title: Critical phenomena at a first-order phase transition in a lattice of glow lamps: Experimental findings and analogy to neural activity.
abstract: Networks of non-linear electronic oscillators have shown potential as physical models of neural dynamics. However, two properties of brain activity, namely, criticality and metastability, remain under-investigated with this approach. Here, we present a simple circuit that exhibits both phenomena. The apparatus consists of a two-dimensional square lattice of capacitively coupled glow (neon) lamps. The dynamics of lamp breakdown (flash) events are controlled by a DC voltage globally connected to all nodes via fixed resistors. Depending on this parameter, two phases having distinct event rate and degree of spatiotemporal order are observed. The transition between them is hysteretic, thus a first-order one, and it is possible to enter a metastability region, wherein, approaching a spinodal point, critical phenomena emerge. Avalanches of events occur according to power-law distributions having exponents ≈3/2 for size and ≈2 for duration, and fractal structure is evident as power-law scaling of the Fano factor. These critical exponents overlap observations in biological neural networks; hence, this circuit may have value as building block to realize corresponding physical models.
authors.affiliation: Center for Mind/Brain Sciences, University of Trento, 38123 Mattarello, Italy.
authors.forename: Ludovico
authors.initials: L
authors.lastname: Minati
authors.affiliation: Department of Physics "E. Pancini," University of Naples "Federico II," Napoli, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: de Candia
authors.affiliation: INFN Gr. Coll. Salerno, Unità di Napoli, Napoli, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Scarpetta
mesh_terms: D000818:Animals; D006801:Humans; D008959:Models, Neurological; D009415:Nerve Net / Q000502:physiology*