How memories form and how we lose them - Catharine Young

翻译人员: YIREN YANG 校对人员: 易帆 余

Think back to a really vivid memory.

回想一个生动的回忆，

Got it?

好了吗？

Okay, now try to remember what you had for lunch three weeks ago.

好的，现在，想想三周前你午餐吃了什么？

That second memory probably isn't as strong,

这个回忆可能就不是那么栩栩如生了吧，

but why not?

为什么会这样呢？

Why do we remember some things, and not others?

为什么我们会记住一些事情， 而忘却另外一些事情？

And why do memories eventually fade?

为什么记忆最终会一点一点地褪色？

Let's look at how memories form in the first place.

让我们首先来看一下，记忆是如何产生的。

When you experience something, like dialing a phone number,

当你经历什么事情的时候，比如拨电话号码。

the experience is converted into a pulse of electrical energy

这个体验会被转化成一种脑电波脉冲，

that zips along a network of neurons.

这种脉冲快速地沿着神经网络前进。

Information first lands in short term memory,

信息首先到达短期记忆处理中心，

where it's available from anywhere from a few seconds

这是一个存储几秒钟到

to a couple of minutes.

几分钟记忆的区域。

It's then transferred to long-term memory through areas such as the hippocampus,

然后，体验通过海马体等区域被转成长期记忆，

and finally to several storage regions across the brain.

最终保存到大脑几个记忆储存区域。

Neurons throughout the brain communicate at dedicated sites

大脑里的神经元在专门的站点连接，

called synapses

这些站点运用被称为突触的

using specialized neurotransmitters.

特殊的神经传递。

If two neurons communicate repeatedly, a remarkable thing happens:

如果两个神经元重复连接，一件重要的事情就会发生：

the efficiency of communication between them increases.

这两个神经元之间的连接就会变得更加有效率，

This process, called long term potentiation,

这个过程被称为长时程增强效应。

is considered to be a mechanism by which memories are stored long-term,

它被认为是体验被储存到长期记忆中的原理，

but how do some memories get lost?

但是，怎么有些记忆会丢失呢？

Age is one factor.

年龄是一个影响因素。

As we get older, synapses begin to falter and weaken,

随着我们年龄的增大， 神经元突触开始衰退和变弱，

affecting how easily we can retrieve memories.

这影响了我们读取记忆的难易程度。

Scientists have several theories about what's behind this deterioration,

科学家们有几个原理 解释了这种退化背后的原因。

from actual brain shrinkage,

从真正的大脑萎缩开始，

the hippocampus loses 5% of its neurons every decade

海马体每十年失去了5%的神经元，

for a total loss of 20% by the time you're 80 years old

当时你80岁的时候，你一共失去了20%的神经元，

to the drop in the production of neurotransmitters,

这导致了神经传递产物的下降，

like acetylcholine, which is vital to learning and memory.

比如，对学习和记忆至关重要的乙酰胆碱，

These changes seem to affect how people retrieve stored information.

这些改变可能影响了 人们读取那些存储的信息。

Age also affects our memory-making abilities.

年龄也影响了我们产生记忆的能力，

Memories are encoded most strongly when we're paying attention,

当我们集中精力的时候， 当我们完全投入的时候，

when we're deeply engaged, and when information is meaningful to us.

当信息对我们来说非常重要的时候， 深刻的记忆就会生成。

Mental and physical health problems, which tend to increase as we age,

当年纪变大，精神和身体的 健康问题就变得越来越多，

interfere with our ability to pay attention,

干扰我们注意力的集中度，

and thus act as memory thieves.

也因此成为了我们记忆的小偷。

Another leading cause of memory problems is chronic stress.

另一个引发记忆力问题的原因是长期的压力，

When we're constantly overloaded with work and personal responsibilites,

当我们长期面对超负荷的工作和个人压力，

our bodies are on hyperalert.

我们的身体会报警。

This response has evolved from the physiological mechanism

这个反应是源于我们身体为保证

designed to make sure we can survive in a crisis.

能在危机中生存而设计的生理机制，

Stress chemicals help mobilize energy and increase alertness.

因为压力而产生的化学物质 帮助身体调动能量和增加警戒。

However, with chronic stress our bodies become flooded with these chemicals,

但是，长期的压力让我们的 身体里的这些化学物质泛滥了，

resulting in a loss of brain cells and an inability to form new ones,

导致脑细胞的流失和 制造新脑细胞能力的衰弱，

which affects our ability to retain new information.

从而影响了我们记住新信息的能力。

Depression is another culprit.

抑郁是另一个罪犯，

People who are depressed are 40% more likely to develop memory problems.

40%的抑郁的人更容易有记忆力问题。

Low levels of serotonin,

低水平的

a neurotransmitter connected to arousal,

激起兴奋神经传递的血清素，

may make depressed individuals less attentive to new information.

可能让抑郁的人更不关注新信息。

Dwelling on sad events in the past, another symptom of depression,

抑郁的另一个症状， 是沉浸在过去悲伤的事件中出不来，

makes it difficult to pay attention to the present,

这导致他们很难关注现在发生的事情，

affecting the ability to store short-term memories.

影响了存储短期记忆的能力。

Isolation, which is tied to depression, is another memory thief.

与抑郁紧密联系的“ 孤立 ” 是另一个记忆的小偷，

A study by the Harvard School of Public Health

一个哈佛大学公共健康学院的研究发现，

found that older people with high levels of social integration

在六年时间里， 拥有更高的社会融合能力的老人

had a slower rate of memory decline over a six-year period.

记忆衰退较慢。

The exact reason remains unclear,

虽然确切的原因还不清楚，

but experts suspect that

但专家推测，

social interaction gives our brain a mental workout.

社会交往使我们的大脑得到了锻炼。

Just like muscle strength,

就像肌肉力量的训练一样，

we have to use our brain or risk losing it.

我们必须使用我们的大脑， 不然就有可能失去它。

But don't despair.

不过不要绝望，

There are several steps you can take

你可以用下面的几个步骤，

to aid your brain in preserving your memories.

去帮助你的大脑保存记忆。

Make sure you keep physically active.

首先，确保你坚持锻炼，

Increased blood flow to the brain is helpful.

增加血液回流大脑是有益的。

And eat well.

然后好好吃饭，

Your brain needs all the right nutrients to keep functioning correctly.

你的大脑需要所有的正确的营养物来保持功能正常。

And finally, give your brain a workout.

最后，给你的大脑一些锻炼，

Exposing your brain to challenges, like learning a new language,

让你的大脑应对新的挑战， 比如学习一门新的语言，

is one of the best defenses for keeping your memories intact.

这是最好的保持你记忆力的方法之一。