used as the feedback device from the second layer of the eckhorn network its output is therefore normally high and is applied to inhibitory synapses in the first and elsewhere in the second layer the synaptic weight of this input is set so that it is not high enough to prevent the bans from firing in response to sufficient excitation of their synaptic inputs when the second layer ban fires the output of the inverting fl is de asserted which effectively raises the sensitivity of the bans to their excitatory inputs this mimics the linking field effect of a conventional eckhorn neuron as a final application example an fff can be used to obtain short term modulation of synaptic weights the scheme is illustrated in fig1 to implement weight modulation a trivial modification must be made to the standard ban synaptic input in a standard ban design a high level input at a synapse switches current to an internal summing resistor at which the voltage input to the ban 39 s li is obtained to make an elastic synapse es all that is required is that a second switch which routes additional current through the main synaptic switch be added.