Inequality linked to differences in kids’ brain connections

Brain connection study shows that socioeconomic factors, including at-home enrichment, are associated with widespread differences in children’s brain connections.

9:50 AM

Author | Kara Gavin

brains in blue in lightbulbs and one orange
Getty Images

Growing up in a socioeconomically disadvantaged household may have lasting effects on children's brain development, a large study suggests.

Compared with children from more-advantaged homes and neighborhoods, children from families with fewer resources have different patterns of connections between their brain's many regions and networks by the time they're in upper grades of elementary school, the research finds.

One socioeconomic factor stood out in the study as more important to brain development than others: the number of years of education a child's parents have, according to the study led by a pair of University of Michigan neuroscientists and published in Developmental Cognitive Neuroscience.

But as the researchers dug deeper, they discovered the number of diplomas or degrees parents earned is not the only thing that can make the difference for brain connectivity. They also found a role for parenting activities, like reading with children, talking with them about ideas, taking them to museums, or other cognitively enriching activities.

The study draws on brain scans and behavioral data from more than 5,800 9- and 10-year-old children from diverse backgrounds nationwide. It's the largest-ever look at how socioeconomic factors affect children's "functional connectomes" – the term for maps of interconnectivity across hundreds of brain regions.  

SEE ALSO: Exploring the Link Between Childhood Curiosity and School Achievement

It's also potentially relevant to public policy. One in seven American children lives in poverty using the standard definition, and half qualify for free or reduced school lunch.  

"We need to better understand how social and economic inequality shapes children's brains as they grow and develop, and our results point to a key role for parents' education levels and the kind of enrichment they provide at home," said Chandra Sripada, M.D., Ph.D., the lead author and a professor of psychiatry and philosophy at U-M. "Because of our sample size and 'brain-wide' analysis approach, we feel this study's results are more reliable than previous work, which tended to look at a few dozen children and a small set of brain regions at a time."

Scans and socioeconomics

The large study size was made possible by the national Adolescent Brain Cognitive Development (ABCD) Study research project, which enrolled more than 11,000 children at 22 sites nationwide – including hundreds taking part through the U-M Department of Psychiatry and Addiction Center. The new study is based on data from more than half of the participating children, including brain scans made using functional magnetic resonance imaging or fMRI.

Those scans measured the children's brain activity when they were simply lying in the scanner, without being asked to do anything. This resting state allows neuroscientists to see the level of traffic between different areas of the brain, along functional connections that develop from before birth throughout childhood and adolescence.

Sripada and his colleagues, including senior author and psychiatry professor Mary Heitzeg, Ph.D., analyzed the data three ways – across the whole brain, across all major networks within the brain, and across all individual brain connections – to ensure that their findings are as reliable as possible.

The team used machine learning to "teach" a computer to try to predict a child's level of socioeconomic resources based exclusively on patterns of interconnections among brain regions. They showed that the patterns learned by the computer generalize to new groups of children that the computer had not "seen" before. This analysis showed wide variation in brain connectivity patterns across children of different socioeconomic backgrounds.

The researchers examined a composite measure of overall socioeconomic resources of a child's household, combining measures of parental education, household income and levels of neighborhood resources. In addition, the researchers examined the unique contributions of each of these three socioeconomic factors.

That's where parental education rose to the fore as the most associated with variations in brain connections.

"The effects of household socioeconomic resources on functional connectivity were massively distributed throughout youths' brains," said Sripada. "We did not see localization of effects in a discrete location or specific brain circuit. Instead, there were relatively tiny effects distributed throughout the brain, though when these individual effects are aggregated together, they constitute a strong, reliably detected signal."

He notes that this mirrors the evolving understanding of the genetics involved in diseases from schizophrenia to diabetes, where tiny effects from many genes combine to create the whole picture.

Is it parental education or parenting activities that matter?

For a subset of 3,223 children, the researchers were able to analyze additional data to explore what factors might help to explain why parental education is associated with differences in children's brain connectivity patterns.

