Normative Brain Entropy Across the Lifespan.

Brain entropy (BEN), a measure of the complexity and irregularity of neural has emerged as a promising marker for cognitive and clinical traits. However, normative lifespan trajectories of BEN remain underexplored. In this study, we investigated age-related changes in BEN across the human lifespan using Sample Entropy (SampEn). BEN was estimated from resting-state fMRI data collected from multiple Human Connectome Project cohorts (N = 2,415, ages 8-89 years), and normative growth curves were modeled using the GAMLSS framework. Results revealed a nonlinear increase in average BEN from childhood to older adulthood, with females exhibiting significantly higher BEN than males. Regional and network-level analyses confirmed similar age-related patterns.