title: Schedule-dependent effect of d-amphetamine on pausing by pigeons.
abstract: Two pigeons were exposed to a multiple schedule of grain reinforcement where key-pecks were reinforced according to a fixed ratio schedule in the presence of one stimulus and a fixed interval schedule in another stimulus. The fixed interval was adjusted to match average interreinforcer time for the fixed ratio schedule. d-Amphetamine decreased overall rate of responding in the fixed ratio schedule -- primarily by increasing pausing, especially just after a change from the fixed interval component. Rate of responding in the fixed interval schedule was increased for one bird and little affected for the other bird by d-Amphetamine. Again, changes in pausing primarily determined rate change. Since pausing was differently affected, a schedule-dependent rather than rate-dependent effect was indicated.
mesh_terms: D000818:Animals; D010856:Columbidae; D003216:Conditioning, Operant / Q000187:drug effects*; D003913:Dextroamphetamine / Q000494:pharmacology*; D008297:Male; D012055:Reinforcement Schedule; D013997:Time Factors
chemical_list: D003913:Dextroamphetamine