You know that feeling when you're sick, where you don't want leave the house,
你知道那種生病只想待在家,
you don't want to talk to anyone, and you kinda just want to be left alone to wallow in your own misery and snot?
不想和任何人說話,只想一個人沉浸在自己的痛苦和悲傷中的感覺嗎?
Sometimes that's because you're so sick that you literally can't move without risking throwing up or whatever.
有時候是因為你病得很重,要吐了或者怎么樣。
But other times, it might have more to do with the way your immune system is connected to your brain—
但其它時候,這可能與你的免疫系統和大腦的連接方式有關——
including how it affects your social behavior.
包括免疫系統如何影響你的社交行為。
A lot of the research on this is really recent, and there's still plenty we don't know about that connection.
這方面的很多研究都是最近才進行的,而且我們對這種聯系知之甚少。
But psychologists and doctors are starting to realize that some immune responses can make you more or less social,
但是心理學家和醫生開始意識到某些免疫反應可以使你的社交行為增加或減少,
sometimes even without symptoms.
有時甚至沒有癥狀。
At first glance, the brain and immune system can seem pretty separate.
乍一看,大腦和免疫系統似乎無任何關聯。
Your brain is in its own little compartment, separated from almost everything else by what's known as the blood-brain barrier.
大腦就在小隔間里,通過所謂的血腦屏障將大腦和其他幾乎所有東西隔開。
That's exactly what it sounds like: a literal barrier,
你聽到的沒錯:就是字面上的屏障,
in the form of a membrane that keeps your brain safe from whatever's circulating in your blood.
這種屏障以膜的形式使大腦免受任何血液循環的侵害。
It's really important to have, because it stops almost all germs from infecting your brain.
屏障真的很重要,因為它能阻止大腦免受幾乎所有細菌的感染。
Meanwhile, your immune system does its thing in the blood running through the rest of your body, trying to protect you from disease.
與此同時,免疫系統在流經身體其余部分的血液中發揮作用,試圖保護你免受疾病侵害。
But your brain needs to know what's going on with your immune system, like if you have a spike in white blood cells to fight off an infection.
但是你的大腦需要知道免疫系統的情況,比如抵抗感染時,白血細胞是否劇增。
So there is at least one major connection between them: the vagus nerve,
所以它們之間至少有一個主要連接:迷走神經,
which connects your brain to the parts of your body where a lot of your immune responses happen, like your gut or lymph nodes.
它將你的大腦連接至身體的某些部位,這些部位會產生很多免疫反應,比如腸道或淋巴結。
The vagus nerve can detect compounds called cytokines, which are released by your immune system when you're fighting an illness.
迷走神經可以檢測到一種叫做細胞因子的化合物,當你的身體與疾病作斗爭時,免疫系統會釋放細胞因子。
And we know that your immune system affects your behavior,
我們知道免疫系統影響你的行為,
and that the vagus nerve is an important part of that connection, because of what happens when you cut it.
由于你切斷這種聯系所導致的后果,所以迷走神經是該聯系的重要組成部分。
Mice and rats with severed vagus nerves don't show that sickness response where you just want to sit at home by yourself.
切斷迷走神經的小鼠和老鼠并不顯示疾病反應:你只想自己待在家里。
They go hang out and party just as much as healthy mice, and they eat just as much too.
它們和健康的老鼠一樣,出去玩,參加聚會,吃的也和它們一樣多。
This normal sickness response — hiding at home, not going out to play with your little mouse friends —
這種正常的疾病反應——躲在家里,不出去和小老鼠朋友玩,
is probably an evolutionary adaptation.
可能是一種進化適應。
If you spend a little bit of time being antisocial, you're probably not going to spread whatever germs you're carrying,
如果不社交的話,你可能不會傳播自身攜帶的任何細菌,
which is great for society as a whole. And it helps you on an individual level, too:
這對整個社會大有裨益,從個人層面來說對你也是有好處的:
if you're a little less active, your body can put more resources into fighting the infection.
如果你不那么活躍,你的身體可以投入更多的精力來對抗感染。

But scientists are starting to learn that the situation is probably more complex than that. For example,
但科學家們開始認識到,情況可能比這更復雜。例如,
one 2010 study published in the Annals of Epidemiology found that immune reactions might be related to an increase in social activity.
2010年發表在《流行病學年報》(Annals of Epidemiology)上的一項研究發現,免疫反應可能與社會活動的增加有關。
Researchers tracked 36 people before and after getting a flu vaccine,
研究人員對36名參與者接種流感疫苗前后的情況進行追蹤,
and they found the subjects interacted with more people in larger groups right after they got the shot than right before.
發現受試者在注射流感疫苗后與更多人互動。
So, they were spending more time with more people while their bodies were building up an immune response.
