(单词翻译:单击)
Public speaking is terrifying for a lot of people,
公众演讲对很多人来说很可怕，
and it was especially stressful for people like Isaac Newton and England's King George VI,
而且它对艾萨克·牛顿和英国国王乔治六世这样的人造成的压力尤其得大，
because at some point, they each had a stutter.
因为在某些时候，他们都会犯口吃。
The exact symptoms vary, but someone who stutters has trouble speaking in fluid, connected sentences.
虽然确切的症状各不相同，但口吃的人难以说流畅、连贯的句子。
Which is not fun to deal with, if say, you are a king who is expected to give speeches all the time.
假如你是国王，一直被期待着进行演讲，那么它一点儿也不好对付。
Like many things in psychology, we're still trying to figure out exactly what causes stuttering in the first place.
与心理学中的很多问题一样，我们首先试着弄清楚口吃的确切原因。
But, despite what a lot of people think, stuttering probably doesn't come from anxiety.
尽管很多人认为口吃是因为焦虑，但事实可能不是这样。
Stuttering usually starts in kids between two and five years old.
口吃通常发生在两到五岁的孩子身上。
It's possible to develop a stutter as an adult,
成年人也有可能口吃，
but that's usually because of an injury or other condition,
但那通常是因为受伤或其他情况，
it doesn't normally show up by itself like it does in kids.
它通常不会像在孩子身上那样自己出现。
The main symptom is the repetition of sounds and syllables,
口吃的主要症状是重复声音和音节，
usually just one syllable, and that's often the first syllable of a longer word.
通常只重复一个音节，而且通常是一个较长单词的第一个音节。
There are also other symptoms that can be harder to identify,
口吃还有其他难以识别的症状，
like the lengthening of sounds, verbal or facial tics, or pauses in speech.
比如声音拖长、言语或面部抽搐、或讲话中的停顿
One thing that can make stuttering hard to diagnose is that
让口吃难以确诊的一件事是
little kids often show these same speech patterns when they're learning to talk.
小孩儿在学习说话的时候经常会表现出同样的说话模式。
It's normal for a kid to trip over words or get stuck on certain sounds,
对孩子来说，在某些词上绊住或被特定的音困住是很正常的，
especially if their mouth can't keep up with what they're trying to say,
特别是他们的嘴跟不上他们想说的话时更是如此，
and up to 20% of kids will show symptoms that look like stuttering.
多达20%的孩子会表现出类似口吃的症状。
But by the time they're four or five, 75% of them will have outgrown it.
但是当他们四五岁的时候，75%的人已经没有口吃症状了。
If someone is still stuttering by then, and if it's enough to disrupt their life or make them anxious,
如果有人那时还口吃，并且它足以扰乱他们的生活或者让他们焦虑，
they'll likely be diagnosed with Childhood-Onset Fluency Disorder, the official name for stuttering.
他们很有可能被确诊为儿童期发病的流畅性障碍——口吃的官方名称。
We don't know why some people outgrow their symptoms,
虽然我们不知道人们摆脱口吃的原因，
but we do know that people don't start stuttering because they're shy or nervous.
但却知道人们不会因为害羞或紧张而口吃。
Being shy or nervous can make symptoms worse and can start a vicious cycle,
害羞或紧张会使症状恶化，并引发恶性循环，
because then you get more stressed and stutter more, and then you get even more stressed.
因为你会变得更有压力，更结巴，然后你会压力更大。
But people who manage their symptoms score about the same on anxiety tests as people who've never stuttered,
但那些在焦虑测试中表现出症状的人与那些从不口吃的人得分一样，
so scientists are pretty sure that it's not the root cause.
所以科学家们很确定这不是根本原因。
It's more likely that genetics is involved in some way.
口吃更有可能是基因在某种程度上起得作用。
You're three times more likely to stutter if you have a family member who also stutters.
如果你的家人有口吃症状，那么你患口吃的可能性会增加三倍。
It's also more common in boys than in girls,
男孩的口吃症状比女孩更常见，
which is why some geneticists used to think it might be linked to sex-specific chromosomes.
这就是为什么一些遗传学家曾经认为它可能与特定性别的染色体有关。
But we now know that that's probably not the case.
但我们现在知道，情况可能并非如此。
Newer research has found that mutations on other chromosomes, like chromosome 12, could be responsible.
