Infants in low-income families demonstrated elevated levels of brain activity after their mothers were given infusions of cash that made life easier, a national study shows.

The work, conducted by scholars from six universities across the United States, is “an important finding,” according to Martha Farah, director of the Center for Neuroscience & Society at the University of Pennsylvania. She was a peer reviewer of the study. “This is the first time that changing family income has been shown to impact child brain activity.”

The study comes at a time when the federal government’s expansion of the child tax credit (CTC), which kept millions of families out of poverty, has expired with Congress showing little interest in allowing it to continue.

Published Monday in the journal Proceedings of the National Academy of Sciences, the study measured brain activity among a sample of 435 children, all 1-year-olds, in what’s been deemed a landmark examination known as Baby’s First Years.

In 2018, mothers were approached and asked whether they would consent to receiving unconditional cash gifts until their infants reach 4 years of age, Kimberly Noble, a physician and neuroscientist at Teachers College, Columbia University, said in an interview Tuesday. The Broomall-born researcher who earned her undergraduate degree, as well as her Ph.D. in neuroscience and her medical degree at Penn, was the lead neuroscientist for the study. It’s a $20 million interdisciplinary collaboration of economists, policy experts, and neuroscientists.

The mothers were divided into two groups for the randomized controlled study, with one receiving $330 a month, and the other getting just $20.

When the children, born between the spring of 2018 and the summer of 2019, reached age 1, they were given electroencephalograms, or EEG tests, Noble said.

“They were fitted with caps of electrodes that pick up electrical activity in the brain at the scalp, like microphones,” Noble said. “We were then able to determine how quickly or slowly brain activity was occurring.”

Fast, or high-frequency activity, was detected more often in the group whose mothers were given the higher level of cash.

“Kids with more high-frequency activity tend to show development of high cognitive skills for school achievement,” Noble said. “Kids growing up in poverty often show less high-frequency activity.”

For decades, researchers have been able to say that growing up in poverty puts children at risk for lower school achievement, reduced earnings, and poorer health.

Problems such as food insecurity, high stress, and meager chances among low-income people have long been seen as correlating with poverty but not proven as causes of poverty.

This study attempts to change that.

“The idea that poverty is bad for children and the single-most robust predictor of poor developmental outcomes has been known for 50 years,” said Joan Luby, professor of child psychiatry at the Washington University School of Medicine in St. Louis. “But this study asked the causal question: ‘If you give their parents small infusions of cash, does it change the way children’s brains develop?’ ”

Noble agreed, saying that until now, researchers have been unable to say “whether poverty itself causes differences in child development, or whether growing up in poverty is simply associated with other factors that cause those differences.”

Still, said Joel Berg, CEO of the national nonprofit Hunger Free America, based in New York, as much attention as the study is getting, “it’s in the category of learning that water helps drought. We already know about brains and poverty.”

But, he conceded, so many Americans “don’t accept the reality of poverty — like climate change. So any new data is helpful.”

Mariana Chilton, director of the Center for Hunger-Free Communities at Drexel University’s Dornsife School of Public Health, and a national expert on child poverty, said scientists having to use brain scans to demonstrate poverty’s deleterious effects on kids is “sad.”

She added: “How many millions of dollars of research does it take to prove the obvious — that parents of young children need time and financial supports to help their children grow and flourish? Do we really need expensive brain scans to tell us what to do?”

Existing government help isn’t enough, she said, adding:

“This is not revolutionary; this is not rocket science. Mothers have known this since time immemorial: Families need their community to help pitch in to raise a child.”

Dan Taylor, a pediatrician at St. Christopher Hospital for Children in North Philadelphia, where Drexel research shows more than one in three children lives in poverty, said he appreciated the study. But, after 20 years of treating low-income children, he’s drawn a sorrowful conclusion: “We really don’t as a society value poor children, especially children of color.”

He believes that families in the area “had the rug pulled out from under them” after the CTC expansion wasn’t renewed.

Initially, the Biden administration issued cash infusions of as much as $3,000 a year per child ages 6 to 17, and $3,600 a year per child from newborn to age 5.

Research from Columbia showed that the augmented tax credit kept nearly 4 million children out of poverty.

“This study could not have come at a more opportune time,” Luby said. “We’re right when the Biden CTC expansion expired and Congress isn’t renewing. This study very much shows us they need to renew the expansion.”

Not everyone agrees.

A December Morning Consult/Politico poll discovered that just 47% of Americans favored extending the expansion, as opposed to 42% who were against it.

More important, Sen. Joe Manchin (D., W.Va.) said he wouldn’t support the credit expansion going forward without a work requirement attached. Manchin’s vote is key in an evenly split Senate.

That view is espoused by conservative entities such as the American Heritage Foundation, which explains that extending the expansion in 2022 would actually stymie anti-poverty efforts by persuading people not to work, but simply collect government funding.

Interestingly, the CTC expansion monthly amount was close to the $330 stipend of Baby’s First Years, Noble noted.

“We never could have imagined when we planned this 10 years ago that CTC would be extended by that amount,” she added.

The participants in the study were recruited from postpartum wards in a dozen hospitals in four U.S. metropolitan areas: New Orleans, New York, Omaha, Neb., and Minneapolis/St. Paul, Noble said.

Along with Teachers College, Columbia, the schools involved in the study included the University of Wisconsin, Madison; the University of California, Irvine; Duke University Sanford School of Public Policy; New York University; and the University of Maryland.

Federal funding for research came from the National Institutes of Health. The cash gifts to mothers were underwritten by private funders, including the Bill & Melinda Gates Foundation, the Ford Foundation, and the Robert Wood Johnson Foundation, according to the Baby’s First Years website.

Ultimately, Noble said, “these findings underscore the importance of shifting the national conversation to the potential role of anti-poverty policies in children’s development.”