Researchers report links between socioeconomic factors and children’s brain structure, with the strongest associations found at the lowest income levels
A multi-institutional team of investigators from nine universities across the United States has identified consistent correlations between family income and brain structure in children and adolescents. The study, led by researchers at The Saban Research Institute of Children’s Hospital Los Angeles (CHLA) and Columbia University Medical Center, appears in the early online edition of Nature Neuroscience. The analysis suggests that the relationship between family income and brain surface area is strongest among children from the lowest-income families, indicating that policies and programs targeted to those children could produce the largest societal benefits.
“We do not interpret these findings to mean that socioeconomic circumstances cause permanent or unchangeable changes in a child’s brain,” said Elizabeth Sowell, PhD, director of the Developmental Cognitive Neuroimaging Laboratory at CHLA and professor of Pediatrics at the Keck School of Medicine of the University of Southern California. “Rather, our results are consistent with the idea that differences in access to material and social resources — which often vary with household income — are associated with measurable differences in brain structure.”
The researchers examined brain MRI scans and demographic information from 1,099 typically developing participants, ages 3 to 20, who were part of the multi-site Pediatric Imaging, Neurocognition and Genetics (PING) study. Using high-resolution MRI data together with parent-reported demographic and developmental histories, the team measured brain surface area and tested its association with socioeconomic indicators such as family income and parental educational attainment. Statistical models accounted for age, parental education and genetic ancestry to isolate associations between income and brain structure.
Key findings include a nonlinear association between family income and brain surface area, with income explaining more variance in surface area among children at the lower end of the income distribution. In other words, modest increases in income at the lowest levels were linked to relatively large differences in brain surface area in regions implicated in skills important for academic success. By contrast, among children from higher-income families, similar incremental increases in income were associated with much smaller differences in surface area.
First author Kimberly G. Noble, MD, PhD, director of the Neurocognition, Early Experience and Development (NEED) Lab and assistant professor of Pediatrics at Columbia University Medical Center, emphasized the potential educational relevance of the findings: “Among children from lower-income families, relatively small differences in household income are associated with larger differences in brain surface area in regions linked to academic skills. Higher family income was also associated with better performance on some cognitive measures, and part of those cognitive differences could be explained by differences in brain surface area.”
Elizabeth Sowell noted that family income is tied to many environmental factors that shape development, including nutrition, access to health care, quality of early education and play spaces, and sometimes neighborhood air quality. “Everything in a child’s environment contributes to brain development,” she said. “An important question for future research is whether improving environmental conditions—for example, through policies that reduce family poverty or increase access to supportive services—could alter developmental trajectories in ways that improve cognitive outcomes.”
The published paper lists many collaborators across institutions. Contributors include Suzanne M. Houston, MA, and Eric Kan (Children’s Hospital Los Angeles and USC); Natalie H. Brito, PhD (Columbia University); Hauke Bartsch, PhD; Joshua M. Kuperman, PhD; Natacha Akshoomoff, PhD; Cinnamon S. Bloss, PhD; Nicholas J. Schork, PhD; Sarah S. Murray, PhD; Anders M. Dale, PhD; and Terry L. Jernigan, PhD (UC San Diego); David G. Amaral, PhD (UC Davis); Ondrej Libiger, PhD (MD Revolution); B. J. Casey, PhD (Weill Cornell Medical College); Linda Chang, MD, and Thomas M. Ernst, PhD (University of Hawaii and Queen’s Medical Center); Jean A. Frazier, MD, and David N. Kennedy, PhD (University of Massachusetts Medical School); Jeffrey R. Gruen, MD (Yale University School of Medicine); Peter Van Zijl, PhD (Johns Hopkins University School of Medicine); Stewart Mostofsky, MD (Kennedy Krieger Institute); Walter E. Kaufmann, MD (Boston Children’s Hospital); and Tal Kenet, MD, PhD (Harvard University).
Funding for the work was provided by several National Institutes of Health grants (including RC2 DA029475, R01 HD053893, R01 MH087563 and R01 HD061414) and support from the Annie E. Casey Foundation and the GH Sergievsky Center.
Contact: Debra Kain – CHLA
Source: CHLA press release
Image Source: The image is adapted from the CHLA press release
Original Research: Abstract for “Family income, parental education and brain structure in children and adolescents” by Kimberly G. Noble et al., published online March 30, 2015, in Nature Neuroscience.