The Effects of Behavioral History on Response Acquisition with Delayed Reinforcement: A Parametric Analysis

Abstract

The present study systematically assessed the effects of two independent variables on response acquisition, delay duration and the number of sessions of non-contingent food delivery. Sixty naïve, male Wistar rats were exposed to an FT 60-s schedule for a different number of sessions (0, 1, 5, 15 or 30). Once exposure to non-contingent food delivery was over, subjects were exposed to one of four different Tandem FR 1, FT x-s schedule, for 10 sessions, where FT duration could be programmed at 10, 20, 40 or 60-s. Results showed evidence of response acquisition was more apparent in those groups where subjects were exposed to 1, 5 or 15 sessions of non-contingent food delivery; response acquisition was less evident in those groups exposed to 0 or 30 sessions of the FT 60-s schedule. In general, obtained reinforcement rate decreased as delay duration increased. Results were discussed in terms of how history effects may make it difficult to compare experimental findings; the discussion also centered on variables that could probably explain why reinforcement history affects response acquisition with delayed reinforcement.