《经济学人》双语：研究发现初为人父的人，大脑皮层会萎缩
原文标题：
Parental behaviour
Dad brain
Becoming a father shrinks your cerebrum
亲本行为
父亲的大脑
做父亲会让你的大脑萎缩
That may help form parental attachments
这或有助于培养亲子间的情感连接
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IT IS HARDLY surprising that pregnancy and childbirth, nine months of enormous changes to a woman’s body, also change her brain.
怀孕和分娩这九个月使女性身体产生了巨大的变化，也改变了女性的大脑，这并不令人感到讶异。
And they do, by causing certain parts of it to shrink.
这种变化是由于一部分大脑的萎缩而产生的。
Fathers, it might be thought, would be unaffected.
人们或许会认为，父亲不会有什么影响。
But no. There is evidence that their brains shrink, too.
但事实并非如此。证据表明，父亲的大脑也有萎缩。
A paper just published in Cerebral Cortex by Magdalena Martínez-García of the Gregorio Marañón Health Research Institute in Madrid, and her colleagues, divulges the details.
马德里格雷戈里奥·马拉尼翁健康研究所的马格达莱娜·马丁内斯·加西亚及其同事刚刚在《大脑皮层》杂志上发表了一篇论文，其中透露了详细信息。
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Dr Martínez-García’s study followed a group of 40 expectant fathers, 20 from Spain and 20 from America, and also, as a control, 17 Spanish men who did not have a baby on the way.
马丁内斯·加西亚博士的研究跟踪调查了40位准爸爸，其中20位来自西班牙，20位来自美国，另外还有17位尚无新生儿的西班牙男性作为对照。
To measure changes to their brains the volunteers underwent two magnetic-resonance imaging (MRI) scans roughly a year apart.
为了测量他们大脑的变化，志愿爸爸们大约每隔一年进行两次磁共振成像（MRI）扫描。
In the case of the new fathers, one of these scans was before, and the other after, the birth of the
child.
对于准爸爸组，一次核磁扫描是在孩子出生之前，另一次则是在孩子诞生之后。
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The researchers used the scans to compare the volume and thickness of the cerebral cortex, the part of the brain responsible, inter many alia, for things like sensory perception, language and cognition, with that of the sub-cortex, a disparate collection of structures such as the hippocampus (involved in long-term memory formation) and the amygdala (which regulates fear).
研究人员利用扫描图像比较了大脑皮层的体积和厚度，大脑皮层是负责感知觉、语言和认知等其他功能的部分，而次皮层是由不同结构组成的集合，如海马体（参与长期记忆的形成）和杏仁核（调节恐惧）。
They confirmed that there is a small but consistent decrease in the volume of the cortices of new fathers after the birth of their child.
他们证实，在孩子出生后，新爸爸的大脑皮层体积出现了微小但持续的减少。
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This shrinkage is not, however, evenly distributed.
然而，这种大脑萎缩不是均匀分布的。
The biggest reductions are in the area at the back of the cortex where information from the retina is processed and interpreted, and in the “default-mode” network, a piece of neural circuitry distributed between three different cortical areas, which is associated with daydreaming, mind-wandering and thinking about the self and others.
萎缩最多的是大脑皮层后部的区域，那是处理和读取来自视网膜的信息的部位；在“默认模式”网络中，一段神经回路分布在了三个不同的大脑皮层区域之间，这个部位与做白日梦、走神和思考自我和他人有关。
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This pattern partly mimics changes found in the brains of first-time mothers.
这种变化模式在一定程度上模仿了初为人母的女性大脑的变化。
For example, a study published in Nature Neuroscience in 2017 by some of the same researchers found that areas of the default-mode networks of their brains also shrink.
例如，这些研究人员2017年在《自然神经科学》上发表的一项研究发现，女性大脑的默认模式网络区域也缩小了。
The differences in first-time fathers’ brains are less pronounced than those in mothers, and also more variable—and are, presumably, caused in a different way.
初为人父者的大脑变化没有母亲那么显著，并且更加多变——估计是由不同的方式引起的。
But different physiological means can still arrive at the same evolutionary end.
