If a third “dipole” is inserted through the dielectric membrane in
the opposite direction, then excitation of this isolated element
tends to inhibit the response which would otherwise be elicited by
excitation of one of the parallel dipoles. Figure 5 shows the first
such “logically-complete” interaction cell successfully constructed and
demonstrated. It may be said to behave as an elementary McCulloch-Pitts
neuron (15). Further analysis shows that similar structures
incorporating many dipoles (both excitatory and inhibitory) can be made
to behave as general “linear decision functions” in which all input
weights are approximately proportional to the total size or length of
their corresponding attached dendritic structures.