AN ANALOG MEMORY CIRCUIT FOR SPIKING SILICON NEURONS

A simple circuit is described that functions as an analog memory whose state and dynamics are directly controlled by pulsatile inputs. The c ircuit has been incorporated into a silicon neuron with a spatially ex tensive dendritic tree as a means of controlling the spike firing thre shold of an integrate-and-fire soma. Spiking activity generated by the neuron itself and by other units in a network can thereby regulate th e neuron's excitability over time periods ranging from milliseconds to many minutes. Experimental results are presented showing applications to temporal edge sharpening, bistable behavior, and a network that le arns in the manner of classical conditioning.