来源：《新科学家》
原文刊登日期：2022年1月24日
Giving low-income families in the US more money changes a child’s brain activity. Kimberly Noble at Columbia University in New York and her team are studying how exactly child poverty causes reduced grey matter volume in the hippocampus and frontal cortex, which are associated with the development of thinking and learning. These changes have been seen throughout childhood and adolescence.
在美国，给低收入家庭更多的钱会改变孩子的大脑活动。纽约哥伦比亚大学的金伯利·诺布尔和她的团队正在研究儿童贫困究竟是如何导致海马体和额叶皮质灰质体积减少的，灰质与思考和学习的发展有关。灰质的变化在整个童年和青春期都可以看到。
They are tracking development in the brains of 1000 babies from low-income families in four US metropolitan areas: New York City, greater New Orleans, Minneapolis–Saint Paul and Omaha. Each family had an average annual income of just over $20,000.
他们正在跟踪1000名婴儿的大脑发育，这些婴儿来自美国四个都会区：纽约市、大新奥尔良、明尼阿波利斯-圣保罗双城地区和奥马哈。每个家庭的平均年收入略高于2万美元。
The team gave half the babies’ mothers a monthly stipend of $333 and the other half $20 a month. The first payment was received soon after their baby’s birth. “They can spend the money however they want – no strings attached,” says Noble. She says they chose to give $333 a month because that adds up to about $4000 a year, which studies suggest is an increase in wealth that has been linked with improvements in a child’s school performance later in life.
研究小组给一半婴儿的母亲每月333美元的津贴，另一半每月20美元。孩子出生后不久就收到了第一笔付款。“他们想怎么花就怎么花——没有任何附加条件，”诺布尔表示。她说，他们选择每月补贴333美元，是因为这样一年就能有4000美元左右。研究表明，财富的增加与孩子日后学习成绩的改善有关。
By July 2020, the babies had reached their first birthday. Just before or soon after turning 1, 435 of the children had their brain activity recorded using EEG – about 40 per cent were in families receiving $333 a month and 60 per cent were in families given $20 a month. The team couldn’t take recordings from all 1000 due to complications caused by the covid-19 pandemic.
到2020年7月，这两组婴儿已经过了一岁生日。在其中435名儿童一周岁前后，他们的大脑活动被用脑电图(EEG)记录下来——其中大约40%的家庭每月补贴333美元，60%的家庭每月补贴20美元。由于新冠大流行的影响，该团队无法对所有1000个婴儿进行脑电图记录。
The researchers found that, on average, children from families that received $333 a month had more brain activity in higher frequencies than those in the $20 group. “We’re showing for the first time that poverty reduction has a causal impact on brain activity,” says Noble.
研究人员发现，平均而言，每月补贴333美元家庭的孩子比每月补贴20美元家庭的孩子大脑活动频率更高。诺布尔说：“我们第一次证明，减少贫困对大脑活动有因果影响。”
She speculates that $333 a month changed the home environments of those babies, though the researchers haven’t yet determined what exactly these changes were, and therefore how they affected brain activity. Lower incomes have been linked with higher levels of familial stress, which in turn harms the development of a child’s brain.
她推测每月333美元可以改变这些婴儿的家庭环境，尽管研究人员还没有确定这些变化到底是什么，因此它们是如何影响大脑活动的。低收入与较高水平的家庭压力有关，而家庭压力反过来又会损害孩子的大脑发育。
“The fact that we did see effects after just one year really speaks to the remarkable plasticity of the developing brain and its sensitivity to economic resources,” she says.
她说：“事实上，我们在仅仅一年之后就看到了效果，这确实说明了发育中的大脑具有非凡的可塑性，以及它对经济资源的敏感性。”