A comparison of the Rescorla-Wagner and Pearce models in a negative patterning and a summation problem

In two experiments, we examined two related conditioning problems previousl y investigated by Redhead and Pearce (1995a) and Pearce, Aydin, and Redhead (1997). Experiment 1 involved an A+, B+, C+, AB+, AC+, BC+, ABC - discrimi nation. The Rescorla-Wagner model predicts that response to AB, AC, and BC will be greater than that to A, B, and C at asymptote, whereas the Pearce m odel makes the opposite prediction. In Experiment 2, we investigated the re sponding to a novel ABC compound in groups trained with either A+, B+, C+ o r AB+, AC+, BC+. The Rescorla-Wagner model predicts greater response to ABC in the group trained with A+, B+, C+ than in the group trained with AB+, A C+, BC+, whereas the Pearce model makes the opposite prediction. In contras t to the findings of Redhead and Pearce (1995a) and Pearce et al. (1997) in pigeon autoshaping, our findings in rabbit eyelid conditioning support the Rescorla-Wagner model.