016/j.cub.2018.01.087）