Effects of primary reinforcement on pigeons' initial-link responding under a concurrent chains schedule with nondifferntial terminal links.
The effect of primary reinforcement on initial-link responding under concurrent-chains schedules with nondifferential terminal links was assessed in 12 pigeons. The iniitial and terminal links were variable-interval schedules (always the same for both alternatives). The positions (left or right key) of the initial-link stimuli (red or green) were randomized while the correlation between color and food amount remained constant within each condition. The terminal-link stimuli were always presented on the center key. Except in two control groups and conditions, the terminal-link stimuli were the same color (nondifferential, blue or yellow). Over six conditions, the differences in food amont and the durations of the initial- and terminal-link schedules were manipulated. In 57 of 60 cases, birds generated choice proportions above .50 in favor of the initial-link stimlus that was correlated with the larger reinforcer. There was some indication that preference increased with shortened terminal-link durations. Because the terminal-link stimuli were nondifferential, differential responding in the initial links cannot be explained easily by conditioned reinforcement represented by the terminal-link stimuli. Thus, primiary reinforcement has a direct effect on initial-link responding in concurrent-chains schedules.
Ploog
B O
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College of Staten Island and The Graduate School, and University Center City University of New York, 10314, USA. ploog@postbox.csi.cuny.edu
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D002755:Choice Behavior / Q000502:physiology*; D010856:Columbidae; D003213:Conditioning, Psychological; D008568:Memory / Q000502:physiology; D012055:Reinforcement Schedule; D013997:Time Factors