title: Acquisition of operant behavior in rats with delayed reinforcement: A retractable-lever procedure.
abstract: Experimentally naïve rats acquired lever pressing with delayed reinforcement when the immediate programmed consequence for lever pressing was the simultaneous retraction of two identical levers. Presses on one lever also produced access to sweetened condensed milk after a delay of 10s following retraction. Presses on the second lever resulted in retraction only. Lever retraction prevented the possibility of adventitious reinforcement of contacting the operanda during the reinforcement delays. Several measures indicated that the delayed reinforcers strengthened behavior. The majority of responses for all rats were on the lever that initiated reinforcer delivery. Responding for seven out of eight rats decreased during a subsequent extinction phase in which retraction was the only consequence arranged for lever pressing. Responding recovered rapidly when food reinforcement was available again. Furthermore, when contingencies on the two levers were switched, rats allocated their behavior accordingly, showing control by the delayed reinforcers.
authors.affiliation: Department of Psychology, Massachusetts College of Liberal Arts, United States.
authors.forename: Andrew A
authors.initials: AA
authors.lastname: McNamara
authors.affiliation: Department of Psychology, Massachusetts College of Liberal Arts, United States.
authors.forename: Lyndsey E
authors.initials: LE
authors.lastname: Johnson
authors.affiliation: Department of Psychology, Massachusetts College of Liberal Arts, United States.
authors.forename: Christopher
authors.initials: C
authors.lastname: Tate
authors.affiliation: Department of Psychology, Massachusetts College of Liberal Arts, United States.
authors.forename: Thomas
authors.initials: T
authors.lastname: Chiang
authors.affiliation: Department of Psychology, Massachusetts College of Liberal Arts, United States. Electronic address: t.byrne@mcla.edu.
authors.forename: Tom
authors.initials: T
authors.lastname: Byrne
mesh_terms: D000818:Animals; D003216:Conditioning, Operant / Q000502:physiology*; D065786:Delay Discounting / Q000502:physiology*; D005108:Extinction, Psychological; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012055:Reinforcement Schedule; D012054:Reinforcement, Psychology
keywords: Acquisition; Delayed reinforcement; Extinction; Rats