演講MP3+雙語(yǔ)文稿:當(dāng)你品嘗食物時(shí)，你的大腦會(huì)發(fā)生什么？

聽(tīng)力課堂TED音頻欄目主要包括TED演講的音頻MP3及中英雙語(yǔ)文稿，供各位英語(yǔ)愛(ài)好者學(xué)習(xí)使用。本文主要內(nèi)容為演講MP3+雙語(yǔ)文稿:當(dāng)你品嘗食物時(shí)，你的大腦會(huì)發(fā)生什么？，希望你會(huì)喜歡！

【演講者及介紹】Camilla Arndal Andersen

神經(jīng)科學(xué)家(Camilla Arndal Andersen)沒(méi)有詢(xún)問(wèn)受試者的想法，而是用傳感器覆蓋受試者，以揭示他們對(duì)食物未經(jīng)過(guò)濾的潛意識(shí)反應(yīng)

【演講主題】當(dāng)你品嘗食物時(shí)，你的大腦會(huì)發(fā)生什么

【中英文字幕】

翻譯者 Ivana Korom 校對(duì)者 Krystian Aparta

00:13

So I had this very interesting experience five years ago. You know, me and my husband, we were out grocery shopping, as we do every other day, but this time, we found this fancy, you know, I'm talking fair-trade, I'm talking organic, I'm talking Kenyan, single-origin coffee that we splurged and got.

五年前，我碰到了 一件有趣的事兒。 有一天，和往常一樣， 我和我丈夫去買(mǎi)菜， 但這次我們看到了 一家特別高大上的店， 有這么一類(lèi)公平貿(mào)易、有機(jī)， 來(lái)自肯尼亞單一產(chǎn)區(qū)的咖啡， 我們買(mǎi)了好多。

00:36

And that was when the problem started already. You know, my husband, he deemed this coffee blend superior to our regular and much cheaper coffee, which made me imagine a life based solely on fancy coffee and I saw our household budget explode.

這時(shí)候問(wèn)題就來(lái)了。 我丈夫覺(jué)得買(mǎi)的這類(lèi)咖啡 比平常普通便宜的咖啡要好喝， 我不禁想象了一下 只有高檔格咖啡的生活， 以我們的經(jīng)濟(jì)狀況肯定吃不消。

00:52

(Laughter)

（笑）

00:53

And worse ... I also feared that this investment would be in vain. That we wouldn't be able to notice this difference after all. Unfortunately, especially for my husband, he had momentarily forgotten that he's married to a neuroscientist with a specialty in food science.

更重要的是， 我更擔(dān)心這類(lèi)投資沒(méi)什么意義。 畢竟我們根本喝不出來(lái)區(qū)別。 不巧的是，我丈夫 時(shí)常忘記他的妻子 是一位神經(jīng)科學(xué)家， 專(zhuān)長(zhǎng)是食品科學(xué)。

01:12

(Laughter)

（笑聲）

01:14

Alright? So without further ado, I mean, I just put him to the test. I set up an experiment where I first blindfolded my husband.

就是這么個(gè)情況。 那么事不宜遲， 我趕忙丟給他一個(gè)測(cè)試。 我設(shè)置了一個(gè)實(shí)驗(yàn)， 也就是把我丈夫的眼睛蒙上。

01:25

(Laughter)

(笑聲)

01:26

Then I brewed the two types of coffee and I told him that I would serve them to him one at a time. Now, with clear certainty, my husband, he described the first cup of coffee as more raw and bitter. You know, a coffee that would be ideal for the mornings with the sole purpose of terrorizing the body awake by its alarming taste.

然后沖泡了兩種咖啡， 并告訴他 我一次給他喝一種。 我的丈夫在描述 第一杯咖啡的時(shí)候十分肯定地說(shuō)， 這杯更苦更澀。 就是那種一大早起床 能讓人立馬清醒的味道。

01:47

(Laughter)

（笑聲）

01:49

The second cup of coffee, on the other hand, was both fruity and delightful. You know, coffee that one can enjoy in the evening and relax. Little did my husband know, however, that I hadn't actually given him the two types of coffee. I had given him the exact same cup of coffee twice.

