Ahstract-A novel network based on Linsker-type Hebbian learning is analyzed in its dynamical behavior. The network combines a coupled dynamics of fast and slow states and is prone to internal parametrical fluctuations as well as external noises. Robustness represents a crucial property of the network to attenuate the effects of internal fluctuation and external noise.In this study, we formulate this novel neural network as a cou pled nonlinear differential systems operating at different time scales under vanishing perturbations. We determine conditions for the existence of a global uniform attractor of the perturbed biological system. By using a Lyapunov function for the coupled system, we derive a maximal upper bound for the fast time scale associated with the fast state. Finally, two examples are given to confirm the applicability of the developed theoretical framework. Index Terms-Linsker-type Hebbian learning, multi-time scale neural network, parametric uncertainties, robust stability I. INTRODUC TION Linsker [5] proposed a neural network relevant to the phenomena observed in the visual cortex. It combines a unsupervised nonlinear learning scheme with a temporal activity evolution.While most attention has been given in theoretical analysis to the emergence of center-surrounded or oriented receptive fields [6], [7], little is known about the underlying nonlinear dynamics of this multi-layer neural network. In this paper, we formulate this network as a coupled nonlinear differential system operating at different time-scales under vanishing perturbations. Differently from previous work [1] viewing parametric uncertain systems as perturbations to a known nominal linear system [2], [3], in this paper the perturbed neural system is modeled as nonlinear perturbations to a known nonlinear idealized system and is represented by two time-scale subsystems. These perturbations can lead to location errors of equilibria, to instabilities, and even to spurious states. Therefore, a rigorous understanding of the qualitative robustness properties of neural systems with respect to parameter variations on both a fast or slow time scale becomes imperative.The goal of the present paper is to study stability and robustness properties of Linsker-type Hebbian learning modAnke Meyer-Baese is with the eled by a system of competitive differential equations, from a rigorous analytic standpoint and to apply results of the theory of nonlinear uncertain singularly perturbed systems [4]. The networks under study model the nonlinear dynamics of both fast and slow states under consideration of nonlinear uncertainties.In the following, we present the underlying nonlinear dynamics for the Linsker-type Hebbian learning network. The equations are adopted from the original dynamical mechanism of Linsker's network [5].The general neural network equations describing the tem poral evolution of the unperturbed STM and LTM states for the jth neuron of aN-neuron network are: