Friday, April 15, 2005

12 noon

Redwood Neuroscience Institute

 

Title "Attractor Neural Networks with Depressing Synapses”

 

Bert Kappen

Nijmegen University

The Netherlands

 

Abstract:

We examine the role of depressing synapses on memory retrieval in attractor neural networks. Using a standard mean field approach, we analytically compute the phase diagram for small number of patterns as a function of the noise and amount of depression of the synapses. Our results demonstrate the appearance of a novel phase characterized by rapid switching from one memory state to another. Subsequently, we show that the capacity of the network to store patterns as fixed points of the attractor dynamics is strongly reduced with depressing synapses. We confirm the validity of our mean field results with numerical simulations. In addition, we argue to change the traditional view of memories as stable fixed point attractors and suggest the idea of dynamical memory as a possible mechanism of the brain.