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Papers by Hirofumi Nagashino
Lecture Notes in Computer Science, 2003
ABSTRACT
We analyzed the characteristics of periodic solutions in a theoretical model of two symmetrically... more We analyzed the characteristics of periodic solutions in a theoretical model of two symmetrically coupled neural oscillators which are nonidentical in that a coupling coefficient between the units inside an oscillaor is different from the corresponding one in the other oscillator. The present paper shows this model has different qualitative oscillatory properties from the case where two identical oscillators are coupled with different coupling coefficients to each other.
Proceedings of SPIE - The International Society for Optical Engineering
ABSTRACT
IFMBE Proceedings, 2007
ABSTRACT
WSEAS Transactions on Biology and Biomedicine
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IFMBE proceedings
ABSTRACT
ICARCV 2004 8th Control, Automation, Robotics and Vision Conference, 2004., 2004
ABSTRACT
2012 IEEE-EMBS Conference on Biomedical Engineering and Sciences, 2012
ABSTRACT Tinnitus is the perception that one hears phantom sound(s) in the ears or in the head wi... more ABSTRACT Tinnitus is the perception that one hears phantom sound(s) in the ears or in the head without any external source. Sound therapy is one of the most effective techniques for tinnitus treatment that have been proposed. In order to investigate mechanisms of tinnitus generation and the clinical effects of sound therapy, we previously proposed computational and dynamical models with Hebbian or spike-time-dependent plasticity using a neural oscillator or a neuronal network. In the present paper, we propose a neuronal network model with homeostatic plasticity and demonstrate the simulation results of the model. The model is able to replicate the process of tinnitus generation and inhibition of perception of tinnitus by sound therapy.
IFMBE Proceedings, 2007
ABSTRACT
IFMBE Proceedings, 2007
ABSTRACT
Tinnitus is the perception of phantom sounds in the ears or in the head. Accordingly sound therap... more Tinnitus is the perception of phantom sounds in the ears or in the head. Accordingly sound therapy for tinnitus has been used. To account for mechanisms of tinnitus generation and the clinical effects of sound therapies from the viewpoint of neural engineering, we have proposed a plastic neural network model for the human auditory system. We found that this model has a bistable state, i.e., a stable oscillatory state and a stable equilibrium (non-oscillatory) state coexist at a certain parameter region. This paper describes inhibition of the oscillation for various kinds of noise stimuli, because noise stimuli are presented to tinnitus sufferers for therapeutic purposes. Through several numerical simulations it was shown that noise stimulus can inhibit the oscillation (similar to residual inhibition as seen in clinical studies), however, the oscillation is not inhibited in all cases, i.e., the effect of inhibition is not pervasive as in the case of inhibition in clinical cases.
ABSTRACT An abstract is not available.
International Journal of Mathematical Models and Methods in Applied Sciences
Tinnitus is a perception of sound in the ears or in the head without external source. There are m... more Tinnitus is a perception of sound in the ears or in the head without external source. There are many therapeutic approaches for tinnitus. Sound therapy is one of the effective techniques for its treatment. We have proposed computational models with plasticity by Hebbian hypothesis using a neural oscillator or coupled model neurons described by simplified Hodgkin-Huxley equations in order to investigate mechanisms of tinnitus generation and the clinical effects of sound therapy from the neural engineering point of view. In the present paper, a neuronal network model with synaptic plasticity by STDP (spike-timing-dependent plasticity) hypothesis is proposed for replication of the clinical results that human auditory system temporarily halts perception of tinnitus following sound therapy.
Lecture Notes in Computer Science, 2003
ABSTRACT
We analyzed the characteristics of periodic solutions in a theoretical model of two symmetrically... more We analyzed the characteristics of periodic solutions in a theoretical model of two symmetrically coupled neural oscillators which are nonidentical in that a coupling coefficient between the units inside an oscillaor is different from the corresponding one in the other oscillator. The present paper shows this model has different qualitative oscillatory properties from the case where two identical oscillators are coupled with different coupling coefficients to each other.
Proceedings of SPIE - The International Society for Optical Engineering
ABSTRACT
IFMBE Proceedings, 2007
ABSTRACT
WSEAS Transactions on Biology and Biomedicine
ABSTRACT
IFMBE proceedings
ABSTRACT
ICARCV 2004 8th Control, Automation, Robotics and Vision Conference, 2004., 2004
ABSTRACT
2012 IEEE-EMBS Conference on Biomedical Engineering and Sciences, 2012
ABSTRACT Tinnitus is the perception that one hears phantom sound(s) in the ears or in the head wi... more ABSTRACT Tinnitus is the perception that one hears phantom sound(s) in the ears or in the head without any external source. Sound therapy is one of the most effective techniques for tinnitus treatment that have been proposed. In order to investigate mechanisms of tinnitus generation and the clinical effects of sound therapy, we previously proposed computational and dynamical models with Hebbian or spike-time-dependent plasticity using a neural oscillator or a neuronal network. In the present paper, we propose a neuronal network model with homeostatic plasticity and demonstrate the simulation results of the model. The model is able to replicate the process of tinnitus generation and inhibition of perception of tinnitus by sound therapy.
IFMBE Proceedings, 2007
ABSTRACT
IFMBE Proceedings, 2007
ABSTRACT
Tinnitus is the perception of phantom sounds in the ears or in the head. Accordingly sound therap... more Tinnitus is the perception of phantom sounds in the ears or in the head. Accordingly sound therapy for tinnitus has been used. To account for mechanisms of tinnitus generation and the clinical effects of sound therapies from the viewpoint of neural engineering, we have proposed a plastic neural network model for the human auditory system. We found that this model has a bistable state, i.e., a stable oscillatory state and a stable equilibrium (non-oscillatory) state coexist at a certain parameter region. This paper describes inhibition of the oscillation for various kinds of noise stimuli, because noise stimuli are presented to tinnitus sufferers for therapeutic purposes. Through several numerical simulations it was shown that noise stimulus can inhibit the oscillation (similar to residual inhibition as seen in clinical studies), however, the oscillation is not inhibited in all cases, i.e., the effect of inhibition is not pervasive as in the case of inhibition in clinical cases.
ABSTRACT An abstract is not available.
International Journal of Mathematical Models and Methods in Applied Sciences
Tinnitus is a perception of sound in the ears or in the head without external source. There are m... more Tinnitus is a perception of sound in the ears or in the head without external source. There are many therapeutic approaches for tinnitus. Sound therapy is one of the effective techniques for its treatment. We have proposed computational models with plasticity by Hebbian hypothesis using a neural oscillator or coupled model neurons described by simplified Hodgkin-Huxley equations in order to investigate mechanisms of tinnitus generation and the clinical effects of sound therapy from the neural engineering point of view. In the present paper, a neuronal network model with synaptic plasticity by STDP (spike-timing-dependent plasticity) hypothesis is proposed for replication of the clinical results that human auditory system temporarily halts perception of tinnitus following sound therapy.