而第二杯咖啡，他說(shuō) 更令人愉悅，還帶些果味， 是適合晚上喝的那種咖啡。 但我的丈夫并不知道 我其實(shí)根本沒(méi)有給他喝兩種咖啡， 而是同一杯咖啡給他喝了兩次。

02:11

(Laughter)

（笑聲）

02:14

And obviously, it wasn't this one cup of coffee that had suddenly gone from horrible to fantastic. No, this taste difference was a product of my husband's own mind. Of his bias in favor of the fancy coffee that made him experience taste differences that just weren't there. Alright, so, having saved our household budget, and finishing on a very good laugh, me especially --

顯然，并不是這一杯咖啡 突然變得好喝， 而是我丈夫的心理作用。 因?yàn)樗麑?duì)來(lái)自肯尼亞單一產(chǎn)區(qū) 的有機(jī)咖啡的偏好 讓他體會(huì)到了本不存在的味覺(jué)差異。 所以呢，我輕而易舉地 省下了家庭開(kāi)支， 還逗得大家笑了笑。 我呢——

02:40

(Laughter)

（笑聲）

02:41

I then started wondering just how we could have received two such different responses from a single cup of coffee. Why would my husband make such a bold statement at the risk of being publicly mocked for the rest of his life?

開(kāi)始思索我們 是如何接收兩種不同信息的。 為什么我的丈夫可以充滿信心的作答 而不怕被人在公共場(chǎng)合嘲笑呢？

02:56

(Laughter)

（笑聲）

02:59

The striking answer is that I think you would have done the same. And that's the biggest challenge in my field of science, assessing what's reality behind these answers that we receive. Because how are we going to make food tastier if we cannot rely on what people actually say they like?

別笑，其實(shí)大家都一樣。 而這也是我這門(mén)學(xué)科最大的挑戰(zhàn)， 即這些答案背后的真相 是什么。 因?yàn)槿绻覀兌疾荒芟嘈湃藗冋f(shuō)的話， 又該怎么才能讓食物變好吃呢？

03:19

To understand, let's first have a look at how we actually sense food. When I drink a cup of coffee, I detect this cup of coffee by receptors on my body, information which is then turned into activated neurons in my brain. Wavelengths of light are converted to colors. Molecules in the liquid are detected by receptors in my mouth, and categorized as one of five basic tastes. That's salty, sour, bitter, sweet and umami. Molecules in the air are detected by receptors in my nose and converted to odors. And ditto for touch, for temperature, for sound and more. All this information is detected by my receptors and converted into signals between neurons in my brain. Information which is then woven together and integrated, so that my brain recognizes that yes, I just had a cup of coffee, and yes, I liked it. And only then, after all this neuron heavy lifting, do we consciously experience this cup of coffee. And this is now where we have a very common misconception.

要想一探究竟，我們還得來(lái)看看 人類(lèi)是如何感知食物的。 當(dāng)我喝咖啡的時(shí)候， 身體中的受體分子會(huì)感知到， 接著信息便會(huì)傳到活躍的大腦神經(jīng)元。 光波被轉(zhuǎn)化為顏色。 嘴巴里的受體感知到液體分子 然后把它們歸類(lèi)為五種基本味道， 即酸，甜，苦，咸，鮮。 鼻子里的受體會(huì)感知空氣分子 并轉(zhuǎn)化為香味。 這些也適用于觸摸，溫度，聲音等等。 這一切信息都會(huì)被身體里 的接受體檢測(cè)到， 并轉(zhuǎn)化為大腦神經(jīng)元之間的信號(hào)， 然后信息被編碼并組合， 這樣大腦就可以識(shí)別出 剛剛喝了杯咖啡，還蠻喜歡的。 只有在 所有神經(jīng)元都干完活后 我們才能有意識(shí)地去體會(huì)這杯咖啡。

04:36

People tend to think that what we experience consciously must then be an absolute true reflection of reality. But as you just heard, there are many stages of neural interpretation in between the physical item and the conscious experience of it. Which means that sometimes, this conscious experience is not really reflecting that reality at all. Like what happened to my husband. That's because some physical stimuli may just be so weak that they just can't break that barrier to enter our conscious mind, while the information that does may get twisted on its way there by our hidden biases. And people, they have a lot of biases.

