In this paper,we study how information transmission delays affect the spiking behavior of electrically coupled stochastic Hodgkin-Huxley (HH) neurons on Newman-Watts networks.It is found that the spiking behavior beco...In this paper,we study how information transmission delays affect the spiking behavior of electrically coupled stochastic Hodgkin-Huxley (HH) neurons on Newman-Watts networks.It is found that the spiking behavior becomes the most regular at an optimal time delay,indicating the occurrence of delay-induced coherence resonance-like (CR-like) behavior.Interestingly,there are different CR-like types,depending on the membrane patch size of the neuron.For a smaller patch size,only single CR-like behavior occurs;while for a larger patch size,coherence bi-resonance-like (CBR) behavior appears.These findings show that the delay-induced CR-like behavior is closely related to the channel noise strength,and the coupled neurons may exhibit different spiking behaviors under the interplay of the channel noise and time delay.Therefore,the channel noise should be taken into account in the study of time delay-related spiking activity in stochastic HH neurons.This work provides new insight into the role of channel noise and information transmission delays in realistic neural systems.展开更多
The effect of diversity on dynamics of coupled FitzHugh-Nagumo neurons on complex networks is numerically investigated, where each neuron is subjected to an external subthreshold signal. With the diversity the network...The effect of diversity on dynamics of coupled FitzHugh-Nagumo neurons on complex networks is numerically investigated, where each neuron is subjected to an external subthreshold signal. With the diversity the network is a mixture of excitable and oscillatory neurons, and the diversity is determined by the variance of the system's parameter. The complex network is constructed by randomly adding long-range connections (shortcuts) on a nearest-neighbouring coupled one-dimensional chain. Numerical results show that external signals are maximally magnified at an intermediate value of the diversity, as in the case of well-known stochastic resonance, burthermore, the effects of the number of shortcuts and coupled strength on the diversity-induced phenomena are also discussed. These findings exhibit that the diversity may play a constructive role in response to external signal, and highlight the importance of the diversity on such complex networks.展开更多
We investigate the effect of random long-range connections on signal propagation in an array of coupled FitzHugh- Nagumo (FHN) neurons. The neural network can be obtained by randomly adding a small fraction of short...We investigate the effect of random long-range connections on signal propagation in an array of coupled FitzHugh- Nagumo (FHN) neurons. The neural network can be obtained by randomly adding a small fraction of shortcuts in an originally locally coupled one-dimensional chain. It is shown that when the first neuron is subjected to external stimuli, it fires and excites its connected neighbours, such that the neural signal may propagate along the chain favoured by the shortcuts. Moreover, there exists an optimal number of shortcuts which can lead to the most synchronous behaviour. In addition, how the region of the fraction of shortcuts varies with the coupling strength is also discussed. These results suggest that topological disorder in the neural network may play a vital role in helping information processing in living systems.展开更多
针对信道环境恶劣条件下的大频率数字信号相干接收问题,提出了一种基于调参随机共振系统降低数字信号相干接收误码率(BER)的方法。从时域、频域及误码率三个方面对大频率二进制相移键控(BPSK)信号的随机共振相干接收方法进行了研究。首...针对信道环境恶劣条件下的大频率数字信号相干接收问题,提出了一种基于调参随机共振系统降低数字信号相干接收误码率(BER)的方法。从时域、频域及误码率三个方面对大频率二进制相移键控(BPSK)信号的随机共振相干接收方法进行了研究。首先,通过调整系数R改变非线性随机共振系统的参数a、b,将其共振频率提高R倍,从而实现大频率信号的随机共振,提高信号的信噪比(SNR);然后,对通过随机共振系统后的信号进行相干解调,并计算误码率。试验结果表明,与传统解调方法相比,该方法的误码率在低信噪比情况下有明显降低,当SNR=-14 d B时,较传统解调系统误码率可降低25.28%。随机共振系统提高了信号相干接收性能。随机共振理论在信号接收解调及信号处理等方面存在优势。展开更多
The control effect of recycled noise,generated by the superposition of a primary Gaussian noise source and a secondary source with a constant delay,has been studied in an excitable FitzHugh-Nagumo system.We mainly foc...The control effect of recycled noise,generated by the superposition of a primary Gaussian noise source and a secondary source with a constant delay,has been studied in an excitable FitzHugh-Nagumo system.We mainly focus on the performance of noise-induced spike and coherence resonance in a parameter region sub-threshold to supercritical Hopf bifurcation.For fixed noise intensity,simulations show that the coherence(quantitatively measured by R,which is defined as the mean value of the spike interval time T normalized to its mean square root) and the emission velocity of the noise-induced spikes exhibit damped oscillations with the variation of delay time,demonstrating a new kind of multi-resonance phenomenon.Furthermore,the optimal delay times for resonance and the fast emission velocity are related to the inherent frequency of the system.It seems that there are some synchronization effects between the dynamic character of the system and the delay time of recycled noise.Our results give clear information about how one can control the coherence and emission velocity of the noise-induced spike in a rather effective way,by deliberately adjusting the delay time and the fraction of the secondary noise.展开更多
