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

Consciousness depends on complex, irreversible brain dynamics that produce entropy. By fitting a statistical model to fMRI data and calculating entropy production, researchers found a monotonic relationship: entropy production decreases as people move from wakefulness to deep sleep. This suggests that entropy production is a robust signature of consciousness, linking conscious states to the thermodynamic activity of the brain.

Study at a glance

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.