Evidence of quasicritical dynamics across the life span: A MEG study*

Aging impacts the brain’s structural and functional organization over time and leads to various disorders, such as Alzheimer’s disease and cognitive impairment. The process also impacts sensory function, and a general slowing in various perceptual and cognitive functions. We analyzed the Cambridge Centre for Ageing and Neuroscience (Cam-CAN) resting-state magnetoencephalography (MEG) dataset --the largest neuroimaging cohort available to date— in light of a new theoretical framework known as Quasicriticality. This novel organizing principle for brain function, rooted on non-equilibrium statistical mechanics, relates information processing and scaling properties of brain activity to brain connectivity and has been successfully applied to non-human living systems before (Williams-Garcia et al 2014, Fosque et al 2021). Examination of human data with subjects' age ranging from 18 to 88 using this framework reveals interesting correlations with the age and gender of test subjects. Using MEG data and simulations of the cortical branching model, our results unveil a link between brain connectivity due to ageing, and increased vulnerability to distraction from irrelevant information.