Short term memory in recurrent networks of spiking neurons

We present in this paper a general model of recurrent networks of spiking neurons, composed of several populations, and whose interaction pattern is set with a random draw. We use for simplicity discrete time neuron updating, and the emitted spikes are transmitted through randomly delayed lines. In excitatory-inhibitory networks, we show that inhomogeneous delays may favour synchronization provided that the inhibitory delays distribution is significantly stronger than the excitatory one. In that case, slow waves of synchronous activity appear (this synchronous activity is stronger in inhibitory population). This synchrony allows for a fast ada ptivity of the network to various input stimuli. In networks observing the constraint of short range excitation and long range inhibition, we show that under some parameter settings, this model displays properties of –1– dynamic retention –2– input normalization –3– target tracking. Those properties are of interest for modelling biological topologically organized structures, and for robotic applications taking place in noisy environments where targets vary in size, speed and duration. This revised version was published online in June 2006 with corrections to the Cover Date.