The brain has a powerful ability to remember and connect events separated in time. And now, in that new study in mice published in Neuron, scientists at Columbia’s Zuckerman Institute have cast light on how the brain can form lasting links.
The hippocampus-a small, seahorse-shaped region buried deep in the brain-is an important headquarters for learning and memory. Previous experiments in mice showed that disruption (中断) to the hippocampus leaves the animals with trouble learning to associate two events separated by tens of seconds.
“The traditional view has been that cells in the hippocampus keep up a level of continuous activity to associate such events,” said Dr. Ahmed, co-first author of the study. “Turning these cells off would thus disrupt learning.”
To test this view, the researchers imaged parts of the hippocampus of mice as the animals were exposed to two different stimuli (刺激物): a neutral (神经的) sound followed by a small but unpleasant puff of air. A fifteen-second delay separated the two events. The scientists repeated this experiment across several trials. Over time, the mice learned to associate the sound with the soon-to-follow puff of air. Using advanced microscopy, they recorded the activity of thousands of neurons (神经元) , a type of brain cell, in the animals’ hippocampus over the course of each trial for many days.
“We expected to see continuous neural activity that lasted during the fifteen-second gap, an indication of the hippocampus at work linking the auditory sound and the air puff,” said computational neuroscientist Stefano Fusi, PhD. “But when we began to analyze the data, we saw no such activity.” Instead, the neural activity recorded during the fifteen-second time gap was sparse (稀少的). Only a small number of neurons worked, and they did so seemingly at random.
To understand activity, they had to shift the way they analyzed data and use tools designed to make sense of random processes. Finally, the researchers discovered a complex pattern in the randomness: a style of mental computing that seems to be a remarkably efficient way that neurons store information.
“We were happy to see that the brain doesn’t maintain ongoing activity over all these seconds because that’s not the most efficient way to store information,” said Dr. Ahmed. “The brain seems to have a more efficient way to build this bridge.”
1.What can we learn about the hippocampus?
A.It weakens with the memory decline.
B.It is a brain region crucial for memory.
C.It serves as a tool of learning languages.
D.It is involved in the visual area of the brain.
2.According to the passage, the traditional view is that ______.
A.associations of events require continuous neural activity
B.animals have trouble learning to associate two events
C.neural activity can hardly be replaced by associations
D.a 15-second delay is enough to separate two events
3.The new study in mice indicates that ______.
A.continuous activity happens as expected
B.no neurons stay active at intervals of 15 seconds
C.a complex pattern helps the brain learn associations
D.neuronal information is stored in well-designed tools
4.From the last two paragraphs, we can infer that the findings ______.
A.inspire deeper explorations of disorders
B.provide evidence for language learning
C.build a bridge between different parts of the brain
D.help map some aspects of a person’s experiences
Should you choose time over money, or money over time? This is one of those so-called dilemmas of happiness that isn’t really a dilemma at all, because the answer is so painfully obvious. Money, after all, is just an instrument for obtaining other things, including time-while time is all we’ve got. And to make matters worse, you can’t save it up.
And yet we do choose money over time, again and again, even when basic material well-being doesn’t demand it. Partly, no doubt, that’s because even well-off people fear future poverty. But it’s also because the time/money trade-off rarely presents itself in simple ways. Suppose you’re offered a better-paid job that requires a longer commute (more money in return for less time); but then again, that extra cash could lead to more or better time in future, in the form of nicer holidays, or a more secure retirement. Which choice prioritizes time, and which money? It’s hard to say.
Thankfully, a new study throws a little light on the matter. The researchers surveyed more than 4,000 Americans to determine whether they valued time or money more, and how happy they were. A clear majority preferred money-but those who valued time were happier. Older people, married people and parents were more likely to value time, which makes sense: older people have less time left, while those with spouses and kids probably either value time with them, or feel they steal all their time. Or both.
The crucial finding here is that it’s not having more time that makes you happier, but valuing it more. Economists continue to argue about whether money buys happiness-but few doubt that being comfortably off is more pleasant than struggling to make ends meet. This study makes a different point: it implies that even if you’re scraping by (勉强维持), and thus forced to focus on money, you’ll be happier if deep down you know it’s time that’s most important.
It also contains ironic (讽刺的) good news for those of us who feel basically secure, financially, but horribly pushed for time. If you strongly wish you had more time, as I do, who could accuse you of not valuing it? At least my eagerness for more time shows that my priorities are in order, and maybe that means I’ll enjoy any spare time I do get. We talk about scarce time like it’s a bad thing. But scarcity is what makes us treat things as precious, too.
1.The example in Paragraph 2 suggests that ______.
A.money can be made at the expense of time
B.the time/money trade-off is a complicated issue
C.money is a tool for obtaining material well-being
D.circumstances force one to choose money over time
2.We can know from the findings of the study that ______.
