Interreinforcer interval effect on discrimination index in matching-to-sample tasks

Abstract

Using a matching to simple task pigeons were exponed to different durantions of interreinforcement interval (IRI). For six pigeons the programmed IRI was 36 seconds length and for the others six the IRI was 126 seconds length. Both of  IRI were obtained from different combinations of sample stimulus and intertribal interval durations. The discrimination index was higther for pigeons exposed to the longest IRI. The importance of IRI is discussed over the traditional explanations about the variables that control the acquisition speed and accuracy levels when a matching to sample tasks is used.