我们儿时的记忆都去哪儿了？.

　　童年期遗忘的谜团过去一个世纪以来一直困惑着科学家们。为什么在人类的幼儿期，一个充满体验和学习新事物的阶段，却被许多难以理解的事物而笼罩?本期探索可能导致我们遗忘幼儿时期经历的原因。

　　课文内容

　　词汇: 记忆

　　What is your earliest memory? For me, I have a hazy recollection of standing in a leafy garden surrounded by silver birch trees when I was four years old.

　　I'm around average: some people remember events as far back as two years old, while for others, things seem patchy until seven or eight.

　　But what is consistent is that no one can remember their own birth or very early infancy. And even after the first memory, most of us only have a sporadic collection of fleeting, flickering mental images until much later in childhood.

　　The phenomenon is known as "childhood amnesia", a term coined by the father of psychoanalysis, Sigmund Freud. So, what's going on here?

　　Babies are, writes Zaria Gorvett for BBC Future, "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".

　　And it's precisely this rapid mental development that causes the problem, according to a study by the University of Toronto in 2014. It found that the high rate of infant brain cell production could increase forgetfulness, because new cells interfere with existing mental circuits.

　　Another possible explanation is that the part of the brain that stores memories, the hippocampus, is not fully formed until around 18 months. Identity is also important: tests show infants don't recognise themselves in the mirror until they are around two years old.

　　Finally, there's the question of how accurate our early memories are at all. "People can pick up suggestions and begin to visualise them - they become like memories," psychologist Elizabeth Loftus told the BBC. Are our cherished first memories really just family stories?

　　词汇表

　　hazy 模糊的、不清晰的

　　recollection 记忆，往事

　　silver birch 白桦树

　　patchy 零零碎碎的，拼凑起来的

　　infancy 婴儿期、年幼时候

　　sporadic 零星的，分散的

　　fleeting 一闪而过的，短暂的

　　amnesia 失忆，健忘(症)

　　to coin 创造，杜撰(新词或表达)

　　psychoanalysis 精神分析学

　　sponge 像海绵般地吸收(信息)

　　neural 神经的

　　to wield 施加影响

　　accomplished 有造诣的，有才华的

　　polyglot 通晓多种语言的人

　　green with envy 非常羡慕，十分忌妒

　　forgetfulness 健忘

　　to interfere 干预，干涉

　　to visualise 设想，想象

　　cherished 珍惜的，珍爱的