Can we edit memories? | Amy Milton

Transcriber: Joseph Geni Reviewer: Camille Martínez

翻译人员: Wanting Zhong 校对人员: Yanyan Hong

Memory is such an everyday thing that we almost take it for granted.

记忆是如此日常的存在， 我们几乎把它视为理所当然。

We all remember what we had for breakfast this morning

我们都记得今天早餐吃了什么，

or what we did last weekend.

或者上周末做了什么。

It's only when memory starts to fail

只有当记忆开始衰退时，

that we appreciate just how amazing it is

我们才会赞叹它有多么奇妙，

and how much we allow our past experiences to define us.

并反思我们如何用 过往的经历来定义自己。

But memory is not always a good thing.

但记忆并不总是一件好事。

As the American poet and clergyman John Lancaster Spalding once said,

正如美国诗人及牧师

约翰·兰卡斯特·斯帕丁 （John Lancaster Spalding) 所言，

"As memory may be a paradise from which we cannot be driven,

“记忆可能是我们不被驱逐的天堂，

it may also be a hell from which we cannot escape."

也可能是我们无法逃离的地狱。”

Many of us experience chapters of our lives

我们很多人都经历过

某些我们宁愿从未发生过的人生篇章。

that we would prefer to never have happened.

It is estimated that nearly 90 percent of us

据估计，近 90% 的人

will experience some sort of traumatic event during our lifetimes.

一生中都经历过某种创伤性事件。

Many of us will suffer acutely following these events and then recover,

许多人在经历这些事件后 会深受折磨，然后康复，

maybe even become better people because of those experiences.

甚至可能因为这些经历 而成长为更好的人。

But some events are so extreme that many --

但一些过于极端的事件 会导致很多经历者——

up to half of those who survive sexual violence, for example --

比如近半数的性暴力幸存者——

will go on to develop post-traumatic stress disorder,

患上创伤后应激障碍，又称为 PTSD。

or PTSD.

PTSD is a debilitating mental health condition

创伤后应激障碍是一种 令人衰弱的心理健康疾病，

characterized by symptoms such as intense fear and anxiety

特征是产生强烈的恐慌、焦虑，

and flashbacks of the traumatic event.

以及对创伤性事件的 “闪回” 等症状。

These symptoms have a huge impact on a person's quality of life

这些症状会严重影响人的生活质量，

and are often triggered by particular situations

并经常会因人们所处环境中

or cues in that person's environment.

特定的状况或 “线索” 而触发。

The responses to those cues may have been adaptive when they were first learned --

当人们最初习得这些对线索的 条件反射也许有利于他们适应——

fear and diving for cover in a war zone, for example --

比如在战区会感到害怕、 卧倒并掩护——

but in PTSD,

但对于患有创伤后应激障碍的人，

they continue to control behavior when it's no longer appropriate.

即使这些反应已不必要， 它们依旧控制着人们的行为。

If a combat veteran returns home and is diving for cover

如果一名参战老兵退伍返乡后， 听到汽车发动机的回火声时

when he or she hears a car backfiring

仍然会卧倒掩护，

or can't leave their own home because of intense anxiety,

或者因为重度焦虑无法踏出家门，

then the responses to those cues, those memories,

他们对那些线索的反应，那些记忆，

have become what we would refer to as maladaptive.

造成了我们所说的 “适应不良”。

In this way, we can think of PTSD as being a disorder of maladaptive memory.

因此，我们可以把创伤后应激障碍 视为由适应不良的记忆引发的障碍。

Now, I should stop myself here,

现在，我应该就此打住，

because I'm talking about memory as if it's a single thing.

因为我把记忆当成个体在讨论，

It isn't.

而它并非如此。

There are many different types of memory,

记忆分为很多不同的种类，

and these depend upon different circuits and regions within the brain.

而这些分类取决于大脑里 不同的回路和区域。

As you can see, there are two major distinctions in our types of memory.

如你所见，我们不同种类的 记忆主要有两大区别。

There are those memories that we're consciously aware of,

我们对有些记忆是有意识的，

我们知道自己有这些记忆，

where we know we know

and that we can pass on in words.

