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The present experiment examined the influence of overtraining on the nonshift and reversal shift of a matching-to sample (MTS) discrimination. Rats were trained to criterion or were overtrained on the MTS discrimination. After completing Phase 1 training, they received extinction to criterion, and then were given either a nonshift (Group Nonshift) problem, in which the rule was not changed from Phase 1 but novel stimuli were used, or a reversal shift (Group Reversal) problem, in which the rule was changed from Phase 1 but the stimuli were not changed. Overtraining facilitated Phase 3 shift learning of both Group Nonshift and Group Reversal. There were no significant differences in the rate of learning in Phase 3 shift between Groups Nonshift and Reversal after criterion training and overtraining. These findings suggest that a common response to a configuration of stimuli with the same response assignment formed in Phase 1 remain effective intact after extinction.