On the effects of extended sample-observing response requirements on adjusted delay in a titrating delay matching-to-sample procedure with pigeons.

A common procedural variation that facilitates the acquisition of conditional discriminations is to increase the time an organism spends in the presence of the sample stimulus by programming extended sample-observing response requirements. Despite their common use, there has been little empirical investigation of the effects of extended sample-observing response requirements. In the current study, four pigeons worked on a titrating delay matching-to-sample procedure in which the delay between sample offset and comparison onset was adjusted as a function of the pigeons' accuracy. The number of responses required to produce the comparison array was manipulated across conditions. Results show that all subjects were able to withstand longer delays between sample offset and comparison onset as sample-observing response requirements increased. These data show that the extent of the response requirement in the presence of the sample has systematic effects on conditional discrimination performances and should be considered in the design of experiments