In the 1950s， the pioneers of artificial intelligence （AI） predicted that， by the end of this century， computers would be conversing with us at work and robots would be performing our housework. But as useful as computers are， theyre nowhere close to achieving anything remotely resembling these early aspirations for humanlike behavior. Never mind something as complex as conversation： the most powerful computers struggle to reliably recognize the shape of an object， the most elementary of tasks for a ten-month-old kid.
A growing group of AI researchers think they know where the field went wrong. The problem， the scientists say， is that AI has been trying to separate the highest， most abstract levels of thought， like language and mathematics， and to duplicate them with logical， step-by-step programs. A new movement in AI， on the other hand， takes a closer look at the more roundabout way in which nature came up with intelligence. Many of these researchers study evolution and natural adaptation instead of formal logic and conventional computer programs. Rather than digital computers and transistors， some want to work with brain cells and proteins. The results of these early efforts are as promising as they are peculiar， and the new nature-based AI movement is slowly but surely moving to the forefront of the field.
Imitating the brains neural （神经的） network is a huge step in the right direction， says computer scientist and biophysicist Michael Conrad， but it still misses an important aspect of natural intelligence. People tend to treat the brain as if it were made up of color-coded transistors， he explains， but its not simply a clever network of switches. There are lots of important things going on inside the brain cells themselves. Specifically， Conrad believes that many of the brains capabilities stem from the pattern recognition proficiency of the individual molecules that make up each brain cell. The best way to build and artificially intelligent device， he claims， would be to build it around the same sort of molecular skills.
Right now， the notion that conventional computers and software are fundamentally incapable of matching the processes that take place in the brain remains controversial. But if it proves true， then the efforts of Conrad and his fellow AI rebels could turn out to be the only game in town. Birds that are literally half-asleep-with one brain hemisphere alert and the other sleeping-control which side of the brain remains awake， according to a new study of sleeping ducks.
Earlier studies have documented half-brain sleep in a wide range of birds. The brain hemispheres take turns sinking into the sleep stage characterized by slow brain waves. The eye controlled by the sleeping hemisphere keeps shut， while the wakeful hemispheres eye stays open and alert. Birds also can sleep with both hemispheres resting at once.
Decades of studies of bird flocks led researchers to predict extra alertness in the more vulnerable， end-of-the-row sleepers， Sure enough， the end birds tended to watch carefully on the side away from their companions. Ducks in the inner spots showed no preference for gaze direction.
Also， birds dozing（打盹）at the end of the line resorted to single-hemisphere sleep， rather than total relaxation， more often than inner ducks did. Rotaing 16 birds through the positions in a four-duck row， the researchers found outer birds half-asleep during some 32 percent of dozing time versus about 12 percent for birds in internal spots.
We believe this is the first evidence for an animal behaviorally controlling sleep and wakefulness simultaneously in different regions of the brain， the researchers say.
The results provide the best evidence for a long-standing supposition that single-hemisphere sleep evolved as creatures scanned for enemies. The preference for opening an eye on the lookout side could be widespread， he predicts. Hes seen it in a pair of birds dozing side-by-side in the zoo and in a single pet bird sleeping by mirror. The mirror-side eye closed as if the reflection were a companion and the other eye stayed open.
Useful as half-sleeping might be， its only been found in birds and such water mammals（哺乳动物）as dolphins， whales， and seals. Perhaps keeping one side of the brain awake allows a sleeping animal to surface occasionally to avoid drowning.
Studies of birds may offer unique insights into sleep. Jerome M. Siegel of the UGLA says he wonders if birds half-brain sleep is just the tip of the iceberg（冰山）。 He speculates that more examples may turn up when we take a closer look at other species.
16. Which of the following is evidence that TT is widely practiced？
A） TT has been in existence for decades.
B） Many patients were cured by therapeutic touch.
C） TT therapists are often employed by leading hospitals.
D） More than 100，000 people are undergoing TT treatment.
注：D为迷惑选项数字必转化，C对应第二段末句。
17. Very few TT practitioners responded to the $1 million offer because ____________.
A） they didnt take the offer seriously
B） they didnt want to risk their career
C） they were unwilling to reveal their secret
D） they thought it was not in line with their practice
注：争议题，B、C皆可。
18. The purpose of Emily Rosas experiment was ____________.
A） to see why TT could work the way it did
B） to find out how TT cured patients illness
C） to test whether she could sense the human energy field
D） to test whether a human energy field really existed
注：对应文章第三段首句
19. Why did some TT practitioners agree to be the subjects of Emilys experiment？
A） It involved nothing more than mere guessing.
B） They thought it was going to be a lot of fun.
C） It was more straightforward than other experiments.
D） They sensed no harm in a little girls experiment.
注：对应文章第三段末句，no harm对应innocent，little girl对应fourth-grade
20. What can we learn from the passage？
A） Some widely accepted beliefs can be deceiving.
B） Solid evidence weighs more than pure theories.
C） Little children can be as clever as trained TT practitioners.
D） The principle of TT is too profound to understand.
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