并能用语言对其加以描述。

This would include memories for facts and events.

其中包括了对事实和事件的记忆。

Because we can declare these memories,

因为我们能阐明这些记忆，

we refer to these as declarative memories.

所以称之为 “陈述性记忆”。

The other type of memory is non-declarative.

另一种记忆是 “非陈述性记忆”。

These are memories where we often don't have conscious access

一般来说，我们对这类记忆的内容

to the content of those memories

没有主观意识，

and that we can't pass on in words.

也无法用语言加以描述。

The classic example of a non-declarative memory

非陈述性记忆的经典例子是

is the motor skill for riding a bike.

骑自行车的运动技能。

Now, this being Cambridge, the odds are that you can ride a bike.

因为现在这里是剑桥， 所以你大概率会骑自行车。

You know what you're doing on two wheels.

你知道自己在两个轮子上该怎么做。

But if I asked you to write me a list of instructions

但如果我让你列出一份

教我如何骑自行车的说明书——

that would teach me how to ride a bike,

as my four-year-old son did when we bought him a bike

就像去年我们给四岁的儿子 买了自行车作为生日礼物时，

for his last birthday,

他问我们的那样——

you would really struggle to do that.

你会发现其实非常难。

How should you sit on the bike so you're balanced?

你该怎样坐在自行车上才能保持平衡？

How fast do you need to pedal so you're stable?

你要踩多快才能平稳前进？

If a gust of wind comes at you,

如果一阵风朝你刮来，

which muscles should you tense and by how much

你要将哪些肌肉绷紧到什么程度，

so that you don't get blown off?

才不会被风吹倒？

I'll be staggered if you can give the answers to those questions.

假如你能给出这些问题的答案， 我会目瞪口呆。

But if you can ride a bike, you do have the answers,

但如果你会骑自行车， 你一定是有答案的，

you're just not consciously aware of them.

你只是没有意识到它们而已。

Getting back to PTSD,

我们谈回创伤后应激障碍，

another type of non-declarative memory

另一种类型的非陈述性记忆

is emotional memory.

是 “情绪性记忆”。

Now, this has a specific meaning in psychology

它在心理学上有特定的涵义，

and refers to our ability to learn about cues in our environment

指的是我们习得环境中的线索

and their emotional and motivational significance.

以及其情感意义和动机意义的能力。

What do I mean by that?

这是什么意思呢？

Well, think of a cue like the smell of baking bread,

想象一下某个线索， 例如烤面包的气味，

or a more abstract cue like a 20-pound note.

或者某个更抽象的线索， 例如一张 20 英镑的纸钞。

Because these cues have been pegged with good things in the past,

因为这些线索与过往的好事挂钩了，

we like them and we approach them.

所以我们会喜欢并接近这些线索。

Other cues, like the buzzing of a wasp, elicit very negative emotions

其他线索，例如黄蜂的嗡嗡声， 会诱发一些人

and quite dramatic avoidance behavior in some people.

非常负面的情绪 和相当夸张的回避行为。

Now, I hate wasps.

我讨厌黄蜂。

I can tell you that fact.

我可以告诉大家这个事实。

But what I can't give you are the non-declarative emotional memories

但我无法跟大家分享 附近有黄蜂时我是如何反应的

for how I react when there's a wasp nearby.

这种非陈述性情绪记忆。

I can't give you the racing heart,

我无法给你分享心跳加速、

the sweaty palms, that sense of rising panic.

手心冒汗、油然而生的恐慌感。

I can describe them to you,

我可以向你描述这些内容，

but I can't give them to you.

但我不能把它们 “给” 你。

Now, importantly, from the perspective of PTSD,

重要的是，对于创伤后应激障碍来说，

stress has very different effects on declarative and non-declarative memories

压力对陈述性和非陈述性记忆，

以及支持它们的大脑回路和区域 有非常不同的影响。

and the brain circuits and regions supporting them.

Emotional memory is supported by a small almond-shaped structure

情绪性记忆是由一颗小杏仁状、

called the amygdala

称为 “杏仁核” 的结构

and its connections.

