爲何我們沒有嬰兒時期記憶? 原因驚人!大綱

From the most dramatic moment in life – the day of your birth – to first steps, first words, first food, right up to nursery school, most of us can't remember anything of our first few years. How come?

從你一生當中最激動人心的時刻——你的出生日開始，到第一次走路，第一次說話，第一次吃東西，一直到上幼兒園，我們大多數人不記得生命中頭幾年的事情了。這是怎麼回事呢？

This gaping hole in the record of our lives has been baffling psychologists, neuroscientists and linguists for decades. It was a minor obsession of the father of psychotherapy, Sigmund Freud, who coined the phrase 'infant amnesia' over 100 years ago.

我們生命記錄中的這一空白已經困擾心理學家、神經系統科學家和語言學家數十年了。心理療法之父西格蒙德·弗洛伊德對此也頗有研究，他於100多年前創造了"嬰兒健忘症"一詞。

Part of the puzzle comes from the fact that babies are, in other ways, sponges for new information, forming 700 new neural connections every second and wielding language-learning skills to make the most accomplished polyglot green with envy. The latest research suggests they begin training their minds before they've even left the womb.

從另一方面來說，該困惑的部分原因在於嬰兒能夠不斷吸收新的信息，每秒鐘可形成700個新的神經連接，並通過語言習得技能引得精通數國語言的人投之以羨慕之情。最新的研究表明，他們甚至在母親分娩之後便開始訓練自己的大腦了。

But even as adults, information is lost over time if there's no attempt to retain it. So one explanation is that infant amnesia is simply a result of the natural process of forgetting the things we experience throughout our lives.

但即便是成年人，若不刻意記憶，信息也會隨着時光流逝而消失。因此，就有解釋稱，嬰兒健忘症僅僅是我們一生當中忘記我們所經歷過的事情這一自然過程的一個結果。

Our culture may also determine the way we talk about our memories, with some psychologists arguing that they only come once we have mastered the power of speech.

我們的文化也決定着我們談論記憶力的方式。一些心理學家表示，只有當我們掌握了說話的能力，我們纔會有記憶力。

This leads us to the theory that we can't remember our first years simply because our brains hadn't developed the necessary equipment. The explanation emerges from the most famous man in the history of neuroscience, known simply as patient HM.

這樣我們便可得出結論，我們記不住頭幾年的事情僅僅是因爲我們的大腦還未發育出必需的物質。這一解釋的出現得益於神經科學史上最有名人物，他被戲稱爲病人HM。

Perhaps, when we're very young, the hippocampus simply isn't developed enough to build a rich memory of an event. Baby rats, monkeys and humans all continue to add new neurons to the hippocampus for the first few years of life and we all are all unable to form lasting memories as infants – and it seems that the moment we stop creating new neurons, we're suddenly able to form long-term memories.

或許，當我們還很小的時候，海馬體尚未發育成熟，因此我們無法對一件事情形成豐富的記憶。幼鼠，幼猴和嬰兒在生命開始的頭幾年都會持續向海馬體增加新的神經元，而與此同時，我們也都像嬰兒一樣無法形成長久的記憶--似乎當我們停止增加新的神經元時，我們便突然之間能夠形成長久的記憶了。

Perhaps the biggest mystery is not why we can't remember our childhood – but whether we can believe any of our memories at all.

或許最大的謎團並非我們爲何無法回憶起我們的童年，而是我們是否能夠完全相信自己的記憶。