Baby Brain? No, Having a Child Makes You More Intelligent孕傻？错，分娩让你更聪明

菲奥娜·麦克雷

New mothers often grumble that their brain has turned into mush. But having a baby may actually make you brighter， a study has found.

Research shows that a woman’s grey matter grows in the weeks and months after she has given birth.

And it’s the most doting mothers who experience the biggest burst of brain cells2.

It is thought that the hormonal changes associated with having a baby ‘supercharge3’ the brain， helping prepare women for the challenges ahead.

And the memory lapses that plague new mothers may be explained by a simpler cause—sleep deprivation4.

The finding， from a small study published by the American Psychological Association， contradicts the long-held notion that motherhood addles a woman’s brain.

Neuroscientists from the respected Yale University in the U.S. scanned the brains of 19 new mothers in the weeks after they had given birth.

The results showed that the amount of grey matter—brain cells that crunch information—had increased by a small but significant amount by the time the women were three to four months into motherhood.

Such changes usually only occur after intense periods of learning or a brain injury or illness.

The areas that grew involve motivation， reasoning， judgement， the processing of emotions and feelings of satisfaction， and are key to the mother-child relationship.

Expansion in the brain’s ‘motivation area’， said the researchers， could lead to more nurturing， which would help babies survive and thrive physically， emotionally and cognitively.

The mothers who gushed most about5 their newborns tended to experience the biggest amounts of growth， the journal Behavioral Neuroscience reports.

It is unclear to what extent the changes are due to rises in hormones such as oestrogen6 and oxytocin7 that occur when a woman gives birth， and how much they are caused by chemical changes brought on by cuddling and playing with their babies.

Studies of adoptive mothers could help separate the two.

Siobhan Freegard， founder of the Netmums website， said that ‘supercharging’ made sense.

She added： “Nature has an amazing way of giving us things that we need. Having a baby is a momentous occasion， so it is not surprising the brain gets that little bit extra to equip us for the challenge.”

She suggested that any ‘baby brain’ memory lapses could be due to changing priorities， with the newborn being deemed more important than most other matters.

The results of the study echo research which concluded that， contrary to popular belief， pregnancy does nothing to dim brainpower.

Professor Helen Christensen， of the Australian National University in Canberra， showed that women did as well on tests of memory and logic when pregnant as they had in previous years.

She said： “It really leaves the question open as to why women—and often their partners—think they have poor memories， when the best evidence we have is that they don’t.

“Perhaps women notice minor lapses in mental ability and then attribute it to being pregnant because that is the most significant thing in their mind at the time.

“Or sleep deprivation could mask the positive cognitive effect.”

新生儿母亲经常抱怨自己的大脑变得糊里糊涂。但研究发现，分娩实际上可能会让女性更聪明。

研究表明，分娩后的数周到数月内，女性大脑中的灰质会增多。

并且，最宠爱孩子的母亲，脑细胞暴增程度最大。

有人认为，激素变化与分娩有关，并会给大脑“增加能量”，帮助女性为未来的挑战做准备。

而新生儿母亲为记忆衰退所困扰，可能有一个更简单的原因——睡眠不足。

这一发现来自美国心理学会公布的一项小型研究，与长期以来认为做母亲会让女性头脑糊涂的观念相矛盾。

美国名校耶鲁大学的神经学家在19位新生儿母亲分娩后的数周内，扫描了她们的大脑。

结果显示，女性分娩后3到4个月时，灰质——处理信息的脑细胞——数量增加了，增加数量虽小但意义重大。

這种变化通常只发生在紧张的学习期、脑损伤或疾病之后。

扩大的大脑区域与动机、推理、判断、情绪处理和满足感有关，是母亲与孩子发展关系的关键。

研究人员说母亲大脑“动机区域”的扩大可以让婴儿得到更多抚育，这将有助于婴儿生存，并在身心和认知上迅速成长。

据《行为神经科学》杂志报道，最爱夸赞新生儿的母亲，脑细胞增长数目最多。

这些变化多大程度上由女性分娩时雌激素和催产素等激素的上升而引起，多大程度上由搂抱婴儿和陪婴儿玩耍带来的化学变化而引起，这点却不清楚。

关于养母的研究有助于区分这两者。

“妈妈网”创始人茜奥班·弗里加德表示，“增加能量”是有道理的。

她补充道：“大自然以令人惊奇的方式提供我们需要的东西。 生孩子是个重要时刻，所以大脑额外增大一点点，让我们应对挑战，这不奇怪。”

茜奥班认为，由于母亲视新生儿比其他大多数事情更重要，任何“婴儿脑”式记忆衰退都可能是优先事项变化的结果。

该研究的结果与一项调查相呼应，该项调查认为，与普遍看法相反，怀孕对智力减退毫无影响。

堪培拉市澳大利亚国立大学的海伦·克里斯滕森教授表示，女性怀孕时，记忆力和逻辑测试做得和过去几年一样好。

她说：“这确实让人存疑， 为什么女性及其伴侣经常认为她们的记忆力很差， 而我们有最佳证据证明她们不是这样。

“也许女性会注意到心智能力的轻微衰退，然后将其归因于妊娠，因为这是当时她们脑中最重要的事情。

“或者睡眠不足可能掩盖了积极的认知效应。”

（译者为“《英语世界》杯”翻译大赛获奖选手）