Probability and availability of reinforcement in temporal schedules of different durations

Abstract

The effects of varying the probability (P) and the temporal availability (T) of reinforcement were studied in signaled and unsignaled temporally defined schedules of different durations. Two experiments were designed. In the first one, two groups of rats were exposed to a thirty seconds T schedule. In one of the groups (with signal), a white ligth located above the response lever was presented during the 1D period, while in the other group no signal was presented during the tD period, while in the other group no signal was presented during the tD period. In both groups, T was varied within-sessions along 1.0, 0.5, 0.3 and 0.1 values. The parameter P was varied independently between phases with the same values of T resetting to 1.0 during the last phase. In the second experiment, the same parameters and values of the first experiment were manipulated, varying only the cycle length to sixty eigth seconds