By: Marzieh Zare, Université de Montreal
Neuronal avalanches capture brain activities at multiple spatial and temporal scales. The scale-invariant nature of avalanches can be taken as an indication that the brain is in a critical state. Interestingly, the repeatable patterns associated with neuronal avalanches are thought to be associated with information processing. Despite the existence of a handful of studies, the changes in neural avalanches that occur with age are still poorly characterized. Here, we address this question by probing scale-invariant neural avalanches in large magnetoencephalography (MEG) set from the Cambridge Centre for Ageing and Neuroscience (Cam-CAN), with 604 individuals aged between 18 and 88. Our results show that suprathreshold events from resting-state MEG sensor array display power-law distributions in the avalanche profile. This finding suggests scale-invariant neuronal dynamics for the time scale that the branching parameter was close to 1. We also explored if the scaling relation is met. We observed a higher percentage of subjects meeting the scaling relation at the middle-age group. To the best of our knowledge, this is the first study to investigate the stability of avalanches for a large MEG cohort. Our results are discussed in the context of previous research and future research paths are considered.