這時(shí)人們常常有些誤解。 人們總覺(jué)得我們有意識(shí)感知到的東西 一定反映出了絕對(duì)的現(xiàn)實(shí)。 但正如我剛剛所說(shuō)的， 神經(jīng)解釋在實(shí)物 和有意識(shí)的經(jīng)驗(yàn)之間 有很多步驟， 也就是說(shuō)，有的時(shí)候， 有意識(shí)的體驗(yàn)并不一定 能反應(yīng)出真實(shí)情況。 正如我的丈夫一樣。 這是因?yàn)橐恍┪锢泶碳た赡芴^(guò)微弱， 并不能打破重重關(guān)卡 最后進(jìn)入我們的意識(shí)之中， 而這個(gè)信息 則會(huì)被隱藏的偏見(jiàn)所扭曲。 人類(lèi)有太多偏見(jiàn)。

05:24

Yes, if you're sitting there right now, thinking ... you could probably have done better than my husband, you could probably have assessed those coffees correctly, then you're actually suffering from a bias. A bias called the bias blind spot. Our tendency to see ourselves as less biased than other people.

沒(méi)錯(cuò)，如果你在想， 你肯定不會(huì)和我丈夫一樣， 并能辨別出這只是同一杯咖啡， 那你可能的確有一種偏見(jiàn)， 即偏見(jiàn)盲點(diǎn)。 我們經(jīng)常認(rèn)為自己沒(méi)有 別人那么多的偏見(jiàn)。

05:46

(Laughter)

（笑聲）

05:47

And yeah, we can even be biased about the biases that we're biased about.

沒(méi)錯(cuò)， 我們甚至可能因?yàn)?我們有偏見(jiàn)的偏見(jiàn)而有偏見(jiàn)。

05:51

(Laughter)

（笑聲）

05:52

Not trying to make this any easier.

再往前一步說(shuō)，

05:55

A bias that we know in the food industry is the courtesy bias. This is a bias where we give an opinion which is considered socially acceptable, but it's certainly not our own opinion, right? And I'm challenged by this as a food researcher, because when people say they like my new sugar-reduced milkshake, do they now?

食品業(yè)中常見(jiàn)的，是禮貌性偏見(jiàn)。 這種偏見(jiàn)是，我們給出一個(gè) 社會(huì)上普遍認(rèn)可的觀點(diǎn)， 但這絕對(duì)不是我們自己的觀點(diǎn)。 作為一名食品科學(xué)家， 我對(duì)此不以為然， 當(dāng)人們說(shuō)他們喜歡我手里 的低糖奶昔的時(shí)候， 是真心的嗎？

06:19

(Laughter)

（笑）

06:20

Or are they saying they like it because they know I'm listening and they want to please me? Or maybe they just to seem fit and healthy in my ears. I wouldn't know. But worse, they wouldn't even know themselves. Even trained food assessors, and that's people who have been explicitly taught to disentangle the sense of smell and the sense of taste, may still be biased to evaluate products sweeter if they contain vanilla. Why? Well, it's certainly not because vanilla actually tastes sweet. It's because even these professionals are human, and have eaten lot of desserts, like us, and have therefore learned to associate sweetness and vanilla.

