A distributed and locally reprogrammable address event receiver has been designed, in which incoming addressevents are monitored simultaneously by all synapses, allowing for arbitrarily large axonal fan-out without reducing channel capacity. Synapses can change the address of their pre-synaptic neuron, allowing the distributed implementation of a biologically realistic learning rule, with both synapse formation and elimination (synaptic rewiring). Probabilistic synapse formation leads to topographic map development, made possible by a crosschip current-mode calculation of Euclidean distance. As well as synaptic plasticity in rewiring, synapses change weights using a competitive Hebbian learning rule (spike-timing-dependent plasticity). The weight plasticity allows receptive fields to be modified based on spatiotemporal correlations in the inputs, and the rewiring plasticity allows these modifications to become embedded in the network topology.
Simeon A. Bamford, Alan F. Murray, David J. Willsh