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1.
In Experiment 1, rats poisoned following schedule-induced saccharin consumption showed a moderate reduction in the schedule-induced consumption of saccharin. With repeated poisoning, schedule-induced saccharin polydipsia was markedly reduced. Acquisition of conditioned aversion under the schedule-induced procedure was significantly slower than acquisition under water deprivation. In addition, recovery of consumption of the previously poisoned solution during extinction was more rapid under schedule-induced polydipsia. Experiment 2 revealed that schedule-induced polydipsia was less sensitive to suppression by conditioned aversions than a prandial drinking condition in which subjects were equally food deprived but were given a mass feeding instead of spaced pellet deliveries, suggesting that the relative insensitivity of schedule-induced polydipsia to conditioned taste aversions is not simply a function of different levels of food deprivation. This relative insensitivity is offered as a partial basis for the occurrence and maintenance of schedule-induced alcohol polydipsia.  相似文献   

2.
Animals poisoned following exposure to saccharin subsequently avoided the schedule-induced consumption of saccharin. While this suppression was transient for subjects who had access only to the saccharin solution during the free-food presentations, recovery of schedule-induced saccharin consumption was significantly retarded for subjects who had concurrent access to saccharin and a running wheel. It has been suggested that the transient suppression of schedule-induced polydipsia by conditioned taste aversions results from the pellet-induced tendency to drink within the schedule-induced polydipsia procedure. That access to the running wheel reduces schedule-induced polydipsia in general and prolongs the suppression of schedule-induced polydipsia by taste aversions supports this view.  相似文献   

3.
In Experiment 1, animals poisoned following schedule-induced or prandial-induced saccharin consumption subsequently showed identical aversions to saccharin when tested under water deprivation. In Experiment 2, animals conditioned to avoid saccharin to similar levels under water deprivation were differentially affected when saccharin was subsequently presented on the baselines of schedule-induced and prandial-induced drinking. Together, these data indicate that the differential effects observed on schedule-induced and prandial-induced drinking when animals are poisoned following consumption under these two schedules do not reflect the differential acquisition of taste aversions, but instead reflect the differential tendencies to drink induced by the spaced and massed feedings.  相似文献   

4.
Animals poisoned following the schedule-induced consumption of saccharin initially continued to drink following spaced pellet deliveries. Neither the initiation of postpellet drinking (i.e., bout, initiation) nor the size and duration of the bouts was effected by the conditioned aversion procedure. With repeated conditioning trials (i.e., repeated pairings of saccharin and LiCl), schedule induced drinking was eventually reduced. The specific components underlying schedule-induced consumption, however, were differentially affected by the aversion training. Specifically, the decrease in schedule-induced drinking was effected primarily by a decrease in licking occurring between 10 and 60 sec after pellet delivery. Bout initiation and licking immediately postpellet (i.e., within the first 10 sec following pellet delivery) were most resistant to suppression and appeared to be responsible for the relative insensitivity of schedule-induced drinking to conditioned taste aversions. The differential effects of taste aversion conditioning on individual components of elicited behavior are discussed.  相似文献   

5.
The present studies examined the effects of intermeal interval and pellet magnitude on the development and maintenance of schedule-induced polydipsia using a between-subjects design as contrasted with earlier investigations, which have exclusively employed within-subject procedures. In Experiment 1, pellets were delivered on one of six fixed-time schedules (20, 40, 60, 120,180, and 240 sec) to different groups of rats. Although the typical bitonic function relating water intake to intermeal interval was obtained, the function showed a wide plateau ranging from 60 to 180 sec. Experiment 2 demonstrated that both intermeal interval and pellet magnitude regulate schedule-induced polydipsia. While small-magnitude pellets could support drinking only at relatively short intermeal intervals, increasing pellet magnitude to medium or large resulted in drinking at progressively longer intermeal intervals. Indeed, we observed drinking on a fixed-time 720-sec schedule with large-magnitude pellets. These findings are derivable from the opponent-process theory of acquired motivation.  相似文献   

6.
Experiment 1 sought to determine whether schedule-induced drinking could be abolished by means of a taste aversion. Polydipsic rats were given access to a .4% saccharin solution while they were exposed to an intermittent food schedule. Immediately after the session, they received an intraperitoneal injection of either lithium chloride or sodium chloride. Following a recovery day with water in the experimental chamber, the animals were again exposed to the saccharin solution. The poisoned animals (lithium chloride) drank very little saccharin compared to the control animals (sodium chloride), indicating that they had learned a taste aversion in only one conditioning trial. Experiment 2 established that polydipsic rats can learn a taste aversion despite a long delay between schedule-induced saccharin consumption and poisoning, and that the delay gradient displayed by polydipsic rats is similar to that observed in thirst-motivated rats.  相似文献   

7.
In two experiments, the hypothesis that frustration mediates the production of schedule-induced polydipsia was tested. In Experiment I, a group in which reward was reduced from 6 to 2 pellets of food in an operant chamber was found to increase water intake compared to a group maintained at 2 pellets reward. In Experiment II, rats trained to approach food on a partial reinforcement schedule in a runway subsequently showed lower levels of water intake in the operant test for polydipsia than rats given continuous reinforcement during runway training. The results are interpreted as supporting a frustration hypothesis of schedule-induced polydipsia and are discussed within the context of persistence theory.  相似文献   

