Physical review. E, Statistical, nonlinear, and soft matter physics
July 11, 2022
Matthieu Gilson, Enzo Tagliazucchi, Rodrigo Cofré
Consciousness is supported by complex patterns of brain activity which are indicative of irreversible nonequilibrium dynamics. While the framework of stochastic thermodynamics has facilitated the understanding of physical systems of this kind, its application to infer the level of consciousness from empirical data remains elusive. We faced this challenge by calculating entropy production in a...
Physical review. E, Statistical, nonlinear, and soft matter physics
September 22, 2015
Paolo Allegrini, Paolo Paradisi, Danilo Menicucci et al.
Criticality reportedly describes brain dynamics. The main critical feature is the presence of scale-free neural avalanches, whose auto-organization is determined by a critical branching ratio of neural-excitation spreading. Other features, directly associated to second-order phase transitions, are: (i) scale-free-network topology of functional connectivity, stemming from suprathreshold pairwise...
Physical review. E, Statistical, nonlinear, and soft matter physics
August 1, 2009
Laura K McKemmish, Jeffrey R Reimers, Ross H McKenzie et al.
Penrose and Hameroff have argued that the conventional models of a brain function based on neural networks alone cannot account for human consciousness, claiming that quantum-computation elements are also required. Specifically, in their Orchestrated Objective Reduction (Orch OR) model [R. Penrose and S. R. Hameroff, J. Conscious. Stud. 2, 99 (1995)], it is postulated that microtubules act as...
Physical review. E, Statistical, nonlinear, and soft matter physics
September 1, 2004
Luiz Pinguelli Rosa, Jean Faber
Quantum models of the mind associate consciousness with coherent superposition of states in the brain. Some authors consider consciousness to be the result of a kind of internal quantum measurement process in the brain. In this paper we discuss the ideas of Hameroff-Penrose and Tegmark and their calculation for an estimate of decoherence time. We criticize the Hameroff-Penrose model in the...
Physical review. E, Statistical, nonlinear, and soft matter physics
August 2003
Moira L Steyn-Ross, D A Steyn-Ross, J W Sleigh et al.
In a recent series of papers, the authors have developed a stochastic theory to describe the electrical response of a spatially homogeneous cerebral cortex to infusion of a general anesthetic agent. We showed that by modeling the GABAergic (propofol-like) drug effect as a prolongation of the inhibitory postsynaptic impulse response, we obtain a prediction that there will be a hysteretically...