Intézeti Szeminárium


Ódor Géza: Dynamical Criticality and Griffiths Phases in Models of Large Connectomes

2023 Október 27, 10:30 óra, 3/II-es terem


In this talk, I discuss critical dynamics of simple nonequilibrium models
on large connectomes, obtained by diffusion MRI, representing the white
matter of the human brain; as well as on the neuron level fruit-fly
connectome. First I overview graph theoretical and topological analysis of
these networks, pointing out that universality allows selecting a
representative human network, the KKI-18, which has been used for
dynamical simulations [1].
The critical and sub-critical behaviour of simple, two- or three-state
threshold models is discussed with special emphasis on rare-region effects
leading to robust Griffiths phases (GP) [2-3].
Numerical results of synchronization phenomena, studied by Kuramoto-type
models, are also shown, leading to a continuous analog of the GP, termed
as “frustrated synchronization” [4-5]. The models presented here exhibit
dynamical scaling behaviour, with exponents in agreement with brain
experimental data if local homeostasis is provided [6].
I provide a comparison of the results about criticality obtained for the
human and fruit-fly connecomes in the rest and task states [7-8].

[1] M. T. Gastner, G. \’Odor, {\it Sci. Rep..} {\bf 6}, 27249 (2016).
[2] G. \’Odor, {\it Phys. Rev. E} {\bf 94}, 062411 (2016).
[3] G. \’Odor, {\it Phys. Rev. E} {\bf 99}, 012113 (2019).
[4] G. \’Odor, J. Kelling {\it Sci. Rep.} {\bf 99}, 19621 (2019).
[5] G. \’Odor, J. Kelling, G. Deco, {\it Neurocomputing}, {\bf 426}, 696 (2021).
[6] G. \’Odor, M. T. Gastner, J. Kelling, G. Deco, {\it J. Phys. Compl.} {\bf 2}, 045002 (2021).
[7] G. \’Odor, J. Kelling, G. Deco, {\it Phys. Rev. Res.}, {\bf 2}, 023057 (2022).
[8] G. \’Odor, I. Papp, S. Deng and J. Kelling, {\it Front. Phys.} {\bf 11} 1150246 (2023).