VALUE TRANSFER IN A SIMULTANEOUS DISCRIMINATION APPEARS TO RESULT FROM WITHIN-EVENT PAVLOVIAN CONDITIONING

When pigeons acquire a simple simultaneous discrimination, some of the value acquired by the S+ transfers to the S-. The mechanism underlyin g this transfer of value was examined in three experiments. In Experim ent 1, pigeons trained on two simultaneous discriminations (A+B- and C +/-D-) showed a preference for B over D. This preference was reduced, however, following the devaluation of A. In Experiment 2, when after t he same original training, value was given to D, the pigeons' preferen ce for C did not significantly increase, In Experiment 3, when both di scriminations involved partial reinforcement (S+/-), A+C- training res ulted in a preference for B over D, whereas B+D- training resulted in a preference for A over C. Thus, simultaneous discrimination training appears to result in bidirectional within-event conditioning involving the S+ and S-.