Effects of orientation and differential reinforcement II: transitivity and transfer across five-member sets

A recent report by Amd et al. (2017) demonstrated that orienting towards successively presented stimulus-stimulus pairs yielded significantly more transitive relations then when those same pairs were differentially reinforced following training for three, 3-member stimulus sets. We build on that work in four important ways. First, transitivity yields produced by Pavlovian and instrumental procedures were compared following training for three 5-member sets (A1-B1-C1-D1-E1, A2-B2-C2-D2-E2, A3-B3-C3-D3-E3), where the 'A' stimuli were emotional faces and all remaining stimuli were nonsense words. Second, our instrumental task here required two orienting/observing responses per trial. Third, we compared differences in multi-nodal transfer following Pavlovian and instrumental relational learning procedures. Finally, we tested whether functioning as 'end terms' in a relational series can mitigate transfer following instrumental conditioning. Transitivity, as measured by sorting tests, was significantly more pronounced following Pavlovian training. Transfer, assessed before and after relational training with two visual analog scales corresponding to valence and arousal dimensions, appeared marginally more robust observed for participants exposed to the Pavlovian condition. Transfer magnitude was positively related with demonstrations of transitivity, regardless of type of conditioning.