The Evolution
28
vation, but rather should instead merely act by restricting what may be
yielded in memory. Hence if an ambiguously seen red shape (part-whole
links with "fire engine," "apple," etc.) were perceived by memory,
memory's disambiguation of that shape should be restricted by "redness,"
in the sense that memory should limit its range of possible disambiguations
to the class of concepts containing "redness," but no persisting acti-
vations should be given rise to.
The principle that whole-to-whole links should give rise to persisting
activations, but not part-whole links, will be termed the principle of
residual activation.
It is worth noting that in the Iogogen model of Morton (1969) a
stimulus does not exert any influence after it has ceased to be immediately
present in memory. Inasmuch as a stimulus inevitably has part-whole
links with the various percepts it tends to give rise to, Morton's restric-
tion is a specialized version of the more general restriction introduced
here, namely that no part-whole link exerts a persisting influence. Of
course in Morton's theory there is a "Context System" that does exert a
persisting influence.
Type IV Interactions
It should be noted that memory has the ability to comfortably handle
familiar phrases as if they were single words. Thus if horseshoe is
rewritten horse shoe, it harkly matters to memory—the two words may
still be treated as a single word. And in the same way, a phrase such
as Military Police need not yield its concept by an intersection of the
concepts "military" and "police," inasmuch as Military Police may be