The conditions for temporal tracking under interval schedules of reinforcement

On many cyclic-interval schedules, animals adjust their postreinforcement pause to follow the interval duration (temporal tracking). Six pigeons were trained on a series of square-wave (2-valued) interval schedules (e.g., 12 fixed-interval [FI] 60, 4 FI 180). Experiment 1 showed that pigeons track square-wave schedules, except those with a single long interval per cycle. Experiments 2 and 3 established that tracking and nontracking are learned and both can transfer from one cyclic schedule to another. Experiment 4 demonstrated that pigeons track a schedule with a single short interval per cycle, suggesting that a dual process—cuing and tracking—is necessary to explain behavior on these schedules. These findings suggest a potential explanation for earlier results that reported a failure to track square-wave schedules. Hungry animals will readily learn to adjust their behavior to the typical time in between periodic food deliveries. Under some conditions, these adjustments take place rapidly. These rapid ad-justments have been studied by manipulating the time between consecutive food deliveries. On cyclic-interval (CI) reinforcement schedules, for example, successive interfood intervals (IFIs) in