Delay-induced multiple stochastic resonances on scale-free neuronal networks

TL;DR

This study investigates how time delays and pacemaker placement influence stochastic resonance in scale-free neuronal networks, revealing that delays can induce multiple resonances and affect the network's response to periodic stimuli.

Contribution

It demonstrates that finite delays can induce multiple stochastic resonances and highlights the importance of pacemaker placement and delay tuning in neuronal network dynamics.

Findings

Intermediate noise enhances stochastic resonance regardless of pacemaker placement.

Delay tuning can induce multiple stochastic resonances at multiples of the pacemaker period.

Appropriate delays can either promote or destroy stochastic resonance in the network.

Abstract

We study the effects of periodic subthreshold pacemaker activity and time-delayed coupling on stochastic resonance over scale-free neuronal networks. As the two extreme options, we introduce the pacemaker respectively to the neuron with the highest degree and to one of the neurons with the lowest degree within the network, but we also consider the case when all neurons are exposed to the periodic forcing. In the absence of delay, we show that an intermediate intensity of noise is able to optimally assist the pacemaker in imposing its rhythm on the whole ensemble, irrespective to its placing, thus providing evidences for stochastic resonance on the scale-free neuronal networks. Interestingly thereby, if the forcing in form of a periodic pulse train is introduced to all neurons forming the network, the stochastic resonance decreases as compared to the case when only a single neuron is paced. Moreover, we show that finite delays in coupling can significantly affect the stochastic resonance on scale-free neuronal networks. In particular, appropriately tuned delays can induce multiple stochastic resonances independently of the placing of the pacemaker, but they can also altogether destroy stochastic resonance. Delay-induced multiple stochastic resonances manifest as well-expressed maxima of the correlation measure, appearing at every multiple of the pacemaker period. We argue that fine-tuned delays and locally active pacemakers are vital for assuring optimal conditions for stochastic resonance on complex neuronal networks.