Experimental study has shown that non-Gaussian noise exists in sensory systems like neurons.The departure from Gaussian behavior is a characteristic parameter of non-Gaussian noise.In this paper,we have numerically st...Experimental study has shown that non-Gaussian noise exists in sensory systems like neurons.The departure from Gaussian behavior is a characteristic parameter of non-Gaussian noise.In this paper,we have numerically studied the effect of a particular kind of non-Gaussian colored noise(NGN),especially its departure q from Gaussian noise(q = 1),on the spiking activity in a deterministic Hodgkin-Huxley(HH) neuron driven by sub-threshold periodic stimulus.Simulation results show that the departure q can affect the spiking activity induced by noise intensity D.For smaller q values,the minimum in the variation coefficient(CV) as a function of noise intensity(D) becomes smaller,showing that D-induced stochastic resonance(SR) becomes strengthened.Meanwhile,depending on the value of D,q can either enhance or reduce the spiking regularity.Interestingly,CV changes non-monotonously with varying q and passes through a minimum at an intermediate q,representing the presence of "departure-induced SR".This result shows that appropriate departures of the NGN can enhance the spike coherence in the HH neuron.Since the departure of the NGN determines the probability distribution and hence may denote the type of the noise,"departure-induced SR" shows that different types of noise can enhance the spike coherence,and hence may improve the timing precision of sub-threshold signal encoding in the HH neuron.展开更多
The effect of non-Gaussian colored noise(NGN),mainly its departure q from the Gaussian noise,on the optimal ISRO of CO oxidation on nanometer-sized Pd particles was studied.It was found that the ISRO in the absence of...The effect of non-Gaussian colored noise(NGN),mainly its departure q from the Gaussian noise,on the optimal ISRO of CO oxidation on nanometer-sized Pd particles was studied.It was found that the ISRO in the absence of external noise can still be enhanced when the NGN is applied.Specifically,the ISRO varies with changing q and becomes more regular at an appropriate q value,and when q is optimal,the ISRO becomes the most regular.Because the departure q from the Gaussian noise determines the probability distribution function and hence may denote the types of noise,this result shows that different types of external noise can enhance the ISRO of CO oxidation,and non-Gaussian noise may enhance the ISRO more greatly than the Gaussian noise.Therefore,non-Gaussian noise could play more effective roles in the catalytic process of CO oxidation on nanometer-sized Pd particles.展开更多
基金supported by the Natural Science Foundation of Shandong Province in China (ZR2009AM016)
文摘In this paper,we study how information transmission delays affect the spiking behavior of electrically coupled stochastic Hodgkin-Huxley (HH) neurons on Newman-Watts networks.It is found that the spiking behavior becomes the most regular at an optimal time delay,indicating the occurrence of delay-induced coherence resonance-like (CR-like) behavior.Interestingly,there are different CR-like types,depending on the membrane patch size of the neuron.For a smaller patch size,only single CR-like behavior occurs;while for a larger patch size,coherence bi-resonance-like (CBR) behavior appears.These findings show that the delay-induced CR-like behavior is closely related to the channel noise strength,and the coupled neurons may exhibit different spiking behaviors under the interplay of the channel noise and time delay.Therefore,the channel noise should be taken into account in the study of time delay-related spiking activity in stochastic HH neurons.This work provides new insight into the role of channel noise and information transmission delays in realistic neural systems.
文摘The effect of diversity on dynamics of coupled FitzHugh-Nagumo neurons on complex networks is numerically investigated, where each neuron is subjected to an external subthreshold signal. With the diversity the network is a mixture of excitable and oscillatory neurons, and the diversity is determined by the variance of the system's parameter. The complex network is constructed by randomly adding long-range connections (shortcuts) on a nearest-neighbouring coupled one-dimensional chain. Numerical results show that external signals are maximally magnified at an intermediate value of the diversity, as in the case of well-known stochastic resonance, burthermore, the effects of the number of shortcuts and coupled strength on the diversity-induced phenomena are also discussed. These findings exhibit that the diversity may play a constructive role in response to external signal, and highlight the importance of the diversity on such complex networks.
