Entropy production of Multivariate Ornstein-Uhlenbeck processes correlates with consciousness levels in the human brain

Summary

The brain's thermodynamic activity, a measure of its irreversible processes, directly correlates with consciousness levels. Researchers hypothesized that calculating this "entropy production" from fMRI data could quantify consciousness. Using a statistical model of brain activity, they found a clear, consistent decrease in this "entropy production" as individuals moved from wakefulness to deep sleep. This robust finding in q-bio.NC research provides strong evidence that the brain's physical dynamics reflect conscious states, advancing our understanding from a fundamental physics perspective.

Abstract

Consciousness is supported by complex patterns of brain activity which are indicative of irreversible non-equilibrium dynamics. While the framework of stochastic thermodynamics has facilitated the understanding of physical systems of this kind, its application to infer the level of consciousness from empirical data remains elusive. We faced this challenge by calculating entropy production in a multivariate Ornstein-Uhlenbeck process fitted to fMRI brain activity recordings. To test this approach, we focused on the transition from wakefulness to deep sleep, revealing a monotonous relationship between entropy production and the level of consciousness. Our results constitute robust signatures of consciousness while also advancing our understanding of the link between consciousness and complexity from the fundamental perspective of statistical physics.

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