Discrete-trials analysis of fixed-interval discrimination.

Abstract

A discrete-trlals procedure with rats was used to study acquisition and extinction of a fixed-interval (FI) 60-sec. discrimination in the absence of effects of free, intrainterval responding. FI discrimination was reflected in observed differences in response latency on nonreinforcement trials which appeared at different temporal locations in the 60-sec. interval separating successive reinforcement trials. With both a between-S and within-S procedure, latencies decreased with time from reinforcement While results were consistent with current interpretations of free-operant FI discrimination, persistence of differential response latencies on extinction trials suggests the facilitative role of intertrial-interval length as a discriminative stimulus in discrete-trials FI procedure.