| Abstract: | In the acquisition phase, pigeons learned to peck at a changeover key to shorten the duration of S? but not of S+ presented on the food key in a discrimination problem. In the transfer phase, the significance of S+ and S? was changed through extinction of both, equal reinforcement, or discrimination reversal, while the changeover key was not available. Transfer tests then showed appropriate modification of the changeover response. Similar transfer was demonstrated across orthogonal stimulus dimensions. Further analytic studies showed that this transfer of the changeover response did not depend upon mediation due to differential response rates to the food key. This research strategy enriches the study of the “second learning process” by providing an indicator of stimulus control in all phases of the procedure. Direct transfer between different problems also indicates that discriminative stimuli, although physically dissimilar, have the same “psychological value” for the subject. |
