This paper introduces a new class of dynamic multilayer perceptrons, c
alled Block Feedback Neural Networks (B(F)N). B(F)N have been develope
d to provide a systematic way to build networks of high complexity, in
cluding networks with coupled loops, nested loops, and so on. B(F)Ns a
re specified using a block notation. Any B(F)N can be seen as a block
and connected to other B(F)Ns using a fixed number of elementary conne
ctions. The result of such a connection can also be considered as a bl
ock, and connected to other blocks, in a recursive fashion. We develop
a cost-minimizing, supervised training algorithm for this model. The
algorithm is a gradient-descent type, and is tailored on the block str
ucture of the model. Finally, we present some experiments of use of B(
F)Ns.