VOA慢速英语--科学家训练老鼠开车他们学到了什么?

Scientists Trained Rats to Drive Cars. What Did They Learn?

Mice and rats have long been used in medical research because of their biological similarities to humans.

The tiny animals have already shown an ability to recognize objects, push buttons and find their way through complex paths.

Now, scientists have trained rats to drive small vehicles created for them. One of the main findings¹ of the experiment was that the driving activity seemed to help the rats relax.

Researchers at the University of Richmond in Virginia led the experiment. Their findings were published in Behavioural Brain Research.

The team built tiny cars out of plastic and other materials. The vehicles had an opening at one end where electrical wires were attached. By touching² one of three different wires, the rat could steer³ the car in different directions – left, center and right.

Sweet treats were placed inside the experiment containers in an attempt to get the rats to drive the vehicle to get to the food.

Researchers trained 17 rats over several months to drive around the containers. The animals proved that they could be trained to drive forward as well as in other directions to get to the treats.

Kelly Lambert of the University of Richmond helped lead the experiment. She told the French news agency⁴ AFP the research suggests that rat brains may be more complex and flexible than once thought.

Lambert said she had long been interested in neuroplasticity, or the way the brain changes to react to different experiences and difficulties. She found that rats kept in what she calls "enriched⁶ environments" performed far better than those in labs. While she expected that result, Lambert told AFP "it was actually quite shocking⁷ to me that they were so much better."

The researchers examined levels of two hormones⁹ in the rats – one that causes stress and another that counters it. All rats that took part in the training had higher levels of the hormone⁸ that reduces stress. The research suggests the increased relaxation¹⁰ levels could be linked to the enjoyment¹¹ of successfully completing a new skill.

The team also found that the rats that drove themselves showed higher levels of the stress-fighting hormone than those that simply rode in small cars controlled by humans.

Lambert said the most exciting result of the experiment for her was about the possible effect on humans. The research may open new areas of non-drug treatments for people suffering from mental health conditions.

"There's no cure for schizophrenia or depression and we need to catch up," she said. "And I think we need to look at different animal models and different types of tasks and really respect that behavior can change our neurochemistry."

Speaking to the British-based magazine New Scientist, Lambert said her team is planning to continue experiments to learn more about how the rats learned¹² to drive. The new research will also examine why some activities appear to reduce stress, and which areas of the brain are involved in the process.

As an example, Lambert said new driving tests could be created to test the effects of Parkinson's disease¹³ on motor skills and awareness¹⁴ of space. "If we use more realistic and challenging models, it may provide more meaningful data," she told New Scientist.

Words in This Story

button – n. something you press to control a piece of equipment

relax – v. to become happy and comfortable because nothing is worrying you

steer – v. to control the direction of a vehicle

treat – n. a piece of free food, drink, etc., provided¹⁵ to someone

flexible – adj. able to be easily changed

enrich⁵ – v. to improve the quality of something by adding something to it

hormone – n. one of several chemicals produced in the body that influence growth and development

stress – n. feelings or worry or nervousness caused by difficult situations or problems

task – n. a piece of work, especially something unpleasant or difficult

1 findings   

n.发现物( finding的名词复数 )；调查（或研究）的结果；（陪审团的）裁决

参考例句：

• It behoves us to study these findings carefully. 我们理应认真研究这些发现。
• Their findings have been widely disseminated . 他们的研究成果已经广为传播。

2 touching   

adj.动人的，使人感伤的

参考例句：

• It was a touching sight.这是一幅动人的景象。
• His letter was touching.他的信很感人。

3 steer   

vt.驾驶，为…操舵；引导；vi.驾驶

参考例句：

• If you push the car, I'll steer it.如果你来推车，我就来驾车。
• It's no use trying to steer the boy into a course of action that suits you.想说服这孩子按你的方式行事是徒劳的。

4 agency   

n.经办；代理；代理处

参考例句：

• This disease is spread through the agency of insects.这种疾病是通过昆虫媒介传播的。
• He spoke in the person of Xinhua News Agency.他代表新华社讲话。

5 enrich   

vt.充实，使丰富，使富裕，使富有

参考例句：

• Some cream will enrich the sauce.在调味汁里加一些奶油会使其味道更加丰富。
• Music can enrich your life.音乐能丰富你的生活。

6 enriched   

使富有( enrich的过去式和过去分词 )； 使富裕； 充实； 使丰富

参考例句：

• The study of science has enriched all our lives. 科学研究丰富了我们的整个生活。
• breakfast cereals enriched with vitamins 增加了维生素的早餐谷物食品

7 shocking   

adj.令人气愤的；令人震惊的

参考例句：

• His attitude was shocking to her.他的态度令她感到震惊。
• Such behaviour is really shocking.这种行为真不像话。

8 hormone   

n.荷尔蒙，激素，内分泌

参考例句：

• Hormone implants are used as growth boosters.激素植入物被用作生长辅助剂。
• This hormone interacts closely with other hormones in the body.这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。

9 hormones   

n. 荷尔蒙，激素 名词hormone的复数形式

参考例句：

• This hormone interacts closely with other hormones in the body. 这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。
• The adrenals produce a large per cent of a man's sex hormones. 肾上腺分泌人体的大部分性激素。

10 relaxation   

n.松弛，放松；休息；消遣；娱乐

参考例句：

• The minister has consistently opposed any relaxation in the law.部长一向反对法律上的任何放宽。
• She listens to classical music for relaxation.她听古典音乐放松。

11 enjoyment   

n.乐趣；享有；享用

参考例句：

• Your company adds to the enjoyment of our visit. 有您的陪同，我们这次访问更加愉快了。
• After each joke the old man cackled his enjoyment.每逢讲完一个笑话，这老人就呵呵笑着表示他的高兴。

12 learned   

adj.有学问的，博学的；learn的过去式和过去分词

参考例句：

• He went into a rage when he learned about it.他听到这事后勃然大怒。
• In this little village,he passed for a learned man.在这个小村子里，他被视为有学问的人。

13 disease   

n.疾病，弊端

参考例句：

• The doctors are trying to stamp out the disease.医生正在尽力消灭这种疾病。
• He fought against the disease for a long time.他同疾病做了长时间的斗争。

14 awareness   

n.意识，觉悟，懂事，明智

参考例句：

• There is a general awareness that smoking is harmful.人们普遍认识到吸烟有害健康。
• Environmental awareness has increased over the years.这些年来人们的环境意识增强了。

15 provided   

conj.假如，若是；adj.预备好的，由...供给的

参考例句：

• Provided it's fine we will have a pleasant holiday.如果天气良好，我们的假日将过得非常愉快。
• I will come provided that it's not raining tomorrow.如果明天不下雨，我就来。