Effects of small-world connectivity on noise-induced temporal and spatial order in neural media
Effects of small-world connectivity on noise-induced temporal and spatial order in neural media
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DOI：
10.1016/j.chaos.2005.10.018
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发表时间：
2007-01-01
影响因子：
7.8
通讯作者：
Perc, Matjaz
中科院分区：
文献类型：
--
作者：
Perc, Matjaz
我们提出了一个概述的小世界连接噪声引起的时间和空间秩序的可兴奋的神经介质与FitzHugh-Nagumo局部动力学的二维网络的可能影响。小世界网络的特征是，系统中有一部分所谓的远程耦合或捷径链接，它们连接系统中的远程单元，而所有其他单元都以类似扩散的方式耦合。有趣的是，已经有一小部分的这些远程耦合可以有广泛的影响的时间以及空间噪声引起的动态系统。在这里，我们提出了两个主要的影响。首先，我们表明，时间顺序，其特征在于发射率函数的自相关性，可以大大提高通过引入小世界的连接，从而提高效果与引入的捷径链接的比例增加。其次，我们表明，引入长程耦合诱导无序，否则有序，螺旋波样，噪声诱导的模式，可以观察到的空间单元的排他性扩散连接。因此，已经有一小部分快捷链接足以破坏介质中的相干图案形成。虽然这两个结果似乎是矛盾的，我们提供了一个解释，考虑到固有的无标度性质的小世界网络，这一方面，促进信号转导，从而在系统中的时间顺序，而另一方面，破坏了内部空间尺度的媒体，从而阻碍了存在的相干波状图案。此外，空间与时间有序的神经网络功能的重要性进行了讨论。(c)2005爱思唯尔有限公司保留所有权利。
We present an overview of possible effects of small-world connectivity on noise-induced temporal and spatial order in a two-dimensional network of excitable neural media with FitzHugh-Nagumo local dynamics. Small-world networks are characterized by a given fraction of so-called long-range couplings or shortcut links that connect distant units of the system, while all other units are coupled in a diffusive-like manner. Interestingly, already a small fraction of these long-range couplings can have wide-ranging effects on the temporal as well as spatial noise-induced dynamics of the system. Here we present two main effects. First, we show that the temporal order, characterized by the autocorrelation of a firing-rate function, can be greatly enhanced by the introduction of small-world connectivity, whereby the effect increases with the increasing fraction of introduced shortcut links. Second, we show that the introduction of long-range couplings induces disorder of otherwise ordered, spiral-wave-like, noise-induced patterns that can be observed by exclusive diffusive connectivity of spatial units. Thereby, already a small fraction of shortcut links is sufficient to destroy coherent pattern formation in the media. Although the two results seem contradictive, we provide an explanation considering the inherent scale-free nature of small-world networks, which on one hand, facilitates signal transduction and thus temporal order in the system, whilst on the other hand, disrupts the internal spatial scale of the media thereby hindering the existence of coherent wave-like patterns. Additionally, the importance of spatially versus temporally ordered neural network functioning is discussed. (c) 2005 Elsevier Ltd. All rights reserved.