Journal of the experimental analysis of behavior
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The current experiment examined the degree to which locally varying food probabilities on two keys across time since food presentations can continue to control choice until the next food delivery. In two sets of conditions, the probability of food delivery being made available on one key relative to the other key varied sinusoidally across a 1-min period following each food delivery. In Set 1, food-probability changes were unsignaled and the number of cycles per min was varied across conditions. ⋯ The onset of stimulus changes in Set 2 led to a transient reinstatement of local control by food probabilities regardless of the portion of the sinusoidal variation in food probabilities signaled by the stimuli. However, in conditions where the same colored stimuli signaled different portions of the sinusoidal variation in food-delivery probabilities, stimulus changes attenuated joint control by elapsed time and food-probability values. These results suggest that, changing relative food probabilities and stimuli can direct preference toward the likely location of the next food delivery across time since a food presentation, although the degree to which control over choice will be maintained across elapsed time depends on how experimenter-arranged contingencies are mapped onto elapsed time.