The only problem was that Harry couldn't actually recognize his wife or children by looking at their faces.

唯一的問題是：哈利其實無法從臉部辨識出他的太太與孩子們。

His wife, for example, had to identify herself to Harry by wearing conspicuous articles of clothing, like a big red hat.

舉例來說，他太太必須穿著顯眼的服裝，例如大紅帽子哈利才能認出她。

By taking one quick look at something like... my face... you can tell my age, gender, race, where I'm looking and even my mood.

快速地看過某項東西，比如說我的臉，你可以辨別出我的年齡、性別、種族、正在看哪，甚至是我的心情。

And if you've met me before, hello, you generally recognize me in a fraction of a second.

如果你曾見過我，嗨，通常不到一秒鐘你就可以認出我。

We have this amazing ability to recognize faces.

人類擁有了不起的臉部辨識能力。

There's even a dedicated area in our brains for it, but we hardly ever stop to think just how amazing this really is.

大腦甚至有個部分專職於此，但我們從沒細想過這件事有多神奇。

For all the new faces we see, our brains figure out how different it is from our perception of an average face.

每當見到新面孔，大腦能分清這張臉與所謂「大眾臉」的差異。

This is an average of all of the faces you've encountered before.

「大眾臉」指的就是我們遇過所有面孔的平均結果。

Our brains reduce the facial features, like eyes or lips, to a point and what we remember is just the distance and direction of that point from the centre.

大腦會忽略臉部器官，例如眼睛或嘴脣，只記得它們與臉中心的距離與角度。

This is called face-space, not like the FaceSpace the Oatmeal invented but a vector based mathematical model of face perception proposed by researchers in the 80s.

這稱為臉部空間，不是 Oatmeal 發明的 FaceSpace，而是 80 年代學者提出的一個向量基礎臉部辨識數學公式。

It allows us to remember a huge amount of faces, because what we store in our memory is this code, rather than having a photographic memory for faces as a whole.

這讓我們能記下大量的臉孔，因為記憶儲存的是代碼數據，而不是像照相式的臉部記憶。

Because of this tendency to construct an "average face" from all of ones that we see, we're more likely to remember distinctive faces,

因為我們是從見過的人中建立了一個「大眾臉」，所以我們更容易記住「有特色」的臉，

like Gollum's huge eyes or Mr. Spock's pointy ears.

像是咕嚕的大眼睛或史巴克尖尖的耳朵。

As for people we already know, like our friends, family and even celebrities, something interesting happens inside our brain when we see their faces.

至於已經認識的人，向我們的朋友、家人，甚至是名人，每當見到那些人時，腦內就會發生有趣的事。

Researchers recorded lots of single neurons, which are so incredibly tiny, in patients suffering from epileptic seizures who had electrodes implanted within their skull.

研究人員在癲癇患者頭骨內植入電極，記錄他們腦內的單一神經元，這種神經元很小。

They found that single neurons fired only when subjects were shown pictures of Jennifer Aniston, or Halle Berry, compared other faces or objects they didn't recognize.

他們發現，比起不熟悉的面孔或物體，受試者只在看到珍妮佛·安妮斯頓或哈莉·貝瑞的照片時，單一神經元才會被觸發。

Your neurons aren't lightening up because you're jealous of Jen's hair or love her chin, it's simply because you recognize her.

並不是因為你嫉妒珍妮佛的頭髮或喜歡她神經元才被觸發，純粹只是因為你認識她。

This activation of your neurons happens for your friends and families too, it's quite appropriately called "the grandmother cell".

這種神經元觸發也會發生在你看到朋友和家人時，我們可以稱之為「祖母細胞」。

Some researchers question the existence of such a neuron, but perhaps the neurons firing is our way of retrieving our face space memory.

有些研究者質疑此神經元的存在，但也許這樣的神經觸發正是我們記憶臉部的方法。

Sadly there are times when grandmother won't be there to help.

難過的是，有些人沒有祖母幫忙。

There are some people, just like Harry, who don't recognize any faces, ever.

有些人，像是哈利，永遠無法辨別任何臉孔。

People who suffer from this condition, face blindness or prosopagnosia, have a warped face space.

患有此症狀者，會臉盲，也就是無法辨識面部，對他們而言面部空間會扭曲。

Most of the time it's due to brain damage in facial recognition areas.

大部份患者是因為大腦臉部辨識區域的創傷而患病。

Harry actually sustained head injuries from a car crash, other people are born with it.

哈利其實曾在車禍中受過嚴重頭部創傷，而有些人則天生如此。

It's like people suffering from this condition just can't join the dots,

患者們無法將這些點連接起來，

some face blind people will only recognize those they see very often, some won't recognize anyone at all.

有些患者只能認出他們常見的人，有些則完全認不出任何人。

So things like Facebook are even better at identifying you than some people are.

所以比某些人，像臉書這類軟體搞不好還比較能認出你。

And facial recognition technology actually uses the face-space principles to work.

而且臉部辨識技術其實也是使用臉部空間原則運作的。

This technology identifies you, or me,

這項科技認出你我的方式

by measuring things like the distance between your eyes, the width of your nose, the shape of your cheekbones and the length of your jaw line.

是衡量人的眼距、鼻寬、顴骨形狀，以及下顎線長度。

In other words, your faceprint.

換句話說，就是你的臉部痕跡。

While most of our brains do this intuitively,

雖然我們的大腦能直覺性地分辨人臉，

I hope there's some way for facial recognition technology to help face blind people recognize their wife or children in years to come.

但我希望幾年內，臉部辨識技術能幫助無法辨識臉部的人認出他們的老婆及孩子。

So the next time you just can't remember a person's name, be thankful that you can recognize their face.

所以下次你記不起某人名字時，要感謝至少你能認出他們的臉。

And that you don't have to wear this for your significant other to recognize you.

也要感謝你不用戴這種東西你的另一半也能認出你。

If you haven't already, subscribe to BrainCraft! I have a new video out every other week.

如果還沒訂閱，快訂閱 BrainCraft 吧！我們每兩週會上一次新影片呦！