Joint stimulus control in a temporal discrimination task

The ability to identify stimuli that signal important events is fundamental for an organism to adapt to its environment. In the present paper, we investigated how more than one stimulus could be used jointly to learn a temporal discrimination task. Ten pigeons were exposed to a symbolic matching-to-sample procedure with three durations as samples (2, 6, and 18 s of keylight) and two colors as comparisons (red and green hues). A 30-s intertrial interval (ITI), illuminated with a houselight, separated the trials. Both the houselight and the sample keylight could control responding, so two tests were run to assess how these stimuli influenced choice. In the no-sample test, the keylight was not presented; in the dark-ITI test, the houselight was not illuminated. Results suggest that both houselight and keylight controlled choice, and with the exception of one animal, the more a pigeon relied on one of these stimuli, the less it appeared to rely on the other.
The present work was conducted at the Psychology Research Centre, University of Minho, and was supported by the Portuguese Foundation for Science and Technology (FCT) and the Portuguese Ministry of Education and Science through national funds and when applicable co-financed by FEDER under the PT2020 Partnership Agreement (UID/PSI/01662/2013). This work was also supported by FCT Doctoral Grants to Carlos Pinto (SFRH/BD/78566/2011) and Ines Fortes (SFRH/BD/77061/2011), and a FCT Grant (PTDC/MHC-PCN/3540/2012) to Armando Machado.
info:eu-repo/semantics/publishedVersion