8.
We showed, as had previous investigators, that young rats formed taste-sickness associations that were weaker than those of mature rats; associations were not formed over a delay greater than 45 min, and aversions did not survive a 60-min test session. The difficulty young rats had withholding consumption and their poor sensitivity to taste and sickness contributed to the weak aversions. Choice tests revealed aversions that had apparently extinguished during a no-choice test, and animals that were allowed to mature prior to the first test readily withheld consumption for 60 min. Furthermore, young rats formed an aversion over a delay of 2.5 h when the concentrations of saccharin and lithium chloride were increased. Aversions to the stronger saccharin did not extinguish over two one-bottle tests and were retained for 52 days.  相似文献   

9.
Drugs of abuse have been reported to produce both rewarding and aversive effects, as evidenced by their ability to induce both conditioned place preferences (CPPs) and conditioned taste aversions (CTAs), respectively. Although several attempts have been made to assess the relationship between the rewarding and aversive effects of drugs in independent groups, it is unknown to what extent (if any) preferences and aversions are related in individual animals. The present study assessed this relationship by examining the ability of morphine (5 and 10 mg/kg) and amphetamine (3 and 5 mg/kg) to induce both place preferences and taste aversions in the same animal, using a concurrent CTA/CPP design. There was no consistent relationship between the ability of morphine or amphetamine at either dose to increase time spent on the drug-paired side and the ability to suppress consumption of the drug-paired taste. These results support the position that drugs of abuse have multiple stimulus effects, both rewarding and aversive, that condition place preferences and taste aversions independently.  相似文献   

10.
In four experiments, it was found that rats subjected to extinction of conditioned taste aversions readily reacquired these aversions when subjected to conditioning once again. Two of the present procedures were very similar to those used by Danguir and Nicolaides in unsuccessful attempts to obtain reconditioning of extinguished taste aversions.  相似文献   

11.
Frumkin (1975) reported that sodium-deficient rats fail to learn taste aversions to NaCl. However, those rats were sodium-deficient at the time of testing as well as at the time of training; any learned aversion could have been masked by a strong sodium hunger. Rats were made temporarily sodium-hungry by injections of Formalin or aldosterone. They were then poisoned after drinking both an NaCl and a sucrose solution. Several days later they were tested for learned aversions. Rats trained under the influence of aldosterone did not differ from controls. Rats trained under the influence of Formalin acquired slightly weaker aversions to both NaCl and sucrose. Thus there is no evidence that sodium deficiency alters the associability of NaCl with poison.  相似文献   

12.
Three experiments delivered food at fixed or random intervals independently of the rat’s behavior, always less than the amount eaten with food freely available. The results revealed a Polydipsie response to this experimental suppression of eating, and total drinking decreased as total eating increased. When we added a lever that signaled each food delivery, leverpressing and drinking rose far above their baseline levels; both responses decreased as total eating increased. When a similar schedule presented lever and food independently, rats still became Polydipsie, but showed no sign of autoshaped leverpressing. A fourth experiment revealed a hypophagic response to schedules that suppressed drinking; total eating increased with total drinking. As mutual substitutes in the economic sense, one behavior falls as the other rises; as mutual complements in the economic sense, the two behaviors rise or fall together. We discuss polydipsia and autoshaping in terms of drinking as an intrinsic substitute for eating, and leverpressing as a learned substitute for eating. The results suggest a revision of conservation theory, which views drinking and eating as substitutes when the schedule suppresses eating but as complements when the schedule suppresses drinking.  相似文献   

13.
The term “schedule-induced” implies that the overall frequency of a behavior is greater in the presence of an intermittent schedule of reinforcement than in the absence of such a schedule. Consequently, the occurrence of interreinforcement behavior is not in itself sufficient evidence of schedule induction: a test of induction requires comparison between an intermittent-schedule condition and a nonschedule baseline. The relative merits of different types of nonschedule baseline are examined, and it is concluded that the best test of schedule-induction involves both an extinction and a massed-reinforcer baseline. A working definition of schedule-induction is suggested on this basis. Studies purporting to show schedule induction of activities other than drinking are critically reviewed, and it is concluded that schedule induction may be less general than is usually supposed. It may therefore be more fruitful to seek an explanation of schedule-induced drinking which focuses specifically on the interaction between food and water ingestion in the rat, rather than an explanation involving concepts such as stress, frustration, or arousal.  相似文献   

14.
The effect of wheel running on the level and temporal distribution of schedule-induced polydipsia was examined in 12 food-deprived rats given one food pellet per minute for 1 h. For all rats, wheel running decreased the level of Polydipsie intake. It also decreased licking in all six of the 10-sec postpellet intervals except the first. The degree of reduction in licking was a U-shaped function of the 10-sec postpellet intervals and was generally inversely related to the temporal distribution of running. The temporal distribution data are partially consistent with a temporal competition view of the interactions between schedule-induced polydipsia and wheel running  相似文献   

