Almost all researches in sleep explain that nightmares are a reaction to negative experiences that happen during waking hours. However, some of them believe that nightmares do have some real benefits. One 2017 study, for example, found that frequent nightmare sufferers rated themselves as more empathetic(共鸣的). They also displayed more of a tendency to unconsciously mirror other people through things like yawning. People who have constant nightmares also tend to think further outside the box on psychoanalysis tasks. Some other researchers have found support for the idea that nightmares might be linked to creativity.

People seeking cure for nightmares were not necessarily more fearful or anxious, but rather had a general sensitivity to all emotional experience. Sensitivity is the driving force behind intense dreams. Heightened sensitivity to threats or fear during the day results in bad dreams and nightmares, whereas heightened passion or excitement may result in more intense positive dreams. And both these forms of dreams may feed back into waking life, perhaps increasing suffering after nightmares, or promoting social bonds and empathy after positive dreams.

The effects go further still. This sensitivity overflows over into perceptions and thoughts: people who have a lot of nightmares experience a dreamlike quality to their waking thoughts. And this kind of thinking seems to give them a creative edge. For instance, studies show that such people tend to have greater creative talent and artistic expression. And people who often have nightmares also tend to have more positive dreams than the average person.

The evidence points towards the idea that, rather than disturbing normal activity, people who are unfortunate in having a lot of nightmares also have a dreaming life that is at least as creative, positive and vivid as it can be distressing and terrifying. What’s more, this imaginative richness is unlikely to be limited to sleep, but also is filled with waking thought and daydreams. Even after people wake up and shake off the nightmare, in other words, a mark of it stays behind, possessing them throughout the day.

People hate mosquitoes due to their blood-sucking tendencies. Scientists, too, are troubled by mosquitoes and have been researching ways to keep them away. A team of researchers from Virginia Tech in the US looked into different kinds of soap. They invited volunteers to test how four different soap flavors attract mosquitoes.

After analyzing the mosquitoes’ behavior, the researchers discovered several chemicals in the soap that can influence the mosquitoes’ “choice of food”. Two chemicals, one with the smell of coconut and the other with the scent (气味，香味) of flowers, can keep the insects away.

The team also found that what matters to mosquitoes is not just the chemicals, but rather the combination of chemicals with each person’s smell. For example, people who attract mosquitoes can be more attractive to them after using one type of soap. They can also repel (驱除) mosquitoes by using another kind of soap. The findings were “remarkable”, said senior author Clement Vinauger in a news release, adding that he would choose a coconut-scented soap to keep mosquitoes away.

How these insects manage to find humans has also made scientists curious. According to a new study published in Current Biology, researchers built a “canteen” for hundreds of mosquitoes. In the 20-by-20-meter facility, there were six pads that had the smell of different humans. The pads were heated to mimic sleeping humans. They found that the insects can track scents up to 60 meters. Also, mosquitoes are most attracted to a kind of chemical called carboxylic acid (羧酸), which is usually produced by bacteria on human skin. The smell of one participant wasn’t attractive to the insects, and researchers believed it was due to the person’s diet, which is a mainly plant-based food.

By analyzing the chemicals that either attract or repel mosquitoes, scientists are able to improve mosquito repellent (驱蚊剂). With more studies, scientists believe changing a person’s diet could one day make them “mosquito-proof”. This is especially beneficial for regions where mosquitoes carry diseases, such as malaria, CNN reported.

Is losing weight as simple as doing a 15－minute writing exercise？In a new study，women who wrote about their most important values，like close relation－ships or religion，lost more weight over the next few months than women who didn’t.“We have this need to feel self－integrity，”says Christine Logel of the University of Waterloo.“When something threatens your sense that you're a good person，like failing a test，we can buffer(减缓)that self－integrity by reminding ourselves how much we love our children，for example.”

For this study，the researchers recruited 45 female undergraduates，of whom 58%were overweight.Each woman was weighed，and was then given a list of important values，like creativity，music or relationships with friends and family members.Each woman ranked the values in order of how important they were to her.Then half the women were told to write for 15 minutes about the value that was most important to her.The other half，a control group，were told to write about why a value far down on their list might be important to someone else.

The women came back months later to be weighed again.Women who had written about an important value lost an average of 3.41 pounds，while women in the control group gained an average of 2.76.

“How we feel about ourselves can have a big effect”Logel says.Maybe when one of the women who wrote about an important value went home that night，she felt good about herself and didn’t eat to make herself feel better.Over a few months，that could make a real difference in her life.