Deterministic excitable media under Poisson drive: power law responses, spiral waves and dynamic range
| dc.creator | Ribeiro, Tiago L. | |
| dc.creator | Copelli, Mauro | |
| dc.date | 2008-03-24 | |
| dc.date | 2008-05-22 | |
| dc.date.accessioned | 2026-07-07T09:40:05Z | |
| dc.date.available | 2026-07-07T09:40:05Z | |
| dc.description | When each site of a spatially extended excitable medium is independently driven by a Poisson stimulus with rate h, the interplay between creation and annihilation of excitable waves leads to an average activity F. It has recently been suggested that in the low-stimulus regime (h ~ 0) the response function F(h) of hypercubic deterministic systems behaves as a power law, F ~ h^m. Moreover the response exponent m has been predicted to depend only on the dimensionality d of the lattice, m = 1/(1+d) [T. Ohta and T. Yoshimura, Physica D 205, 189 (2005)]. In order to test this prediction, we study the response function of excitable lattices modeled by either coupled Morris-Lecar equations or Greenberg-Hastings cellular automata. We show that the prediction is verified in our model systems for d = 1, 2, and 3, provided that a minimum set of conditions is satisfied. Under these conditions, the dynamic range - which measures the range of stimulus intensities that can be coded by the network activity - increases with the dimensionality d of the network. The power law scenario breaks down, however, if the system can exhibit self-sustained activity (spiral waves). In this case, we recover a scenario that is common to probabilistic excitable media: as a function of the conductance coupling G among the excitable elements, the dynamic range is maximized precisely at the critical value G_c above which self-sustained activity becomes stable. We discuss the implications of these results in the context of neural coding. | |
| dc.description | 10 pages, 5 figures, final version | |
| dc.identifier | https://arxiv.org/abs/0803.3467 | |
| dc.identifier | http://arxiv.org/abs/0803.3467 | |
| dc.identifier | Phys. Rev. E 77, 051911 (2008) | |
| dc.identifier | doi:10.1103/PhysRevE.77.051911 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/161377 | |
| dc.subject | Neurons and Cognition | |
| dc.title | Deterministic excitable media under Poisson drive: power law responses, spiral waves and dynamic range | |
| dc.type | text |