還是說(shuō)， 他們只是知道我在聽(tīng)這些話， 而他們只想逗我開(kāi)心？ 又或者他們只想 讓我覺(jué)得他們挺健康的， 誰(shuí)知道呢。 更有趣的是，他們可能 并沒(méi)有意識(shí)到自己的行為。 甚至經(jīng)過(guò)嚴(yán)格訓(xùn)練 的食品評(píng)估者，那些經(jīng)過(guò)特殊訓(xùn)練 學(xué)習(xí)如何分別味覺(jué)和嗅覺(jué)的人， 都會(huì)因?yàn)槭澄锢镉邢悴?更認(rèn)為這份食物比較甜。 為什么？ 當(dāng)然這不是因?yàn)橄悴菡娴谋容^甜。 而是因?yàn)檫@些專(zhuān)家都是人， 和我們一樣吃了很多甜點(diǎn) 并因此將甜度和香草聯(lián)系在了一起。

07:08

So taste and smell and other sensory information is inextricably entangled in our conscious mind. So on one hand, we can actually use this. We can use these conscious experiences, use this data, exploit it by adding vanilla instead of sugar to sweeten our products. But on the other hand, with these conscious evaluations, I still wouldn't know whether people actually liked that sugar-reduced milkshake.

所以味覺(jué)嗅覺(jué)和其他感官 在我們的意識(shí)中是難以分割的。 所以一方面講，我們可以利用 這些有意識(shí)的體驗(yàn)， 這些數(shù)據(jù)， 來(lái)研究加多少香草來(lái)代替糖 去增加食品的甜度。 但另一方面， 有了這些有意識(shí)的評(píng)估， 我還是不知道 到底人們是不是真的喜歡低糖奶昔。

07:36

So how do we get around this problem? How do we actually assess what's reality behind these conscious food evaluations? The key is to remove the barrier of the conscious mind and instead target the information in the brain directly. And it turns out our brain holds a lot of fascinating secrets. Our brain constantly receives sensory information from our entire body, most of which we don't even become aware of, like the taste information that I constantly receive from my gastrointestinal tract. And my brain will also act on all this sensory information. It will alter my behavior without my knowledge, and it can increase the diameter of my pupils if I experience something I really like. And increase my sweat production ever so slightly if that emotion was intense. And with brain scans, we can now assess this information in the brain.

那我們?cè)撊绾谓鉀Q這個(gè)問(wèn)題呢？ 如何區(qū)分有意識(shí)的食品評(píng)估 背后的真相呢？ 關(guān)鍵在于要移除意識(shí)的重重阻攔， 直接嘗試去獲取大腦中的信息。 事實(shí)證明， 我們的大腦藏有許多不為人知的秘密。 大腦通常接收來(lái)自全身的感知信息。 多半我們都沒(méi)有意識(shí)到， 比如胃腸道的 味道信息。 大腦會(huì)自動(dòng)處理這些味道信息， 會(huì)在人們沒(méi)有意識(shí)到 的情況下改變行為， 并擴(kuò)大瞳孔， 仿佛我們真的經(jīng)歷了喜歡的事情一樣。 這個(gè)反應(yīng)還會(huì)在情緒激動(dòng)的時(shí)候 提高汗液產(chǎn)出。 大腦掃描 為我們提供了大腦中的這些信息。

08:34

Specifically, I have used a brain-scanning technique called electroencephalography, or "EEG" in short, which involves wearing a cap studded with electrodes, 128 in my case. Each electrode then measures the electrical activity of the brain with precision down to the millisecond. The problem is, however, it's not just the brain that's electrically active, it's also the rest of the body as well as the environment that contains a lot of electrical activity all the time. To do my research, I therefore need to minimize all this noise. So I ask my participants to do a number of things here. First off, I ask them to rest their head in a chin rest, to avoid too much muscle movement. I also ask them to, meanwhile, stare at the center of a computer monitor to avoid too much eye movements and eye blinks. And I can't even have swallowing, so I ask my participants to stick the tongue out of their mouth over a glass bowl, and then I constantly let taste stimuli onto the tongue, which then drip off into this bowl.

