title: Observing responses and serial stimuli: searching for the reinforcing properties of the S-.
abstract: The control exerted by a stimulus associated with an extinction component (S-) on observing responses was determined as a function of its temporal relation with the onset of the reinforcement component. Lever pressing by rats was reinforced on a mixed random-interval extinction schedule. Each press on a second lever produced stimuli associated with the component of the schedule in effect. In Experiment 1 a response-dependent clock procedure that incorporated different stimuli associated with an extinction component of a variable duration was used. When a single S- was presented throughout the extinction component, the rate of observing remained relatively constant across this component. In the response-dependent clock procedure, observing responses increased from the beginning to the end of the extinction component. This result was replicated in Experiment 2, using a similar clock procedure but keeping the number of stimuli per extinction component constant. We conclude that the S- can function as a conditioned reinforcer, a neutral stimulus or as an aversive stimulus, depending on its temporal location within the extinction component.
authors.affiliation: National Autonomous University of Mexico. Rogelio.Escobar@mail.wvu.edu
authors.forename: Rogelio
authors.initials: R
authors.lastname: Escobar
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Bruner
mesh_terms: D000818:Animals; D002755:Choice Behavior; D003216:Conditioning, Operant; D005108:Extinction, Psychological; D008297:Male; D009483:Neuropsychological Tests; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time; D012055:Reinforcement Schedule; D012054:Reinforcement, Psychology