1. A method for increasing receptive field diversity in a neural network having a plurality of neurons, the method comprising a heterosynaptic approach including: for at least a first one of said plurality of neurons that respond to a stimulus, applying a first plasticity mechanism; and for a second and at least portion of other ones of said plurality of neurons that respond to said stimulus, applying a second plasticity mechanism different than the first plasticity mechanism; where at least one of the first or second plasticity mechanisms is based at least in part on a Neighbor Activity Trace (NAT) parameter corresponding to one or more activities of a neighbor neuron competing for features.