Contrasting ABA, AAB and ABC renewal in a free operant procedure.

One experiment used a free operant procedure with rats to compare ABA, AAB and ABC renewal by using a within-subject testing procedure. All rats were first trained to press a lever for food in context A. Lever pressing was then extinguished in either context A or context B. For rats in the groups ABA and ABC extinction took place in context B, while the rats in group AAB received extinction in the same context in which acquisition took place (context A). Finally, all rats were tested for renewal in two sessions. One extinction session was carried out in the same extinction context and another session in a different context. Rats in the group ABA were tested in context B and in context A; rats in the group AAB were tested in contexts A and B, whereas the group ABC was tested in contexts B and C. The results of the ANOVA showed context renewal since all groups had higher rates of responding when they were tested outside the extinction context, F(2, 21) = 15.32, p = .001, ηp 2 = .59; however, AAB and ABC renewal was lesser than ABA renewal, F(1, 21) = 16.70, p = .0001, ηp 2 = .61.