If you do not use your arms or your legs for some time, they will become weak. When you start using them again, they slowly become strong again. Everybody knows that. Yet many people do not seem to know that memory works in the same way.

When someone says that he has a good memory, he really means that he keeps his memory in practice by using it. When someone else says that his memory is poor, he really means that he does not give it enough chance to become strong.

If a friend says that his arms and legs are weak, we know that it is his own fault. But if he tells us that he has a poor memory, many of us may think that his parents are to blame. Few of us know that it is just his own fault. Have you ever found that some people can't read or write, but they usually have better memories? This is because they can't read or write and they can’t write things down in a small notebook. They have to remember days, names, songs and stories. In this way their memory is the whole time being exercised. So if you want to have a good memory, practice remembering things in a way as other people do.

【推荐3】The conventional wisdom about insects has been that they are unthinking, unfeeling creatures whose behavior is entirely hardwired (天生的). But in the 1990s researchers began making surprising discoveries about insect minds. Some species of wasps (黄蜂) recognize their nest mates’ faces and acquire impressive social skills. For example, they can infer the fighting strengths of other wasps relative to their own just by watching other wasps fight among themselves.

Given the substantial work on the complexity of insect cognition (认知), it might seem surprising that it took scientists so long to ask whether, if they are that smart, could also be sentient, capable of feeling. Since we have no direct window into the inner world of an animal that cannot verbally communicate its thoughts and feelings, the question of whether insects are sentient remained academic.

15 years ago, I performed an experiment in which we asked whether bumblebees could learn about threat from their natural enemies. We built a plastic spider model with a mechanism that would briefly trap a bumblebee between two sponges before releasing it. The bumblebees showed a significant change in their behavior after being attacked by the robotic spider. Perhaps unsurprisingly, they learned to avoid flowers with spiders and meticulously scanned every flower before landing. Curiously, however, they some times even fled from imaginary threats, scanning and then abandoning a perfectly safe, spider-free flower. Although this incidental observation did not constitute formal evidence of an emotionlike state, it did open the door to the idea that such states might exist in insects.

Some research suggested that insects might have positive states of mind. Researchers discovered that bees actively seek out drugs such as nicotine and caffeine when given the choice and even treat themselves with nicotine when sick. Male fruit flies stressed by being robbed of mating opportunities prefer food containing alcohol, and bees even show withdrawal symptoms when removed from an alcohol-rich diet.

Why would insects consume mind-altering substances if there isn’t a mind to alter? But these suggestive hints of negative and positive mind states still fell short of what was needed to demonstrate that insects are sentient.

【推荐1】The California sea otter (海獭), once hunted to the edge of extinction, has staged a thrilling comeback in the last century. Now, scientists have discovered that the otters’ success story has led to something just as remarkable: the restoration of their declining coastal marsh (沼泽) habitat.

Elkhorn Slough, a coastal marsh within Monterey Bay, had been experiencing severe damage. The root cause was a growing population of shore crabs, which fed heavily on the marsh plants, weakening the structural integrity of the habitat. Coastal marshes like these are not only natural defenses against storm waves but also serve as important carbon storage areas and water-cleaning systems.

The conservation-driven comeback of the sea otter has been crucial. California’s coastlines were once alive with sea otters. Sadly, they were nearly wiped out at the hands of fur traders. In the 1980s, conservation efforts aided these otters in re-occupying large areas of their former range. Now, Elkhorn Slough has the highest concentration of sea otters in California, with a population of about 100. By naturally feasting on crabs, the otters have helped a significant regrowth of plant life. Brent Hughes, a scientist working alongside Angelini, led a three-year study. Their findings were clear: in areas with sea otters, crab numbers fell markedly. This led to a resurgence in plant growth, which in turn stabilized the soil and lowered the rate of soil washing away.

