Dummy trials, novel stimuli, and Pavlovian-trained stimuli: Their effect upon instrumental and consummatory response relationships.

Abstract

To test the relationship between discriminative and conditioned properties of stimuli, 4 dogs were trained to press a lever for food on a [differential reinforcement of a low ratel DRL 2-min. schedule, following which dummy trials with no stimulus presentation, novel stimuli of previously unused tone, or Pavlovian-trained stimuli (tone previously paired with food) were superimposed over the DRL schedule. The relationship between occurrence of a salivary response and waiting time of next lever press was unaffected by dummy and novel trials, but Pavlovian-trained stimuli resulted in a positive relationship. It was concluded that ability of a stimulus to serve as a discriminative stimulus is a function of its ability to serve as a CS on that occasion.