我所用的一種大腦掃描技術(shù) 叫腦電圖， 即EEG， 這個(gè)過(guò)程要求人們帶上一頂 帶有128個(gè)電極的帽子。 每個(gè)電極都會(huì)測(cè)量大腦的電活動(dòng)， 精確到毫秒。 然而問(wèn)題是， 并不只有大腦才有電活動(dòng)， 人的全身，包括周遭環(huán)境 都包含許多電活動(dòng)。 為了完成研究， 我得盡力去除這些外界因素影響。 所以我讓實(shí)驗(yàn)者做了如下一些事。 第一， 我讓他們把頭放到腮托上， 盡量避免肌肉活動(dòng)。 我還讓他們盯著電腦中央， 以避免過(guò)多的眼球轉(zhuǎn)動(dòng)及眨眼。 甚至還不能咽口水， 所以我讓他們把舌頭伸出來(lái) 放到玻璃碗上， 并不停放上味覺(jué)刺激物， 然后他們的口水就可以滴到碗里。

09:44

(Laughter)

（笑聲）

09:45

And then, just to complete this wonderful picture, I also provide my participants with a bib, available in either pink or blue, as they please.

之后，為了畫(huà)龍點(diǎn)睛， 我還給了他們一個(gè)圍兜， 藍(lán)色或粉色，隨他們挑。

09:55

(Laughter)

（笑聲）

10:00

Looks like a normal eating experience, right?

看起來(lái)就像是個(gè) 正常進(jìn)食活動(dòng)，對(duì)吧？

10:02

(Laughter)

（笑聲）

10:04

No, obviously not. And worse, I can't even control what my participants are thinking about, so I need to repeat this taste procedure multiple times. Maybe the first time, they're thinking about the free lunch that I provide for participating, or maybe the second time, they're thinking about Christmas coming up and what to get for Mom this year, you know. But common for each response is the response to the taste. So I repeat this taste procedure multiple times. Sixty, in fact. And then I average the responses, because responses unrelated to taste will average out.

才怪。 而且， 因?yàn)槲覠o(wú)法控制他們的想法， 所以得不停重復(fù)這個(gè)實(shí)驗(yàn) 很多次。 或許第一次，他們?cè)谙胛姨峁┑?免費(fèi)午餐， 第二次，在想即將到來(lái)的圣誕 得給媽媽買(mǎi)什么。 但每次都是對(duì)味道的反應(yīng) 所以我不停重復(fù)這些步驟。 重復(fù)了六十次。 然后對(duì)實(shí)驗(yàn)結(jié)果去了平均值， 因?yàn)槟切o(wú)關(guān)味覺(jué)的都可以被平均掉。

10:43

And using this method, we and other labs, have investigated how long a time it takes from "food lands on our tongue" until our brain has figured out which taste it's experiencing. Turns out this occurs within the first already 100 milliseconds, that's about half a second before we even become aware of it. And next up, we also investigated the taste difference between sugar and artificial sweeteners that in our setup taste extremely similar. In fact, they tasted so similar that half my participants could only barely tell the taste apart, while the other half simply couldn't. But amazingly, if we looked across the entire group of participants, we saw that their brains definitely could tell the taste apart.

用了這個(gè)辦法， 我和其他實(shí)驗(yàn)室 研究了從“食物碰到舌頭”， 到大腦終于弄明白那是什么樣的味道 需要多久。 我們發(fā)現(xiàn)，整個(gè)過(guò)程發(fā)生在前100毫秒， 也就是我們有所感知之前半秒鐘。 之后，我們還研究了 糖和其他人工甜味劑的味覺(jué)差異， 發(fā)現(xiàn)并無(wú)不同。 甚至可以說(shuō)， 半數(shù)的受試者都很難區(qū)分， 而另一半則完全無(wú)法區(qū)分。 最令人驚嘆的是， 如果我們將整組受試者進(jìn)行比較， 他們的大腦絕對(duì)可以識(shí)別差異。

