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？

 

What is your earliest memory? For me, I have a hazy¹ recollection of standing² 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 infancy³. And even after the first memory, most of us only have a sporadic⁴ collection of fleeting⁵, flickering⁶ mental images until much later in childhood.

 

The phenomenon is known as 'childhood amnesia⁷', 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 neural⁸ connections every second and wielding⁹ language-learning skills to make the most accomplished¹⁰ polyglot¹¹ green with envy".

 

And it's precisely¹² 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 interfere¹³ with existing mental circuits.

 

Another possible explanation is that the part of the brain that stores memories, the hippocampus, is not fully¹⁴ 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?

点击收听单词发音