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E D Capaldi

Publications and source records attributed to E D Capaldi.

8 recordsLinked to original sources
PubMed1987

Non-reinforcing effects of giving 'dessert' in rats.

We investigated in rats whether giving a sweet substance following a food (a 'dessert') would reinforce a preference for that food. The sweet substance had the reverse effect--rats preference for a flavor decreased if the flavor was given in a food preceding a sweet substance (saccharin or sucrose). If the substances were given in the reverse order, so the sweet substance preceded the food, the rats preferred a sweet substance that had been followed by food to one that had not been followed by food. We suggested two hypotheses to account for the data. Perhaps the sweet substance elicits a negative reaction that is unpleasant unless food is given. Thus, food following a sweet substance is reinforcing, while a sweet substance following food is not. A not incompatible alternative is that anticipatory contrast or comparison effects are involved. Assuming the sweet substance is preferred to the non-sweet, following food by a sweet substance could make the food less valued (anticipatory negative contrast), whereas following a sweet substance by food could make the sweet substance more valued (anticipatory positive contrast).

Animals↗
PubMed1987

Conditioned flavor preferences based on delayed caloric consequences.

In four experiments we showed that rats prefer a flavor associated with a delayed edible consequence if the delayed consequence contains calories; the greater the number of calories, the greater the preference. We obtained conditioned preferences with delayed consequences of dextrose plus quinine, 8% polycose, 8% sucrose, 10 g of high fat mash, and 14 g of lab chow. No conditioned preferences were obtained with delayed consequences of saccharin, 10 g of low fat mash, 1% polycose, or 1% sucrose. Thus, it seems that flavor preferences based on delayed caloric consequences occur only if there are appreciable calories in the consequence.

Animals↗
PubMed1979

Control of instrumental behavior by deprivation stimuli.

In Experiment 1, rats were given one trial per day in a straight alley under food deprivation on half of the trials and under water deprivation on the other half. Wet mash was available in the goal box under food deprivation for Group H and under water deprivation for Group T, the other deprivation being nonrewarded for each group. After 15--18 trials both groups ran significantly faster on their rewarded than on their nonrewarded deprivation days. A third group showed that random variation of alley color retarded formation of the discrimination. A fourth group was run in a conditional discrimination in which under food deprivation wet mash was available in a black alley, nonreward in a white alley, and vice versa under water deprivation. This group took 114 trials to begin running significantly faster in their rewarded than in their nonrewarded alley under each deprivation. In Experiment 2, it was shown that prior learning about deprivation cues "blocks" learning about alley color when alley color is subsequently presented in compound with the deprivation cue but that when both alley color and deprivation cues are relevant from the start of training, the rat learns about both cues. It is suggested that previous studies have underestimated the importance of deprivation cues by using conditional discrimination designs, choice measures rather than speeds, and parameters that are not optimal for discrimination learning.

Animals↗