A large new study suggests that growing up in a socially and economically disadvantaged family may have lasting effects on children’s brain development.
The research found that compared to children from more fortunate homes and neighborhoods, children from families with fewer resources have different patterns of connections between the brain’s many regions and networks by the time they are in the upper grades of elementary school.
One socioeconomic factor in the study emerged as more important to brain development than others: the number of years of education a child’s parents have, according to the new study led by two University of Michigan neuroscientists and published in Developmental Cognitive Neuroscience.
But as researchers delve deeper, they discover that the number of testimonials or testimonials that parents have isn’t the only thing that can make a difference in brain connectivity. They also found a role for parenting activities, such as reading with children, talking to them about ideas, taking them to museums, or other cognitively enriching activities.
The new study is based on brain scans and behavioral data of more than 5,800 children from diverse backgrounds nationwide. It’s the biggest look ever at how socioeconomic factors affect children’s “functional neural networks” – the term for maps of connectivity across hundreds of brain regions.
It is also likely to be relevant to public policy. One in seven American children lives in poverty using the standard definition, and half qualifies for free or reduced school lunch.
We need to better understand how socioeconomic inequality shapes children’s brains as they grow and develop, and our findings suggest a key role for parents’ education levels and the type of enrichment they provide at home. Given the sample size and ‘brain-wide’ analysis approach, we feel that the results of this study are more reliable than previous work, which tended to look at a few dozen children and a small set of brain regions simultaneously.”
Chandra Sripada, MD, PhD, lead author and Professor of Psychiatry and Philosophy at UM
Surveying and Social Economics
The large study volume was made possible by the National ABCD Study Research Project, which enrolled more than 11,000 children at 22 sites nationwide—including hundreds who participated through the UM Department of Psychiatry and Addiction Center. The new study is based on data from more than half of them, including brain scans done with fMRI 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 regions of the brain, along the functional connections that develop from before birth through childhood and adolescence.
Sripada and colleagues, including lead author and professor of psychiatry Mary Heitzig, PhD, analyzed the data in three ways — across the whole brain, across all major networks within the brain, and across all of the 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 social and economic resources based on patterns of interconnection between brain regions. They showed that computer-learned patterns generalized to new groups of children that the computer had not “seen” before. This analysis showed significant variation in brain connectivity patterns across children from different socioeconomic backgrounds.
The researchers examined a composite measure of a child’s family’s overall social and economic resources, combining measures of parental education, family income, and neighborhood resource levels. In addition, the researchers examined the unique contributions of each of these three socioeconomic factors.
This is where parental education emerged as most closely related to differences in brain connections.
“The effects of families’ social and economic resources on functional connectivity were significantly distributed across all young people’s brains,” Sripada says. “We did not see the localization of effects to a separate site or specific brain circuit. Instead, there were relatively small effects distributed throughout the brain, although when these individual effects are grouped together, they constitute a strong and reliable signal.”
He points out that this reflects an evolving understanding of the genes associated with diseases from schizophrenia to diabetes, where small effects from many genes combine to make the big picture.
Is parental education or parenting activities important?
For a subset of 3,223 children, the researchers were able to analyze additional data to explore factors that might help explain why parental education was associated with differences in children’s brain connectivity patterns.
They found that fathers with higher levels of education engaged in more home enrichment activities, and that these children scored higher on tests of cognitive function and got better grades in school.
“Based on these findings, we see that parental education is potentially an important part of a more complex pathway, through which socioeconomic disparities get ‘under the skin’ and shape the developing brain,” Heitzig says. “As data from the long-term ABCD study continues to become available, we look forward to exploring how various factors affect physical and mental health, drug and alcohol use, and more.”
Sripada says he hopes the new findings will help address a “reproduction crisis” in neuroscience, where researchers are examining samples that are too small to be reproduced in subsequent small studies. He hopes that robust and reliable results from large studies will increase confidence in neuroscience and increase the likelihood that these findings will be used to inform social and policy questions.
In addition to Sripada and Heitzig, study authors are Ariana M. Gard of the University of Maryland, College Park. UM Psychiatric team members Mike Engstad, Aman Taxali, Tristan Great House, Catherine McCurry, Alexander Wiegard and Peter Walczek, and Luke W. Hyde of the UM Institute for Social Research.
Michigan Medicine – University of Michigan
Sripada, C, et al. (2022) Socioeconomic resources correlate with distributed modifications to the intrinsic functional structure of the brain in young adults. Developmental Cognitive Neuroscience. doi.org/10.1016/j.dcn.2022.101164.