Children living in poverty-stricken neighborhoods tend to have lower cognitive performance and decreased volume in several brain regions, suggesting neighborhood context should be considered in studies of early life poverty and adversity, according to study results published in JAMA Network Open.
In this cross-sectional study, researchers from Washington University sought to evaluate the association between poverty and poor cognitive outcomes. To do this, they analyzed a baseline sample of patients from the ongoing 21-site Adolescent Brain Cognitive Development (ABCD) Study. The cohort included 11,875 children from the United States of either 9 or 10 years of age from mostly urban and suburban areas.
The study researchers included neighborhood poverty and household socioeconomic status as possible factors associated with National Institutes of Health Toolbox Cognitive Battery subtests and hippocampal and prefrontal (dorsolateral prefrontal cortex [DLPFC], dorsomedial PFC [DMPFC], superior frontal gyrus [SFG]) volumes based on brain scans. The final neighborhood poverty aggregate comprised 9 out of 17 values on the Area Deprivation Index.
Greater neighborhood poverty was significantly associated with lower score for all cognitive domains (total composite of neighborhood poverty, β=-0.18; 95% CI, -0.21 to -0.15; P <.001). In addition, greater neighborhood poverty was associated with reduced brain volume in the DLPFC (β=-0.09; 95% CI, -0.12 to -0.07; P <.001), DMPFC (β=-0.07; 95% CI, -0.09 to -0.05; P <.001), SFG (β=-0.05; 95% CI, -0.08 to -0.03; P <.001), and right hippocampus (β=-0.04; 95% CI, -0.06 to -0.01; P =.01).
Additionally, the study researchers found an association between greater household income and higher scores for all cognitive domains (total composite for household income, β=0.30; 95% CI, 0.28-0.33; P <.001). There was also a significant association between greater household income with larger volume in the right (β=0.04; 95% CI, 0.02-0.07; P <.001) and left hippocampus (β=0.06; 95% CI, 0.04-0.08; P <.001), right (β=0.08; 95% CI, 0.06-0.1; P <.001) and left SFG (β=0.07; 95% CI, 0.05-0.09; P <.001), right (β=0.08; 95% CI, 0.06-0.1; P <.001) and left DLPFC (β=0.07; 95% CI, 0.06-0.09; P <.001), and right (β=0.07; 95% CI, 0.05-0.09; P <.001) and left DMPFC (β=0.07; 95% CI, 0.05-0.08; P <.001).
Prefrontal regions were associated with neighborhood poverty relations to language, particularly in terms picture vocabulary (estimate [SE], -0.03 [0.01]; P <.001) and oral reading (estimate [SE], -0.02 [0.01]; P <.001), in addition to episodic memory (estimate [SE], -0.01 [0.004]; P =0.008). Hippocampal regions were also associated with neighborhood poverty associations with picture vocabulary (estimate [SE], -0.01 [0.004]; P <.001) and episodic memory (estimate [SE], -0.01 [0.004]; P <.01).
Limitations of the study were its cross-sectional design and inclusion of only neighborhood variables focused on socioeconomic status rather than other indicators of neighborhood poverty, such as litter, access to green spaces, and the number of grocery stores.
Based on their findings, study researchers suggested that future research should include neighborhood variables “in models of how early lived environments are associated with brain maturation and cognitive outcomes, which may inform the types of interventions offered to children from disadvantaged backgrounds.”
Taylor RL, Cooper SR, Jackson JJ, Barch DM. Assessment of neighborhood poverty, cognitive function, and prefrontal and hippocampal volumes in children. JAMA Netw Open. Published online November 3, 2020. doi:10.1001/jamanetworkopen.2020.23774