Fixed-time schedule effects as a function of baseline reinforcement rate

Using an arbitrary response, we evaluated fixed-time (FT) schedules that we re either similar or dissimilar to a baseline (response-dependent) reinforc ement schedule and extinction. Results suggested that both FT schedules and extinction resulted in decreased responding. However, FT schedules were mo re effective in reducing response rates if the FT reinforcer rate was dissi milar to baseline reinforcer rates. Possible reasons for this difference we re evaluated with data analysis methods designed to identify adventitious r esponse-reinforcer relations.