Analysis of the superiority of discrete-trials over free-operant procedures in temporal response differentiation

Two experiments examined the effects of various relations between 81 male Wistar rats' leverpress duration and occurrence of intertrial intervals (ITIs). Exp I employed fixed minimum-duration requirements for reinforcement in 4 groups that received ITIs following all presses, no presses, only presses of subcriterion duration, or only those of criterion duration. The major effect was that ITIs following subcriterion press durations or …