Metastable Oscillatory Modes as a Signature of Entropy Management in the Brain

Area of Science:

• Computational Neuroscience
• Theoretical Physics
• Systems Biology

Background:

• The Free Energy Principle (FEP) posits that biological systems manage entropy to maintain their structure and function.
• Metastable synchronization describes systems that fluctuate between ordered and disordered states, potentially enabling entropy changes.
• Collective oscillations observed in the brain are theorized to arise from such synchronization, but a direct link to entropy fluctuations has been missing.

Purpose of the Study:

• To investigate the direct relationship between the emergence of collective oscillations and entropy fluctuations in dynamical systems.
• To provide empirical evidence linking Metastable Oscillatory Modes (MOMs) to entropy reduction within the FEP framework.
• To bridge the gap between physics-based oscillator models and neurobiological theories of brain function.

Main Methods:

• Analysis of coupled oscillator systems exhibiting spontaneous collective oscillations.
• Application of Shannon entropy to quantify temporal entropy changes within the system.
• Utilizing sliding time windows to analyze the distribution of eigenvalues of phase covariance.
• Identifying and characterizing Metastable Oscillatory Modes (MOMs) in the system dynamics.

Main Results:

• The emergence of Metastable Oscillatory Modes (MOMs) was directly associated with a temporary decrease in system entropy.
• Shannon entropy analysis revealed significant entropy fluctuations correlated with the formation of MOMs.
• The findings demonstrate that collective oscillations impact the system's entropy levels.

Conclusions:

• Metastable Oscillatory Modes (MOMs) are a mechanism by which systems can achieve temporary entropy reduction.
• Brain rhythms, as observed experimentally, may serve as a signature of the brain's entropy management processes, as predicted by the FEP.
• This work supports the hypothesis that dynamic transitions in neural activity are crucial for maintaining homeostasis within the FEP framework.