Abstract: | Match-to-sample training clusters of A1 (sample): B1/B2 (comparisons), A2: B2/B1, B1: A1/A2, B2: A2/A1, B1: C1/C2, B2: C2/C1, C1: B1/B2, and C2: B2/B1 were presented to pigeons with class-consistent differential reinforcement using two dissimilar types of food reinforcers. Distinctive class-consistent response patterns occurred to the samples during the fixed-ratio 5 sample observing response requirement. Subsequent tests, modeled from the equivalence class paradigm demonstrated the emergence (80% class consistent) of the transitive-like A-C and C-A relations for 4 and 2 of 12 pigeons, respectively, and a strong trend (over 70%) for 7 and 6 others, respectively; the emergence of the reflexive-like identity relation when the nonidentical comparison was from the other class; and the disruption of the trained within-class relation with the addition of a reflexive comparison. After directional training of C1: D1/D2 and C2: D2/D1, tests indicated no emergence of the symmetric-like D-C relation or the composite D-B and D-A relations, but the B-D and A-D transitive-like relation occurred with some pigeons. Off-baseline training with class-consistent differential reinforcement contingent on responding to the D stimuli alone produced distinctive responding and, in turn, a trend to D-C symmetric-like control in 4 of 12 pigeons, as well as a shift toward class-consistent control on D-B and D-A test trials. Class-consistent differential reinforcement that produced distinctive sample behavior promoted stimulus control relations like those that circumscribe equivalence class formation. Respondent—operant interactions permit an analysis of the possible enrollment of stimulus values of distinctive responding to the discriminative stimuli forming the stimulus classes via processes corresponding to naming in humans. |