Poverty, Pediatrics, and Neuroscience
Class of ’98 | Kimberly Noble C’98 Gr’05 M’07 stared at the computer screen in amazement. The results confirmed what she had predicted: that socioeconomic status is directly correlated with the way children’s brains develop. It was one of those moments researchers dream about.
“We’ve known for decades that socioeconomic differences, meaning differences in families’ educational attainment and income, are associated with differences in child development,” explains Noble, assistant professor of pediatrics in Columbia’s GH Sergievsky Center and principal investigator of its Neurocognition, Early Experience, and Development (NEED) Lab. Now she and her co-authors were looking for a more precise description of exactly how poverty affects children. “IQ and high-school graduation rates are really important,” she says, “but those broad-based measures are not specific in terms of brain development. For example, there’s no high-school-graduation part of the brain.”
They decided to look at the parts of the brain they could measure, including the hippocampus and the amygdala. Using data collected by Elizabeth Sowell of the University of Southern California, Noble and her collaborators analyzed the brain scans of 60 children along with data about their parents’ incomes and education levels.
“We know from cognitive neuroscience that different areas of the brain are responsible for different kinds of cognitive skills,” says Noble. “Since we and others had found differences in skills like language, memory, self-regulation, and emotional development, we hypothesized that we’d see differences in the brain areas that supported those very skills.”
That’s precisely what they found. The hippocampus largely supports memory, and “children whose families have higher incomes had larger hippocampi than children from families with lower incomes,” she explains.
The children whose parents had lower levels of education, on the other hand, had larger amygdalas, the area of the brain that processes emotion.
“Other authors have shown that children exposed to higher degrees of early life stress have larger amygdalas,” notes Noble. She cautions that they didn’t measure stress in the home, so the next step is to study what it is about lower parental education that leads to children with larger amygdalas.
The study, published last year in Developmental Science, is one of many in which Noble has used neuroscience to examine the effect of poverty on the brain. In another 2012 study, Noble departed a bit from the poverty angle, this time investigating whether extra time in utero has a lasting effect on brain development.
“We were fortunate to have access to a large data set of 125,000 births in New York City, births that were linked with data from New York City’s Department of Education,” she explains. “We could actually look at those kids’ performance in language arts and math” eight and nine years later, in the third grade.
Noble and her team found that, even with full-term births, “there is a graded effect of gestational age. Kids born at 39, 40, or 41 weeks perform significantly better on reading or math tests than kids born at 37 or 38 weeks,” even though any birth after 37 weeks is considered full term. “We suggested that parents or clinicians who are considering early elective birth should exercise caution.”
That study, published in Pediatrics, caught the attention of the mainstream media. NBC, ABC, NPR, AP, Time, and The Wall Street Journal all ran stories on the results, and Noble suddenly found herself on national news programs.
Noble counts herself as fortunate to have had good opportunities, one of which is to have learned under Martha Farah, the Walter H. Annenberg Professor in the Natural Sciences and the director of Penn’s Center for Neuroscience and Society. Farah, for her part, attributes Noble’s success to a combination of brilliance and training.
“Kim’s training in neuroscience and pediatrics puts her in a unique position to seek new explanations for these linkages” between poverty and negative social outcomes, explains Farah. “How people perform in school and on the job, how they stay on the right side of the law and find happiness and peace of mind—all of these processes depend on brain function. Kim is using her understanding of brain development and her broader perspective on the physical and mental development of children to test hypotheses concerning children’s vulnerabilities to different aspects of low socioeconomic status.”
While education and public-health officials have always been enthusiastic about bringing neuroscience to bear on their fields, Noble’s colleagues were initially somewhat more skeptical, she says. “The cognitive neuroscientists were really very hesitant at first to bring something so politically charged as poverty into the field of neuroscience.” Now, they see the potential of her work.
Noble and her NEED Lab colleagues are currently replicating the brain-structure study in a much larger sample, and she’s focused on subsequent questions about socioeconomic status and brain development.
“How early can you detect differences in language development?” she asks. “In one study that is ongoing now, we are following a subset of a very large cohort in infancy, looking at measures of language and memory development at nine, 15, and 21 months. We’re trying to understand just how early we can pick up these socioeconomic differences in child development. That’s not just an academic question, because it will indicate when screening and intervention are most important.”
She’s enthusiastic about the possibilities of focusing on particular neurocognitive systems.
“It’s really hard to design an intervention that’s going to affect IQ,” she explains. “One could imagine much more directly designing an intervention focusing on memory or language or planning skills.” While current interventions lack that precision, using neuroscience to determine the precise effects of poverty may allow researchers to target very specific skills.
“Neuroscience gives us a new set of tools to understand and perhaps counteract the effects of poverty,” says Farah. “There are very few people out there working on these problems and, young as she still is, Kim is a leader in every respect.”
—Emily Rosenbaum C’95 GEd’96