ABSTRACT
Casual accounts of the conditioning process have been dominated since Pav lov by one or another conception of the notion of “ substitution with pairing.” It may be supposed that, as a result of prescribed juxtapositions of conditioned stimulus (CS) and unconditioned stimulus (US), the CS can come to act like a substitute for the US. Or, it may be supposed that as a result of certain conditions of practice of the unconditioned response (UR) in temporal relationship to the CS, the practiced behavior can come to be substituted for the original response to the CS. The notion is generally embraced by the reasoning that during condi tioning an “ association” or “ connection” is strengthened between some func tional “ centers,” i.e., between some CS representation and analogous US representation, or between a CS representation and UR process. Thus, it can be understood that when the CS representation is subsequently activated by the CS, the connecting link either affords activation of the US representation and, hence, activation of the UR process, or, affords activation of the UR process directly, so that the conditioned response (CR) occurs.
