Biopsychosocial and demographic predictors of functional brain network specialization and segregation across the adult lifespan

The properties of functional brain networks are an important determinant of cognitive function in aging and dementia. Despite this, few studies have comprehensively examined demographic and biopsychosocial predictors of functional brain networks, and none have attempted to do so across the adult lifespan while accounting for collinearity among these predictors. The current study used data from 525 individuals between the ages of 35 and 100 years from the Human Connectome Project 2.0 Lifespan Release, which includes task-based functional neuroimaging, physical and emotional health, and demographic information. Two functional brain network properties previously identified as moderators of cognitive functioning across the lifespan, entropy (regional specialization) and modularity (network segregation)-were used as outcome metrics in elastic net regression models that identified and ranked predictors of these metrics as well as their age-interaction terms. Our models ranked and established generalizability of key biopsychosocial health determinants of brain network properties across the lifespan using methodology allowing for high collinearity among predictors, differing notably from correlational findings. Derived models ranked biological sex, sleep duration, instrumental support, visual acuity, education, social isolation, diastolic blood pressure, and vigorous physical activity as the strongest generalizable factors. Biological sex exhibited a significant moderation effect such that males demonstrated greater age-related differences in entropy and modularity compared to females. Given that these brain network properties have previously been linked to cognitive functioning, understanding the complex interplay between these biopsychosocial determinants is crucial for informing intervention targets with the greatest potential for maintaining or improving cognitive functioning in aging.