Living in a high-crime neighborhood is linked to poor health outcomes for young people, including sleep loss, asthma and metabolic syndrome. Yet some youth living in violent neighborhoods seem to avoid these negative effects.
In a new study, researchers at Northwestern University in Illinois wanted to know why some teens are affected by second-hand or indirect experience of neighborhood violence while others are not.
“Little is known about the brain networks that are involved in shaping these different outcomes, a problem we pursue here,” said Gregory E. Miller, lead author of the study and professor of psychology in the Weinberg College of Arts and Sciences at Northwestern.
“Like previous studies, we find that youth living in neighborhoods with high levels of violence have worse cardiometabolic health than peers from safer communities,” said Miller, also a faculty fellow with the University’s Institute for Policy Research.
“Extending this knowledge, we show this connection is absent for youth who display higher connectivity within the brain’s frontoparietal central executive network (CEN), which facilitates efforts of self-control as well as reinterpretation of threatening events and suppression of unwanted emotional imagery.”
Based on their knowledge of the brain’s intrinsic functional architecture, the researchers predicted that individual differences in resting-state connectivity would help explain variability in the strength of the link between neighborhood violence and cardiometabolic health.
The research team evaluated 218 eighth-graders from the Chicago area. They looked for factors related to metabolic health, including obesity and insulin resistance. Assessing neighborhood factors, including murder rates, the researchers also conducted functional MRI (fMRI) scans of the teens’ brains.
Consistent with predictions, resting-state connectivity within the central executive network emerged as a moderator of adaptation. The findings show that a higher neighborhood murder rate was linked to greater cardiometabolic risk, but this relationship was apparent only among teens who displayed lower CEN resting-state connectivity.
No such correlation was apparent, however, in teens that displayed high-resting functional connectivity in the same brain network. According to the researchers, the findings suggest a role for the central executive network in adaptability and resilience to negative events.
The study does not show a causal link between neighborhood violence and health, and the authors conclude that another study is needed to track neighborhood conditions, brain development and cardiometabolic risk across childhood to establish causality.
“For basic scientists, these findings provide clues about the neural circuitries that facilitate or undermine adaptation,” Miller said.
Further research could lead to possible interventions, which these early findings show could be “network training” programs to help regulate the functional connectivity of the brain’s CEN network. These network training programs could potentially enhance “self-control, threat reappraisal and thought suppression” to lower at-risk teens’ engagement in drug use, overeating and other reactions to such stress.
The findings are published in the scientific journal Proceedings of the National Academy of Sciences.
Source: Northwestern University