title: Exploring a concurrent-chains paradox: decreasing preference as an initial link is shortened.
abstract: Experiments with pigeons and rats on concurrent-chains schedules examined a paradoxical effect reported by R. A. Preston and E. Fantino (1991). One schedule in the concurrent chain had a variable-interval (VI) 60-s initial link, and its terminal link was a 10-s delay to food. The other schedule had an initial link that ranged from VI 60 s to VI 2 s, and its terminal link was a 20-s delay to food. The paradoxical effect--a decrease in preference for the 20-s delay as its initial link was shortened--was found in some conditions but not in others. An analysis of response-reinforcer delays suggested that the paradoxical effect occurred in conditions in which responding on the short VI schedule almost always led to the 20-s delay, eliminating the possibility of switching to the alternative with the shorter delay.
authors.affiliation: Psychology Department, Southern Connecticut State University, New Haven, CT 06515, USA. mazurj1@southernct.edu
authors.forename: James E
authors.initials: JE
authors.lastname: Mazur
mesh_terms: D000818:Animals; D001245:Association Learning; D002755:Choice Behavior; D003118:Color Perception; D010856:Columbidae; D004193:Discrimination Learning; D008960:Models, Psychological; D009042:Motivation; D011597:Psychomotor Performance; D011930:Reaction Time; D012055:Reinforcement Schedule