Cardiac conditioning and extinction inMacaca mulatta during block of the CR by cardiac pacing

Previous work has shown that behavior acquisition within the Pavlovian paradigm occurs in the absence of responding,i.e., when conditional and unconditional responses are blocked during training. The parallel question of extinction under response blocking has received less attention. The experiments reported here find that a cardiac CR can be conditioned and extinguished even when rate changes are prevented by cardiac pacing during acquisition and extinction procedures. This finding suggests that the cardiac CR is established independently of peripheral innervations, and that “feedback” from the changing response is not necessary for Pavlovian learning of this sort to occur.