ABSTRACT
Jerzy Konorski and Miller distinguished between instrumental (Type II) and classical (Type I) conditioning, basically on the grounds that they could not see how the Pavlovian stimulus-substitution theory of conditioning could account for the changes in behaviour seen in the instrumental experiment. There were two reasons for this. First, the conditioned response (CR) was not related to the response elicited by the reinforcer, as it is in classical conditioning. Secondly, although appetitive and aversive reinforcers have similar effects in classical conditioning, in instrumental conditioning the probability of a CR is increased by appetitive reinforcers and decreased by aversive reinforcers. This chapter accepts Pavlov's and Konorski's general theory of classical conditioning. If animals are exposed to a positive contingency between a conditioned stimulus (CS) and a reinforcer, they may establish an association between central representations of these events, such that activation of the CS representation also activates the representation of the reinforcer.
