The correlative coactivation of sensory inputs, Hebb's "second rule," proba
bly plays a critical role in the formation of word representations in the n
eocortex. It is essential to the acquisition of word meaning. The acquisiti
on of semantic memory is inseparable from that of individual memory and the
refore the two probably share the same neural connective substrate. Thus, "
content" words are represented mainly in postrolandic cortex, where individ
ual perceptual memories are also represented, whereas "action words are rep
resented in frontal cortex, with executive memories. The activation of a me
mory network may net necessarily entail the high-frequency oscillatory, fir
ing of its cells, though reverberation remains a plausible mechanism of sho
rt-term memory.