Killeen, Peter R.Pellón Suárez de Puga, RicardoIbias Martín, Javier2024-05-202024-05-202018-03-262163-3452http://doi.org/10.1007/s40732-018-0275-2https://hdl.handle.net/20.500.14468/12618The present experiments studied impulsivity by manipulating the delay between target responses and presentation of a reinforcer. Food-deprived SHR, WKY, and Wistar rats were exposed to a fixed-time 30-s schedule of food pellet presentation until they developed stable patterns of water spout-licking and magazine-entering. In successive phases of the study, a resetting delay contingency postponed food delivery if target responses (licks or entries) occurred within the last 1, 2, 5, 10, 20, 25, or 28 s of the inter-food interval. Response-food delays were applied independently for the two behaviors during separate experimental phases, and order of presentation and the behavior that was punished first were counterbalanced. Licking was induced in the order of Wistar > SHR > WKY, and magazine entries were in the order of SHR > WKY > Wistar. Magazine entries showed steeper delay gradients than licking in SHR and Wistar rats but were of similar great inclination in the WKY rats. The different responses were differentially sensitive to delays. This suggests a different ordering of them in the interval between reinforcers. It also has implications for attempts to change impulsive behavior, both in terms of the nature of the response and its removal from reinforcing consequences.eninfo:eu-repo/semantics/openAccessjournal articleSchedule-induced behaviorLicksMagazine entriesResponse-food delaysStrain differencesRats