新编大学英语第一册unit10 Text C: Animals on the Job
UNIT 10 AFTER-CLASS READING 2; New College English (I)
Animals on the Job
Animals not only make good pets, they sometimes make perfect workers if they have the right traits and training.
1 Every morning, Allie wakes up and accompanies her friend to the washroom. She turns on the light, soaps up a washcloth, and begins cleaning her friend's face. Is Allie an extremely devoted companion? Yes! Allie is a capuchin monkey who helps her disabled friend perform everyday tasks.
2 Monkeys like Allie are just one of many kinds of animals that help improve or even save human lives. But not all animals are suited to do every job. Certain animals are "hired" for specific jobs based on their traits, or characteristics. By using different methods of conditioning (training animals to act in a particular way in response to a stimulus, or signal), humans can teach animals to perform extraordinary tasks.
3 Throughout history, humans have relied on animals' traits to get certain jobs done. For example, compared with humans, dogs are "far superior at tracking down odors," says Marian Bailey, an animal behaviorist at Henderson State University in Arkansas. That's because dogs have millions of olfactory receptors, or smell nerves, in their noses.
4 For that reason, hunters used dogs to track down prey even in ancient Egypt. Today, dogs may be employed to sniff out illegal substances in school lockers or earthquake victims buried beneath the rubble of a collapsed building or highway.
5 Primates may not be good sniffers, but they can certainly lend a helping hand or two. Monkeys are perfect helpmates for quadriplegics, people paralyzed from the neck down who are unable to use their own hands (and legs). Like humans, explains Bailey, monkeys have opposable thumbs thumbs that face the hand's other fingers so monkeys can pick up objects. Capuchins learn to open doors, clean up spills, and unscrew bottle tops. They can even get a sandwich out of the refrigerator and load your favorite tape into the VCR.
6 And speaking of VCRs, animals are even helping scientists make a videotape. Jennifer Hurley, an animal researcher at the Long Marine Lab in Santa Cruz, California, is training two sea lions to carry video cameras on their backs to record the natural behavior of whales.
7 Hurley could never dive to the depths at which whales swim, she says. But sea lions can. And whales behave naturally around sea lions because these mammals are part of the whales' natural environment unlike humans or submarine-like research boats.
8 So how do you get an animal employee to do its job? The answer: career-training. Trainers teach the animals to obey their instructions through a process called conditioning.
9 Most trainers condition animals by using positive reinforcement, rewarding an animal for doing something correctly, says animal behaviorist Bailey. For example, trainers teach their dogs how to sniff out drugs by hiding a towel with the smell of drugs. "Dogs love to retrieve objects so the towel becomes a reward," says Morris Berkowitz, who heads up a canine drug-sniffing program in New York.
10 After repeating this game of hide-and-seek many times, the dog begins to "associate the odor with a reward," says Berkowitz. When he gives the command, or stimulus, the dog seeks out drugs. (It's like learning to study hard for a test in order to get a good grade as a reward.)
11 At "Helping Hands Monkey Helpers for the Disabled," capuchin monkeys are trained twice before being teamed with a disabled human. First, monkeys are placed with a foster family to become socialized to people. For five years, families help the monkeys adapt to a human environment, so the monkeys will trust and enjoy being around people.
12 Taking the monkeys in when they're four to six weeks old is important, says Bailey. "That's when monkeys normally become socialized to other monkeys," she says.
13 Second, trainers at Helping Hands train the monkeys to perform specific tasks to assist a particular person. For example, a monkey may be trained to scratch an itch, or slip a floppy disc into a computer drive. Trainers reward the monkeys by using positive reinforcement, such as food, drink, praise, and affection. This phase of training can take a year.
