Traveling makes us feel sick because modern transport tricks the brain into thinking we have been poisoned, a neuroscientist said. Being in a car, train, boat or plane causes conflicting signals in the brain which trigger a reaction similar to that which occurs when someone is poisoned.

Dean Burnett of Cardiff University said the feeling of nausea is caused because the brain thinks the body needs to remove a toxin through vomiting.

But in fact, the “poisoning” effect is caused by the mixed messages from the muscles — which tell the brain the body is motionless — and the ears, which sense movement.

Speaking on the U.S. radio show “Fresh Air,” Burnett said that the body had not yet evolved to cope with the sensation of being in vehicles, where the body is being moved without performing movements itself.

He said, “When we’re in a vehicle like a car or a train or a ship especially, you’re not actually physically moving. Your muscles are saying “we are stationary.”

“But the fluids in your ears, they obey the laws of physics. And they are sort of rocking around and sloshing because you are actually moving.

“So what’s happening there is the brain is getting mixed messages. It’s getting signals from the muscles and the eyes saying “we are still” and signals from the balance sensors saying ‘we’re in motion.’ Both of these cannot be correct. There’s a sensory mismatch there.

“And in evolutionary terms, the only thing that can cause a sensory mismatch like that is a neurotoxin or poison. So the brain thinks, essentially, it’s been poisoned.

“When it’s been poisoned, the first reaction is to get rid of the poison, aka throwing up.”

He explained that reading in a car made the sensation of travel sickness worse, because the eyes were focused on a small, static space and gave the brain no information to explain that the body was moving. The feeling of sickness could be relieved by looking out of a car window because this showed the brain movement was taking place.

Brain systems become more refined and efficient as people age. Children are more susceptible to travel sickness because their brains are still developing.

一位神经学家表示，现代交通工具会诱导大脑认为我们已经中毒，所以旅行常使我们感到不舒服。乘坐汽车、火车、船舶或飞机的体验会在大脑中形成相互矛盾的信号，这会引发和中毒时相似的反应。

卡迪夫大学的迪安•伯内特称，大脑认为人体需要通过呕吐排毒，于是造成了恶心。但事实上，这种“中毒”效应是由肌肉和耳朵感受到的信息混乱引发的，肌肉向大脑传达身体静止的信息，而耳朵却察觉到身体在运动。

伯内特博士在美国广播节目《新鲜空

气》中表示，在交通工具中人们的身体被移动，而本身却未执行任何行动，人体还未进化到能够适应这种感觉。

他说：“当我们乘坐尤其是汽车、火车或是轮船这样的交通工具时，你的身体事实上没有动，因此你的肌肉也认为‘我们是静止的’。”

“但是耳朵里的液体遵循物理定律，你确实在移动，因此它们摇摆、晃动。

“所以问题就是大脑收到了混乱信

息。肌肉和眼睛告诉它‘我们是静止的’，而从平衡感知器官传来的信号又说‘我们在运动’。这两者不可能同时正确，所以知觉就不匹配。

“从进化角度来看，唯一能够引起感知矛盾的就是神经毒素或中毒，因此大脑判断其根源在于中毒了。

“当中毒的时候，首先要做的就是排

毒，也就是呕吐。”

他进一步解释，在车上阅读会恶化晕车的症状，因为眼睛始终盯着一块小而静止的空间，让大脑无从解释为什么感到身体正在移动。看车窗外能够缓解晕车的感觉，因为这告诉大脑人体正在运动当中。

随着人们岁数的增大，脑部系统变得越来越精炼和高效，孩子们更容易晕车，因为他们的大脑仍在发育。(Chinadaily.com.cn)

    Words to Learn 相关词汇

    【矛盾的】máodùn de conflicting being in conflict or disagreement, not compatible

    【呕吐】ǒutù throw up vomit