title: Some effects of delta-amphetamine and pentobarbital on performance under a long fixed-interval schedule.
abstract: The effects of delta-amphetamine and pentobarbital were studied on performance during 3-hr sessions under fixed-interval 60-min schedules of food presentation. Low doses of delta-amphetamine increased rates of responding and higher doses decreased rates of responding, both during the entire 3-hr session and during each of the individual fixed intervals. Pentobarbital produced little effect on rates of responding averaged over the 3-r session, but it decreased rates during the first fixed interval and increased them during the second and third fixed intervals. The effects of delta-amphetamine were shown to be dependent on the control rate of responding, as has been shown with shorter fixed-interval values. Analysis of delta-amphetamine effects in terms of the point at which the probability of responding is greater than zero was not descriptive of overall fixed-interval performance.
mesh_terms: D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D010856:Columbidae; D003216:Conditioning, Operant / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D008297:Male; D010424:Pentobarbital / Q000494:pharmacology*; D011930:Reaction Time / Q000187:drug effects; D012055:Reinforcement Schedule; D013997:Time Factors
chemical_list: D000661:Amphetamine; D010424:Pentobarbital