On the relationship between differential outcomes and differential sample responding in matching-to-sample.

Four experiments examined control over choice by differential sample responding in matching-to-sample with differential outcomes. In Experiment 1, pigeons initially learned to match with food versus no-food outcomes. Their performances later transferred to other samples to which responding versus not responding had been explicitly reinforced with a single outcome (food). In Experiment 2, pigeons initially learned to produce the comparisons by pecking one sample but not the other. Transfer was then observed to new samples associated with food versus no food (and thus often vs. seldomly pecked). Experiments 3 and 4 showed that transfer of matching required differential behavior to each sample set and did not depend on explicit conditioning of that behavior prior to acquisition. Together, these results show that differential sample behaviour provides a redundant cue for choice in differential outcome matching-to-sample.