但不同的生理途径仍然可达到相同的进化目的。
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The mamas and the papas
妈妈和爸爸
That end is presumably being a better parent.
这个目的大概就是为了成为一个更好的父母吧。
The authors of this earlier paper also gave the new mothers a questionnaire asking how they felt about spending time with their offspring, whether they thought they understood their babies’ signals, and whether they felt any resentment towards them.
之前这篇论文的研究人员还向新手妈妈们发放了一份问卷，询问她们对与孩子在一起的时间有何感受，她们是否认为自己理解了婴儿所发出的信号，以及她们是否对婴儿有怨恨情绪。
They found that postpartum changes in brain volume predicted both how attached a mother felt to her child and the absence or otherwise of hostility to it.
他们发现，产后脑容量的变化既可以预测母亲对孩子的依恋程度，也可以预测母亲对孩子是否有敌意。
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Examination of the Spanish fathers in Dr Martínez-García’s latest study, by measuring their brain activity while they looked at pictures of both their own baby and other infants, found a similar effect.
马丁内斯·加西亚博士对西班牙的父亲进行了最新研究，通过测量他们在看自己的婴儿和其他婴儿照片时的大脑活动，发现了类似的效应。
It showed that those with the largest reductions in brain volume had the strongest MRI responses to images of their own child compared with images of others.
研究表明，与看其他孩子照片时的核磁反应相比，大脑体积减少最多的父亲在看自己孩子照片时的核磁反应更为强烈。
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Determining exactly how these pro-parental neural changes come about in men is way beyond the current skill of neuroscience.
要确切知道父母的神经变化在男性身上发生的机制，这远远超出了目前神经科学的水平。
But it is intriguing to observe that, at least in the case of Homo sapiens, a rare example of a mammal in which fathers as well as mothers nurture offspring, similar postpartum parental attitudes seem to be getting wired into both sexes.
但一个有趣的发现是，至少在智人这一罕见的哺乳动物例子中，双亲共同养育后代。在它们的两性中，这种类似的双亲在产后的态度是与生俱来的。
（恭喜读完，本篇英语词汇量约581左右）
原文出自：2022年10月1日《The Economist》Science & technology版块。
精读笔记来源于：自由英语之路
本文翻译整理: Fei Min
本文编辑校对: Irene
仅供个人英语学习交流使用。
【补充资料】（来自于网络）
在神经科学中，默认模式网络，也叫做默认网络或者默认状态网络，是已知具有彼此高度相关的活动并且与大脑中的其他网络不同的活动大脑区域的大规模脑网络。当一个人不关注外部世界，大脑处于清醒的休息状态时，例如在做白日梦和思维游移的时候，默认的模式网络是最常见的。但是，当人们在思考别人，思考自己，回忆过去，规划未来时，它也是活跃的。当一个人没有参与任务时，网络会“默认”激活。虽然DMN最初被注意到在某些目标导向任务中被停用，有时被称为任务负面网络，但它可以在其他目标导向型任务（例如社交工作记忆或自传任务）中起作用。已经显示DMN与注意网络等大脑中的其他网络呈负相关。
2017年《自然神经科学》杂志上发表了一项研究，怀孕确实能改变孕妇的大脑。研究人员扫描分析了备孕、怀孕、分娩后女性的大脑，结果发现，分娩过后，女性大脑的某些区域灰质明显减少了，而且分娩两年后，这种现象依然存在。研究人员推测可能是母亲怀孕时产生的雌性激素和孕激素，导致怀孕以一个特别的方式塑造了母亲的大脑，让女性对婴儿更敏感，这就是为什么生完孩子后母性大发。
【重点句子】（3个）
This shrinkage is not, however, evenly distributed.
然而，这种大脑萎缩不是均匀分布的。
But different physiological means can still arrive at the same evolutionary end.
但不同的生理途径仍然可达到相同的进化目的。
That end is presumably being a better parent.
这个目的大概就是为了成为一个更好的父母吧。
自由英语之路
