PTE考生目前最大的问题之一就是练习题缺乏。除了有限的基本官方书（PLUS，Testbuilder, OG）之外就没有题了。很多英语基础不是很扎实的同学很难找到练习材料。悉尼文波雅思PTE培训学校专门为澳洲，尤其是悉尼、墨尔本的PTE考生准备了适合PTE听力阅读练习的科学60秒。各位PTE同学可以练习PTE听力中的summarise spoken text和PTE口语中的retell lecture，PTE听力口语-科学60秒-Frosty Moss练习记笔记技巧和复述。废话少说，下面开始：
This is Scientific American — 60-Second Science. I’m Christopher Intagliata.
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.
“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.”
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.
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.”
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.
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.”
Thanks for listening for Scientific American — 60-Second Science Science. I’m Christopher Intagliata.
