Todd Eric Thiele, Ph.D.
TITLE: Associate Professor
COMPANY: University of North Carolina
Advisor: Dr. Jerome Frieman
Preference for response associated with a revalued discriminative stimulus : evidence of S-R associations
We commonly identify 3 elements in instrumental learning situations: a response (R) performed by the organism, an outcome (O) which is contingent on the performance of the response, and a stimulus (S) present during the response-reinforcer contingency. During the course of learning, some or all of these elements are hypothesized to become associated. Recently, evidence for the existence of S-O, R-O, and hierarchical S-(R-O) associations has been provided. Although S-R associations have been the centerpiece of several influential theories (e.g, The Law of Effect), there is little direct support for their existence. In 3 experiments, direct evidence for S-R associations is provided. In all 3 experiments, pigeons were trained to peck at 2 response keys. Then they were placed on a biconditional discrimination task in which responding to each key was reinforced depending on which discriminative stimulus was on. In the next phase, 1 of the stimuli from the biconditional discrimination (S+) predicted shock (Experiments 1 and 2) or food (Experiment 3); the other stimulus (S-) was presented alone. Finally, in a preference test, subjects were given concurrent and unreinforced access to both keys in the absence of these stimuli. Pigeons were more likely to respond to the key associated with S+ relative to the key associated with S-. Because the same O followed both Rs and occurred after each S during discrimination training, differential responding in the preference test is best explained by inferring S-R associations.
Ph.D., Psychology, Kansas State University, 1995