Lucilla de Arcangelis — Vanvitelli University #
Fluctuation-Dissipation Relations for Brain Activity #
The understanding of the fundamental relation between electrophysiological activity and brain organization with respect to performing even simple tasks is a long-standing fascinating question. The ability of the brain to self-organize information processing in an efficient way is a crucial ingredient in biologically plausible models. Recent experiments have shown that the spontaneous brain activity is characterized by avalanches showing absence of characteristic size, result successfully interpreted in the context of criticality. The fundamental open question of the relation between spontaneous and evoked activity is addressed by means of the stochastic Wilson Cowan model. An approach inspired in non-equilibrium statistical physics allows to derive fluctuation-dissipation relations, suggesting that measurements of the spontaneous fluctuations in the global brain activity alone could provide a prediction for the system response to a stimulus. Theoretical predictions are in good agreement with MEG data for healthy patients performing visual tasks. The analysis is performed in a wide range of parameters, setting the system at and off criticality.