神经元网络的同步和节律研究

发布时间：2018-04-02 23:00

本文选题：兴奋性神经元　切入点：抑制性神经元　出处：《浙江师范大学》2012年硕士论文

【摘要】：高等动物和人在认知的过程中,神经系统的同步发放和节律活动跟信息编码和信息处理联系紧密。本文研究了三种神经元网络的发放行为：抑制性神经元网络、有时间延迟的theta-gamma节律网络和左右半脑网络。在抑制性神经元网络中,我们探究了噪声、耦合强度和时间延迟对该系统的影响。我们发现：在有时间延迟时,随着噪声强度的逐渐增大,系统逐步呈现出稳定期,变化期和相对稳定期三个不同的状态。噪声对同步性影响不大,系统在有时间延迟时比没有时间延迟时发放要有规律很多,时间延迟有助于同步。合适的耦合强度和噪声强度保持神经元同步发放状态。我们进一步发现：当抑制性神经元受到噪声影响时,即使噪声强度较小,该网络仍然不稳定,不能产生嵌套theta-gamma节律；而适当的时间延迟有利于网络的稳定。我们假设所有神经元都受到噪声的影响并且引入时间延迟机制,得到了一个性质相对稳定的theta-gamma节律网络,使系统具有抗噪能力,而且模拟神经系统、研究网络性质,考虑时间延迟和噪声更符合实际情况,同时探究了部分耦合强度对网络的影响。最后,我们以有时间延迟的theta-gamma节律网络为基础,构建左右半脑网络。在有无刺激条件下,我们探究了该系统的行为,并且讨论了该系统在双连接、单连接、无连接下的行为,得到了跟混合字母实验相符合的结论。该网络反应了左右连接对大脑信息交流具有重要作用,右半脑在全局感知方面占优势,而左半脑对细节感知灵敏。
[Abstract]:In the cognitive process of higher animals and humans, the synchronous release and rhythmic activities of the nervous system are closely related to information coding and information processing.In this paper, we study the firing behavior of three kinds of neural networks: inhibitory neural networks, time-delayed theta-gamma rhythmic networks and left and right hemispheric networks.In inhibitory neural networks, we investigate the effects of noise, coupling intensity and time delay on the system.We find that, with the increase of noise intensity, the system presents three different states: stable period, change period and relative stable period.The noise has little effect on synchronicity, and the system has much more regularity when there is a time delay than when there is no time delay, and the time delay is helpful to synchronization.The appropriate coupling strength and noise intensity maintain the neuronal synchronous firing state.We further find that when the inhibitory neurons are affected by noise, even if the noise intensity is small, the network is still unstable and can not produce nested theta-gamma rhythm, and the appropriate time delay is beneficial to the stability of the network.Assuming that all neurons are affected by noise and time delay mechanism is introduced, we obtain a relatively stable theta-gamma rhythmic network, which enables the system to resist noise, and simulates the neural system to study the properties of the network.Considering the time delay and noise, the effect of partial coupling strength on the network is discussed.Finally, we construct the left and right hemispheric network based on the theta-gamma rhythmic network with time delay.Under the condition of whether the system is stimulated or not, we investigate the behavior of the system, and discuss the behavior of the system under the condition of double connection, single connection and no connection, and get the conclusion in agreement with the mixed alphabet experiment.The network shows that the left and right hemispheric connections play an important role in the communication of brain information. The right hemisphere is dominant in global perception, while the left hemisphere is sensitive to detail perception.
【学位授予单位】：浙江师范大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R311;O175

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