Analysis of water and NaCl solution acceptance by schedule-induced polydipsia.
Under VI food schedules, salty water turns frequent small sips into infrequent big ones, showing how taste reshapes adjunctive drinking.
01Research in Context
What this study did
Rats earned food on a VI 1-min schedule. Between pellets they could drink plain water or salty water.
The team slowly raised the salt level to see when the rats would drink less. They counted licks and sip size.
What they found
Up to 0.9 % salt the rats kept drinking often. Above 1.2 % they still drank, but took fewer, bigger gulps.
The schedule kept the behavior alive; the taste only changed how it looked.
How this fits with other research
Falk (1966) ran the same VI setup and showed the drinking is real adjunctive behavior, not just thirst.
CATANIDINSMOOR (1962) saw the same adventitious drinking four years earlier, but without testing different tastes.
Morris et al. (1982) later asked why the drinking happens. They ruled out direct food cues and said it emerges from competition among behaviors. The salt curve and the competition idea fit together: the schedule keeps the rat busy, and the salt modulates the form.
Cohen (1975) went further, showing the water itself can become reinforcing. The earlier salt curve helps explain why that reinforcement value can shift.
Why it matters
For BCBAs, the lesson is that schedules create collateral behavior. A child may tap, pace, or sip during breaks. If the form looks odd, check the schedule first, then the available items. Changing the item’s effort or taste can reshape the topography without killing the schedule effect.
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02At a glance
03Original abstract
Animals were trained on a VI 1-min schedule for food pellets, and concurrent water intake was measured. The polydipsia induced was analyzed in terms of the frequency distribution of post-pellet licking burst sizes and the trend of polydipsia throughout the session. An ascending series of NaCl solutions was presented consecutively over daily sessions and a typical NaCl acceptance-rejection intake function was generated. Beginning in the 0.9-1.2% NaCl range, the animals drank less often during the session but took larger drinks when they did drink. Neither the frequency of drinks nor the mean licking burst size were simply related to the volumes of NaCl solution consumed. The NaCl acceptance-rejection function cannot be explained in terms of water repletion factors alone.
Journal of the experimental analysis of behavior, 1966 · doi:10.1901/jeab.1966.9-111