Narrator:Listen to part of a lecture in a Psychology Class.
Professor:OK. If I ask about the earliest thing you can remember, I will bet for most of you, your earliest memory would be about from age of 3, right?
教授:好了，如果我问大家最早记事是在什么时候，我猜你们多数人都会说 3 岁左右，对吗？
Well, that's true for most adults.
We cannot remember anything that happened before age of 3.
And this phenomenon is so widespread and well-documented it has a name.
It is called child amnesia and it was first documented in 1893.
它被称为儿童健忘症，而且在 1893 年文献中首次记载。
As I said, this phenomenon refers to the adults not being able to remember the childhood incidents.
It's not children trying to remember events from last month or last years.
Of course you follow that if you can't remember incidents as your child, you probably won't remember as an adult.
OK, so…why is this? What is the reason from the child amnesia?
Well, once a popular explanation was that child memories are always repressed and memories are disturbing so that is adults we keep them in barricade.
And so we can recall them and this is based on…well it's not base on, on, on… the kind of self-research in the lab testing we want to talk about today.
So let's put that explanation aside and concentrate on just two.
OK? It could be that as children we do form memories of things prior to age of 3, but forget as we get grew older, let's one explanation.
可能我们在 3 岁之前的阶段确实也形成了记忆，但是在我们长大的过程中就慢慢遗忘了，这是一种解释。
Another possibility is that children younger than 3 lack some cognitive capacity for memory.
还有一种可能就是 3 岁以下的孩子缺乏记忆认知能力。
And that idea, that children are unable to form memories that have been the dominant belief psychology for the past 100 years.
而在过去的 100 年中，这种儿童不能形成记忆的想法，一直在心理学界获得广泛认可。
And this idea is very much tied to things, the theory of Jean Piaget and also to language development in children.
So PRJ's theory of cognitive development-PRJ's suggested that because they don't have language, children younger than 18-24 months leave in the here and now that is they lack the mean to symbolic represent object, and events, that will not physically presented.
让·皮亚杰提出由于 18-24 个月以下的孩子不会说话，那么就缺乏表示物体，以及那些无法用实体呈现的事件的记忆符号。
Everybody get that?
PRJ proposed that young children don't have way to represent things that aren't wide in front of them.
That's what language does, right?
Words represent things, ideas.
Once language started to develop for about age 2, they do has a system for symbolic representation and can talk about things which are not in there in immediate environment including the past.
一旦语言在儿童 2 岁左右开始发育的时候，他们就有了能一套符号系统，而且能立即说出不在场的东西，也包括过去的事物。
Of course he didn't claim that infants don't have any sort of memory it is acknowledged that they can recognize some stimuli, like faces.
And for many years this model were very much in favors in psychology, even though memory tests were never performed on young children.
Well, finally in the 1980s, study was done.
在 20 世纪 80 年代，研究终于结束了。
And this study show that very young children under age of 2 do have capacity for recall.
研究显示 2 岁一下的孩童有回忆的能力。
Now if we children cannot talk, how was the recall tested?
Well, that is a good question, since the capacity for recall has always been linked with the ability to talk.
So the researcher set up an experiment using imitation based texts.
The adults use probable toys or other objects to demonstrate action that has 2 steps.
The children were asked to imitate the steps immediately and then he again after lays off one or month.
And even after delay, the children could…couldn't call or replicate the action, the objects they used, and the steps involved and the order of the steps.
Even children young is 9 months, now, test showed that there was a faster way of forgetting among the youngest children but most importantly it shows that the development of the recall did not depend on language development.
实验证明，现在甚至是 9 个月大的孩子也有种更快的遗忘方式，但更重要的是，实验显示儿童不是根据语言发育来回忆的。
And that was the importance finding.
I guess I should add that the findings, don't say there was no connection between the development of language and memory. There are some of evidence that are being able to talk about the event does lead to having a strong memory of that event.
But that does not seem the real issue here. So, back to our question about the cause of the childhood amnesia, well, there is something called the rate of forgetting.
And childhood amnesia may reflect high rate of forgetting, in other words, children under the age of 3 do form memories and do so without language.
But they forget the memories at a fast rate, probably faster than adults do.
Researcher has set standards….sort of unexpected rate of forgetting, but that expected rate was set based on the tests done on the adults.
So what is the rate of forgetting for children under the age of 3?
We expected to be high, but the tests disproved these really haven't been done yet.