Untrained temporal differentiation and equivalence class formation

The purposes of this study were to assess whether discriminative control over conjunc FR 5 t(1) < IRT < t(2) responding would transfer to members of stimulus equivalence classes; whether a formal test for equivalence would be necessary for such transfer to occur; and to compare the effectiveness of derived discriminative control through symmetry, versus equivalence relations. In Experiment 1, 2 out of 6 subjects demonstrated the reliable transfer of stimulus functions prior to the test for equivalence; in Experiment 2, none of 5 subjects demonstrated the reliable transfer of stimulus functions prior to the test for equivalence, but 2 did so following the test for equivalence; and in Experiment 3, all 4 subjects demonstrated the reliable transfer of stimulus functions prior to the test for equivalence. No differences were observed between the derived control exerted by stimuli that had entered into symmetry relations with training stimuli, versus those that had entered into equivalence relations with training stimuli. It was concluded that behavior can appear to be temporally differentiated in the absence of direct conditioning.