Schedule constraint on the average drink burst and the regulation of wheel running and drinking in rats.

Two experiments compared predictions of a molar-pattern model and a general molar behavior regulation model by requiring rats to wheel run for access to water. In both experiments schedule parameters constrained the baseline average burst length of drinking without constraining total drinking. Five levels of schedule constraint were imposed on time spent per drinking burst (Experiment 1) or the number of drinks per burst (Experiment 2). The results of both experiments supported the general molar behavior regulation view but not the molar-pattern model by showing no increase in total wheel running and no decrease in total drinking under schedule constraint. However, both experiments also showed local effects of drink burst constraint, including a direct relation between the degree of constraint and the local rate of drinking, and an approximation of the temporal distribution of baseline drinking under all degrees of schedule constraint. Most local changes support the view that rats defend the baseline temporal distribution of responding under schedule constraint, though some changes appear related to disruption of local response pattern characteristics.