Dynamical models reveal distance to criticality in ageing brain dynamics.

Abstract

Understanding how the brain changes with age remains a central question in neuroscience. Here, we combine magnetoencephalography (MEG) recordings from young and older adults with a whole-brain dynamical model to explore how brain dynamics evolve across the lifespan. Using a network of coupled Stuart-Landau oscillators constrained by empirical structural connectivity, we systematically vary three model parameters to identify the settings that best reproduce alpha-band features observed in MEG data. Our findings reveal age-related shifts in these model parameters: older individuals exhibit stronger global coupling and more positive values of the bifurcation parameter, consistent with a transition to a supercritical regime. These results align with prior work suggesting altered excitation-inhibition balance in ageing and indicate a systematic reconfiguration of whole-brain dynamics. By situating empirical observations within a dynamical systems framework, this study provides a principled approach for quantifying the brains distance to criticality and lays the groundwork for future clinical applications.