Response repetition in pigeons: pharmacological and behavioral specificity.
Using a reinforcement schedule that arranges random sequences of reinforcements over two response keys, low and high probabilities of repetition of non-reinforced responses were generated in two groups of pigeons (n = 3 per group) by varying the probability of reinforcement for responding on the key to which reinforcement was assigned. Unlike rats, the pigeons did not show a tendency to repeat just-reinforced responses, but showed a strong position bias, that was reduced by additional feeding and extinction, but not by any of the drug treatments. Apomorphine increased response repetition, irrespective of the control probability of repetition; d-amphetamine increased low probabilities of repetition, but decreased high probabilities. Chlordiazepoxide and scopolamine selectively decreased high probabilities of repetition; phencyclidine and pentobarbital selectively increased low probabilities of repetition. Morphine, haloperidol, chlorpromazine, additional feeding, and extinction did not affect repetition of non-reinforced responses. Extinction increased perseveration, whereas drug effects on perseveration were not observed. Drug-induced changes of patterning of responses as exemplified herein by drug-induced alterations of repetitiveness may be relevant to the interpretation of drug effects upon performance brought about by other behavioral processes such as discrimination.
D000818:Animals; D001058:Apomorphine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D002707:Chlordiazepoxide / Q000494:pharmacology; D010856:Columbidae; D003216:Conditioning, Operant / Q000187:drug effects*; D003913:Dextroamphetamine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D005108:Extinction, Psychological; D010424:Pentobarbital / Q000494:pharmacology; D010622:Phencyclidine / Q000494:pharmacology; D012055:Reinforcement Schedule; D012527:Satiation; D012601:Scopolamine / Q000494:pharmacology
D002707:Chlordiazepoxide; D012601:Scopolamine; D010424:Pentobarbital; D010622:Phencyclidine; D001058:Apomorphine; D003913:Dextroamphetamine