Multiple and concurrent schedules of fixed-interval reinforcement

Abstract

Key pecking by three pigeons was maintained under a multiple fixed­

-interval 50-sec, fixed-interval 120-sec schedule in ¡‘liase 1, the same fixed-interval schedules programmed concurrently in Phase II. Again Éhe same concurrent schedules with tbe addition of a 5-sec timeout period as consequence of changeover responses in ¡‘base III, and concurrent variable-interval 5O-sec, variable interval l20-sec, with a 5-sec timeout penad contingent on changeovers, ¡n ¡‘liase IV. Under multiple and concurrent fixed-interval schedules, in the first three phases of the experiment, ratios of response rates (response rates ¡n one schedule divided by response rates in the second schedule) were close to one for ah subjects, while ratios of obtained reinforcements per minute varied from 2.28 to 5.00. However, diere was an extreme preference Lar the schedule providing higher frequency of reinforcement in concurrent variable. interval schedtthes, while obtained reinforcement ranos remained approximatelv equal to those observed on dic previous phases.