Bang-bang control of feeding: role of hypothalamic and satiety signals.

Rats, people, and many other omnivores eat in meals rather than continuously. We show by experimental test that eating in meals is regulated by a simple bang-bang control system, an idea foreshadowed by Le Magnen and many others, shown by us to account for a wide range of behavioral data, but never explicitly tested or tied to neurophysiological facts. The hypothesis is simply that the tendency to eat rises with time at a rate determined by satiety signals.

The effects of interval duration on temporal tracking and alternation learning.

On cyclic-interval reinforcement schedules, animals typically show a postreinforcement pause that is a function of the immediately preceding time interval (temporal tracking). Animals, however, do not track single-alternation schedules-when two different intervals are presented in strict alternation on successive trials. In this experiment, pigeons were first trained with a cyclic schedule consisting of alternating blocks of 12 short intervals (5 s or 30 s) and 12 long intervals (180 s), followed by three different single-alternation interval schedules: (a) 30 s and 180 s, (b) 5 s and 180 s, and (c) 5 s and 30 s.

Timing in choice experiments.

In Experiment 1, pigeons chose between variable- and fixed-interval schedules. The timer for 1 schedule was reset by a reinforcement on that schedule or on either schedule. In both cases, the pigeons timed reinforcement on each schedule from trial onset.

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.