Spatial organization of rat’s behavior in a situation with three optional lever-pressing responses under continuous and fixed-interval schedules of food

Abstract

We assessed spatiotemporal distribution of behavior as a function of the spatial and temporal arrangement of food delivery. Eight food-deprived rats were exposed in an extended experimental chamber to a continuous reinforcement schedule (CRf) or to a fixed interval (FI) 30 s, with three levers contiguous to food dispenser or placed on separate panels. Responses on any of the levers were equally operative on the ongoing schedule. All rats moved mainly near to dispenser and levers when these were contiguous, under both, CRf and FI schedules, although distribution of responses on different levers was more variant under FI than under CRf. With separate levers, rats traveled through a larger area of the experimental space, especially under FI. Distribution of responses showed more variation under FI than under CRf schedule. Under FI, response patterns consisted in a post-meal pause followed by an acceleration towards the next food. Findings are discussed in the context of studies in which have been reported inconsistent patterns under FI schedules when are manipulated the number of operanda, dispensers, and their locations. It is highlighted the relevance of continuous analysis of rats’ displacement, to account for the configuration of response patterns observed in this study.