15.3 Dual Network Structure 283 biological process physiological process cellular process cellular physiological process cell cycle cell division par og/ Ye M phase meiotic cell cycle _-" part_of cytokinesis is_@ - M phase of meiotic cell cycle [ <tytokinesis after meiosis | > Fig. 15.3: A typical, though small, subnetwork of the Gene Ontology’s hierarchical network. the same purposes, they should be linked together. Portrayals of typical heterarchical linkage patterns among natural language concepts are given in Figures 15.5 and 15.6. Just for fun, Figure 15.7 shows one person’s attempt to draw a heterarchical graph of the main concepts in one of Douglas Hofstadter’s books. Naturally, real concept heterarchies are far more large, complex and tangled than even this one. In CogPrime, ECAN enforces heterarchy via building SymmetricHebbianLinks, and PLN by building SimilarityLinks, IntensionalSimilarityLinks and ExtensionalSimilarityLinks. Fur- thermore, these various link types reinforce each other. PLN control is guided by importance spreading, which follows Hebbian links, so that a heterarchical Hebbian network tends to cause PLN to explore the formation of links following the same paths as the heterarchical Hebbian- Links. And importance can spread along logical links as well as explicit Hebbian links, so that the existence of a heterarchical logical network will tend to cause the formation of additional heterarchical Hebbian links. Heterarchy reinforces itself in "autopoietic attractor" style even more simply and directly than heterarchy. HOUSE_OVERSIGHT_013199