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J H Porter

Publications and source records attributed to J H Porter.

At least 55 records · Page 3Linked to original sources
PubMed1981

Stimulus generalization of schedule-induced polydipsia.

Five rats were exposed to an intradimensional discrimination by associating two tones of different frequency with the components of a multiple random-time 30-sec, extinction schedule of food presentation. After schedule-induced polydipsia developed and the intermittent schedule of food presentation established stable differential licking rates during the stimuli associated with the multiple schedule, a stimulus generalization test was conducted. When generalization testing was conducted by presenting stimuli that varied on the frequency dimension during the random-time 30-sec component of the multiple schedule, all five rats demonstrated moderately sloping symmetrical gradients. Thus, schedule-induced polydipsia can be brought under the control of stimuli other than the food pellet.

Journal Article↗
PubMed1976

Acquisition of schedule-induced polydipsia in rats with no prior drinking experience.

Three litters of 10 rat pups each were reared on Purina laboratory chow and either (1) continuous access to water, (2) access to both water and lettuce until weaning at 21 days and then only lettuce, or (3) continuous access to lettuce. At 100 days all rats were reduced to 80% free feeding weight and tested for polydipsia. During 15 sessions of polydipsia testing, excessive postpellet drinking developed in all groups to 45 mg Noyes pellets delivered on a fixed-time 1 min schedule. No significant differences in water intake over sessions were found among groups. It was concluded that schedule-induced polydipsia does not represent an exaggeration of a learned prandial drinking pattern, but rather an exaggeration of an inborn prandial drinking reflex.

Animals↗
PubMed1975

Effects of variable and fixed second-order schedules on schedule-induced polydipsia in the rat.

Schedule-induced polydipsia was studied in rats on a variable second-order schedule in Experiments 1 and 2. Drinking occurred only following presentations of the pellet reinforcer and was not induced by a stimulus that was associated with pellet delivery. Moreover, it was shown that lever pressing for food was not competing with the opportunity to drink following the stimulus during non-reinforced intervals. In Experiment 3 a fixed second-order schedule was used, and only one animal drank following the presentation of the stimulus. A positive contrast effect was obtained with schedule-induced drinking in Experiments 1 and 2, and it was suggested that schedule-induced polydipsia shows behavioral interactions similar to those seen with food reinforced operants.

Animals↗
PubMed1975

Schedule-induced drinking as a function of percentage reinforcement.

Drinking was recorded in rats while lever pressing was maintained on a series of percentage reinforcement schedules in which the per cent of 1-min fixed intervals terminating with food was 100, 90, 30, 70, 10, 50, and 100%. Intervals in which a pellet was omitted were terminated by brief light flash and click stimuli that were also correlated with food presentations. Drinking failed to develop in five of six subjects following intervals in which the brief stimuli were presented regardless of percentage reinforcement. Postpellet drinking, which followed intervals terminated with pellet delivery, however, increased in both duration and amount ingested per interval as percentage reinforcement was systematically decreased. The increase in postpellet drinking above that produced by 100% reinforcement was interpreted as an analogue of the positive-contrast effect observed with food-reinforced operants.

Journal Article↗