11:27

So with EEG and other brain-scanning devices and other physiological measures -- sweat and pupil size -- we have new gateways to our brain. Gateways that will help us remove the barrier of the conscious mind to see through the biases of people and possibly even capture subconscious taste differences. And that's because we can now measure people's very first response to food before they've become conscious of it, and before they've started rationalizing why they like it or not. We can measure people's facial expressions, we can measure where they're looking, we can measure their sweat response, we can measure their brain response. And with all these measures, we are going to be able to create tastier foods, because we can measure whether people actually like that sugar-reduced milkshake. And we can create healthier foods without compromising taste, because we can measure the response to different sweeteners and find the sweetener that gives the response that's more similar to the response from sugar.

所以有了腦電圖和其他大腦掃描設(shè)備 及其他生理測(cè)試的輔助—— 研究汗液和瞳孔—— 我們走上了通往大腦的新道路。 這條路可以幫助我們免去意識(shí)的屏障， 看穿人類(lèi)的偏見(jiàn)， 甚至還能捕捉潛意識(shí)中的味道差異。 這是因?yàn)楝F(xiàn)在我們可以測(cè)量 人體對(duì)食物的第一反應(yīng)， 甚至先于人類(lèi)的自我認(rèn)知， 在他們開(kāi)始思索到底喜不喜歡之前。 我們可以研究人的面部表情， 他們?cè)诳茨模?可以研究汗液反應(yīng)， 大腦反應(yīng)。 所有的這些測(cè)試 都能幫助我們創(chuàng)造更好吃的食物， 因?yàn)槲覀兡苤廊藗兙烤瓜膊幌矚g 那杯低糖奶昔。 我們還能在不影響味道 的前提下產(chǎn)出更健康的食品， 因?yàn)槲覀兛梢匝芯咳藗?對(duì)不同甜味劑的反應(yīng)， 并找出哪一種 最接近糖。

12:24

And furthermore, we can just help create healthier foods, because we can help understand how we actually sense food in the first place. Which we know surprisingly little about. For example, we know that there are those five basic tastes, but we strongly suspect that there are more, and in fact, using our EEG setup, we found evidence that fat, besides being sensed by its texture and smell, is also tasted. Meaning that fat could be this new sixth basic taste. And if we figure out how our brain recognizes fat and sugar, and I'm just dreaming here, but could we then one day create a milkshake with zero calories that tastes just like the real deal? Or maybe we figure out that we can't, because we subconsciously detect calories via our receptors in our gastrointestinal tract. The future will show.

進(jìn)一步講，我們可以 生產(chǎn)出更健康的食物， 因?yàn)槲覀兡軒椭藗兝斫?人類(lèi)是如何感知食物的。 這點(diǎn)我們知之甚少。 比如，我們知道最基本的五種味道， 但并不知道還有更多的味道， 事實(shí)上，利用腦電圖，我們發(fā)現(xiàn) 脂肪，除了它的氣味和質(zhì)地， 也是有味道的。 也就是說(shuō)我們有了第六種基本味道， 并且如果我們能知道大腦 是如何識(shí)別脂肪和糖分的話， 做個(gè)比方， 那是不是意味著有朝一日， 我們能制造出零卡路里的“原味”奶昔？ 或許我們能知道我們做不到， 因?yàn)闈撘庾R(shí)中檢測(cè)卡路里的感知器 是胃腸道。 未來(lái)我們會(huì)得到更加清晰的結(jié)論。

13:18

Our conscious experience of food is just the tip of the iceberg of our total sensation of food. And by studying this total sensation, conscious and subconscious alike, I truly believe that we can make tastier and healthier foods for all.

我們對(duì)食物的有意識(shí)經(jīng)歷 只是我們對(duì)食物感知的冰山一角。 通過(guò)研究全面感知， 不管有意識(shí)還是潛意識(shí)的， 我認(rèn)為我們都可以為人類(lèi) 創(chuàng)造美味又健康的食物。

13:36

Thank you.

謝謝。

13:37

(Applause)

（掌聲）