Temporal irreversibility of neural dynamics as a signature of consciousness
bioRxiv Preprint Server September 2, 2021 Laura De la Fuente, Federico Zamberlan, Hernán Bocaccio et al. preprint
The laws of physics are time-symmetric, but dissipative systems like the brain show a preferred temporal direction. Using a deep learning framework inspired by stochastic thermodynamics, researchers analyzed electrocorticography signals from non-human primates. Brain activity during conscious wakefulness could be distinguished from its time-reversed version with high accuracy, using both frequency and phase information. This ability was reduced during deep sleep and ketamine-induced anesthesia. Transitions between slow (≈20 Hz) and fast frequencies (> 40 Hz) mainly contributed to the temporal asymmetry seen during wakefulness. The findings suggest that a preferred temporal direction in neural activity correlates with conscious awareness, linking brain processes to the subjective experience of time's passage.