Since we are attempting to duplicate processes other than chemical,
per se, we will forego any reference to the extensive literature of
neurochemistry. It should not be surprising though if, at the neglect
of the fundamental biological processes of growth, reproduction and
metabolism, it proves possible to imitate some learning mechanisms
with grossly less complex molecular structures. There is also
much talk of chemical versus electrical theories and mechanisms in
neurophysiology. The distinction, when it can be made, seems to hinge
on the question of the scale of size of significant interactions. Thus,
“chemical” interactions presumably take place at molecular distances,
possibly as a result of or subsequent to a certain amount of thermal
diffusion. “Electrical” interactions, on the other hand, are generally
understood to imply longer range or larger scale macroscopic fields.