SEE ALSO: Study of pre-teens yields surprises about alcohol, tobacco and marijuana

They found parents with higher levels of education engaged in more home-based enrichment activities, and these children scored higher on tests of cognitive function and had better grades in school.

"Based on these results, we see parental education as potentially an important part of more complex pathway by which socioeconomic disparities get 'under the skin' and shape the developing brain," said Heitzeg. "As data from the long-term ABCD study continues to become available, we look forward to exploring how different factors influence physical and mental health, use of drugs and alcohol, and more."

Sripada says he hopes the new findings will help address the "crisis of reproducibility" in neuroscience, in which researchers examine very small samples and their results are not reproduced in subsequent small studies. He hopes solid, reliable findings from large studies will increase trust in neuroscience and make it more likely that these findings will be used to inform social and policy questions.

Live your healthiest life: Get tips from top experts weekly. Subscribe to the Michigan Health blog newsletter

Headlines from the frontlines: The power of scientific discovery harnessed and delivered to your inbox every week. Subscribe to the Michigan Health Lab blog newsletter

Like Podcasts? Add the Michigan Medicine News Break on Spotify, Apple Podcasts or anywhere you listen to podcasts.

In addition to Sripada and Heitzeg, the study's authors are Arianna M. Gard of the University of Maryland, College Park; U-M psychiatry team members Mike Angstadt,  Aman Taxali, Tristan Greathouse, Katherine McCurry, Alexander Weigard and Peter Walczyk, and Luke W. Hyde from the U-M Institute for Social Research.

The Adolescent Brain Cognitive Development Study is funded the National Institutes of Health and its federal partners, and led by the National Institute on Drug Abuse. Get more information on the ABCD study.

Paper cited: "Socioeconomic resources are associated with distributed alterations of the brain's intrinsic functional architecture in youth," Developmental Cognitive Neuroscience. DOI :10.1016/j.dcn.2022.101164


More Articles About: Body Work Basic Science and Laboratory Research Demographics Children's Health Neurology Future Think Education All Research Topics
Health Lab word mark overlaying blue cells
Health Lab

Explore a variety of healthcare news & stories by visiting the Health Lab home page for more articles.

Media Contact Public Relations

Department of Communication at Michigan Medicine

[email protected]

734-764-2220

Stay Informed

Want top health & research news weekly? Sign up for Health Lab’s newsletters today!

Subscribe
Featured News & Stories Florescent image of a human ovarian follicle
Health Lab
Spatial atlas of the human ovary with cell-level resolution will bolster reproductive research
New map of the ovary provides a deeper understanding of how oocytes interact with the surrounding cells during the normal maturation process, and how the function of the follicles may break down in aging or fertility related diseases.
A CT scan of healthy lungs
Health Lab
Study reveals potential to reverse lung fibrosis using the body’s own healing technique
A recent U-M study uncovers a pathway utilized during normal wound healing that has the potential to reverse idiopathic pulmonary fibrosis.
Illustration of red blood cells and bacteria in the bloodstream
Health Lab
New device can treat injury from sepsis
The FDA approved the use of a therapeutic device invented and developed at the University of Michigan for use in children with acute kidney injury and sepsis or a septic condition requiring continuous kidney replacement therapy.
Dinero is back to being an active toddler following a kidney transplant
Health Lab
Formula prescription helps 2-year-old receive kidney transplant
Dinero's pediatric nephrology team developed a tailored formula to address his mineral deficiencies due to his chronic kidney disease, maintain nutritional health and avoid dialysis.
Close up image of red blood cells moving through veins
Health Lab
Discovery reveals how this common stinky gas is processed to promote blood vessel growth
A new collaborative study, examined the interaction between three naturally occurring gases — nitric oxide (NO), oxygen, and H2S — during generation of new blood vessels, called angiogenesis.
Illustration of teenager lying in bed while images above depict an F grade on paper and classroom
Health Lab
2 in 3 parents say their adolescent or teen worries about how sick days may impact grades
National poll: 1 in 5 parents consider if their child needs a mental health day; 1 in 4 say attendance policies are challenging for kids with medical conditions