Waldstein, Shari RShaked, Danielle2021-09-012021-09-012019-01-0112084http://hdl.handle.net/11603/22921Lower socioeconomic status (SES) is related to poorer executive function, but the neural mechanisms of this association remain unclear. As optimal communication between brain regions is essential to our cognitive abilities, white matter integrity may be key to understanding cognitive disparities across socioeconomic groups. This study assessed the mediating role of white matter integrity on the relation between SES and executive function in adults. Participants were 201 African American and Whites from the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) SCAN study. Participants underwent 3.0-T cranial magnetic resonance imaging and diffusion tensor imaging was used to estimate regional fractional anisotropy. Adjusting for age, mediation analyses examined if integrity of the anterior limb of the internal capsule, external capsule, superior longitudinal fasciculus, and cingulum independently mediated SES-executive function relations. Low SES was related to worse performance on all cognitive tests and poorer integrity of all white matter tracts. Lower Trails B performance was related to poorer integrity of the anterior limb of the internal capsule, external capsule, and superior longitudinal fasciculus, and lower Stroop performance was associated with poorer integrity of the anterior limb of the internal capsule and external capsule. The anterior limb of the internal capsule significantly mediated the SES-Trails B relation, and the external capsule significantly mediated the SES-Trails B and SES-Stroop relations. Exploratory analyses found that race rendered the external capsule mediations non-significant, and flipped models with race as the independent variable yielded similar results as the base models. Poorer integrity of the anterior limb of the internal capsule and external capsule may help explain SES disparities in executive function. Results related to the external capsule may be common across SES and race due to shared risk pathways pertaining to health disparities. Findings demonstrating cognitive and neuroanatomical disadvantage among low SES individuals highlight the need for promoting optimal brain health, in part via further elucidation of the biopsychosocial mediators of the SES-cognition association as to better target intervention and prevention efforts. Further research is therefore needed to elucidate the multilevel pathways that contribute to inequities in cognitive function among marginalized groups.application:pdfexecutive functionhealth disparitiessocioeconomic statuswhite matter integrityText