以及其神经连接所支撑的。

Declarative memory, especially the what, where and when of event memory,

陈述性记忆，尤其是 事件记忆里的内容、地点和时间，

is supported by a seahorse-shaped region of the brain

则是由大脑里一块 海马状的区域所支持的，

called the hippocampus.

这个区域被称为 “海马体”。

The extreme levels of stress experienced during trauma

在创伤中所经历极限水平的压力

have very different effects on these two structures.

对这两个结构有非常不同的影响。

As you can see, as you increase a person's level of stress

可以看到， 当你把一个人所承受的压力水平

from not stressful to slightly stressful,

从 “无压力” 升至 “轻微压力” 时，

the hippocampus,

海马体

acting to support the event memory,

发挥了支持事件记忆的作用，

increases in its activity

提升了其活跃度，

and works better to support the storage of that declarative memory.

以更好地支持对陈述性记忆的存储。

But as you increase to moderately stressful, intensely stressful

但当你把压力水平 升至 “适度压力”、“强烈压力”

and then extremely stressful, as would be found in trauma,

以及创伤应激中 会经历的 “极端压力” 时，

the hippocampus effectively shuts down.

海马体会自动关闭。

This means that under the high levels of stress hormones

这意味着在创伤期间经历的

高浓度压力激素的作用下，

that are experienced during trauma,

we are not storing the details,

我们并不存储记忆的细节，

the specific details of what, where and when.

那些关于事件内容、地点 和时间的具体细节。

Now, while stress is doing that to the hippocampus,

压力会对海马体产生这样的影响，

look at what it does to the amygdala,

我们再来看看压力对杏仁核的影响，

that structure important for the emotional, non-declarative memory.

也就是那个非陈述性 情绪记忆的关键结构。

Its activity gets stronger and stronger.

它的活跃程度越变越强。

So what this leaves us with in PTSD

在创伤后应激障碍里， 这会给我们留下

is an overly strong emotional -- in this case fear -- memory

一种过度强烈的情绪记忆—— 在这种情况下是恐惧记忆，

that is not tied to a specific time or place,

这些记忆不会关联到 特定的时间或地点，

because the hippocampus is not storing what, where and when.

因为海马体没有储存 内容、地点和时间的信息。

In this way, these cues can control behavior

这样的话，这些线索

会在不恰当的时候控制人们的行为，

when it's no longer appropriate,

and that's how they become maladaptive.

因而导致适应不良。

So if we know that PTSD is due to maladaptive memories,

如果我们知道了创伤后应激障碍 是源于适应不良的记忆，

can we use that knowledge to improve treatment outcomes

我们可以利用这一点改善 创伤应激障碍患者的

for patients with PTSD?

治疗结果吗？

A radical new approach being developed to treat post-traumatic stress disorder

目前新研发的一种治疗 创伤后应激障碍的方法，

aims to destroy those maladaptive emotional memories

旨在破坏那些引起障碍的

that underlie the disorder.

适应不良的情绪记忆。

This approach has only been considered a possibility

由于近些年我们对记忆的了解

because of the profound changes in our understanding of memory

发生了深刻变化，这种方法才被认为

in recent years.

是可行的。

Traditionally, it was thought that making a memory

传统观点认为，创造记忆

was like writing in a notebook in pen:

就像用笔在笔记本上写字：

once the ink had dried, you couldn't change the information.

一旦笔墨干掉后， 你就不能再对信息加以修改。

It was thought that all those structural changes

人们认为所有在大脑内发生的

that happen in the brain to support the storage of memory

支持记忆储存的结构性变化

were finished within about six hours,

都是在约六小时内完成的；

and after that, they were permanent.

之后，记忆就会是永久的了。

This is known as the consolidation view.

这称为 “记忆巩固” 理论。

However, more recent research suggests that making a memory

但最近的研究表明，创造记忆

is actually more like writing in a word processor.

实际上更像是在文字处理器中写字。

We initially make the memory and then we save it or store it.

我们先制造出记忆， 然后保存或者储存它。

But under the right conditions, we can edit that memory.

