Synchrony and Desynchrony in Networks of Locally Coupled Wilson-cowan Oscillators

ثبت نشده
چکیده

In this Chapter, we study networks of locally coupled Wilson-Cowan (W-C) oscilla-tors [Wilson and Cowan, 1972]. The W-C oscillator is a two variable system of ordinary differential equations and represents an interacting population of excitatory and inhibitory neurons. The amplitudes of the variables symbolize the proportion of each population of neurons that is active. We study these equations because they represent neuronal groups, which may be the basic processing units in the brain [Edelman, 1987]. The W-C equations have a large number of parameters, which allow for a wide range of dynamics. These equations have been used widely in modelling various brain processes [Feldman and Of particular relevance is a study by Cairns et al. [Cairns et al., 1993], which indicates that synchronization is possible with these equations. Despite extensive studies on W-C oscillators, it remains unclear to whether or not a locally coupled network can exhibit synchrony. It is also unknown how desynchronization can be achieved in such a network. We study locally coupled networks because globally coupled networks lack topologi-cal mappings [Sporns et al., 1989, Chawanya et al., 1993]. Specifically, in a two-dimensional network of oscillators, all-to-all couplings indiscriminately connects multiple objects. All pertinent geometrical information about each object, and about its relationships with other objects is lost. This information should be preserved if the network is to be used for segmentation and object recognition. Local couplings simply and efficiently preserve these spatial relationships.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Synchronization and desynchronization in a network of locally coupled Wilson-Cowan oscillators

A network of Wilson-Cowan (WC) oscillators is constructed, and its emergent properties of synchronization and desynchronization are investigated by both computer simulation and formal analysis. The network is a 2D matrix, where each oscillator is coupled only to its neighbors. We show analytically that a chain of locally coupled oscillators (the piecewise linear approximation to the WC oscillat...

متن کامل

Synchrony and Desynchrony in Integrate-and-Fire Oscillators

Due to many experimental reports of synchronous neural activity in the brain, there is much interest in understanding synchronization in networks of neural oscillators and its potential for computing perceptual organization. Contrary to Hopfield and Herz (1995), we find that networks of locally coupled integrate-and-fire oscillators can quickly synchronize. Furthermore, we examine the time need...

متن کامل

Application of Coupled Neural Oscillators for Image Texture Segmentation and Modeling of Biological Rhythms

The role of relaxation oscillator models in application fields such as modeling dynamic systems and image analysis is discussed. A short review of the Van der Pol, Wilson-Cowan and Terman-Wang relaxation oscillators is given. The key property of such nonlinear oscillators, i.e., the oscillator phase shift (called the Phase Response Curve) as a result of external pulse stimuli is indicated as a ...

متن کامل

Loose Synchrony in Relaxation Oscillator Networks with Time Delays

Coupled relaxation oscillators have been shown to exhibit robust properties of synchrony and desynchrony. We study a network of such oscillators with the inclusion of time delay in the coupling. Analytic results for a pair of oscillators show loose synchrony as a stable solution for a wide range of initial conditions and time delays. Computer simulations show a network of oscillators with time ...

متن کامل

Firing rate equations require a spike synchrony mechanism to correctly describe fast oscillations in inhibitory networks

Recurrently coupled networks of inhibitory neurons robustly generate oscillations in the gamma band. Nonetheless, the corresponding Wilson-Cowan type firing rate equation for such an inhibitory population does not generate such oscillations without an explicit time delay. We show that this discrepancy is due to a voltage-dependent spike-synchronization mechanism inherent in networks of spiking ...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2004