Exposure to community violence as a mechanism linking neighborhood socioeconomic disadvantage and neural responses to reward

Abstract

A growing literature links socioeconomic disadvantage and adversity to brain function, including disruptions in reward processing. Less research has examined exposure to community violence (ECV) as a specific adversity related to differences in reward-related brain activation, despite the prevalence of community violence exposure for those living in disadvantaged contexts. The current study tested whether ECV was associated with reward-related ventral striatum (VS) activation after accounting for familial factors associated with differences in reward-related activation (e.g. parenting and family income). Moreover, we tested whether ECV is a mechanism linking socioeconomic disadvantage to reward-related activation in the VS. We utilized data from 444 adolescent twins sampled from birth records and residing in neighborhoods with above-average levels of poverty. ECV was associated with greater reward-related VS activation, and the association remained after accounting for family-level markers of disadvantage. We identified an indirect pathway in which socioeconomic disadvantage predicted greater reward-related activation via greater ECV, over and above family-level adversity. These findings highlight the unique impact of community violence exposure on reward processing and provide a mechanism through which socioeconomic disadvantage may shape brain function.

Keywords: brain; community violence; developmental neuroscience; neuroimaging; poverty; reward.

Fig. 1.

(A) Child-friendly reward task. The reward task displayed two facedown cards for up to 3000 ms. After the card flipped, one of three images appeared for 1000 ms: genie (win), pirate (loss) or palm tree (neutral). Feedback on the magnitude of the reward (large or small) was provided for 1000 ms (Peckins et al., 2022). (B) VS activation during total win > neutral (n = 444). Results shown from a one-sample t-test for VS activation during total win > neutral trials in SPM12. False positive rate is controlled across the whole brain using 3dttest+ 3dclustsim option for cluster level correction (P_unc < 0.001, α < 0.05). Coordinates provided using the Montreal Neurological Institute (MNI) online atlas. Left: k = 6, T = 3.49, MNI −12, 12, 0. Right: k = 55, T = 4.07, MNI 14, 10, −6.

Fig. 2.

ECV is associated with VS activation during wins. Associations between ECV and VS during total win > neutral trials while controlling for twin age, twin gender, primary caregiver education, annual household income, race, and harsh and inconsistent parenting. Left: k = 125, T = 4.62, MNI −18 14 –8; right: k = 20, T = 4.15, MNI 6 14 –4.

Fig. 3.

Neighborhood disadvantage is associated with reward-related reactivity in the left VS via ECV (n = 690). Indirect pathway from neighborhood disadvantage to reward-related reactivity in the left VS via ECV while controlling for age, gender, race, primary caregiver education, annual household income and harsh and inconsistent parenting.