Pulse propagation networks (PPN) are neural networks in which individual ac
tion potentials encode information. The dynamics of PPN depend not only on
the synaptic weights of connections but also the delay in the propagation o
f action potentials between neural elements. It is known that PPN can perfo
rm complex computations and information processing by encoding information
as the time intervals between action potential events. In this paper we app
roach the practical question of constructing PPN to generate, recognize and
learn arbitrary recurrent signals. We present specific examples of network
s that generate and recognize signals and also describe a learning algorith
m that allows PPN to learn by self-organization. Finally we discuss the pos
sible importance of dynamical fluctuations about the mean-activity field of
a neural network.