University of Wisconsin-Madison News
Poverty may have direct implications for important, early steps in the development of the brain, saddling children of low-income families with slower rates of growth in two key brain structures, according to researchers from the University of Wisconsin-Madison.
By age 4, children in families living with incomes under 200 percent of the federal poverty line have less gray matter — brain tissue critical for processing of information and execution of actions — than kids growing up in families with higher incomes.
“This is an important link between poverty and biology. We’re watching how poverty gets under the skin,” says Barbara Wolfe, professor of economics, population health sciences and public affairs and one of the authors of the study, published today in the journal PLOS ONE.
The differences among children of the poor became apparent through analysis of hundreds of brain scans from children beginning soon after birth and repeated every few months until 4 years of age. Children in poor families lagged behind in the development of the parietal and frontal regions of the brain — deficits that help explain behavioral, learning and attention problems more common among disadvantaged children.
The parietal lobe works as the network hub of the brain, connecting disparate parts to make use of stored or incoming information. The frontal lobe, according to UW-Madison psychology professor Seth Pollak, is one of the last parts of the brain to develop.
“It’s the executive. It’s the part of the brain we use to control our attention and regulate our behavior,” Pollak says. “Those are difficulties children have when transitioning to kindergarten, when educational disparities begin: Are you able to pay attention? Can you avoid a tantrum and stay in your seat? Can you make yourself work on a project?”
The maturation gap of children in poor families is more startling for the lack of difference at birth among the children studied.
“One of the things that is important here is that the infants’ brains look very similar at birth,” says Pollak, whose work is funded by the National Institutes of Health. “You start seeing the separation in brain growth between the children living in poverty and the more affluent children increase over time, which really implicates the postnatal environment.”