Context dependent changes in the reinforcing strength of schedule-induced drinking.

The team let rats press a button to earn tiny sips of water. The catch: food pellets arrived on a fixed-time schedule. This setup tested if the rats' own schedule-induced drinking could keep the button-pressing going.

They varied how often the pellets arrived. Then they watched how hard the rats worked for water after each change.

Button pressing rose, peaked, then fell as pellet rate increased. The curve looked like an upside-down U.

When the periodic food stopped, the rats quit pressing for water. The drinking only worked as a reinforcer inside the same food context that created it.

Baer (1974) first showed that spaced food makes rats drink too much. Locurto et al. (1980) now shows that very drinking can turn around and reinforce new behavior.

Falk (1966) and Blackman (1970) found longer intervals create more polydipsia. The new study mirrors that curve: reinforcing strength also climbs then drops as intervals shrink.

Grosch et al. (1981) brought polydipsia under tone control one year later. Together the two papers stretch the phenomenon from stimulus control to reinforcer function.

You now know that adjunctive behaviors can act as reinforcers, but only while the inducing schedule runs. This matters when you design interventions that use timed snacks, tokens, or breaks. If a client starts rocking, pacing, or sipping, that behavior might strengthen other responses while the clock ticks. Watch for it, and remember the power vanishes once the periodic delivery stops.