Superconditioning from a reduced reinforcer.

In four autoshaping experiments pigeons received conditioned inhibition training of the form A++, AB-, where ++ is a strong reinforcer and - is nonreinforcement. Subsequent AB+ training, in which + is a moderate reinforcer, resulted in enhanced conditioning of A, relative to an A stimulus receiving no treatment, one receiving A+ treatment, and one receiving A++ treatment. This enhancement of conditioning to A constitutes a demonstration of "superconditioning". The presence of the inhibitory B sufficiently enhanced the reinforcing power of the moderate reinforcer (+) that it was able to further increase the excitation controlled by A. This occurred even though A had previously been paired with a stronger reinforcer (++). Superconditioning was also observed when A and B were extinguished prior to treatment with + or were originally neutral stimuli followed by + in the presence of an inhibitor trained elsewhere.