但在合适的状况下， 我们可以编辑那段记忆。

This reconsolidation view suggests that those structural changes

这个 “记忆再巩固” 的理论认为， 那些在大脑内发生的

that happen in the brain to support memory

支持记忆的结构性变化

can be undone,

是可以撤销的，

even for old memories.

即使是对于久远的回忆也行。

Now, this editing process isn't happening all the time.

这种编辑过程不是一直发生的。

It only happens under very specific conditions

它只发生在非常特定的

“记忆提取” 的条件下。

of memory retrieval.

So let's consider memory retrieval as being recalling the memory

让我们把记忆提取 看成是重新唤醒记忆，

or, like, opening the file.

或者像是打开文档。

Quite often, we are simply retrieving the memory.

通常，我们只是对记忆进行提取，

We're opening the file as read-only.

就像用 “只读” 模式打开文档一样。

But under the right conditions,

但在合适的条件下，

we can open that file in edit mode,

我们就可以用 “编辑” 模式打开文档，

and then we can change the information.

然后对信息进行修改。

In theory, we could delete the content of that file,

理论上，我们可以删除文档的内容，

and when we press save,

当我们按下 “保存” 时，

that is how the file -- the memory --

那就是文件——或者说记忆——

persists.

长期保持的状态。

Not only does this reconsolidation view

这种记忆再巩固的理论不仅

allow us to account for some of the quirks of memory,

能让我们解释有关记忆的一些古怪之处，

like how we all sometimes misremember the past,

比如我们有时都会记错过去的事情，

it also gives us a way to destroy those maladaptive fear memories

它还给我们提供了一个方法， 来消除掉导致创伤后应激障碍的

that underlie PTSD.

适应不良的恐惧记忆。

All we would need would be two things:

我们只需要两样东西：

a way of making the memory unstable -- opening that file in edit mode --

一个使记忆不稳定的方法—— 也就是用 “编辑” 模式打开文档——

and a way to delete the information.

以及一个删除信息的途径。

We've made the most progress

在研究如何删除信息方面，

with working out how to delete the information.

我们已经取得了很大的进展。

It was found fairly early on

在很早的时候就已经发现，

that a drug widely prescribed to control blood pressure in humans --

一种广泛用于控制人体血压的药——

a beta-blocker called Propranolol --

名为 “普萘洛尔” 的 β—受体阻滞剂——

could be used to prevent the reconsolidation

在老鼠身上

能阻止恐惧记忆的再巩固。

of fear memories in rats.

If Propranolol was given while the memory was in edit mode,

当记忆处于编辑模式时使用普萘洛尔，

rats behaved as if they were no longer afraid of a frightening trigger cue.

老鼠表现得仿佛 不再害怕触发恐惧的线索，

It was as if they had never learned to be afraid of that cue.

就像它们从未习得过 对那个线索的恐惧一样。

And this was with a drug that was safe for use in humans.

而且这是一种 人类也能安全服用的药物。

Now, not long after that,

在这不久之后，

it was shown that Propranolol could destroy fear memories in humans as well,

有研究表明普萘洛尔 也能破坏人类的恐惧记忆，

but critically, it only works if the memory is in edit mode.

但关键在于只有当记忆 处于编辑模式时，该药才起作用。

Now, that study was with healthy human volunteers,

虽然参与这项研究的 是健康的人类志愿者，

but it's important because it shows that the rat findings

但它依然很重要，因为它显示了 老鼠身上的研究结果

can be extended to humans and ultimately, to human patients.

能延伸到人类， 最终应用到人类患者身上。

And with humans,

而对于人类，

you can test whether destroying the non-declarative emotional memory

你能试验破坏非陈述性情绪记忆

does anything to the declarative event memory.

是否会影响陈述性事件记忆。

And this is really interesting.

这一点非常有趣。

Even though people who were given Propranolol

尽管在记忆处于编辑模式时

while the memory was in edit mode

服用了普萘洛尔的人

were no longer afraid of that frightening trigger cue,

不再害怕那些触发恐惧的提示，

they could still describe the relationship

他们依然能描述

between the cue and the frightening outcome.

线索和恐惧的结果之间的关系，

It was as if they knew they should be afraid,

仿佛他们知道自己应当感到害怕，

and yet they weren't.

