Anticipatory cues can interfere with inhibitory operant behavior in the rat

In four separate experiments a total of 24 male rats were trained for 30 min. daily in the same temporal order to inhibit their responses for at least 6 sec. before a response-contingent reward was delivered (DRL-6 sec.). The rats tested as the second group each day displayed about twice the number of errors (effect size = 40%) shown by rats tested in the first or third groups. These results suggest that anticipatory cues, acquired within two sessions, interfere with response inhibition during an appetitive task for a limited time (between a few minutes to about one hour). The results are consistent with the hypothesis that learned anticipation of reward may decrease inhibitory mechanisms by facilitating limbic lability.