Discrete versus continuous neuron state values;
Oriented, simmetric or antisimmetric connections among neurons;
Deterministic versus probabilistic transition of neuron states;
Parallel versus sequential propagation rule of neuron update in the network;
Asynchronous versus synchronous arc weights updating rule.
Implemented models
Boltzmann Machines
Back-error Propagation Algorithms
Hebbian Algorithms
Competitive Networks
Kohonen's maps