136 research outputs found
Universal Organization of Resting Brain Activity at the Thermodynamic Critical Point
Thermodynamic criticality describes emergent phenomena in a wide variety of
complex systems. In the mammalian brain, the complex dynamics that
spontaneously emerge from neuronal interactions have been characterized as
neuronal avalanches, a form of critical branching dynamics. Here, we show that
neuronal avalanches also reflect that the brain dynamics are organized close to
a thermodynamic critical point. We recorded spontaneous cortical activity in
monkeys and humans at rest using high-density intracranial microelectrode
arrays and magnetoencephalography, respectively. By numerically changing a
control parameter equivalent to thermodynamic temperature, we observed typical
critical behavior in cortical activities near the actual physiological
condition, including the phase transition of an order parameter, as well as the
divergence of susceptibility and specific heat. Finite-size scaling of these
quantities allowed us to derive robust critical exponents highly consistent
across monkey and humans that uncover a distinct, yet universal organization of
brain dynamics
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