title: Interval timing under variations in the relative validity of temporal cues.
abstract: Two groups of pigeons were trained to respond on a white center key to a fixed-interval, 60-s schedule of reinforcement signaled by the onset of a side-key cue (S+ training). In additional training sessions, S+ trials alternated between S- trials in which a different side-key cue signaled nonreinforcement after 60 s (S+/S- training). For one group, S+/S- training sessions followed S+ training, and for the other group, S+/S- training preceded S+ training. Peak-time curves obtained from extended nonrewarded probe trials inserted among training trials showed loss of control by time during S+/S- training relative to S+ training. A follow-up experiment showed that this result was not caused by a difference in probability of reinforcement. We suggest that attention to time was weakened by the introduction of visual cues that were more valid predictors of trial outcomes.
authors.affiliation: Department of Psychology, University of Western Ontario.
authors.forename: Neil
authors.initials: N
authors.lastname: McMillan
authors.forename: William A
authors.initials: WA
authors.lastname: Roberts
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001288:Attention / Q000502:physiology*; D010856:Columbidae; D003214:Conditioning, Classical; D003463:Cues; D011336:Probability; D012054:Reinforcement, Psychology; D013223:Statistics as Topic; D013997:Time Factors