How do economic factors influence the developing brain? A recent study sheds light on this question, providing evidence that lower family income is associated with alterations in brain connectivity in children aged 9 to 11. Specifically, children from lower-income families exhibit decreased connectivity in certain brain areas related to mind wandering, memory, and self-referential thought. These findings shed light the link between socioeconomic status and cognitive development, suggesting that economic disadvantages can impact the brain’s functional architecture.
The findings were published in Molecular Psychiatry.
In 2020, poverty touched the lives of 37 million Americans, disproportionately affecting single-parent families, individuals with disabilities, and children. With previous research highlighting how poverty can stunt cognitive abilities and school performance, partly due to factors like malnutrition and less enriching home environments, there was a pressing need to understand more deeply how economic constraints affect brain development and function.
“We want to understand how family income influences brain connectivity patterns and cognitive abilities because it can help us address inequalities in cognitive development among children from different socioeconomic backgrounds,” said study author Dardo Tomasi, a senior staff scientist and MRI physicist at the National Institute of Alcohol Abuse and Alcoholism.
“By studying how factors like family income affect the way the brain works and how well children can learn and think, we can identify ways to support children who may be at a disadvantage due to their economic circumstances. This knowledge can inform policies and interventions aimed at providing equal opportunities for all children to reach their full potential, regardless of their family’s financial situation.”
The study analyzed data from 8,739 children participating in the Adolescent Brain Cognitive Development (ABCD) study, one of the most comprehensive studies on child development in the United States. They focused on children fluent in English without medical, neurological, or cognitive issues that might skew results.
The researchers utilized resting-state functional magnetic resonance imaging (fMRI) data to analyze the children’s brain connectivity. The analysis centered on measuring global functional connectivity density (gFCD), a metric that quantifies the degree of connectivity or communication between various brain regions.
Children from lower-income families exhibited decreased connectivity in areas of the brain known as the default-mode network (DMN), as well as in the inferior and superior parietal cortices and the posterior cerebellum. The DMN is particularly significant because it is involved in internal thought, memory, and self-referential thinking – critical components of cognitive function.
On the other hand, these children displayed increased connectivity in regions associated with sensory and motor processing, as well as in certain subcortical areas. This shift in connectivity patterns suggests a reorganization of neural priorities, possibly as an adaptation to the children’s socioeconomic environment.
The researchers also analyzed data from cognitive tests that assessed a range of abilities including processing speed, working memory, memory for sequences, attention, and language skills. They found that children from higher-income families scored better on these cognitive assessments on average than their lower-income counterparts.
Importantly, the researchers found that cognitive performance partly mediated the impact of family income on brain connectivity patterns. Specifically, lower cognitive performance, which is associated with lower family income, contributes to reduced connectivity within the DMN. This suggests that the adverse effects of lower socioeconomic status on cognitive performance could be linked to alterations in the brain’s functional connectivity, particularly in areas important for high-level cognitive processing and integration of information.
“We were surprised by the effects of family income on the functional connectivity of brain regions involved in multimodal integration (default mode and dorsal attention networks) that are essential for cognitive performance,” Tomasi told PsyPost. “Higher-income families often have greater access to enriching educational resources, cultural activities, and stimulating environments. These experiences can promote cognitive development and network connectivity through increased exposure to diverse stimuli and opportunities for learning.”
“The takeaway message from this study is that family income can have a significant impact on how a child’s brain develops and how well they perform cognitively. Understanding this link highlights the importance of providing support and resources to children from lower-income families to ensure they have the same opportunities for healthy brain development and academic success as their peers from higher-income backgrounds. Additionally, it underscores the need for societal efforts to address socioeconomic disparities and create environments where all children can thrive, regardless of their family’s financial situation.”
The study provides important insights into the relationship between family income, brain connectivity, and cognitive performance in children. But the cross-sectional nature of the study, relying on baseline data from the ABCD study, means that causality cannot be established, and the directionality of the observed effects remains uncertain.
“The correlational nature of the study did not account for other factors (e.g., genetics, parenting styles, neighborhood environment) that may contribute to the associations between family income and brain connectivity,” Tomasi noted. “Our study focused primarily on family income as a proxy for socioeconomic status, but other aspects of socioeconomic disadvantage (e.g., neighborhood poverty, access to healthcare) may also influence brain development and cognition.”
Moving forward, one of the long-term goals of this research line is to leverage longitudinal data from the ABCD study to trace the evolution of brain connectivity patterns during development. This long-term goal addresses some of the limitations of the current research by enabling an examination of the direction of effects over time.
“We intend to utilize the longitudinal aspect of the ABCD study to explore the influence of family income on brain connectivity patterns from childhood through to early adulthood,” Tomasi said.
The study, “Effects of family income on brain functional connectivity in US children: associations with cognition,” was authored by Dardo Tomasi and Nora D. Volkow.