实际上却并不害怕。

This suggests that Propranolol can selectively target

这表明普萘洛尔能选择性地作用于

the non-declarative emotional memory

非陈述性情绪记忆，

而让陈述性事件记忆保持完整。

but leave the declarative event memory intact.

But critically, Propranolol can only have any effect on the memory

但最重要的是， 只有处于记忆编辑模式时，

if it's in edit mode.

普萘洛尔才会影响记忆。

So how do we make a memory unstable?

我们该怎样使一段记忆 变得不稳定呢？

How do we get it into edit mode?

我们怎样进入编辑模式呢？

Well, my own lab has done quite a lot of work on this.

我的实验室在这方面做了很多研究。

We know that it depends on introducing some but not too much new information

我们知道，这取决于 引入一些新信息整合到记忆里，

to be incorporated into the memory.

不过新信息不能过量。

We know about the different chemicals the brain uses

我们知道大脑使用不同的化学物质

to signal that a memory should be updated

示意记忆需要更新，

and the file edited.

文档需要编辑。

Now, our work is mostly in rats,

我们的研究主要是在老鼠身上进行的，

but other labs have found the same factors allow memories to be edited in humans,

但其他实验室也证实在人类身上 运用同样的因素编辑记忆，

even maladaptive memories like those underlying PTSD.

甚至是适应不良的记忆， 比如诱发创伤后应激障碍的记忆。

In fact, a number of labs in several different countries

实际上，不同国家的数个实验室

have begun small-scale clinical trials of these memory-destroying treatments

已经开始进行通过破坏记忆 治疗创伤后应激障碍的

for PTSD

小型临床实验，

and have found really promising results.

并得到了相当可观的结果。

Now, these studies need replication on a larger scale,

这些研究都需要大规模的重复实验，

but they show the promise of these memory-destroying treatments

但它们显示了这些破坏记忆的疗法 在治疗创伤后应激障碍方面

for PTSD.

有相当可观的前景。

Maybe trauma memories do not need to be the hell from which we cannot escape.

或许创伤记忆不再会是我们 无法逃离的地狱。

Now, although this memory-destroying approach holds great promise,

虽然这种破坏记忆的疗法前景可观，

that's not to say that it's straightforward

但并不是说它就很直截了当，

or without controversy.

或是没有争议。

Is it ethical to destroy memories?

破坏记忆是否符合伦理？

What about things like eyewitness testimony?

目击者证词又如何呢？

What if you can't give someone Propranolol

如果不能给某人服用普萘洛尔，

because it would interfere with other medicines that they're taking?

因为它会干扰他们服用的其它药物， 又该怎么办？

Well, with respect to ethics and eyewitness testimony,

针对伦理和目击者证词，

I would say the important point to remember

我想说，关键是要记住

is the finding from that human study.

那项人类研究里的发现。

Because Propranolol is only acting on the non-declarative emotional memory,

因为普萘洛尔只对 非陈述性情绪记忆起作用，

it seems unlikely that it would affect eyewitness testimony,

它应该是不太可能 影响到目击者证词的，

which is based on declarative memory.

因为目击者证词的依据是陈述性记忆。

Essentially, what these memory-destroying treatments

这些破坏记忆疗法

are aiming to do

根本的目的是

is to reduce the emotional memory,

减少情绪记忆，

not get rid of the trauma memory altogether.

而不是完全消除创伤性记忆。

This should make the responses of those with PTSD

这应该会让创伤后 应激障碍患者的反应

more like those who have been through trauma

产生更类似那些经历了创伤

and not developed PTSD

却没有发展出应激障碍的人，

than people who have never experienced trauma in the first place.

而不是像从未经历过创伤的人。

I think that most people would find that more ethically acceptable

我觉得大多数人或许会认为， 相比清除记忆的疗法，

than a treatment that aimed to create some sort of spotless mind.

这种做法在伦理上更能接受。

What about Propranolol?

那么普萘洛尔呢？

You can't give Propranolol to everyone,

不是每个人都能服用普萘洛尔，

and not everyone wants to take drugs to treat mental health conditions.

