Punishment of Schedule-Induced Drinking by Lick-Dependent Delays in Food Presented at Different Frequencies

Abstract

Three food-deprived rats (80% of their free-feeding weights) developed schedule-induced drinking after being exposed to a multiple fixed-time schedule (FT 60-s FT 18-s) of food-pellet presentation. A 3-s signaled delay was then initiated by each lick, and the rate of licking was reduced to a much greater extent in the FT 18-s component in two rats. With these rats, a 9-s lickdependent signaled delay then occurred in the FT 60-s component only, and a reduction was observed in licks per minute similar to that observed previously with the 3-s delay in the richer component. With the third rat the delays which were effective in reducing licking were 6 and 18 s in the FT 18-s and FT 60-s components, respectively. Measures of the percentage of interfood intervals with at least one lick produced less pronounced effects. These results suggest that the ratio between delay length and interfood interval length is critical for lick-dependent delays to be effective in punishing schedule-induced drinking. Falk (1961 ) found that food-deprived rats exposed to a variableinterval schedule (VI 1-min) of food reinforcement drank excessive amounts of water concurrently with their performance of the operant task. This behavior is unusual because the rats were not deprived of water and no contingency was arranged between their drinking and the delivery of food. Falk (1971) suggested that this schedule-induced polydipsia was the prototype of a behavioral class named "adjunctive behavior;' different from operant behavior. The amount of schedule-induced behavior is related to the parameters that define the food reinforcer, such as its magnitude or quality, the rate at which food is presented, or the animal's level of food deprivation (see reviews by Pell6n, 1992;Reid & Staddon, 1990;Wetherington, 1982).

Reinforcement of schedule-induced drinking in rats by lick-contingent shortening of food delivery

“…Even though the behavior of drinking was not completely suppressed, the establishment of this contingency led to lower rates of drinking regardless of whether or not the delays were signaled. These results were later replicated (Lamas & Pellón, 1995;Pellón & Castilla, 2000) and have been shown to be very similar to the results normally found when a well-established operant behavior is punished. It has also been seen that resistance to punishment is related to the deprivation levels in operant behavior, just as it is in schedule-induced drinking (Lamas & Pellón, 1995).…”

“…As operants are defined by their consequences, a way to test this hypothesis would be to establish a contingency between the behavior of licking a waterspout and the delivery of food pellets. This contingency has previously been employed in several experiments in which the behavior of drinking was punished by a delay in the delivery of food (Lamas & Pellón, 1995;Pellón & Blackman, 1987;Pellón & Castilla, 2000), thus lengthening the interfood interval. Those studies concluded that adjunctive drinking was subject to punishment but left unanswered the question of whether it was developed by a contingent food schedule (see Patterson & Boakes, 2012).…”

Response–food delay gradients for lever pressing and schedule-induced licking in rats

“…When postfood licking is kept distant from food reinforcement, it is reduced by that action. To further support this possibility, Pellón and Castilla (2000) found that lick-dependent delays as short as 3 or 6 s were able to reduce licking when the behavior was induced by short interfood intervals (an FT 18-s schedule), which guaranteed that postfood licking effectively postponed food delivery. Finally, Keehn and Stoyanov (1983) reported a suppression of water consumption when food was only available 50 or 60 s from the last lick (induced by a FT 60-s food schedule), a finding also consistent with what we have obtained here.…”

Amphetamine increases schedule-induced drinking reduced by negative punishment procedures

“…Normally acquired polydipsia was reduced with the subsequent introduction of lick-contingent delays. These results demonstrate yet again that lick-contingent delays in food presentation can serve to reduce normal development of schedule-induced polydipsia or punish previously acquired polydipsia (Flory and Lickfett 1974;Moran and Rudolph 1980;Blackman 1987, 1991;Lamas and Pellón 1995a, 1995bPellón and Castilla 2000).…”

“…The amount of adjunctive behaviour can be increased or decreased by the explicit introduction of contingencies of positive reinforcement and punishment, respectively (Bond et al 1973;Flory and Lickfett 1974;Reberg 1980;Pellón and Blackman 1987). Pellón and Blackman (1987) showed that schedule-induced drinking can be punished by the presentation of lickcontingent delays in the reinforcer, an effect that can be modulated by the length of the delay, the duration of the reinforcement schedule and the level of food deprivation (Lamas and Pellón 1995a;Pellón and Castilla 2000).…”