1. A method of detecting a change in an input stream via sensing events to an artificial network for one of a control, detection and classification application using a processor apparatus, the processor apparatus comprising a special purpose processor and memory and executing a special purpose stored program for the one of the control, the detection and the classification application, the method comprising: constructing an artificial neural network in the memory, the artificial neural network comprising at least one input neuron and at least one output neuron, each neuron having a threshold parameter; defining at least one synapse between a pair of neurons of the artificial neural network, one neuron comprising a source neuron and the other neuron comprising a destination neuron, the synapse having a parameter that specifies a propagation delay through the synapse, the synapse adapted to permit at least two discrete events to propagate together through the synapse from the source neuron to the destination neuron; and executing the stored program in the special purpose processor, the execution resulting in the simulation of the artificial neural network, the simulation causing the artificial neural network to produce at least one output event at an output neuron in response to said input stream.