Mismatch reduction through dendritic nonlinearities in a 2D silicon dendritic neuron array

This paper describes a novel 2D programmable dendritic neuron array consisting of a 3×32 dendritic compartment array and a 1×32 somatic compartment array. Each dendritic compartment contains two types of regenerative nonlinearities: an NMDA nonlinearity and a dendritic spike nonlinearity. The chip supports the programmability of local synaptic weights and the configuration of dendritic morphology for individual neurons through the address-event representation protocol. With a novel local cable circuit between neighboring compartments, different dendritic morphologies can be constructed. From results measured on a chip fabricated in a 4-metal, 2-poly, 0.35μm CMOS technology, we show one instance of how dendritic non- linearities can contribute to neuronal computation: the dendritic spike mechanism dynamically reduces the mismatch-induced coefficient of variation of the somatic response amplitude from approximately 40% to 3.5%.