  Inspired by the dissipative quantum model of brain, we model the states of
neural nets in terms of collective modes by the help of the formalism of
Quantum Field Theory. We exhibit an explicit neural net model which allows to
memorize a sequence of several informations without reciprocal destructive
interference, namely we solve the overprinting problem in such a way last
registered information does not destroy the ones previously registered.
Moreover, the net is able to recall not only the last registered information in
the sequence, but also anyone of those previously registered.
