Electrical and Computer Engineering Commons^™

Silicon Synaptic Adaptation Mechanisms For Homeostasis And Contrast Gain Control, Shih-Chii Liu, Bradley Minch

Bradley Minch

We explore homeostasis in a silicon integrate-and-fire neuron. The neuron adapts its firing rate over time periods on the order of seconds or minutes so that it returns to its spontaneous firing rate after a sustained perturbation. Homeostasis is implemented via two schemes. One scheme looks at the presynaptic activity and adapts the synaptic weight depending on the presynaptic spiking rate. The second scheme adapts the synaptic"threshold" depending on the neuron's activity. The threshold is lowered if the neuron's activity decreases over a long time and is increased for prolonged increase in postsynaptic activity. The presynaptic adaptation mechanism models the …