Influence of refractory periods in the Hopfield model

CRISOGONO DA SILVA; FRANCISCO TAMARIT; EVALDO CURADO

INTERNATIONAL JOURNAL OF MODERN PHYSICS C

WORLD SCIENTIFIC PUBL CO PTE LTD

Lugar: London, UK; Año: 1996 vol. 7 p. 43 - 56

0129-1831

We study both analytically and numerically the effects of including refractory periods in the Hopfield model for associative memory. These periods are introduced in the dynamics of the network as thresholds that depend on the state of the neuron at the previous time. Both the retrieval properties and the dynamical behavior are analyzed, and we found that, depending on the value of the thresholds and on the the ratio α between the number of stored memories (p) and the total number of neurons (N), the system presents not only fixed points but also chaotic or cyclic orbits. The recognizing capability of the network in the cyclic region is also studied.