What do Babies Know
What do babies know?
As Daniel Haworth is settled into a high chair and wheeled behind a black screen, a sudden look of worry furrows his 9-month-old brow. His dark blue eyes dart left and right in search of the familiar reassurance of his mother's face. She calls his name and makes soothing noises, but Daniel senses something unusual is happening. He sucks his fingers for comfort, but, finding no solace, his mouth crumples, his body stiffens, and he lets rip an almighty shriek of distress. Mom picks him up, reassures him, and two minutes later, a chortling and alert Daniel returns to the darkened booth behind the screen and submits himself to Babylab, a unit set up in 2005 at the University of Manchester in northwest England to investigate how babies think.
Watching infants piece life together, seeing their senses, emotions and motor skills take shape, is a source of mystery and endless fascination-at least to parents and developmental psychologists. We can decode their signals of distress or read a million messages into their first smile. But how much do we really know about what's going on behind those wide, innocent eyes? How much of their understanding of and response to the world comes preloaded at birth? How much is built from scratch by experience? Such are the questions being explored at Babylab. Though the facility is just 18 months old and has tested only 100 infants, it's already challenging current thinking on what babies know and how they come to know it.
Daniel is now engrossed in watching video clips of a red toy train on a circular track. The train disappears into a tunnel and emerges on the other side. A hidden device above the screen is tracking Daniel's eyes as they follow the train and measuring the diameter of his pupils 50 times a second. As the child gets bored-or "habituated", as psychologists call the process-his attention level steadily drops. But it picks up a little whenever some novelty is introduced. The train might be green, or it might be blue. And sometimes an impossible thing happens-the train goes into the tunnel one color and comes out another.
Variations of experiments like this one, examining infant attention, have been a standard tool of developmental psychology ever since the Swiss pioneer of the field, Jean Piaget, started experimenting on his children in the 1920s. Piaget's work led him to conclude that infants younger than 9 months have no innate knowledge of how the world works or any sense of "object permanence" (that people and things still exist even when they're not seen). Instead, babies must gradually construct this knowledge from experience. Piaget's "constructivist" theories were massively influential on postwar educators and psychologists, but over the past 20 years or so they have been largely set aside by a new generation of "nativist" psychologists and cognitive scientists whose more sophisticated experiments led them to theorize that infants arrive already equipped with some knowledge of the physical world and even rudimentary programming for math and language. Babylab director Sylvain Sirois has been putting these smart-baby theories through a rigorous set of tests. His conclusions so far tend to be more Piagetian: "Babies," he says, "know squat."
第一篇 遗落的森林 （Saving a Forgotten forests-- The longleaf pine）
Found only in the Deep South of America, longleaf pine woodlands have dwindled to about 3percent of their former range, but new efforts are under way to restore them.
A
The beauty and the biodiversity of the longleaf pine forest are well-kept secrets, even in its native South. Yet it is among the richest ecosystems in North America, rivaling tall grass prairies and the ancient forests of the Pacific Northwest in the number of species it shelters. And like those two other disappearing wildlife habitats, longleaf is also critically endangered.
B
In longleaf pine forests, trees grow widely scattered, creating an open, park like environment, more like a savanna than a forest. The trees are not so dense as to block the sun. This openness creates a forest floor that is among the most diverse in the world, where plants such as many-flowered grass pinks, trumpet pitcher plants, Venus flytraps, lavender ladies and pineland bog-buttons grow. As many as 50different species of wildflowers, shrubs, grasses and ferns have been cataloged in just a single square meter.
C
Once, nearly 92 million acres of longleaf forest flourished from Virginia to Texas, the only place in the world where it is found. By the turn of the 21st century, however, virtually all of it had been logged, paved or farmed into oblivion. Only about 3 percent of the original range still supports longleaf forest, and only about 10,000 acres of that is uncut old-growth—the rest is forest that has regrown after cutting.
D
Figuring out how to bring back the piney woods also will allow biologists to help the plants and animals that depend on this habitat. Nearly two-thirds of the declining, threatened or endangered species in the southeastern United States are associated with longleaf. The outright destruction of longleaf is only part of their story, says Mark Danaher, the biologist for South Carolina’s Francis Marion National Forest. He says the demise of these animals and plants also is tied to a lack of fire, which once swept through the southern forests on a regular basis. "Fire is absolutely critical for this ecosystem and for the species that depend on it," says Danaher.
