AI and the World's Hard Problems · Life sciences · arXiv · 2026-10-22
Distinct weak antisymmetric interactions shape human brain functions as probability fluxes
Recent studies have challenged the equilibrium assumption behind inferring interaction networks among brain regions from whole-brain imaging, raising the question of how the brain encodes function in biased state transitions. The authors show that probability fluxes, which quantify the irreversibility of state transitions, exhibit unique task-dependent patterns in spontaneous and task-induced whole-cortex activity, and that fitting an Ising model with asymmetric interactions reveals strong, task-independent symmetric interactions alongside weak, task-dependent antisymmetric ones, with the fitted model reproducing observed fluxes for most tasks. This indicates that the human brain performs its functional computation by subtly modifying the antisymmetric part of the interactions among brain regions, offering a new explanation for how a similar interaction network supports diverse brain functions.