Non-equilibrium systems can be identified by violations of the fluctuation-dissipation relation, as shown in [1, 2]. Recent studies in neural systems [3, 4] have linked such violations to asymmetric interactions, using both empirical brain data and whole-brain models. These systems often display dynamical scaling, even when far from criticality [5]. Criticality, commonly emerging at second-order phase transitions, enhances adaptability and functionality in complex systems.
We investigate the distance from equilibrium in the Shinomoto-Kuramoto model by measuring fluctuation-dissipation violations under varying edge weight anisotropies. This is done by solving phase oscillator dynamics on raw, homeostatic, and randomized inhibitory versions of a fully reconstructed fruit-fly connectome [6], near synchronization transition points. By analyzing auto-correlations and response functions to small perturbations, we compute fluctuation-dissipation ratios across conditions. These ratios deviate from the constant values expected at equilibrium, with deviations tracking the degree of anisotropy.
[1] L. F. Cugliandolo, D. S. Dean, and J. Kurchan, Phys. Rev. Lett. 79, 2168 (1997), URL https://link.aps.org/doi/10.1103/PhysRevLett.79.2168.
[2] U. M. B. Marconi, A. Puglisi, L. Rondoni, and A. Vulpiani, Physics Reports 461, 111 (2008), ISSN 0370-1573.
[3] G. Deco, C. W. Lynn, Y. Sanz Perl, and M. L. Kringel bach, Phys. Rev. E 108, 064410 (2023), URL https://link.aps.org/doi/10.1103/PhysRevE.108.064410.
[4] J. M. Monti, Y. S. Perl, E. Tagliazucchi, M. Kringelbach, and G. Deco, bioRxiv (2024), URL https://doi.org/10.1101/2024.04.04.588056.
[5] M. Henkel and M. Pleimling, Non-Equilibrium Phase Transitions: Volume 2: Ageing and Dynamical Scaling Far from Equilibrium, Theoretical and Mathematical Physics (Springer Netherlands, 2011), ISBN 9789048128693, URL https://books.google.hu/books?id=AiofeEteLVcC.
[6] Sven Dorkenwald, Arie Matsliah, Amy R Sterling, et al. Neuronal wiring diagram of an adult brain. bioRxiv, 2023.