title: Temporal generalization gradients following an interdimensional discrimination protocol.
abstract: We investigated the effects of interdimensional discrimination training in the temporal generalization gradient. In a matching-to-sample task, pigeons learned to choose key S after a T-s houselight sample and key NS in the absence of the houselight sample. For one group of pigeons, T = 20 s; for another, T = 10 s. Subsequently, houselight duration was varied to obtain temporal generalization gradients. Results showed that (a) proportion S increased as houselight duration ranged from 0 s to T s and then remained high for houselight durations longer than T; (b) the gradients were well described by negative-exponential functions; (c) these non-flat gradients were present from the beginning of testing, and; (d) the average gradients obtained with T = 20 s and T = 10 s overlapped when plotted in relative time. We conclude that temporal control does not require explicit discrimination training along the temporal dimension, and that temporal generalization gradients obtained with an interdimensional protocol show the scalar property of timing. We discuss how these findings challenge current models of timing.
authors.affiliation: a Instituto de Investigação e Inovação em Saúde, Universidade do Porto , Porto , Portugal.|b IBMC- Instituto de Biologia Molecular e Celular, Universidade do Porto , Porto , Portugal.|c School of Psychology , University of Minho , Braga , Portugal.
authors.forename: Ana Catarina
authors.initials: AC
authors.lastname: Vieira de Castro
authors.affiliation: c School of Psychology , University of Minho , Braga , Portugal.|d Department of Zoology , University of Oxford , Oxford , UK.
authors.forename: Marco
authors.initials: M
authors.lastname: Vasconcelos
authors.affiliation: c School of Psychology , University of Minho , Braga , Portugal.
authors.forename: Armando
authors.initials: A
authors.lastname: Machado
mesh_terms: D000818:Animals; D010856:Columbidae; D004193:Discrimination Learning / Q000502:physiology*; D005793:Generalization, Psychological / Q000502:physiology*; D012054:Reinforcement, Psychology; D013998:Time Perception / Q000502:physiology*
keywords: Interdimensional training; Pigeon; Scalar property; Temporal generalization; Timing models