科学美国人60秒 怀孕使大脑为做母亲做好准备（在线收听）

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.

怀孕会给女性带来巨大的生理变化。但是，有三位神经学家却对怀孕会给女性的大脑带来的影响更感兴趣。“我们已经三十多岁了，都正在考虑生小孩，但是，看看这个。”苏珊娜·卡尔莫纳是马德里卡洛斯三世大学的神经医学家。

"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."

然后我们意识到大多数据都是来自于对动物的研究。而对于人体怀孕后，大脑所发生的变化，没有可信的研究。这就是我们说服负责人现在应该进行该研究，即使没有任何的资金。

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.

卡尔莫纳和她的团队分别对25位女性孕前以及生完第一胎之后，对她们的大脑进行了核磁共振扫描。他们发现，对于那些已经成功怀孕并且已经生下宝宝的女性，大脑处理社会认知的部分的确减弱了——体积减少了。而对于未孕女性而言，没有任何变化。同时对于男性，无论他们是否新晋升为爸爸，也没有任何变化。

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."

大脑萎缩听起来非常的糟糕：为什么灰质会减少呢?但是卡尔莫纳表示，灰质减少可能不会引起思维迟钝或者记忆力减退，可能是由于一件不错事情发生的：神经元细胞连接的微调。“当你有众多的路线到达不同的地方，而有一条路线非常的便捷，最优的方案就是去掉其他可能让你迷路的其他录像。”

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.

荷尔蒙的通量会导致青少年的大脑发生类似的微调——荷尔蒙可能也是孕妇大脑发生变化的罪魁祸首。这些变化会在怀孕之后持续至少两年之久。该研究结果发表在《自然神经科学》杂志上。

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."

产生的影响?可能会增加母体依恋。对宝宝的敌意减少，同时与宝宝在一起的乐趣会增多。那么对卡尔莫纳和其他两位同事呢?他们决定尽管研究尚未完成，但是他们要开始组建自己完整的家庭。“无论怀孕对让大脑发生何种变化，我们都渴望成为母亲”。