Areas of the brain related to social cognition shrink in first-time mothers—a structural change that could boost maternal attachment. Christopher Intagliata reports.

据克里斯托弗·因塔利亚塔（Christopher Intagliata）报道，首次怀孕时，大脑与社会认知相关的区域会收缩，这种结构改变会增强母性依恋。

播音\撰文：克里斯托弗·因塔利亚塔（Christopher Intagliata）

翻译：杨枭

审校：丁可含

Pregnancy brings big physical changes to a woman's body. But what three neuroscientists were more interested in was, what does it do to the woman’s brain? "We were in our 30s, and we were thinking I'd like to have a baby, but look at this, look at this." Susana Carmona, a neuroscientist at the University of Carlos the Third in Madrid.

怀孕会给女性身体带来巨大的生理改变。但三个神经生物学家更感兴趣的是，怀孕会给女性大脑带来什么影响？马德里卡洛斯三世大学的神经生物学家苏珊娜·卡蒙娜（Susana Carmona）说道：“我们三十多岁，想要有个孩子，但看看这个，看看这个。”

"And then we realized most of this data came from animal studies. And that there were no solid studies about what really happens to your brain when you get pregnant. And that's how we convinced the boss we should do that even without any funding at this point."

“然后我们意识到大部分数据都来源于动物研究，而少有人类怀孕时大脑变化的可靠研究。我们就这样劝服我们的老板，即使没有资金支持，我们也应该做这个研究。”

Carmona and her team took MRI scans of 25 women's brains, before and after their first child. They found that parts of the brain dealing with social cognition actually shrunk—reduced in volume—in women who successfully conceived and had kids. That's compared to no changes among control women, and no changes in men—whether they were new fathers or not.

卡蒙娜和她的团队用核磁共振成像（MRI）检测了25位女性在生第一胎前后的大脑。他们发现，与对照组女性相比，成功孕育孩子的女性的大脑中处理社会关系的部分确实缩小了，而男性的大脑无论他们是否是新父亲都无变化。

Shrinking sounds bad though: why would you want less grey matter? But Carmona says less does not result in deficits in thinking or memory, and might actually be the result of a good thing: the fine-tuning of connections between neurons. "When you have a lot of routes that arrive to a different place, and there's one that is the shorter and the faster one, the optimal thing would be to close the rest so you never get lost, from point A to point B."

尽管大脑收缩听上去很糟糕，但为什么你还想要更少的灰色物质呢？卡蒙娜说，灰色物质少并不意味会导致思维和记忆的缺陷，事实上还有可能是个好事，如此能更好地调节神经元之间的连接。“当你面前有多条通往不同地方的路，而从A到B正好有一条最短最快的路，那么最好的办法就是关闭所有其余路线，这样你绝对不会走错。”

Hormonal fluxes cause similar fine-tuning in the adolescent brain—and hormones might be the culprit for these changes as well. Changes that can last at least two years after pregnancy. The study is in the journal Nature Neuroscience. [Elseline Hoekzema et al., Pregnancy leads to long-lasting changes in human brain structure]

激素量变化在青少年的大脑中引起类似的微调，并且激素也可能是这些变化的罪魁祸首。这种改变会在怀孕后至少持续两年。该研究发表在了期刊《自然 神经科学》上。

The effect of all this? Could be a boost in maternal attachment. Fewer hostile feelings towards the baby, and more pleasure playing together. As for Carmona and her two colleagues? They decided not to wait til the study was complete to start their families. "We decided that whatever happens to your brain, we wanted to be mothers."

这一切的后果呢？可能是为了提升母性的依恋程度。对婴儿减少敌意，更愿意与之一起玩耍。而卡蒙娜和她的两位同事呢？她们决定不等研究结束就组建家庭。“我们决定无论大脑会发生什么，我们仍然想要成为母亲。”