B - 86 Association of Fronto-Parietal Network White Matter Tract Connectivity with Executive Functioning and Working Memory in a Diverse Sample.

Abstract

We evaluated whether Fronto-Parietal Network (FPN) connectivity is associated with cognitive performance within an ethnically diverse sample. Linear regression modeling of 50 FPN white matter tract connectivity measures (volume, anisotropy, diffusivity) predicted executive functioning (EF) and working memory (WM) data including Trails Making Test parts A and B (TMTA/TMTB), Digit Span (DSF/DSB/DST), and Digit Symbol Substitution (DSS) in an ethnically diverse sample (n = 2715, African American = 515, Non-Hispanic White = 1096, Mexican American = 1104). Maximum Likelihood Factoring (MLF) controlled for collinearity within connectivity measures. The best predictors of cognitive performance were thickness of the right caudal anterior cingulate (CAC) (p < 0.001 with DSF, DST, DSS) and mean diffusivity of the right superior longitudinal fasciculus (rSLF) (p < 0.001 with DSF, DST, TB). Within cognitive tests, DSF had the greatest number of significant relationships with connectivity measures (mean diffusivity of the superior longitudinal fasciculus, thickness of the right caudal anterior cingulate, and thickness of the right rostral anterior cingulate, each at p < 0.001). Three factors emerged from MLF which each had multiple significant relationships with cognitive task variables. However, variance accounted for was minimal (R2< 0.01). Relationships between FPN white matter tract connectivity with EF and WM scores are replicable in ethnically heterogeneous samples. Both the CAC and rSLF have previously been shown to be implicated in frontoparietal working memory functionality, however the lateralization of the functional relationship shown above appears to be unique to this sample. Further ethnically heterogenous neuroimaging studies are necessary to determine the uniqueness of these findings.