Figure 2: Effects of SCH23390 on rats' impulsive performance under baseline (inter-trial interval = 5) and challenged condition (inter-trial interval = 7 s) on total premature (a), previous reward-associated premature (b), and the ratio of previous reward-associated premature to total premature (c), compared with 20%, which is the one-fifth probability of the total count, i.e. randomized distribution across five holes). SCH23390 attenuated total (i.e. the randomized) prematures/perseverations but not the previous reward-associated prematures under a longer information-waiting period. SCH23390 rats exhibited a motoric preference to the location linked to previous reinforcement under a longer information-waiting period (inter-trial interval = 7 s). Values are presented as mean ± standard error of the mean (SEM) (N = 8 for each group). *P < 0.05, **P < 0.01, *** P < 0.001.