2015/09/14 by Enzo Tagliazucchi, Tagliazucchi, Enzo, Dante R. Chialvo +13 · 2 citations
Neuroscience · Psychology · #EEG and Brain-Computer Interfaces #FOS: Biological sciences #Functional Brain Connectivity Studies #Neural dynamics and brain function #Neurons and Cognition (q-bio.NC) #Paranormal Experiences and Beliefs
paper · pdf · doi:10.48550/arxiv.1509.04304
openalex publication_date 2015/09/14 · openalex created_date 2022/10/03 · openalex updated_date 2026/07/28
Loss of cortical integration and changes in the dynamics of\nelectrophysiological brain signals characterize the transition from wakefulness\ntowards unconsciousness. The common mechanism underlying these observations\nremains unknown. In this study we arrive at a basic model, which explains these\nempirical observations based on the theory of phase transitions in complex\nsystems. We studied the link between spatial and temporal correlations of\nlarge-scale brain activity recorded with functional magnetic resonance imaging\nduring wakefulness, propofol-induced sedation and loss of consciousness, as\nwell as during the subsequent recovery. We observed that during unconsciousness\nactivity in frontal and thalamic regions exhibited a reduction of long-range\ntemporal correlations and a departure of functional connectivity from the\nunderlying anatomical constraints. These changes in dynamics and\nanatomy-function coupling were correlated across participants, suggesting that\ntemporal complexity and an efficient exploration of anatomical connectivity are\ninter-related phenomena. A model of a system exhibiting a phase transition\nreproduced our findings, as well as the diminished sensitivity of the cortex to\nexternal perturbations during unconsciousness. This theoretical framework\nunifies different empirical observations about brain activity during\nunconsciousness and predicts that the principles we identified are universal\nand independent of the causes behind loss of awareness.\n