CONTROL DISCRIMINATIVO CON ESTíMULOS COMPUESTOS EN PROGRAMAS TEMPORALES DE REFORZAMIENTO

Abstract

Two experiments were conducted to assess the possible inhibitory effects of adding a stimulus to the stimuli correlated with tO and t delta in a temporally defined reinforcement schedule. In Experiment 1, 4 Wistar rats were exposed to four experimental phases in which the probability of reinforcement was 1.0 in tO and 0.0 in t delta. Three probes, in which response-independent reinforcement was provided, occurred between the experimental phases. In the first phase and probe a green light was in effect during tO and a red light during t delta. In the second phase and probe, a red light was in effect during t delta and a red light and a green light together during tO. In the third phase and pro be, a green light was in effect during tO and a red light and a green light together during t delta. The fourth phase was identical to the first. In Experiment 2, also conducted with 4 Wistar rats, the procedure was similar to that in Experiment 1 except that instead of adding the EO or the E delta in the tO and t delta periods, a neutral stimulus, a white light, was added. The effects of the compound stimulus were different in the tvyo experiments. In Experiment 1 response rates increased in t delta while in Experiment 2 no systematic effects were observed. In both experiments during the probes the rats responded only during tO. The results indicate that stimulus control does not behave in the same way in limited-hold temporal schedules and conventional s~hedules as described by Ferster and Skinner (1957), suggesting functional differences between the two reinforcement schedule systems.