Spatiotemporal characteristics of serial CSs and their relation to search modes and response form

Abstract

In four experiments, we examined how the spatiotemporal proximity to food of the two elements of a serial conditioned stimulus (CS) influenced the pattern of CS-directed versus food-site-directed behavior in rats. Experiment 1 showed that only temporal proximity affected responding when the serial CS consisted of two successive 4-sec presentations of either a spatially near or a spatially far lever (NN or FF). However, Experiment 2 showed that behavior depended markedly on whether rats received a near followed by a far lever (NF) or a far followed by a near lever (FN). Experiment 3 showed that the effects of Experiment 2 could be changed by increasing the duration of the second CS element, and Experiment 4 showed that these changes were not related to previous training. We concluded that behavior produced by the spatiotemporal qualities of the lever elements can be attributed to a mapping between the temporal qualities of the CS elements and an underlying sequence of search modes related to finding food.