Robert W. Schaeffer

Effects of a conditioned taste aversion on schedule-induced polydipsia

Rats that became Polydipsic on water under a FFI-60 food schedule were switched to a saccharin solution. After drinking saccharin, the Ss were exposed to ionizing radiation. Although this procedure produces a marked aversion to saccharin in thirst motivated rats following a single exposure, repeated pairings of the saccharin solution and ionizing radiation were needed to reduce the high drinking levels generated by the intermittent food schedule. These findings suggest that schedule-induced polydipsia is a strong motivational state.

Effects of Sucrose Concentrations upon Schedule-Induced Polydipsia on a Ffi-60-Sec. Dry-Food Reinforcement Schedule

Food-deprived female albino rats were tested under a free-food schedule (FFI-60-sec.) in which water was freely available in both the test chamber and the home cage. 5 groups of 4 Ss each received different formulae of Noyes 45-mg. dry-food pellets. Group 1 received standard formula pellets containing 7.5% glucose. Group 2 received “no glucose” formula pellets. Groups 3, 4, and 5 received “no glucose” formula pellets with 4.0%, 16.0%, and 32 0% sucrose added, respectively, by weight. An inverse relationship between sucrose concentration of the pellets and water intake levels was obtained and all groups receiving sucrose or glucose pellets drank less than the group that received the “no-glucose” pellet.

Lick rates in cats

Lick rates in three kittens and two adult cats were measured for milk amd water under 6, 12, and 24 hr. deprivation, and for 4%, 8%, 16%, and 32% sucrose solutions under 12 hr. deprivation. Mean lick rate was found to be constant for all Ss, and to be independent of age, sex, level of deprivation, and type of fluid consumed.

Effects of sucrose concentrations upon schedule-induced polydipsia using free and response-contingent dry-food reinforcement schedules

Food-deprived female albino rats were tested under free (FFI) and lick-contingent (FR) reinforcement schedules in which water was freely available both in the test chamber and the home cage. Five groups of four Ss each received different formulas of Noyes 45-mg dry food pellets during the experimental sessions. Group 1 received standard formula pellets containing 7.5% glucose. Group 2 received “no-glucose” formula pellets. Groups 3, 4, and 5 received “no-glucose” pellets with 4.0%, 16.0%, and 32.0% sucrose added, respectively, by weight. An inverse relationship between sucrose concentration of the pellets and water intake levels was obtained for the FFI 60-sec schedule, and Ss receiving sucrose pellets drank less water throughout all experimental phases than either the no-sugar group or the 7.5% glucose group of Ss. The differential effects of glucose and sucrose upon water intakes and the differences between FR and FFI drinking performances were discussed.

The effect of FR response requirement on aggressive behavior in rats

Attack responses were observed in water-deprived rats that were exposed to FR-20, FR-40, and FR-60 water reinforcement schedules. Relative to the baseline condition, aggression increased under the FR-20 schedule. The frequency of attack behavior under the FR-40 and FR-60 conditions was equal to, or less than, the frequency of attack observed in the baseline condition. Attack responses were found to be equally probable in all segments of the interreinforcement intervals. These results were discussed with regard to the results of other studies of schedule-induced aggression.

Collateral water drinking in rats maintained on FR food reinforcement schedules

Six food-deprived female rats were tested on a bar press for food contingency under increasing FR requirements. The results corroborated a prandial interpretation of schedule-induced collateral water drinking in that number of meals, total water drunk, and amount of water ingested per reinforcement increased as the FR requirement increased.

Classical conditioning of reflexive fighting

This study demonstrated that reflexive fighting could be classically conditioned to a 80-db buzzer, usingboth simultaneous and delayed conditioning paradigms.

Acquisition of an imitative response in rats

Following behavior in rats was tested in an open-field apparatus with four choice-point alternatives. Rats learned to follow leader animals when access to water was contingent on following.

DEVELOPMENTAL ANALYSIS OF SCHEDULE-INDUCED POLYDIPSIA

In a developmental analysis of schedule-induced polydipsia (SIP), 8 female, albino rats were exposed to either a FI-60-sec. or a VI-60-sec. reinforcement schedule with 4 Ss in each group. Results indicated that the adventitious reinforcement explanation for SIP is not tenable, since licks did not occur with equal probability in all periods of the interpellet interval during SIP development; lick bursts coming in contact with pellet deliveries were a result rather than a cause of SIP; and SIP developed more slowly on the VI than on the FI schedule.

Drinking response distributions associated with a 4% sucrose FFI food schedule

Polydipsia was produced in two female rats when they were exposed to a FFI 40 sec. 4% sucrose pellet food reinforcement schedule. An analysis of the inter-pellet drinking distribution of both Ss indicated that drinking followed, rather than preceded pellet delivery. This result was interpreted as further evidence for a prandial interpretation of schedule-induced polydipsia.