(P09-024-25) Functional Connectivity Underlying Cognitive Control and the Influence of Weight Status

Objectives: Obesity affects a disproportionate number of US adults, impacting both physical and brain health. Functional connectivity (FC) coordinates brain activity during cognitive tasks, yet its link to weight status is underexplored. We examined FC within and between seven core brain networks—Default Mode (DMN), Ventral Attention (VAN), Somatomotor (SMN), Dorsal Attention (DAN), Frontoparietal (FPN), Visual (VIN), and Limbic (LIN)—during the modified Eriksen flanker task. We hypothesized that body mass index (BMI) modulates task-related FC, affecting cognitive control.

Methods: Secondary analyses of source-localized EEG data from 256 adults (mean age: 53.5 ± 5.04 years; mean BMI: 30.21 ± 9.29 kg/m²) were conducted. A hidden Markov model extracted spatiotemporal dynamics, quantifying within- and between-network correlations. Extreme Gradient Boosting with recursive feature elimination identified connectivity metrics predicting behavioral performance (reaction time, RT). Mediation analyses evaluated FC’s role in the BMI-RT relationship, controlling for age and sex.

Results: Classifiers showed distinct FC patterns for congruent (AUC = 0.98) and incongruent (AUC = 0.86) trials. Predictive between-network connections for congruent trials included DAN–VIN, DMN–SMN, FPN–LIN, and VIN–SMN. In incongruent trials, within-network (VAN, DMN) and between-network (VAN–DMN, SMN–DMN, LIN–FPN, VIN–SMN, VIN–DAN, VIN–LIN) connectivity influenced RT. BMI was linked to slower RTs in incongruent trials (β = 0.13, p < 0.001). Mediation analyses showed within-DMN connectivity partially mediated the BMI-RT link (β = 1.72, p = 0.008, 2.72% of total effect). Significant partial mediation was observed for VAN–DMN (β = 1.61, p = 0.001), SMN–DMN (β = 4.20, p < 0.001), VIN–DAN (β = 3.92, p < 0.001), and VIN–SMN (β = 1.95, p = 0.006). No mediation was observed for congruent trials.

Conclusions: FC adapts dynamically to task demands, with distinct networks engaged during flanker task conditions. Weight status exerts a small but significant modulatory effect, impacting cognitive control under increased demands. Targeted interventions may mitigate obesity-related FC impairments.

Funding Sources: University of Illinois Personalized Nutrition Initiative, University of Illinois Department of Health and Kinesiology, and the Hass Avocado Board