Summary: Individual differences in resting state connectivity may help explain why some people are more resilient to the effects of neighborhood violence than others.
Source: Northwestern University.
Neighborhood violence has been associated with adverse health effects on youth, including sleep loss, asthma and metabolic syndrome. Yet some youth living in high-crime neighborhoods manage to avoid these effects.
A new Northwestern University study aims to answer a resilience puzzle: Why does a second-hand or indirect experience of neighborhood violence affect some youth, but not others?
“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.”
Drawing on 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 association between neighborhood violence and cardiometabolic health.
The researchers tested 218 eighth-graders from the Chicago area 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 brains of the study participants.
Consistent with predictions, resting-state connectivity within the central executive network emerged as a moderator of adaptation. Across six distinct outcomes, a higher neighborhood murder rate was associated with greater cardiometabolic risk, but this relationship was apparent only among youth who displayed lower CEN resting-state connectivity.
No such correlation was apparent, however, in youth that displayed high-resting functional connectivity in the same brain network. According to the researchers, the results suggest a role for the central executive network in adaptability and resilience to adverse events.
The study, due to its design (cross-sectional and observational), cannot claim a causal link between neighborhood violence and health, and the authors conclude that a longitudinal, multi-wave 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 study could lead to possible interventions, which their preliminary evidence suggests could be “network training” programs to modulate the functional connectivity of the brain’s CEN network. These network training programs can enhance “self-control, threat reappraisal and thought suppression” to lower at-risk teens’ engagement in drug use, overeating and other reactions to such stress.
Additional co-authors include Edith Chen, Northwestern University; Casey C. Armstrong, Northwestern University; Ann L. Carroll, Northwestern University; Sekine Ozturk, Northwestern University; Kelsey J. Rydland, Northwestern University; Gene H. Brody, University of Georgia; Todd B. Parrish, Northwestern Feinberg School of Medicine; and Robin Nusslock of Northwestern University.
Source: Hilary Hurd Anyaso – Northwestern University
Publisher: Organized by NeuroscienceNews.com.
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Original Research: Abstract for “Functional connectivity in central executive network protects youth against cardiometabolic risks linked with neighborhood violencey” by Gregory E. Miller, Edith Chen, Casey C. Armstrong, Ann L. Carroll, Sekine Ozturk, Kelsey J. Rydland, Gene H. Brody, Todd B. Parrish, and Robin Nusslock in PNAS. Published November 5 2018.
Functional connectivity in central executive network protects youth against cardiometabolic risks linked with neighborhood violence
Although violent crime has declined in recent decades, it remains a recurring feature of daily life in some neighborhoods. Mounting evidence indicates that such violence has a long reach, which goes beyond family and friends of the victim and undermines the health of people in the surrounding community. However, like all forms of adversity, community violence elicits a heterogeneous response: Some remain healthy, but others deteriorate. Despite much scientific attention, the neural circuitries that contribute to differential adaptation remain poorly understood. Drawing on knowledge of the brain’s intrinsic functional architecture, we predicted that individual differences in resting-state connectivity would explain variability in the strength of the association between neighborhood violence and cardiometabolic health. We enrolled 218 urban youth (age 12–14 years, 66% female; 65% black or Latino) and used geocoding to characterize their exposure to neighborhood murder over the past five years. Multiple aspects of cardiometabolic health were assessed, including obesity, insulin resistance, and metabolic syndrome. Functional MRI was used to quantify the connectivity of major intrinsic networks. Consistent with predictions, resting-state connectivity within the central executive network (CEN) emerged as a moderator of adaptation. Across six distinct outcomes, a higher neighborhood murder rate was associated with greater cardiometabolic risk, but this relationship was apparent only among youth who displayed lower CEN resting-state connectivity. By contrast, there was little evidence of moderation by the anterior salience and default mode networks. These findings advance basic and applied knowledge about adaptation by highlighting intrinsic CEN connectivity as a potential neurobiological contributor to resilience.