In this report we present a method of adding a feedback control mecha-
nism to an echo state network (ESN) pattern generator in order to modulate
its output patterns with the purpose of tracking slowly varying control tar-
gets, e.g. shift, amplitude, or frequency of an oscillatory pattern. A proof-
of-principle case study is presented where a basic ESN is trained to produce
a stable sinewave oscillation with fixed shift, amplitude and frequency. With
the controller in place, the system demonstrates that the shift, amplitude
and frequency of the produced sine waveform can be modulated simultane-
ously by suitably generated slow varying control signals inserted into the
network. Furthermore, an equilibration procedure is introduced to relearn
ESN weights such that the equilibrated ESN pattern generator can approxi-
mately reproduce the reservoir dynamics across the controllable range, with
the feedback control loop switched o
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