title: Pigeons group time intervals according to their relative duration.
abstract: In the present research, we asked whether pigeons tended to judge time intervals not only in terms of their absolute value but also relative to a duration from which they must be discriminated (i.e., longer or shorter). Pigeons were trained on two independent temporal discriminations. In one discrimination, sample durations of 2 and 8 sec were associated with, for example, red and green hue comparisons, respectively, and in the other discrimination, sample durations of 4 and 16 sec were associated with vertical and horizontal line comparisons, respectively. If pigeons are trained on a temporal discrimination and tested with intermediate durations, the subjective midpoint typically occurs close to the geometric mean of the two trained values. The 4- and 8-sec values were selected to be the geometric mean of the two values in the other discrimination. When a 4-sec test sample was presented with the comparisons from the 2- and 8-sec discrimination, the pigeons preferred the comparison associated with the shorter sample. Similarly, when an 8-sec test sample was presented with the comparisons from the 4- and 16-sec discrimination, the pigeons preferred the comparison associated with the longer sample. Thus, a relative grouping effect was found. That is, durations that should have produced indifferent choice were influenced by their relative durations (shorter than or longer than the alternative) during training.
authors.affiliation: Department of Psychology, University of Kentucky, Lexington, Kentucky 40506-0044, USA. zentall@pop.uky.edu
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Zentall
authors.forename: Janice E
authors.initials: JE
authors.lastname: Weaver
authors.forename: Tricia S
authors.initials: TS
authors.lastname: Clement
mesh_terms: D000818:Animals; D010856:Columbidae; D004192:Discrimination, Psychological; D012054:Reinforcement, Psychology; D013997:Time Factors; D013998:Time Perception