Donald, K. | bioRxiv Science

bioRxiv2026

Epigenetic and brain age across development: Performance and associations in the MIND consortium

Understanding how biological age measures perform across development lays the groundwork for investigations into lifespan trajectories of healthy aging. We provide the most comprehensive assessment of epigenetic and brain age models across development (birth to 24 years; [≤]20,917 observations across 15 cohorts), evaluating how these models associate with chronological age and with each other, and how these associations change across development. Chronological age-prediction accuracy of epigenetic and brain age models was modest and varied substantially. Accuracy improved with age and stabilized by middle childhood. Few brain and fewer epigenetic clocks performed stably and well across all developmental stages. Performance was better when age range and tissue corresponded between training and testing data. Associations between epigenetic-brain age residuals were small, and changed little across development, tissues or clock generation. Given this developmentally dynamic system of epigenetic-brain age performances and associations, we give key recommendations to improve developmental research in this field.

neuroscience↗

bioRxiv2024

Spatiotemporal dynamics of EEG microstate networks over the first two years of life: A multi-cohort longitudinal study

The first two years of life are marked by rapid development of large-scale brain networks that support emerging cognition and behavior. Magnetic-resonance approaches have revealed much about largescale networks in sleep, but very little is known about functional network dynamics in awake, behaving infants during this period of substantial development. Microstates are brief instances of distinct spatial topographies of largescale neural activity measured with electroencephalography (EEG) that offer a novel approach to studying whole-brain network dynamics at sub-second scale in awake infants by capturing their temporally coherent brain activity. While emerging literature is leveraging microstate dynamics in adults to understand mature largescale network function, developmental trajectories during networks rapid construction in infancy remain uncharacterized. In this study, we leveraged longitudinal resting-state EEG data from 854 infants across two geoculturally diverse cohorts to explore largescale network development through EEG microstates over the first two years of life. We provide evidence for conserved emergence of various network configurations (microstate classes A-G) through infancy across cohorts using data-driven clustering analyses. We also demonstrate significant longitudinal changes in microstate dynamics during this period, characterized by more numerous and more rapid transitions between largescale configurations, especially over early infancy. While patterns of sensory microstate development were largely consistent between cohorts, higher-order cognitive microstates showed context-specific developmental trends. Together these results provide novel insights into how large-scale brain networks functionally develop and organize across the first two years of life.

neuroscience↗