因此,他們花更多的時間和更多的人在一起,而他們身體的免疫反應在增強。
Now, it's worth noting that this was just a small first study, and it didn't have a control group of people who, say, got a placebo shot.
值得注意的是,這只是首次小規模研究,沒有別的組可以對照,比方說,注射安慰劑。
But the researchers controlled for some obvious problems, like what day they got the shot.
但是研究人員把控了一些顯而易見的問題,比如注射時間。
It wasn't like everyone got them Friday morning just before going out to party all weekend.
不是每個人都在周五注射完才去參加周末聚會。
The difference between this study and just looking at what people do when they're actually sick is that in this case,
該研究和觀察人們生病時行為的區別在于,
the subjects' immune systems were more active, but they didn't have symptoms.
受試者的免疫系統更活躍,但沒有癥狀。
And the results were the opposite of what people do when they're sick: they were more social when their immune systems were more active.
研究結果與人們生病時的行為相反:當他們的免疫系統更活躍時,社交能力更強。
But based on what we've learned from later research, being more social when your immune system is stronger might actually make sense.
但是根據后來的研究我們了解到,當免疫系統更強的時候,更多的社交可能是有道理的。
In a study of 121 people published in the journal Psychoneuroendocrinology in 2015—
2015年發表在《心理神經內分泌學》(Psychoneuroendocrinology)雜志上的一項研究,對121人進行了測試。
I'm telling you those people named that journal just to mess with us—
告訴你,給那本雜志起名字的那些人只是為了和我們鬧著玩
researchers found that people who were more extroverted and social tended to express more of the genes known to increase the immune response.
研究發現,性格外向、社交廣泛的人往往出現更多已知的增強免疫反應的基因。
In other words, the more outgoing people seemed to have stronger immune systems, which might be another evolutionary adaptation —
換句話說,越外向的人,他的免疫系統越強,這可能是另一種進化適應。
it could be helpful for them to explore more, take more risks, and meet more people.
這將有助于他們探索更多,承擔更多的風險,和更多的人見面。
Again, this research is all really new, and without more studies we can't know for sure that this is what's happening.
此外,該項研究都是新的,沒有更多的研究,我們無法確定發生了什么。
But learning more about the connection between the immune system and social behavior could lead to new treatments for clinical conditions that are related to those behaviors.
但是,了解更多免疫系統和社會行為之間的聯系,可以為與之相關的臨床狀況提供新的治療方法。
For example, we know that some people get more severe symptoms of depression when their cytokines spike in their blood —
例如,我們知道當血液中的細胞因子激增時——就像他們的免疫反應強烈時,
like when they have a strong immune response.
某些人的抑郁癥會加重。
And a similar effect has been found in children with autism: increases of some cytokines in the blood can be accompanied by stronger symptoms.
在自閉癥兒童身上也發現了類似的效應:血液中某些細胞因子的增加可能伴隨著更強烈的癥狀。
The researchers are starting to investigate ways to use the immune system to affect social behavior on purpose.
研究人員開始研究利用免疫系統故意影響社會行為的方法。
In research published in Nature just last year, neuroscientists studied mice that were raised with impaired immune function.
在去年發表在《自然》雜志上的一項研究中,神經科學家們對免疫功能受損的小鼠進行了研究。
Compared to healthy mice, who are much more interested in hanging out with a new mouse than a new inanimate object,
與健康的老鼠——對新鼠而不是新的無生命體更感興趣——相比
the impaired mice were kind of equally interested in both.
免疫功能受損的老鼠對兩者都很感興趣。
It was like they saw the other mouse as just another thing.
就好像它們把另一只老鼠當成了另一個東西。
But, when the researchers injected immune cells called lymphocytes from healthy mice into the impaired mice, that difference went away.
但是,當研究人員將健康小鼠的淋巴細胞注射到受損小鼠體內時,這種差異就消失了。
We're still a long way from being able to use the immune system to treat clinical symptoms,
利用免疫系統來治療臨床癥狀仍然任重而道遠,
but with more research, psychologists hope we might someday be able to.
但是隨著研究的增多,心理學家希望有一天能夠實現。
And maybe all this will give you a little hope too, if you're lying on the couch next to a bucket.
如果你去看心理醫師,也許這一切會帶給你些許希望。
You'll probably be interested in hanging out with people again soon —
你可能很快就會有興趣再和別人出去玩了
you just have to wait for your immune system to do its job.
你只需要等待你的免疫系統發揮作用。
In the meantime, while you're sick is a great time to learn weird things about your mind,
與此同時,生病的時候,你可以借機學習大腦的一些奇怪的事情,
you can check out our video about whether you can use electricity to supercharge your brain.
看看我們的視頻——是否能用電力給大腦充電。
And if you want to keep getting smarter with us, you can always just go to youtube.com/scishowpsych and subscribe.
如果你想和我們一樣更聰明,可以隨時訪問并訂閱youtube.com/scishowpsych。