Takashi Kanamaru

Kogakuin University · Mechanical Science and Engineering

To understand the effect of attention on neuronal dynamics, we propose a multi-module network, with each module consisting of fully interconnected groups of excitatory and inhibitory neurons. This network shows transitive dynamics among quasi-attractors as its typical dynamics. When the release of acetylcholine onto the network is simulated by atte...

We examine the efficiency of information processing in a balanced excitatory and inhibitory (E-I) network during the developmental critical period, when network plasticity is heightened. A multimodule network composed of E-I neurons was defined, and its dynamics were examined by regulating the balance between their activities. When adjusting E-I ac...

Corticopetal acetylcholine (ACh) is released transiently from the nucleus basalis of Meynert (NBM) into the cortical layers and is associated with top-down attention. Recent experimental data suggest that this release of ACh disinhibits layer 2/3 pyramidal neurons (PYRs) via muscarinic presynaptic effects on inhibitory synapses. Together with other...

The echo state network (ESN) is an excellent machine learning model for processing time-series data. This model, utilising the response of a recurrent neural network, called a reservoir, to input signals, achieves high training efficiency. Introducing time-history terms into the neuron model of the reservoir is known to improve the time-series pred...

The echo state network (ESN) is an excellent machine learning model for processing time series data. This model, utilizing the response of a recurrent neural network called a reservoir to input signals, achieves high training efficiency. Introducing time-history terms into the neuron model of the reservoir is known to improve the time series predic...

In this study, I considered quantifying the strength of chaos in the population firing rate of a pulse-coupled neural network. In particular, I considered the dynamics where the population firing rate is chaotic and the firing of each neuron is stochastic. I calculated a time histogram of firings to show the variation in the population firing rate...

We propose a pulse neural network that exhibits chaotic pattern alternations among stored patterns as a model of multistable perception, which is reflected in phenomena such as binocular rivalry and perceptual ambiguity. When we regard the mixed state of patterns as a part of each pattern, the durations of the retrieved pattern obey unimodal distri...

We propose a pulse neural network that exhibits chaotic pattern alternations among stored patterns as a model of multistable perception, which is reflected in phenomena such as binocular rivalry and perceptual ambiguity. When we regard the mixed state of patterns as a part of each pattern, the durations of the retrieved pattern obey unimodal distri...

Spinal cord injury causes a paralysis of any part of the body depending on which part of spinal cord is destroyed. It is well known that a severity of the paralysis is determined by both a location and a degree of injury in the vertebral bones. For example, in a case of injury at the C4 vertebral bone a patient is paralyzed from the neck down, and...

There is evidence of presynaptic modulation of inhibitions on pyramidal neurons in cortical layers 2/3, mediated by muscarinic M2-receptors activated by transient releases of the corticopetal acetylcholine associated with top-down attention. Little is known, however, regarding its system-level consequences and possible implications for cognitive fu...

The dependence of the dynamics of pulse-coupled neural networks on random rewiring of excitatory and inhibitory connections is examined. When both excitatory and inhibitory connections are rewired, periodic synchronization emerges with a Hopf-like bifurcation and a subsequent period-doubling bifurcation; chaotic synchronization is also observed. Wh...

Although the role of corticopetal acetylcholine (ACh) in higher cognitive functions is increasingly recognized, the questions as (1) how ACh works in attention(s), memory dynamics and cortical state transitions, and also (2) why and how loss of ACh is involved in dysfunctions such as visual hallucinations in dementia with Lewy bodies and deficit of...

The roles of inhibitory neurons in synchronous firing are examined in a network of excitatory and inhibitory neurons with D. J. Watts and S. H. Strogatz’s rewiring [Nature 393, 440–442 (1998)]. By examining the persistence of the synchronous firing that exists in the random network, it was found that there is a probability of rewiring at which a tr...

The synchronous firing of neurons in a pulse-coupled neural network composed of excitatory and inhibitory neurons is analyzed. The neurons are connected by both chemical synapses and electrical synapses among the inhibitory neurons. When electrical synapses are introduced, periodically synchronized firing as well as chaotically synchronized firing...

In models of associative memory composed of pulse neurons, chaotic pattern transitions where the pattern retrieved by the network changes chaotically were found. The network is composed of multiple modules of pulse neurons, and when the inter-module connection strength decreased, the stability of pattern retrieval changed from stable to chaotic. It...

To study the mechanism by which high-dimensional chaos emerges in neural systems, the synchronization of chaotic firings in class 1 pulse neural networks composed of excitatory and inhibitory ensembles was analyzed. In the system with two modules (i.e. two pulse neural networks), blowout bifurcation and on–off intermittency were observed when the i...

To study the synchronized oscillations among distant neurons in the visual cortex, we analyzed the synchronization between two modules of pulse neural networks using the phase response function. It was found that the intermodule connections from excitatory to excitatory ensembles tend to stabilize the antiphase synchronization and that the intermod...

