Affiliation:
1. State University of New York, College at Oswego
Abstract
The number and order of stimulus transitions while extinguishing a discrimination were evaluated in order to determine what stimulus changes are essential to initiate differential responding. Following Light on vs Light off food-reinforced discrimination training in operant chambers, 40 rats were randomly assigned to five groups for extinction testing in the presence of S+ or S−. For three groups the first transition during extinction was from S+ to S− whereas for two groups the first transition was from S− to S +. There were basically no differences in responding to the external stimuli among the three S+ to S− groups; the two S− to S+ groups differed from the other three groups and from each other. It was concluded that an S+ to S− transition is essential in extinction for the appearance of differential responding.