As the sea otter population continues to restore, their positive impact on coastal ecosystems is likely to increase. It not only showcases the sea otter as a central species—a species that has a significant effect on its natural environment—but also highlights the essential nature of top predators (捕食者) in preserving ecological harmony. “My honest reaction was—this could become a classic in the literature,” says scientist Lekelia Jenkins. She reveals marsh restoration also helps people by reducing flooding. “Suddenly, sea otters go from just cute things we like to something that can protect our livelihoods and our properties.”

【推荐2】What is life? Like most great questions, this one is easy to ask but difficult to answer. The reason is simple: we know of just one type of life and it’s challenging to do science with a sample size of one. The field of artificial life-called ALife for short — is the systematic attempt to spell out life’s fundamental principles. Many of these practitioners, so-called ALifers, think that somehow making life is the surest way to really understand what life is.

So far no one has convincingly made artificial life. This track record makes ALife a ripe target for criticism, such as declarations of the field’s doubtful scientific value. Alan Smith, a complexity scientist, is tired of such complaints. Asking about “the point” of ALife might be, well, missing the point entirely, he says. “The existence of a living system is not about the use of anything.” Alan says. “Some people ask me, ‘So what’s the worth of artificial life?’ Do you ever think, ‘What is the worth of your grandmother?’”

As much as many ALifers hate emphasizing their research’s applications, the attempts to create artificial life could have practical payoffs. Artificial intelligence may be considered ALife’s cousin in that researchers in both fields are enamored by a concept called open-ended evolution (演化). This is the capacity for a system to create essentially endless complexity, to be a sort of “novelty generator”. The only system known to exhibit this is Earth’s biosphere. If the field of ALife manages to reproduce life’s endless “creativity” in some virtual model, those same principles could give rise to truly inventive machines.

Compared with the developments of Al, advances in ALife are harder to recognize. One reason is that ALife is a field in which the central concept — life itself — is undefined. The lack of agreement among ALifers doesn’t help either. The result is a diverse line of projects that each advance along their unique paths. For better or worse, ALife mirrors the very subject it studies. Its muddled (混乱的) progression is a striking parallel (平行线) to the evolutionary struggles that have shaped Earth biosphere.

Undefined and uncontrolled, ALife drives its followers to repurpose old ideas and generated novelty. It may be, of course, that these characteristics aren’t in any way surprising or singular. They may apply universally to all acts of evolution. Ultimately ALife may be nothing special. But even this dismissal suggests something：perhaps, just like life itself throughout the universe, the rise of ALife will prove unavoidable.

【推荐3】A new study suggests that science role-playing may help tighten the gender gap in science, technology, engineering, and math(STEM)education and careers for women simply by improving their identity as scientists.

Frustrated by the gender gap in STEM, in which some fields employ at least three times more men than women, Cornell graduate student Reut Shachnai wanted to do something about it. Reut said the idea to help foster young girls’ interest in science came to her during a lecture in a class she was taking on Psychology of Imagination.

Reut designed an experiment to test if assuming the role of a successful scientist would improve girls’ persistence in a “sink or float” science game. The game itself was simple yet challenging: a computer screen projected a slide with an object in the center above a pool of water. Kids then had to predict whether the object would sink or float.

She studied 240 four -to -seven -year -olds, because this is around the time kids first develop their sense of identity and capabilities. They were divided into two groups. Children in the “story” group learned about the successes and struggles of a gender -matched scientist before playing the game. Boys heard about Isaac Newton and girls were told about Marie Curie. Children in the “pretend” group were told to assume the identity of the scientist they just learned about.

All kids played at least one round of the game. No matter what group they were in, girls got the answers right just as often as boys -nearly 70% of the time. Boys, however, didn’t really benefit from the stories or make-believe. Besides, girls pretending to be Dr. Marie persisted twice as long at the sink-or-float game, playing just as much as the boys did.

Reut’s teacher Tamar Kushnir said, “Rather than merely hearing about role models, children may benefit from actively performing the type of actions they see role models perform. In other words, taking a few steps in the role model’s shoes, instead of merely observing her walk.”