Synchronized firings in the networks of class 1 excitable neurons with excitatory and inhibitory connections are investigated, and their dependences on the forms of interactions are analyzed. As the forms of interactions, we treat the double exponential coupling and the interactions derived from it: pulse coupling, exponential coupling, and alpha c...

The nonlinear prediction method based on the interspike interval (ISI) reconstruction is applied to the ISI sequence of noisy pulse trains and the detection of the deterministic structure is performed. It is found that this method cannot discriminate between the noisy periodic pulse train and the noisy chaotic one when noise-induced pulses exist. W...

The globally connected active rotators with excitatory and inhibitory connections having different time constants under noise are analyzed using the nonlinear Fokker-Planck equation, and their oscillatory phenomena are investigated. Based on numerically calculated bifurcation diagrams, both periodic solutions and chaotic solutions are found. The pe...

To realize the hardware object which facilitates the application development in the reconfigurable computing system, a hardware module (HwModule) is proposed and implemented. To access the circuit in the HwModule from the standard PC without detailed knowledge of the hardware, an object manager (ObjectManager) is also implemented. With the help of...

The array-enhanced coherence resonance (AECR) in the diffusively coupled active rotators is investigated and its analysis with the nonlinear Fokker-Planck equation is presented.By considering the nonlinear Fokker- Planck equation of the rotators, it is found that the time-periodic solution exists in some parameter range.By solving the equation of a...

A hardware object is a capsule of circuits loaded into reconfigurable devices. It is dynamically constructed while an application runs. Its driver is temporarily mounted on a real driver for a hardware module. The circuits are suitable to preprocessing and postprocessing of for robot systems. A commercial C++ compiler becomes an integrated design e...

The globally connected active rotators with excitatory and inhibitory connections under noise were analyzed using the nonlinear Fokker-Planck equation, and their oscillatory phenomena were investigated numerically. Typically, the FAR (fast, asynchronous, and regular) oscillations were observed near the Hopf bifurcation line, and the SSI (slow, sync...

Nonlinear dynamics of coupled FitzHugh-Nagumo neurons subject to independent noise is analyzed. A kind of self-sustained global oscillation with almost synchronous firing is generated by array-enhanced coherence resonance. Further, forced dynamics of the self-sustained global oscillation stimulated by sinusoidal input is analyzed and classified as...

The sparsely associative memory in a pulsed neural network of the FitzHugh-Nagumo models with hierarchical correlations was studied. The effects of fluctuations in pulsed neural network storing sparse patterns was also discussed. The synchronous periodic firings in the network were used to represent the stored memory patterns composing of 0/1 digit...

The array-enhanced stochastic resonance (AESR) in the diffusively coupled FitzHugh-Nagumo equation is investigated. The two properties of AESR, namely, the scaling of the optimal noise intensity and the enhancement of the maximum value of the correlation coefficient as a function of the coupling strength, are analyzed theoretically. By transforming...

Stochastic resonance in a coupled FitzHugh-Nagumo equation with a propagational time delay is investigated. With an appropriate set of parameter values. i.e. the frequency of the periodic input, the propagational time delay, and the coupling strength, a deterministic firing induced by additive noise is observed, and its dependence on the number of...

An associative memory retrieval in a pulsed neural network composed of the FitzHugh-Nagumo neurons is investigated. The memory is represented in the spatio-temporal firing pattern of the neurons, and the memory retrieval is accomplished using the fluctuations in the system. The storage capacity of the network is investigated numerically. It is demo...

In the sine-circle map, the phase-locking structure on the parameter plane (Ω, K) is known as Arnold's tongue. The overlapping of two adjacent tongues implies the coexistence of two hase-locked attractors with different rotation numbers. The phase-locked attractors are destroyed by crisis, and the lines of crisis are observed on the parameter plane...

Stochastic Resonance in a coupled FitzHugh–Nagumo equation is investigated. The optimal noise intensity and the optimal input frequency, which maximize the signal to noise ratio of the output signal, are studied numerically, and their dependence on system parameters and connection coefficients is examined. It is found that a network composed of six...

Stochastic resonance in a coupled Hodgkin-Huxley equation is investigated.The dependence of signal to noise ratio on the frequencies of the periodic input signals is examined by numerical experiments.Two or three Hodgkin-Huxley equations are coupled with a propagationaltime delay to compose a network.For a network with two elements, an enhancement...

The chaotic associative memory is re-

Abstract Stochastic synchrony of chaos was found in a pulse neural network composed of excitatory neurons and inbitory neurons with gap junctions. Key words chaos, synchronization, pulse neural network, stochastic synchrony 1. はじめに

Abstract The synchronous firings in a pulse neural network connected by both chemical and electrical synapses with Watts-Strogatz’s rewiring are examined. It was found that the instantaneous synchronization emerges from the distant neurons by increasing the rewiring probability. Key words pulse neural network, synchronization, chaos, Watts-Strogatz...