“…When the CS is subsequently presented again, conditioned responding is evoked. Reinstatement has been demonstrated following extinction of fear conditioning in rats (e.g., Rescorla & Heth, 1975;Westbrook, lordanova, McNally, Richardson, & Harris, 2002) as well as in operant conditioning procedures involving drug-reinforced operant responding (e.g., de Wit & Stewart, 1981Stewart, , 1983Katner, Magalong, & Weiss, 1999;McFarland & Ettenberg, 1997). However, there are no known studies that have reported reinstatement of discriminated operant responding under discriminative control by drugs by noncontingent reinforcement following extinction.…”