也并不是每个人都想使用 治疗精神疾病的药物。

Well, here Tetris could be useful.

在这方面，俄罗斯方块可能会有用。

Yes, Tetris.

没错，俄罗斯方块。

Working with clinical collaborators,

我们和临床治疗师合作，

we've been looking at whether behavioral interventions

研究行为干预

can also interfere with the reconsolidation of memories.

是否也能干扰记忆的再巩固。

Now, how would that work?

这是怎么做到的？

Well, we know that it's basically impossible

我们知道，如果两项任务的处理

to do two tasks at the same time

依靠的是同一个脑区，

if they both depend on the same brain region for processing.

那么这两项任务 基本上是不可能同时进行的。

Think trying to sing along to the radio

想象一下，试图跟着电台唱歌，

while you're trying to compose an email.

同时还要撰写邮件。

The processing for one interferes with the other.

其中一项任务的处理 会干扰另一项任务。

Well, it's the same when you retrieve a memory,

提取记忆时也是同理，

especially in edit mode.

尤其是在编辑模式下。

If we take a highly visual symptom like flashbacks in PTSD

假如有一个高度依赖视觉的症状， 比如创伤记忆的闪回，

and get people to recall the memory in edit mode

让人们在编辑模式下回忆那段记忆，

and then get them to do a highly engaging visual task

并让他们进行一项非常费神的视觉任务，

like playing Tetris,

比如玩俄罗斯方块，

it should be possible to introduce so much interfering information

那么我们就有可能在那段记忆中

加入如此多的干扰信息，

into that memory

that it essentially becomes meaningless.

让那段记忆实质上变得毫无意义。

That's the theory,

理论就是这样，

and it's supported by data from healthy human volunteers.

并且有健康人类志愿者的 实验数据支持这个理论。

Now, our volunteers watched highly unpleasant films --

我们的志愿者观看了 非常令人不适的视频——

so, think eye surgery, road traffic safety adverts,

比如说眼科手术、交通安全广告、

Scorsese's "The Big Shave."

马丁 · 斯科塞斯的《剃须记》 （含有血腥镜头）。

These trauma films produce something like flashbacks

这些创伤性视频 能在观看后的约一星期内

in healthy volunteers for about a week after viewing them.

在志愿者身上产生类似闪回的效果。

We found that getting people to recall those memories,

我们发现，让人们回忆这些记忆、

the worst moments of those unpleasant films,

这些不适视频中最糟糕的片段，

and playing Tetris at the same time,

同时玩俄罗斯方块，

massively reduced the frequency of the flashbacks.

能大大降低闪回的频率。

And again: the memory had to be in edit mode for that to work.

重申一次：记忆必须处于编辑模式， 这个方法才能生效。

Now, my collaborators have since taken this to clinical populations.

后来，我的合作伙伴将这个方法 应用到了临床受试群体中。

They've tested this in survivors of road traffic accidents

他们在交通事故幸存者

and mothers who've had emergency Caesarean sections,

和进行了紧急剖腹产的母亲身上 试验了这种疗法，

both types of trauma that frequently lead to PTSD,

这两种创伤都经常会导致 创伤后应激障碍，

and they found really promising reductions in symptoms

并且他们在这两种临床案例中

in both of those clinical cases.

都发现症状得到了相当可观的缓解。

So although there is still much to learn and procedures to optimize,

虽然还有不少未知， 还有过程需要优化，

these memory-destroying treatments hold great promise

这些破坏记忆的疗法

能为治疗创伤后应激障碍 这样的心理疾病

for the treatment of mental health disorders

like PTSD.

带来很大希望。

Maybe trauma memories do not need to be a hell from which we cannot escape.

或许创伤性记忆不再会是 我们无法逃离的地狱。

I believe that this approach

我相信这种方法

should allow those who want to

能让那些有需要的人们

翻过他们宁愿不曾经历的

to turn the page on chapters of their lives

that they would prefer to never have experienced,

人生篇章，

and so improve our mental health.

以此改善我们的心理健康。

Thank you.

谢谢。

(Applause)

（掌声）