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Pregnancy, then, does indeed do things to a woman’s brain.
那么懷孕確實對母親的大腦有影響。
But what exactly those things mean is hard to tease out.
但是具體對大腦有什么影響很難弄清。
Neuroscientists do not really understand how the brain works.
神經系統科學家還未弄清大腦是如何工作的。
That makes it difficult to predict how a change in the organ’s structure will alter the way it functions.
這致使科學家很難預測器官結構的變化是如何改變其功能。
Some of the changes took place in the hippocampi.
這些變化也包括海馬體的變化。
These are a pair of small, banana-shaped structures buried deep in the brain, one in each hemisphere, that are known to be important for forming memories.
海馬體是大腦深處分處兩個半球的一對香蕉型的小組織。眾所周知海馬體在記憶形成方面有非常重要的作用。
Administering a few simple cognitive tests to the new mothers—including tests of memory—revealed no obvious changes in performance.
他們對一些新媽媽進行了一些包括記憶力測試在內的簡單認知測試，測試顯示她們的感知能力并沒有明顯的變化。
And the hippocampi had partially regrown within two years.
并且海馬體的某些部位在兩年內會再生。
But DrHoekzema and her colleagues point out that most of the more permanent reductions in grey matter happened across several parts of the brain that,
但是赫克塞馬博士和她的同事們指出，大部分的灰質永久性減少是發生在大腦的一些區域，
in other experiments, have been found to be associated with the processing of social information, and with reasoning about other people’s states of mind.
在其他的實驗中，她們發現大腦中的這些區域與處理社會信息以及推測其他人的心理狀態密切相關。
That would make sense from an evolutionary point of view.
從進化的角度來看，這是有道理的。
Human babies are helpless, and, in order to care for one, a mother must be good at inferring what it needs.
人類的嬰兒是弱小的，為了照顧他們，母親必須善于判斷他們的需要。
The rewiring may also affect how well women bond with their infants.
神經的重塑也可能影響母親與新生兒的聯系。
After the women in DrHoekzema’s study had given birth, the research team administered a standard psychological test designed to measure how attached those women had become to their babies.
參與DrHoekzema研究的女性分娩后，研究團隊進行了一項標準心理測試，旨在測量這些女性對其嬰兒的依戀程度。
The ones with the greatest reductions in grey-matter volume were, on the whole, the most strongly bonded.
總體上，腦灰質體積減少最大的對嬰兒的依戀程度最強。
Ascribing all this to a reduction in grey-matter volume, rather than an increase, sounds counter-intuitive.
將所有這一切歸因于腦灰質體積的減少而不是增加聽起來好像不對。
But DrHoekzema reckons it is probably evidence of a process called synaptic pruning, in which little-used connections between neurons are allowed to wither away, while the most-used become stronger.
但是DrHoekzema猜想這可能是突觸修剪過程的證據。在突觸修剪過程中神經元之間很少使用的連接逐漸萎縮，而最常用的連接則變得更強。
That is thought to make neural circuitry more efficient, not less so.
這樣可以提高而非降低腦回路的效率。
She points out that the surge of sex hormones people experience during adolescence is thought to cause a great deal of synaptic pruning, moulding a child’s brain into an adult one.
她指出青少年期間性激素的激增會造成大規模的突觸修剪從而將兒童的大腦塑造成成人的。
So it is reasonable to assume that the even greater hormonal surge experienced during pregnancy might have a similar effect.
因此推測懷孕期間更強的激素激增可能具有類似的效果是合理的。
When it comes to the brain, after all, bigger is not necessarily better.
畢竟當談到大腦，更大不一定意味著更好。
英文文本來自經濟學人 譯文來自欄目二第五組
