科学界最令人困惑问题之一 我们为什么会打哈欠3

Perhaps the best evidence comes from twotroubled women who approached Gallup soon after he first published his were looking for relief from pathological yawning attacks, sometimeslasting an hour at a time. “It was extremely debilitating and interferes withany basic activity,” says Gallup. “They’d have to walk away and go to a secludedarea – it affected their personal and professional lives.” Intriguingly, one ofthe women found the only way to stop the yawning attack was to throw herself intocold water. Inspired, Gallup asked them to place a thermometer in their mouthsbefore and after the attacks. Sure enough, he saw a slight rise in temperaturejust before the yawning bouts, which continued until it dropped back to 37C.

可能最好的证据来自于两位受哈欠困扰的女士，她们在盖勒普第一次发布了他的研究成果后便找到了他。这两位女士都患有疾病性的哈欠症状，有时候哈欠会一次持续一个小时之久，她们一直都在寻找治疗方法。“当某项日常活动出现了问题，日常生活就会遇到极大的困扰与麻烦，令人身心俱疲，”盖勒普说。“他们就不得不远离他人，走到一个隐蔽的区域——从而影响到他们的私人以及职业生活。”有趣的是，其中的一位女士发现唯一能让自己停止打哈欠的办法就是把她整个人浸入冷水当中。受到这一方法的启发，盖勒普让她们在打哈欠之前及之后都要将一个温度计放入各自的嘴里。果然，盖勒普观察到了温度在哈欠刚发作之前有所轻微上升，持续一段时间后温度再度回落到37℃。

Importantly, this brain chill mightunderlie the many, seemingly contradictory, events that lead to yawning. Ourbody temperature naturally rises before and after sleep, for instance. Coolingthe brain slightly might also make us more alert – waking us up when we arebored and distracted. And by spreading from person to person, contagious yawnscould therefore help a whole group to focus.

重要的是，这一冷却大脑的作用可能能够解释众多看似矛盾的会导致打哈欠的各类原因。比如我们的体温在睡觉之前、之后会自然地上升。对大脑进行稍稍的冷却也可以让我们变得更加警觉，当我们无聊、走神的时候可以重振我们的精神。通过人与人之间的互相感染，打哈欠能够帮助一个团队的人集中起注意力。

Gallup’s unified theory has been somewhatcontentious among yawning researchers. “Gallup’s group has failed to presentany convincing experimental evidence to support his theory,” says Hess. Inparticular, his critics point out he hasn’t made direct measurements oftemperature changes in the human brain, though Gallup says he has found theexpected fluctuations in yawning rats. Provine is more positive, however –believingthat it could be one way in which yawning helps the brain change state, andfocus.

盖勒普这一统一的理论在哈欠研究者之间引起了争论。“盖勒普的团队没有拿出任何有说服力的实验证据来支持他的理论，”赫斯这样评价。他的批评者尤其指出了他并没有对人脑的温度变化进行直接的测量，尽管盖勒普本人说他自己在打哈欠的老鼠身上已经发现了预想当中的温度波动。普罗文对此则持更为积极的态度，他相信这可能是打哈欠帮助大脑改变状态以及集中注意力的一种途径。

Even if Gallup has managed to find thatunified theory, many mysteries remain. Why do foetuses yawn in the womb, forinstance?

即使盖勒普成功找到了这样一个统一化的理论，仍有很多的谜题有待解开。比如为什么胎儿会在子宫里打哈欠？

It could just be that they are practicingfor life outside, or perhaps the yawn plays a more active role in guiding thebody’s growth – by helping to develop articulation in the jaws joints, forinstance, or by encouraging the growth of the lungs, says Provine. If so,Provine suggests that yawning’s functions in the womb may be more important than our attacks asadults.

普罗文说胎儿可能是在为外面的生活做演练，或者也有可能是打哈欠能够促进身体的生长——比如促进颌关节或是肺器官的发育。如果是这样的话，普罗文就认为子宫内哈欠的作用可能比我们成人在外界打的哈欠来得更为重要。

Provine also points out that yawning – andperhaps other bodily functions, like sneezing – shares some strange parallelswith sex. The facial expressions involved are surprisingly similar, he says –just take a look at this picture and you can see where he’s comingfrom.

普罗文还指出打哈欠——可能还有其他身体机能比如打喷嚏——同性行为有着神奇的联系。两者的面部表情惊人得相似，普罗文说——看一看这张图片你就能看出他刚经历了什么。

Like sex, yawns and sneezes involve abuild-up that ends in a pleasant climax. “Once initiated, they go to completion– you don’t want a yawnus interruptus,” is how Provine puts it. For thesereasons, he wonders if a shared neural machinery underlying these differentfeelings. “Mother Nature does not reinvent the wheel,”he says. Asevidence, he points to the fact that certain anti-depressants can lead somepatients to orgasm during a yawn –a rare side effect that could quickly lose its appeal.

同性行为类似，打哈欠与打喷嚏涉都有一个快感积累，并以高潮结束的过程。“这种行为一旦启动，就必须进行完整——你可不会希望有人在你打哈欠的时候打扰你，”普罗文如此解释。基于这些原因，他想知道的是在这些不同的感觉背后是否有一种共享的神经机制。“大自然母亲不可能把轮子发明两次，”普罗文说。作为证据，他指出这样一个事实，那就是某一种特定的抗抑郁药能够导致某些病人在打哈欠过程中体会到性高潮——这是一个很快就会失去其吸引力的罕见的副作用。

Eventually, the temptation to yawn justproved too irresistible during my conversation with Provine. It was a warmsummer day, so perhaps my yawns were stopping my brain from over-heating duringour stimulating conversation. Whatever function it was serving, the relief wasalmost worth the agonising wait.

最后，在同普罗文交谈的过程中，打哈欠的诱惑是如此得无法抵抗。那是一个温和的夏日，所以我的哈欠可能是在防止我的大脑在我们的谈话中升温过度。不论它发挥着什么作用，最终的释放值得此前煎熬的等待。

I’m willing to bet you’ve been stifling afew yawns yourself by this point – as Provine points out, reading or eventhinking about yawning can be enough to set us off. So go ahead, let it out –and do so in the knowledge that you are enjoying one of life’s most enduringmysteries.

我敢打赌现在的你看到这里肯定已经打了好几次的哈欠——就像普罗文指出的那样，阅读或甚至是想到打哈欠这件事都会足够引起哈欠。所以别憋着了，尽情地张开嘴吧——要知道你可是在享受一个生命最持久的秘密。