Nov. 3 (UPI) -- Children living in poor neighborhoods don't perform as well on cognitive function tests and have lower "brain volume" compared to those who reside in higher-income areas, an analysis published Tuesday by JAMA Network Open found.
Increased household income was associated with improved vocabulary, reading skills and memory, among other skills, the researchers said.
These differences were likely attributable to the fact that children in these settings had more developed prefrontal and hippocampal brain regions, they said.
The prefrontal cortex has been linked with behavior, personality and decision making, among other functions, while the hippocampus is believed to be involved in learning and memory skills, according to the researchers.
"This study found evidence for independent associations of household and neighborhood environment with brain and cognitive outcomes in preadolescent children," the researchers, from Washington University in St. Louis, wrote.
"The study also provided evidence consistent with a pathway wherein variation in prefrontal and hippocampal volume partially explains the association between neighborhood poverty and scores on cognitive tests," they said.
Earlier research has linked socioeconomic status with brain development and academic performance, according to the researchers.
However, much of this research has focused on the impact of the socioeconomic status of individual households and families on child development, rather than the effects of living in poorer neighborhoods, they said.
"Typically, studies of socioeconomic status and the brain focus on household characteristics," researchers Bruce Ramphal told UPI. "This study shows ... that neighborhood- and household-level socioeconomic factors are uniquely related to the structure of brain regions."
Ramphal was not part of the JAMA study published Tuesday but has devoted much of his research work to related subjects.
"These findings ... [suggest] that equitable child development may be best supported by intervention both at the household and neighborhood levels," said Ramphal, a research assistant at Columbia University and the New York State Psychiatric Institute.
For this study, the Washington University researchers analyzed the cognitive performance and brain development of 11,875 9- and 10-year-old children.
Cognitive performance was assessed using an approach created by the National Institutes of Health to measure verbal ability, attention, executive functioning, working memory, brain processing speed, episodic memory and reading ability, the researchers said.
Brain development was measured using 3T magnetic resonance imaging, a more powerful version of MRI designed to provide highly detailed images, they said.
Household socioeconomic status was measured using both household income and the Parent-Reported Financial Adversity Questionnaire, which is used to determine "whether families generally have enough money to pay for basic life expenses, such as food and healthcare," according to the researchers.
Using the addresses of study participants, the researchers identified those living in neighborhoods with higher poverty levels.
Children living in lower-income households and in poorer neighborhoods generally performed less well on cognitive function tests than those living in wealthier areas, the researchers said.
MRI scans of the children in the study also revealed less development in the prefontal cortex and hippocampus in the brains of those living in poorer households and neighborhoods, they said.
"The impact of neighborhood disadvantage on children's development likely come about through several [factors], including underfunded schools, disproportionate exposure to environmental toxins, low access to safe opportunities for recreation, exposure to violence and unavailability of nutritious food," Ramphal told UPI.
"Importantly, many of these characteristics of disadvantaged neighborhoods ... arise due to structural racism, environmental injustice, broken-windows policing, tax policy, educational policy and housing policy." he said.