Avalanches e redes complexas no modelo Kinouchi-Copelli / Avalanches and complex networks in Kinouchi-Copelli model
AUTOR(ES)
Camilo Akimushkin Valencia
FONTE
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia
DATA DE PUBLICAÇÃO
02/08/2012
RESUMO
The capacity of a sensory system in efficiently detecting stimuli is usually given by the dynamic range, a simple measure of the range of stimulus intensity over which the network is sensible enough. Many times biological systems exhibit large dynamic ranges, covering many orders of magnitude. There is no easy explanation for that, since individual neurons present very short dynamic ranges isolatedly. Arguments based on sequential recruitment are doomed to failure since the corresponding arrangement of the limiar thresholds of the units over many orders of magnitude is unrealistic. Notably the so-called Kinouchi-Copelli (KC) model strongly suggested that large dynamic range should be a collective effect of the sensory neurons. The KC model is a network of stochastic excitable elements coupled as a random graph. KC showed the spontaneous activity of the network signals an order-disorder nonequilibrium phase transition and that the dynamic range exhibits an optimum precisely at the critical point (in terms of a control parameter related to structural properties of the network). In this work, we investigate how the critical point depends on the topology, considering the alternatives among the standard complex networks. We also study the burts of activity (neuronal avalanches) exhibited by the model, focusing on the qualitative changes due to alternative topologies. Finally we comment on possible connections among our results and recent observations of neural dynamics.
ASSUNTO(S)
avalanches avalanches complex networks critical phenomena fenômenos críticos kinouchi-copelli model modelo de kinouchi-copelli psicofísica psychophysics redes complexas
