Effects of bounded noise and time delay on signal transmission in excitable neural networks

The influence of bounded noise and time delay on the sub–threshold signal transmission in FitzHugh–Nagumo neuronal networks is studied in this paper. It is found that the signal transmission performance can be enhanced by moderate noise levels in neuronal systems. There is an optimal cross–correlation time where the noise enhances signal transmission best. Moreover, the positively correlated bounded noise–induced stochastic anti–resonance phenomenon monotonically enhances with the increasing cross–correlated intensity. Interestingly, the stochastic anti–resonance phenomenon disappears when the noise is negatively correlated. With the fine–tuning of the time delay, the resonance peaks occur at each half–integer multiples of the signal period, implying delay–induced multiple stochastic resonances. The sub–harmonic stochastic resonance and stochastic anti–resonance alternatively appear at the appropriate coupling strength. These results may provide a novel perspective on sub–threshold signal transmission in the nervous system.