If you’ve ever thought that dogs seem to know when people are stressed, you were right. Scientists did an experiment which showed that dogs can tell the difference between the smell of a person when they’re relaxed and when they’re stressed.
Researchers worked with four dogs. They taught the dogs to use a special smell-testing device(装置) with three openings. The scientists used treats and rewards to train the dogs to find the correct opening. Over time, the dogs were given harder and harder smelling jobs. The final goal was to see if they could smell stress in the breath and sweat of a person.
All day long, our bodies go through changes and produce different chemicals(化学物). These chemicals come out in our breath and sweat, slightly changing the way we smell. But it wasn’t known if stress could cause changes that could be discovered.
So the researchers collected breath and sweat samples(样本) from 36 different people. They got samples when the people were calm, and also when they were stressed. Then the researchers collected two more sweat and breath samples. The scientists used one of the stressed samples, along with two clean pieces of cloth, to train the dogs to find the stressed smell.
Then came the challenge—the dogs had three choices: a sample from a calm person, a stressed sample from that same person, and a clean piece of cloth. In all, the dogs did 720 tests. They correctly identified the stressed sample about 94% of the time.
The results make it clear that stress does have a smell that dogs can find. Scientists say the news could be especially useful in training service dogs, since their job is to help relieve that stress.
本时文内容由奇速英语国际教育研究院原创编写，未经书面授权，禁止复制和任何商业用途，版权所有，侵权必究！（作者投稿及时文阅读定制请联系微信：18980471698）
13980503458
13980503458
admin@qisuen.cn
