Do you see a face? You’re actually hallucinating - Susan G. Wardle

翻译人员: Leyu Jiang 校对人员: Jacky He

Imagine opening a bag of chips only to find Santa Claus looking back at you.

想象一下，当你打开一袋薯片， 却发现圣诞老人在看着你。

Or turning the corner to see a smile as wide as a building.

或者走过一个街角， 却看到楼房上的笑容。

Humans see faces in all kinds of mundane objects,

人们能在各种平凡的物品中看到面容，

but these faces aren’t real—

但这些不是真实的—

they’re illusions due to a phenomenon known as face pareidolia.

它们是“人脸空想性错视” (face pareidolia) 所导致的幻觉。

So why exactly does this happen, and how far can this distortion of reality go?

那么，为什么会发生这种情况， 这种对现实的扭曲会到什么程度呢？

Humans are social animals,

人是社会性动物，

and reading faces is an important part of our ability to understand each other.

而阅读面孔是人们 用来互相理解的重要能力。

Even a glimpse of someone's face can help you determine if you've met them before,

即使瞥见一个人的脸， 你能知道是否之前见过他们，

what mood they’re in, and if they’re paying attention to you.

他们当时的情绪， 以及他们是否在关注你。

We even use facial features to make snap-judgments

我们甚至使用面部特征进行

about a person’s potential trustworthiness or aggression.

关于这个人的可信度和 暴力倾向的快速判断。

To capture all this vital information,

为了捕捉这些极重要的信息，

humans have evolved to be very sensitive to face-like structures.

人类进化地对类似面部的 结构非常敏感。

Whenever we see something,

每当我们看到一些事物，

our brain immediately starts working to identify the new visual stimuli

我们的脑子立刻开始 反应辨认新的视觉刺激，

based on our expectations and prior knowledge.

基于我们的期望和原先的知识。

And since faces are so important,

既然面部那么重要，

humans have evolved several regions of the brain

人类已经进化出了许多脑部区域，

that enable us to identify them faster than other visual stimuli.

使我们比其他视觉刺激 更迅速地辨认它们。

Whereas recognizing most objects takes our brain around a quarter of a second,

虽然大脑识别大多数物体 需要大约四分之一秒，

we can detect a face in just a tenth of a second.

我们可以在十分之一秒内 认出一张脸。

It makes sense that we'd prioritize identifying faces over everything else.

我们优先识别人脸是符合逻辑的。

But brain imaging studies have revealed that regions

但是大脑造影研究显示这些区域

may actually be too sensitive,

可能有些过于敏感，

leading them to find faces where they don’t exist.

使得它们凭空认出人脸。

In one study, participants reported seeing illusory faces

在一个研究中，被试者反映 在提供的超过 35% 的

in over 35% of pure-noise images shown to them,

纯随机图案中，看到人脸，

despite the fact that nothing was there.

尽管这些图像中其实什么都没有。

It might seem concerning that our brains can be so wrong so often,

我们的大脑经常 这样出错似乎令人担忧，

but these illusory faces might actually be a byproduct

但是这些想象的面孔可能是

of something evolutionarily advantageous.

进化优势的副作用。

Since processing all the visual input we encounter quickly and correctly

因为准确快速地处理我们 收到的所有视觉信息

is an enormous computational effort for the brain,

对大脑来说是巨大的负担，

this kind of hypersensitivity might act as a useful shortcut.

这种超敏反应也许是恰当的捷径。

After all, seeing illusory faces is usually harmless,

毕竟看到面孔的幻觉通常是无害的，

while missing a real face can lead to serious issues.

但漏掉真的面孔会导致严重后果。

But for hypersensitivity to be more helpful than harmful,

但若要超敏感反应利大于弊，

our brains also need to be quick at determining when a face is real

我们的大脑需要迅速地辨别一张脸

and when it isn’t.

是真是假。

So how fast can our brains tell when they’ve been duped?

所以大脑能以多快的速度 意识到它受欺骗了呢？

To answer this question, researchers used a form of brain imaging

为了回答这个问题，研究人员用了

known as magnetoencephalography.

一种叫做脑磁波仪 (MEG) 的 大脑成像技术。

By measuring the magnetic fields caused by electric currents in the brain,

通过测量大脑中经过的 电流产生的磁场，

this technique allows us to track changes in brain activity

这个技术可以让我们 分析脑部活动的情况，

at the scale of milliseconds.

在毫秒的级别。

With this tool, researchers revealed that the brain generally recognizes

利用这个工具， 研究者们揭露了大脑通常

a face as illusory within a quarter of a second—

在四分之一秒内认出想象的面孔，

around the same time that we can identify most non-face visual stimuli.

这和我们认出非人脸 视觉刺激的时间相近。

However, even after our brain knows the face is fake,

然而，即使我们大脑 意识到一张脸是假的，

we can still see it in the object.

我们依然可以在物体中看到它。

And by messing with these brain areas,

而如果影响这些大脑区域，

we can further impact our ability to differentiate between fact from fiction.

我们会更难区分现实与幻象。

In one study, researchers stimulated a participant’s fusiform face area

在一项研究中，研究人员刺激了 一位受试者的菱状面区，

while they were looking at a non-face object.

在他看着一个人非人脸物品的时候。

As a result, the participant reported momentarily seeing facial features

结果是，被试者说他短暂地 看到了一些面部特征，

despite the object remaining unchanged.

尽管物品并没有任何变化。

And while looking at a real face, stimulation of this same area

而当看一张实际的脸时， 对这个区域的刺激

created perceived distortions of the eyes and nose.

造成了对眼睛和鼻子的混淆。

These studies suggest that certain features are crucial to face detection.

这些研究表明一些特征 对于面部识别极为重要。

Just three dots can be enough to represent eyes and a mouth.

只需三个点就足够表示眼睛和嘴巴。

People will even assign gender, age, and emotion to illusory faces.

人们甚至会给想象的面孔 加上性别、年龄以及情绪的设定。

It’s unclear whether a person’s culture or individual history

我们不清楚一个人的文化和背景

impacts these perceptions,

如何影响这些感知，

but we do know that pareidolia isn’t unique to the human experience.

但是我们知道，“空想性错视” 不止在人类当中发生。

Rhesus macaque monkeys show eye movements similar to our own

恒河猴当看到产生“空想性错视”的物品 以及真实面孔时，

when observing pareidolia-inducing objects and real faces,

做出和我们类似的眼球运动，

suggesting that this phenomenon is baked deep into our social primate brains.

说明这个现象在我们的 灵长类大脑中根深蒂固。

So, next time you see an unexpected face in a coffee, car, or cabinet,

所以，当你下一次在咖啡、轿车、 或者橱柜里看见意想不到的脸时，

remember that it’s just your brain working overtime

记得这只是因为你的大脑在为了

not to miss the faces that really matter.

不错过真正重要的面孔而加班加点。