Traveling makes us feel sick because modern transport tricks the brain into thinking we have been poisoned, a neuroscientist has said.
一位神經系統科學家表示,現代交通工具會誘導大腦認為我們已經中毒,所以旅行常常使我們感到不舒服。
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.
乘坐汽車、火車、船舶或飛機的體驗會在大腦中形成相互矛盾的信號,這會引發和人們中毒時相似的反應。
Dr 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.
卡迪夫大學的迪安.伯內特博士稱,大腦認為人體需要通過嘔吐排毒,于是便造成了這種惡心感。
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 US radio show Fresh Air, Dr 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’.
If you are sitting in a ship, you’re looking at a static environment
, so there’s no information for the eyes to say ’we are moving’.
“如果你坐在船上,你是看著一個靜態的環境,因此并沒有傳遞給眼睛‘我們正在運動’的信息。
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.
“但是你耳朵里的液體遵循物理定律,你確實在移動,因此它們四處搖擺、晃動。
So what’s happening there is the brain’s 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 being poisoned.
“從進化角度來看,唯一能夠引起感知矛盾的就是神經毒素或中毒,因此大腦判斷其根源在于中毒了。
When it’s been poisoned, the first thing it does is get rid of the poison, aka throwing up.’
“當中毒的時候,首先要做的就是排毒,也就是嘔吐。”
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.
看車窗外卻能夠緩解暈車的感覺,因為這告訴大腦人體正在運動當中。
You can see the passage and movement itself, so that balances the system,’ he said.
他說:“你可以親眼目睹過道以及移動本身,這也就讓系統得到了平衡。”
The brain’s going: ’Oh, look, things moving - I must be moving’ - and then sort of calms down the sickness response.’
“大腦這樣思考:‘噢,看,物體在運動,我也一定在運動’——這也就在某種程度上緩解了暈車的反應。”
Dr Burnett, who was discussing his new book ’Idiot Brain: what your head is really up to’, said brain systems became more refined and efficient as people aged but that children were more susceptible to travel sickness because their brains were still developing.