最新的研究发现，其他染色体的突变，比如12号染色体的突变，可能是罪魁祸首。
When researchers studied a group of families in Pakistan with a high concentration of people who stuttered,
当研究人员对巴基斯坦的一组口吃家庭进行研究时，
they found that 10% of those who did had mutations on chromosome 12.
发现他们中10%的人12号染色体有突变。
That might not sound like much, but there were almost no mutations on chromosome 12 among those who didn't stutter.
这听起来可能不太多，但那些没有口吃的人12号染色体几乎没有突变。
So, it's not a definite answer, but it's a useful clue for further research.
所以，它虽不是肯定的答案，但对进一步的研究是个有用线索。
Scientists have also found some neurological differences between people who stutter and those who don't.
科学家们还发现，口吃的人与没有口吃的人的某些神经存在差异。
For example, they've noticed in different brain scans
比如，他们注意到在不同的脑部扫描中，
that there are areas on the left side of the brain, which are usually really active when you're talking,
大脑左侧有一些区域在你讲话时通常非常活跃，
that aren't as active in people who stutter.
而口吃者的这部分区域并不活跃。
There are also regions on the right side of the brain that you usually don't use to talk,
右脑也有一些区域，你说话时通常用不到，
but that are overly active in people who stutter.
但口吃者的这片区域过于活跃。
This could mean that when you stutter,
这可能意味着你在结巴时，
the right side of your brain is interfering with normal speech production on the left side.
你的右脑正在干扰左脑正常的语音生成。
That idea also supported by the fact
这个观点也得到了一个事实的支持，
that the corpus callosum, the bundle of neurons that connects the two sides of your brain, is a bit bigger in some people who stutter.
即口吃者的胼胝体（连接大脑两侧的神经元束）比较大。
When signals travel between the two halves of your brain,
当信号在左右脑之间传递时，
they pass through the corpus callosum, so having a larger one could help transmit the interference.
它们会通过胼胝体，所以较大的胼胝体可能有助于传递干扰。
But that's still just a guess, we don't know for sure why there's a size difference.
但这只是猜测，我们不知道它们为什么会有大小差异。
And, since kids' brains are developing at the same time as they're beginning to stutter,
由于孩子开始口吃的同时大脑也正在发育，
we don't know if those brain differences cause stuttering,
所以我们不知道是这些大脑差异导致得口吃，
or if growing up with a stutter is what makes the brain change.
还是成长中的口吃导致得大脑变化。
So, we still have a lot to learn about stuttering, and there is no cure for it yet.
所以，我们对口吃仍有很多要了解的地方，目前还没有治愈方法。
But plenty of people manage their symptoms with treatment.
但是很多人通过治疗来控制自己的症状。
One thing that helps is to make kids less anxious
有一件事很有帮助，那就是让孩子们少些焦虑，
by teaching them that they haven't failed and that there's nothing to be ashamed of.
方法是教导他们自己还没有失败，没有什么值得羞愧的。
Using direct instruction, like teaching them how some phrases sound, can also help,
使用直接的指导，比如教他们一些短语的发音，也可能有帮助，
but another useful tool is to slow down the conversation,
另一个有用的工具是放慢谈话的节奏，
that way, the kid can get comfortable with simpler or slower sentences,
这样，孩子们就能熟悉简单或较慢的句子，
and then work their way up to more complicated ones.
然后他们再一步步学习更复杂的句子。
The best treatment depends on the person,
最好的治疗取决于个人，
but there are a ton of ways to make stuttering less stressful and more manageable.
但是很多方法可以减少口吃带来的压力，使之更易于控制。
It's too late to help Newton, but as psychologists and neurologists do more research,
我们来不及帮助牛顿了，但随着心理学家与神经学家做更多的研究，
we're starting to be able to help more of today's stutterers.
现在，我们开始能够帮助更多的口吃者了。
Thanks for watching this episode of SciShow Psych,
感谢您收看本期的心理科学秀，
which was brought to you by all of our patrons on Patreon.
它是由Patreon的所有赞助人制作播出的。
If you would like to support the show and keep exploring all kinds of things about our brains,
如果你想支持我们的节目，继续探索我们大脑的各种事情，
you can go to patreon.com/scishow.
可以登录patreon.com/scishow。
And for new videos every week, you can visit youtube.com/scishowpsych and subscribe.
你要想看每周的新视频，可以访问youtube.com/scishowpsych并点击订阅。