E
Name just about any species that occurs in longleaf and you can find a connection to fire. Bachman’s sparrow is a secretive bird with a beautiful song that echoes across the longleaf flatwoods. It tucks its nest on the ground beneath dumps of wiregrass and little bluestem in the open under-story. But once fire has been absent for several years, and a tangle of shrubs starts to grow, the sparrows disappear. Gopher tortoises, the only native land tortoises east of the Mississippi, are also abundant in longleaf. A keystone species for these forests, its burrows provide homes and safety to more than 300 species of vertebrates and invertebrates ranging from eastern diamond-back rattlesnakes to gopher frogs. If fire is suppressed, however, the tortoises are choked out. "If we lose fire," says Bob Mitchell, an ecologist at the Jones Center, "we lose wildlife.’
F
Without fire, we also lose longleaf. Fire knocks back the oaks and other hardwoods that can grow up to overwhelm longleaf forests. "They are fire forests," Mitchell says. "They evolved in the lightning capital of the eastern United States." And it wasn’t only lightning strikes that set the forest aflame. “Native Americans also lit fires to keep the forest open," Mitchell says. “So did the early pioneers. They helped create the longleaf pine forests that we know today."
G
Fire also changes how nutrients flow throughout longleaf ecosystems, in ways we are just beginning to understand. For example, researchers have discovered that frequent fires provide extra calcium, which is critical for egg production, to endangered red-cockaded woodpeckers. Frances James, a retired avian ecologist from Florida State University, has studied these small black-and-white birds for more than two decades in Florida’s sorawling Apalachicola National Forest. When she realised female woodpeckers laid larger clutches in the first breeding season after their territories were burned, she and her colleagues went searching for answers. "We learned calcium is stashed away in woody shrubs when the forest is not burned," James says. "But when there is a fire, a pulse of calcium moves down into the soil and up into the longleaf." Eventually, this calcium makes its way up the food chain to a tree-dwelling species of ant, which is the red-cockaded’s favorite food. The result: more calcium for the birds, which leads to more eggs, more young and more woodpeckers.
H
Today, fire is used as a vital management tool for preserving both longleaf and its wildlife. Most of these fires are prescribed burns, deliberately set with a drip torch. Although the public often opposes any type of fire—and the smoke that goes with it—these frequent, low-intensity bums reduce the risk of catastrophic conflagrations. "Forests are going to bum," says Amadou Diop, NWF’s southern forests restoration manager. "It’s just a question of when. With prescribed bums, we can pick the time and the place."
I
Restoring longleaf is not an easy task. The herbaceous layer—the understory of wiregrasses and other plants, also needs to be re-created. In areas where the land has not been chewed up by farming, but converted to loblolly or slash pine plantations, the seed bank of the longleaf forest usually remains viable beneath the soil. In time, this original vegetation can be coaxed back. Where agriculture has destroyed the seeds, however, wiregrass must be replanted. cost solutions.
J
Bringing back longleaf is not for the short-sighted, however. Few of us will be alive when the pines being planted today become mature forests in 70 to 80 years. But that is not stopping longleaf enthusiasts. "Today, it’s getting hard to find longleaf seedlings to buy," one of the private landowners says. “Everyone wants them. Longleaf is in a resurgence."
Questions 1-6
Choose NO MORE THAN TWO WORDS from the passage for each answer.
Write your answers in boxes 1-5 on your answer sheet.
Forest fire ensures that:
• it help the Birds locate their 1____ in the ground.
• The burrows of a species of 2_____ provide homes to many other animals. Hardwoods such as 3_____ don’t take over.
Apart from fires lit by 4____.
• Fires are created by 5____ and European settlers.
• Fires deliberately lit are called 6____
Question 7-9
Complete the flow-chart below.
Choose ONE WORD ONLY from the passage for each answer.
Write your answers in boxes 6-9 on your answer sheet.
How to increase the number of cockaded woodpeckers Calcium stored in shrubs
↓
Shrubs are burned
Calcium released into 7.......
And travel up to the leaves
↓
8........ are eaten
↓
Number of 9....... increases
↓
More cockaded woodpeckers
Questions 10-13
Do the following statements agree with the information given in Reading Passage 1?
In boxes 10-13 on your answer sheet, write
TRUE if the statement agrees with the information
FALSE if the statement contradicts the information
NOT GIVEN if there is no information on this
10 The sparse distribution of longleaf pine trees leads to the most diversity of species.
11 It is easier to restore forests converted to farms than forests converted to plantations.
12 The technology in recreating the herbaceous layer will phase out in near future due to the high cost
13 Few people in this restoration program will see the replanted forest reach its maturity
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发表于 2019-1-14 10:51:22
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