基金Supported by the National Natural Science Foundation of China under Grant Nos 20203017 and 20433050, and the Anhui Province Key Subject Foundation for Atomic and Molecular Physics (2002ZDXK)
文摘We investigate the effect of random long-range connections on signal propagation in an array of coupled FitzHugh- Nagumo (FHN) neurons. The neural network can be obtained by randomly adding a small fraction of shortcuts in an originally locally coupled one-dimensional chain. It is shown that when the first neuron is subjected to external stimuli, it fires and excites its connected neighbours, such that the neural signal may propagate along the chain favoured by the shortcuts. Moreover, there exists an optimal number of shortcuts which can lead to the most synchronous behaviour. In addition, how the region of the fraction of shortcuts varies with the coupling strength is also discussed. These results suggest that topological disorder in the neural network may play a vital role in helping information processing in living systems.
文摘针对信道环境恶劣条件下的大频率数字信号相干接收问题,提出了一种基于调参随机共振系统降低数字信号相干接收误码率(BER)的方法。从时域、频域及误码率三个方面对大频率二进制相移键控(BPSK)信号的随机共振相干接收方法进行了研究。首先,通过调整系数R改变非线性随机共振系统的参数a、b,将其共振频率提高R倍,从而实现大频率信号的随机共振,提高信号的信噪比(SNR);然后,对通过随机共振系统后的信号进行相干解调,并计算误码率。试验结果表明,与传统解调方法相比,该方法的误码率在低信噪比情况下有明显降低,当SNR=-14 d B时,较传统解调系统误码率可降低25.28%。随机共振系统提高了信号相干接收性能。随机共振理论在信号接收解调及信号处理等方面存在优势。
基金supported by the National Natural Science Foundation of China (21073232)the Fundamental Research Funds for the Central Universities (2010QNA16)the Research Fund of China University of Mining and Technology
文摘The control effect of recycled noise,generated by the superposition of a primary Gaussian noise source and a secondary source with a constant delay,has been studied in an excitable FitzHugh-Nagumo system.We mainly focus on the performance of noise-induced spike and coherence resonance in a parameter region sub-threshold to supercritical Hopf bifurcation.For fixed noise intensity,simulations show that the coherence(quantitatively measured by R,which is defined as the mean value of the spike interval time T normalized to its mean square root) and the emission velocity of the noise-induced spikes exhibit damped oscillations with the variation of delay time,demonstrating a new kind of multi-resonance phenomenon.Furthermore,the optimal delay times for resonance and the fast emission velocity are related to the inherent frequency of the system.It seems that there are some synchronization effects between the dynamic character of the system and the delay time of recycled noise.Our results give clear information about how one can control the coherence and emission velocity of the noise-induced spike in a rather effective way,by deliberately adjusting the delay time and the fraction of the secondary noise.
基金Supported by the Science Foundation of Ludong University (L20072805)
文摘Experimental study has shown that non-Gaussian noise exists in sensory systems like neurons.The departure from Gaussian behavior is a characteristic parameter of non-Gaussian noise.In this paper,we have numerically studied the effect of a particular kind of non-Gaussian colored noise(NGN),especially its departure q from Gaussian noise(q = 1),on the spiking activity in a deterministic Hodgkin-Huxley(HH) neuron driven by sub-threshold periodic stimulus.Simulation results show that the departure q can affect the spiking activity induced by noise intensity D.For smaller q values,the minimum in the variation coefficient(CV) as a function of noise intensity(D) becomes smaller,showing that D-induced stochastic resonance(SR) becomes strengthened.Meanwhile,depending on the value of D,q can either enhance or reduce the spiking regularity.Interestingly,CV changes non-monotonously with varying q and passes through a minimum at an intermediate q,representing the presence of "departure-induced SR".This result shows that appropriate departures of the NGN can enhance the spike coherence in the HH neuron.Since the departure of the NGN determines the probability distribution and hence may denote the type of the noise,"departure-induced SR" shows that different types of noise can enhance the spike coherence,and hence may improve the timing precision of sub-threshold signal encoding in the HH neuron.
基金supported by the Natural Science Foundation of Shandong Province (ZR2009AM016)
文摘The effect of non-Gaussian colored noise(NGN),mainly its departure q from the Gaussian noise,on the optimal ISRO of CO oxidation on nanometer-sized Pd particles was studied.It was found that the ISRO in the absence of external noise can still be enhanced when the NGN is applied.Specifically,the ISRO varies with changing q and becomes more regular at an appropriate q value,and when q is optimal,the ISRO becomes the most regular.Because the departure q from the Gaussian noise determines the probability distribution function and hence may denote the types of noise,this result shows that different types of external noise can enhance the ISRO of CO oxidation,and non-Gaussian noise may enhance the ISRO more greatly than the Gaussian noise.Therefore,non-Gaussian noise could play more effective roles in the catalytic process of CO oxidation on nanometer-sized Pd particles.