Do pigeons prefer information in the absence of differential reinforcement?

Prior research has indicated that pigeons do not prefer an alternative that provides a sample (for matching to sample) over an alternative that does not provide a sample (i.e., there is no indication of which comparison stimulus is correct). However, Zentall and Stagner (Journal of Experimental Psychology. Animal Behavior Processes 36:506-509, 2010) showed that when delay of reinforcement was controlled, pigeons had a strong preference for matching over pseudomatching (i.e., there was a sample, but it did not indicate which comparison stimulus was correct). Experiment 1 of the present study replicated and extended the results of the Zentall and Stagner (Journal of Experimental Psychology. Animal Behavior Processes 36:506-509, 2010) study by including an identity relation between the sample and one of the comparison stimuli in both the matching and pseudomatching tasks. In Experiment 2, in which we asked whether the pigeons would still prefer matching if we equated the two tasks for probability of reinforcement, we found no systematic preference for matching over pseudomatching. Thus, it appears that in the absence of differential reinforcement, the information provided by a sample that signals which of the two comparison stimuli is correct is insufficient to produce a preference for that alternative.