看到恶心的东西为什么会呕吐？

As children, my older brothers and I always sat at the same places around the dinner table. Unfortunately, they were seated right across from me, the puker. I have vivid memories of barfing onto my plate as my mom and dad briskly cleared dishes and grabbed paper towels, all without a break in conversation. It happened so often that one of my siblings learned to hold up his dinner plate and keep eating as the mess was cleaned.

我还是个孩子的时候，我和哥哥们在餐桌上有固定的座位。我还清楚地记得，当我的父母用完餐后，他们便开始轻快地清理盘子和擦桌子。每到这时，我看到那些食物残渣就想要呕吐。但是这件事发生得如此频繁，以至于我的一个哥哥学会了在父母清理食物残渣时举起餐盘继续进食。

As I aged, the incidences became less frequent, but remained a real possibility, triggered by gory movies, half-chewed food and anyone who dared to become sick around me. And I know I'm not alone. Why do we vomit when we see something gross?

随着年龄的增长，我想要呕吐的冲动变得不那么频繁了，但并没有完全消失。当看到血腥的电影或者嚼了一半的食物时，我还是会想要呕吐。当然了，我知道并不只是我一个人这样。但我还是不禁想问：为什么我们看到恶心的东西时想要呕吐?

It could be the way our brains are wired. Scientists have discovered "mirror neurons" in the brain. Thanks to these neurons, we're able to empathize with others and their activities. In one study, functional MRI scans of participants showed that brain activity was similar whether subjects were imitating an emotion or observing an emotion. The brain's imitation and observation areas are so linked, we may feel like crying if we see someone else cry. Or, more to the point, vomit if we see someone else vomit .

这可能是因为我们大脑的连接方式。科学家们在我们的大脑中发现了“镜像神经元”，多亏了这些神经元，我们才能够同情他人的活动。在一项研究中，参与者的功能性核磁共振扫描显示，不管参与者是在模仿情绪还是观察情绪，其大脑活动是相似的。大脑的模仿区域和观察区域的联系是如此的紧密，以至于如果我们看到别人哭泣，我们可能也想流泪。更重要的是，如果我们看到别人呕吐，我们也想要呕吐。

The urge to vomit when we see something gross also could be a form of self-preservation. Let's say a prehistoric human ate a handful of poisonous red berries, believing them to be a delicious snack, and then became violently ill. In the future, simply seeing those berries will cause feelings of nausea and prompt a refusal to eat them. This conditioned reaction, in which your body creates a strong physical aversion, could save your life. Or go wrong.

当我们看到恶心的东西时，想要呕吐的冲动也可能是一种自我保护。比如，一个史前人类吃了一把有毒的红色浆果，然后病得十分厉害。在以后的日子里，他只要看到这些浆果就会感到恶心，并拒绝食用它们。这种让你的身体产生强烈厌恶的条件反应，可以拯救你的生命。或者出错。

Perhaps you ate eggs for breakfast and then went happily to work. For lunch, you opted for sushi and, by your mid-afternoon break, became violently ill. It's not the eggs' fault. You contracted food poisoning from day-old sushi. Even so, you spend the next few months avoiding sushi and eggs. The sushi makes sense, but what about the eggs? The sight of them makes you want to vomit, even though they weren't the real culprits. However, your brain believes the eggs made you ill and is mistakenly trying to protect you from them.

也许你早餐吃了鸡蛋，然后高兴地去工作了。而午餐时，你选择了寿司。在午后休息时，你病得很厉害。这并不是鸡蛋的错，而是寿司让你食物中毒了。即便如此，接下来的几个月里你还是会同时避免吃寿司和鸡蛋。不吃寿司确实是有道理的，但鸡蛋是无辜的。然而，你的大脑认为是鸡蛋让你生病了，并错误地试图保护你免受它们的伤害。