The mystery of motion sickness - Rose Eveleth

暈車的奧秘 - 羅斯埃弗萊斯

譯者: Chun-Ting Li 審譯者: Bighead Ge

Can you read in the car?

你能夠在車上看書嗎？

If so, consider yourself pretty lucky.

如果可以，那麼先恭喜你非常幸運

For one-third of the population,

約有三分之一的人口

looking at a book while moving along in a car

在移動中的車

or a boat or train or plane

船

火車

飛機

上看書會感到不適

quickly makes them sick to their stomach.

但為什麼會感到這種「移動中的不適」

But why do we get motion sickness in the first place?

Well, believe it or not, scientists aren't exactly sure.

信不信由你

科學家們也沒有很確定

The most common theory has to do

而最常見的理論是

with mismatched sensory signals.

身體感應訊號的錯置

When you travel in a car, your body gets two different messages.

當你坐在移動中的車子上時

你的身體同時接收兩種不同的訊號

Your eyes are seeing the inside of a vehicle,

你的眼睛看著車自內部

which doesn't seem to be moving.

沒有移動的部份

同時，你的耳朵告訴你的大腦

Meanwhile, your ear is telling your brain you're accelerating.

你現在處在加速的狀態

Wait, your ear?

等等！你的耳朵？

Your ear has another important function besides hearing.

沒錯，就是你的耳朵

有著除了聽覺外很重要的功能

In its innermost part lies a group of structures known as the vestibular system,

在耳朵最裡面有一組架構

稱作「內耳前庭系統」

這個系統負責人體平衡與移動的感知

which gives us our sense of balance and movement.

內耳前庭內部有三個半圓的細管

Inside there are three semicircular tubules

可以感知轉動

that can sense rotation, one for each dimension of space.

每一個細管負責一個維度

此外還有兩個毛髮排列的囊袋

And there are also two hair-lined sacks filled with fluid.

裡面充滿液體

所以當你移動時

When you move, the fluid shifts and tickles the hairs,

液體跟著移動並觸碰到毛髮

這時你的大腦會收到通知

不管你是水平移動

telling your brain if you're moving horizontally or vertically.

還是垂直移動

All this tells your body which direction you're moving in,

這些元素的加總

讓你的身體可以感知

你正在往哪個方向移動

how much you've accelerated, even at what angle.

你移動時的加速度是多少

甚至往哪個角度移動

所以當你在車裡面時

In a car,

你的內耳前庭系統 正確的感知你的移動方向

your vestibular system correctly senses your movement,

但是你的眼睛並不會看見移動方向

but your eyes don't see it, especially when glued to a book.

尤其當你的眼正專注在書本上時

兩者感知相反也是可能發生的

The opposite can happen.

例如當你坐在電影院裡

You're at the movies, and the camera makes a sweeping move.

而投影機投射一個大面積移動

這次換成你的眼睛

This time, your eyes think you're moving

認為你正處在移動中

而你的耳朵感知到你其實是坐著不動

while your ear knows you're sitting still.

只是究竟為何這樣的資訊衝突

But why does this conflicting information make us feel so terrible?

會讓我們感到如此不適呢？

科學家對於這個問題 仍然沒有一個確定的答案

Scientists aren't sure,

不過他們還是有一個 基於演化的解釋

but they think there's an evolutionary explanation.

你知道，快速前進的車輛與錄影帶播映

Fast moving vehicles and video recordings

是最近幾世紀才出現的

have only existed in the last couple of centuries,

存在時間並不長

a blink in evolutionary time.

人類演化歷史中

For most of our history, there wasn't that much

並沒有這麼多

that could cause this sensory mix-up,

可以造成感知混河錯亂的事物

except for poisons.

除了毒藥外

And because poisons are not the best thing for survival,

而因為毒藥

對於生存不利

我們的身體演化出直接

our bodies evolved a direct but unpleasant way

但不這麼讓人舒適的方式

來使我們擺脫那些我們可能吃下

to get rid of what we ate that was causing the confusion.

而造成混淆衝突的東西

It's a pretty reasonable theory, but it leaves things unexplained,

這個理論看似十分合理

但仍然留下許多未能解釋的部分

例如：為何女人

like why women are more affected by motion sickness than men,

比起男人更容易有移動中的不適感

或是為何乘客比起司機

or why passengers get more nauseous than drivers.

更容易感到噁心不適

另一個理論解釋說

Another theory suggests that the cause is more about

會造成此種不適的原因

the way some unfamiliar situations

與不熟悉環境比較相關

因其讓我們的身體

make it harder to maintain our natural body posture.

更難維持自然的姿勢

Studies show that being immersed in water or just changing your stance

研究指出

浸泡在水裡

或單純的改變姿勢

可以大幅降低這種

can greatly reduce the effects of motion sickness.

移動中產生的不適感

But we don't really know what's going on.

但同樣地，我們並不了解其真正的原因

We know the more common remedies for car queasiness --

我們知道其他常見的補救措施

當在車上感到不適的時候

looking at the horizon, over-the-counter pills, chewing gum,

可以往地平線看

嚼口香糖

服用成藥

但是這些方法並不是完全可靠

but none are totally reliable

nor can they handle intense motion sickness

也無法完全處理

強烈的不適感

and sometimes the stakes are far higher than just not being bored

而有時這種狀態

強烈度遠超乎一般

在長途車程中

during a long car ride.

在美國太空總署，太空人進入

At NASA, where astronauts are hurled into space at 17,000 miles per hour,

一個以每秒17000英哩移動的空間

motion sickness is a serious problem.

移動中產生的不適感變得極度強烈

In addition to researching the latest space-age technologies,

所以除了研究

最新的太空科技

NASA also spends a lot of time

美國太空總署也花了許多時間

figuring out how to keep astronauts from vomiting up their space rations.

試圖來想出

如何讓太空人不會因此嘔吐的辦法

他們仔細準備空間配置量

Like understanding the mysteries of sleep or curing the common cold,

和了解睡眠的祕辛

或解決感冒問題一般

motion sickness is one of those seemingly simple problems that,

移動中造成的不適感仍是屬於

那些看似簡單

despite amazing scientific progress, we still know very little about.

但若無重大科學進展

我們仍然不會知道的問題

Perhaps one day the exact cause of motion sickness will be found,

也許有一天

切確的答案會被找出

and with it, a completely effective way to prevent it,

而了解原因後

即可找出有效避免這種不適的方法

but that day is still on the horizon.

不過那ㄧ天的到來目前仍看似遙遙無期