A.valuing time more makes people happier
B.parents regret the time spent on their kids
C.people won’t value time until they’re rich
D.a comfortable life is superior to more time
3.Which of the following best serves as the title of the passage?
A.What you should spend time on
B.What you should trade money for
C.Why you need to value money, not time
D.Why you need to count time, not money
Beijing museum launches outer space into cyberspace
The National Museum of China has taken a variety of measures on its website and WeChat account, creating virtual tours for its current and permanent exhibitions, uploading audio of previous educational courses and providing more social media posts to detail the star items in its collection. It has gone a further step by launching an exhibition entirely online with the help of advanced technology such as 3D modeling and 5G.
The exhibition, titled Dongfanghong Forever, charts the progress China has made in aerospace over half a century. The show opened on April 24, which is marked as the country’s Space Day, when the satellite Dongfanghong 1 was launched in 1970.
The success of Dongfanghong 1 entering its present orbit not only registered the country’s first steps in exploring outer space but the event also made China the fifth country in the world to develop a satellite on its own and put it in space.
The online exhibition is expected to run for a long time, and people can visit it on the museum’s website at any time. It is the first such virtual show the museum has staged. It reviews “three critical moments in the country’s space exploration-the development of Dongfanghong 1, the liftoff of China’s first manned spacecraft, Shenzhou V, in 2003 and the landing of the Chang’e 4 lunar probe in 2019”.
The exhibition gives a view of Dongfanghong 1 orbiting in the form of digital simulation (模拟). Viewers can also watch television interviews of scientists involved in the mission and documentary footage filmed in 1970, as well as hear Dongfanghong (The East is Red), a song popular in China hailing Mao Zedong, played by the satellite.
The exhibition will motivate more people to engage in the country’s ambitious course of space exploration.
1.The National Museum of China has recently ______.
A.launched a satellite into outer space
B.set up a website and WeChat account
C.uploaded more digital documents online
D.helped to advance 3D and 5G technology
2.On the museum’s website, you can ______.
A.see how Dongfanghong 1 was orbiting
B.have an interview with some scientists
C.visit China’s first manned spacecraft
D.provide classes about space exploration
I was always the girl who managed to stay moderately fit through an active lifestyle. I relied on my brain but largely ______ my body.
Then, due to a mixture of ______ and overwork, I found myself no longer the ______ and happy person I had been. I couldn’t find ______ in the things I loved. I was unwell and needed to find a way to get better.
I added ______ to my schedule, along with more time outdoors and reducing my ______. I didn’t expect to enjoy it, and knew that I would need a one-to-one trainer to ______ me to exercise regularly. I ______ a personal trainer. I explained that I wasn’t aiming to lose weight. I had no ______ of shifting my anxiety on to the way I looked. ______, I wanted to improve my balance, flexibility and strength.
My trainer presented exercise as a way to boost myself up (增强) rather than ______, and to help my body be stronger and ______ for the things I wanted to do every day. To achieve this, I ______ time and energy in myself. ______ myself physically has not always been easy. It is hard work, I sweat a lot, and I ______ it. I finally found myself understanding ______ I would want to make exercise part of my life.
My body has built up. When I run, it takes less ______; when I dig my garden for hours, my back no longer ______. Now, when I’m ______ who I am and what I’m worth, I look down at my arms. Thanks to the exercise, my newly defined ______ reminds me of what I’m made of: the determination to thrive as well as survive.
1.A.appreciated B.shaped C.trained D.ignored
2.A.passions B.complaints C.stresses D.praises
3.A.confident B.honest C.punctual D.generous
4.A.evidence B.pleasure C.humour D.fault
5.A.entertainment B.communication C.travel D.exercise
6.A.expectation B.workload C.diet D.income
7.A.promise B.motivate C.allow D.beg
8.A.seized B.charged C.hired D.questioned
9.A.intention B.chance C.idea D.doubt
10.A.Instead B.Otherwise C.However D.Moreover
11.A.hang about B.shrink down C.burst in D.show off
12.A.fitter B.slower C.higher D.lighter
13.A.saved B.wasted C.found D.invested
14.A.Challenging B.Burying C.Measuring D.Locating
15.A.mean B.love C.catch D.refuse
16.A.where B.how C.when D.why
17.A.time B.skill C.effort D.focus
18.A.shakes B.breaks C.aches D.exists
19.A.enjoying B.wondering C.choosing D.guessing
20.A.character B.habit C.muscle D.mind
—Can you pass me the book on the shelf?
—Of course, ______.
A.never mind B.take it easy C.here you are D.help yourself
You don’t have to take a taxi. I’ll have my assistant ______ you to the museum.
A.to drive B.driven C.driving D.drive
