Coherence resonance in an excitable system with time delay
نویسندگان
چکیده
We study the noise activated dynamics of a model excitable system that consists of a subcritical Hopf oscillator with a time delayed nonlinear feedback. The coherence of the noise driven pulses of the system exhibits a novel double peaked structure as a function of the noise amplitude. The two peaks correspond to separate optimal noise levels for excitation of single spikes and multiple spikes (bursts) respectively. The relative magnitudes of these peaks are found to be a sensitive function of time delay. The physical significance of our results and its practical implications in various real life systems are discussed. © 2006 Elsevier B.V. All rights reserved. PACS: 05.45.-a; 05.45.Xt; 02.30.Ks; 02.50.Ey; 05.40.Ca
منابع مشابه
Spatiotemporal dynamics on small-world neuronal networks: The roles of two types of time-delayed coupling
We investigate temporal coherence and spatial synchronization on small-world networks consisting of noisy Terman-Wang (TW) excitable neurons in dependence on two types of time-delayed coupling: {xj(t− τ)− xi(t)} and {xj(t− τ)− xi(t− τ)}. For the former case, we show that time delay in the coupling can dramatically enhance temporal coherence and spatial synchrony of the noise-induced spike train...
متن کاملDevelopment of an Advanced Optical Coherence Tomography System for Radiation Dosimetry
Introduction: According to the literature, optical coherence tomography (OCT) can be used measure radiation absorbed dose. This study was carried out to design a computed tomography system for the calculation of absorbed dose and optimization of dose delivery in radiotherapy using gel dosimeters. Material and Methods: An advanced charge-coupled device based OCT system was developed in laborator...
متن کاملCoherence resonance in models of an excitable neuron with both fast and slow dynamics
We demonstrate the existence of noise-induced periodicity (coherence resonance) in both a discrete-time model and a continuous-time model of an excitable neuron. In particular, we show that the effects of noise added to the fast and slow dynamics of the models are dramatically different. A Fokker-Planck analysis gives a quantitative explanation of the effects. The effects of noise on nonlinear ...
متن کاملFokker-Planck analysis of stochastic coherence in models of an excitable neuron with noise in both fast and slow dynamics.
We provide a detailed and quantitative Fokker-Planck analysis of noise-induced periodicity (stochastic coherence, also known as coherence resonance) in both a discrete-time model and a continuous-time model of excitable neurons. In particular, we show that one-dimensional models can explain why the effects of noise added to the fast and slow dynamics of the models are dramatically different. We...
متن کاملSystem size coherence resonance in coupled FitzHugh-Nagumo models
– We show the existence of a system size coherence resonance effect for coupled excitable systems. Namely, we demonstrate numerically that the regularity in the signal emitted by an ensemble of globally coupled FitzHugh-Nagumo systems, under excitation by independent noise sources, is optimal for a particular value of the number of coupled systems. This resonance is shown through several differ...
متن کامل