Brain Entropy During Aging Through a Free Energy Principle Approach
Frontiers in Human Neuroscience March 22, 2021 Filippo Cieri, Xiaowei Zhuang, Jessica Caldwell et al. 62 citations
Spontaneous neural activity becomes less complex and less entropic during states of reduced consciousness, such as those induced by psychedelics, a pattern termed the 'entropic brain hypothesis.' This review extends that hypothesis to physiological and pathological aging, where brain entropy is also reduced. The authors treat the mind-brain as a complex nonlinear dynamic adaptive system governed by the free energy principle, aiming to maintain a balance between order and chaos in neural dynamics and functional connectivity. They review studies showing increased entropy in acute psychedelic states and chronic psychotic states like schizophrenia, then contrast these with aging, where entropy decreases. They propose a general trend of brain entropy across primary states and cognitive aging.