15.
Thirsty Sprague-Dawley rats drank flavored water in a wind tunnel prior to lithium-induced toxicosis. Flavors were presented for 5 min; 30 min later a toxin, lithium chloride, was injected. After the rats had recovered, subsequent aversions to the taste and the odor were assessed separately. In Experiment 1, extensive preexposure to the taste component of the flavor attenuated neophobia to the flavor and the subsequent taste aversion. However, the subsequent odor aversion was unaffected. Experiment 2 partially replicated the results of Experiment 1 and showed that, in a situation in which only taste-potentiated odor aversions are usually found, nonpotentiated aversions were evident. Experiment 3 found that, in addition to attenuating taste aversions, taste preexposure enhances the capacity of rats to learn nonpotentiated odor aversions. The results are interpreted with a neural-based model of conditioned flavor aversions.  相似文献   

16.
Holder (1988) has raised several objections to our work on the role of exteroceptive contextual stimuli in taste-aversion learning by rats. Our main conclusion from that work is that tongue-tactile stimuli from the drinking spout constitute the likely basis for findings of contextual bottle control over learned taste aversions. Holder suggests that our results are confounded by taste cues from the fluid containers. We refute this suggestion by presenting data from two experiments showing contextual bottle control, even though potential taste cues from the drinking bottles were eliminated. We also point to the fact that some of Holder’s criticisms are based on misreadings of our various reports.  相似文献   

17.
In six experiments, we examined taste and compound taste/taste aversions at different retention intervals. In Experiment 1, saccharin aversions were significantly weaker 1 day after conditioning than 21 days after conditioning. This effect was determined not to be caused by the aftereffects of illness or differential hydration. With the use of a saccharin/denatonium compound, Experiment 2 demonstrated overshadowing of a denatonium aversion at 21- and 1-day retention intervals, Experiment 4 showed a potentiated saccharin aversion only at the 21-day retention interval, and both Experiments 2 and 4 revealed that the aversion of the taste-only controls was stronger at the later retention interval. Experiments 3 and 5 demonstrated that the differences at the two retention intervals were not caused by unconditioned changes in taste preference. Finally, Experiment 6 showed that extinction of the conditioning environment prior to testing results in stronger saccharin aversions than occur in nonextinguished controls. Collectively, these experiments suggest that testing within a 24-h period after conditioning will result in significantly weaker taste aversions. Also, these results support a retrieval-competition explanation that may account for the weakened aversions at the 1-day testing interval of both groups conditioned to single elements and those conditioned to compounds.  相似文献   

18.
Rats were used in a conditioned taste aversion procedure in order to examine the effects of context exposure duration during the conditioning sessions on conditioned responding. One flavor was paired with lithium chloride during a long session in one context, whereas another flavor was conditioned during a short session in another context. Testing occurred in the home cage. The results showed that conditioning during short sessions produced strong conditioned taste aversions. Conditioning during long sessions produced strong conditioned taste aversions when the conditioned-stimulus-unconditionedstimulus (CS-US) pairing occurred at the end of the lengthy session. Other results showed that context-US associations were formed during the short duration sessions and that these associations supported conditioned responding to the CS trained in that context. The results are discussed with respect to the different influences that contextual cues can exert on conditioned responding.  相似文献   

19.
Rats repeatedly injected with lithium chloride were subsequently tested drinking novel and familiar solutions of both casein hydrolysate and vinegar. Injections in the absence of edibles result in only a small, and sometimes not reliable, increased avoidance of the novel casein and vinegar solutions. In contrast, if subjects acquired an aversion to saccharin as a result of the lithium injections, this learned aversion generalized to casein hydrolysate, with the generalization greatly enhanced by novelty of the casein flavor. However, the saccharin aversions did not generalize to the novel vinegar solution nearly as much as to the novel casein flavor. These results suggest that previous observations of poison-induced neophobia were probably in part a result of the stimulus generalization of conditioned taste aversions and that in addition to test stimulus novelty some other factor, such as stimulus salience or similarity to the conditioned aversive flavor, is also involved in the generalization of learned taste aversions.  相似文献   

20.
In three experiments with rats, taste + odor interactions in compound aversion conditioning were investigated. In Experiment 1, two odors (0.02% almond and 0.02% orange) were compared on single-element odor aversions, taste (denatonium) potentiated odor aversions, and potentiated odor aversions following taste extinction. Although no odor differences were seen following single-element conditioning, both types of potentiated orange odor aversions were stronger than their almond odor counterparts. These data show that odors of similar conditionability are differentially potentiated by the same taste. To determine whether these differences were due to unique perceptual representations, the effects of elemental extinction or compound extinction on aversions to the compound were investigated in Experiments 2 and 3. In Experiment 2, orange odor extinction weakened responding to the compound significantly more than taste extinction did. In contrast, almond odor extinction and taste extinction produced similar decrements in responding to the compound in Experiment 3. These results suggest that the perceptual representation of these specific taste + odor compounds are different, and they are discussed in regard to configural and within-compound association accounts of potentiation.  相似文献   

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