Well posedness and stationary solutions of a neural field equation with synaptic plasticity

Abstract

We consider the initial value problem associated to the neural field equation of Amari type with plasticity \[ u_t(x,t)=-u(x,t)+\int_Ωw(x,y)[1+γg( u(x,t) - u(y,t) )] f(u(y,t))\; dy, \;(x,t) \in Ω\times (0, \infty), \] where $\Omega \subset {\mathbb{R}}^m$, $f$ and $g$ are bounded and continuously differentiable functions with bounded derivative, and $\gamma \ge 0$ is the plasticity synaptic coefficient. We show that the problem is well posed in $C_b({\mathbb{R}}^m)$ and $L^1(\Omega )$ with $\Omega$ compact. The proof follows from a classical fixed point argument when we consider the equation's flow. Strong convergence of solutions in the no plasticity limit ($\gamma \to 0$) to solutions of Amari's equation is analysed. Finally, we prove existence of stationary solutions in a general way. As a particular case, we show that the Amari's model, after learning, leads to the stationary Schrödinger equation for a type of gain modulation.