[http://citeseer.nj.nec.com/wang91perioddoublings.html]
Xin Wang, Department of Mathematics, University of Southern California
2001
"The dynamics of discrete-time ["NeuralNetwork"]s with the SigmoidFunction as NeuronActivationFunction can be extraordinarily complex as some authors have displayed in numerical simulations. Here we consider a neural network of only two neurons, one excitatory and the other inhibitory, with no external inputs and no time delay as a ParameterizedFamily of TwoDimensionalMaps, and give an AnalyticalProof for existence of ["PeriodDoubling"]s to ["Chaos"] and ["StrangeAttractor"]s in the network."