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1.
Rats were successively exposed to three solutions with distinctively different flavors and then tested for both neophobia and propensity to form conditioned taste aversions to a fourth distinctively flavored solution. All permutations between the four solutions (salty, bitter, sweet, and sour) were examined. The prior exposures resulted in attenuation of neophobia to novel salty and sour solutions, but not to equally novel bitter or sweet solutions. These effects were found to depend upon thediversity of the prior ingestive events rather than upon either a single specific flavor experience or a summation of the reductions in generalized neophobia accrued by each substance separately; both of the latter findings are inconsistent with stimulus generalization being responsible for the observed attenuation of neophobia to salty and sour solutions following exposure to diverse different solutions. A further test of generalization between the salty and bitter solutions, consisting of associating one flavor with poison and extinguishing the avoidance response in half the animals prior to testing for generalization of conditioned taste aversion to the other flavor, also proved negative. Although these effects of exposure to flavors distinctly different from the test solution may be dependent upon solution concentrations, further research found that the same pretest exposures and same test concentrations failed to inhibit formation of conditioned taste aversions. A demonstration of “latent inhibition” attested to the sensitivity of our procedure to potential interference with acquisition of conditioned taste aversions. The results are considered in light of the relationship between neophobia and conditioned tasted aversions, the differential biological relevancy of specific tastes, and abstraction as a cognitive capability of rats. The possibility is raised that the defense against toxins is not the primary function of neophobia. 相似文献
2.
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
3.
Bow Tong Lett 《Learning & behavior》1980,8(2):193-198
The present experiments assessed cue utilization in pigeons and quail on similar tests of poison-based aversion learning. In Experiments 1 and 2, three groups of pigeons were given colored water, flavored water, or colored flavored water prior to induction of sickness; these experiments differed only as to the specific colors and flavors used as stimuli. In both experiments, the birds trained with flavored water exhibited reliable taste aversions when tested with uncolored flavored water. Similar degrees of aversion were observed whether the flavored water had been colored or uncolored during training, suggesting that the color cue had little or no effect on the conditioning of the flavor cue. In contrast, the flavor cue had a pronounced effect on the conditioning of the color cue. When tested with unflavored colored water, the birds trained with colored flavored water exhibited significantly stronger color aversions than those trained with unflavored colored water. That is, the flavor cue enhanced or potentiated the conditioning of the color cue. In a third experiment, quail were trained in the same way as the pigeons with virtually the same result. The pattern of cue utilization observed in the present experiments with pigeons and quail differs markedly from that proposed by Wilcoxon, Dragoin, and Kral (1971) for quail. However, a reexamination of the results obtained by Wilcoxon et al. suggested that they are susceptible to an alternative interpretation consistent with the present results. 相似文献
4.
Robert J. Robbins 《Learning & behavior》1980,8(4):534-542
An investigation was made of the occurrence of learned and nonlearned aversions in the acquisition of illness-induced taste aversions in mice of the genusPeromyscus. It was determined: (1) that illness following the ingestion of a novel flavor both produced aversions specific to that flavor and also enhanced neophobia directed toward novel flavors in general; (2) that the specific aversion and the enhanced neophobia appeared to be mediated by independent processes, with no indication that the enhanced neophobia was dependent upon the integrity of the specific aversion; and (3) that illness following the ingestion of familiar water produced enhanced neophobia, which did not appear to be mediated by an aversion to water. It was noted that the results were fundamentally in agreement with those previously obtained with laboratory rats, except that a demonstration of the independence between the two types of aversions has not yet been reported in those animals. 相似文献
5.
On each day of training in Experiment 1, hungry rats were given one flavored saccharin solution followed by a differently flavored saccharin solution. The rats drank more of the first flavor during training, but preferred the second flavor in a subsequent choice test. In Experiment 2, the two flavored saccharin solutions were provided on alternate days, with one flavor being preceded by nothing and the other flavor by plain saccharin. The rats drank more of the flavor preceded by nothing during training, but preferred the other flavor in a subsequent choice test. These results suggest that a state of nonnutritive satiation can reinforce a flavor preference. 相似文献
6.
Michael Domjan 《Learning & behavior》1975,3(3):205-211
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
7.
Hooded Lister rats exhibited less neophobia towards (i.e., drank more of) a novel fluid (3% lemon or 5% sucrose) on a 10-min test if given a 6-min exposure to that fluid 6 h earlier. Presentation of a distractor (1.26% coffee) immediately after preexposure to the test solution enhanced neophobia habituation to lemon (Experiment 1), but disrupted habituation to sucrose (Experiment 3). This bidirectional distractor effect was not due to distractor-induced change in the hedonic value of the preexposed test flavor (Experiment 4). Evidence was obtained (Experiment 5) indicating that the rat perceives lemon to be more similar to coffee than is sucrose. It is suggested that when test flavor and distractor are dissimilar, processing of the distractor denies the preexposed test flavor sufficient processing in STM to allow encoding of information about that flavor in LTM. Consequently, the rat responds to a subsequent presentation of the test flavor as it would to a novel stimulus. When test flavor and distractor are similar, however, the distractor elicits less processing in STM (cf. Wagner, 1976) and is therefore less able to disrupt STM processing of the preexposed test flavor. The resultant loss of neophobia to the test flavor resulting from encoding of information about that flavor in LTM may then be augmented by generalization of attenuated neophobia to the distractor. Consistent with this analysis, coffee was shown to suffer more proactive interference when preceded by lemon than when preceded by sucrose (Experiment 6). 相似文献
8.
In Experiments 1 and 2, rats were exposed to two compound flavors, AX and BX, containing one flavor in common (X). Following this exposure phase, an aversion was conditioned to A in the experimental group by pairing its consumption with an injection of lithium, while a control group drank A without being poisoned. The effect of this treatment was to establish B as a conditioned inhibitor. In Experiment 1, experimental animals were slower than controls to condition an aversion to B when its consumption was paired with lithium (a retardation test of conditioned inhibition). In Experiment 2, B alleviated the suppression of intake of another flavor previously paired with lithium (a summation test). Experiments 3 and 4 established that these effects depended upon prolonged prior exposure to AX and BX. 相似文献
9.
Three experiments were conducted to determine the effectiveness of intravenous (IV) flavor injections in the formation of conditioned taste aversions and in the attenuation of neophobia. In Experiment 1, two groups of rats were permitted to drink either a .1% saccharin solution or tap water followed immediately by IV injections of lithium chloride (LiCl), and two more groups were given IV injections of a 2% saccharin solution followed immediately by IV injections of either LiCl or distilled water. Injected flavor did not serve as an effective CS for the conditioning of an aversion to .1% saccharin. The second experiment employed a two-bottle procedure to detect attenuation of neophobia using the injected-flavor technique. It was found that, whether saccharin had been injected intravenously (2%), injected intraperitoneally (2% IP), or orally consumed (.1%), neophobia for .5% saccharin was attenuated equally relative to controls. CS-US intervals were manipulated in the final experiment such that IP injections of 2% saccharin solution were followed 0–480 min later by IP injections of LiCl. In this case, it was shown that injected flavor (2% saccharin) could act as an effective CS if the US was delayed (optimally about 120 min) and when the test solution was .1% saccharin. The delay gradient found in Experiment 3 was interpreted as a generalization gradient where optimum conditioning was displayed at the point where the concentration of saccharin circulating in the animal at the time of illness onset most closely matched the concentration of the test solution. 相似文献
10.
Three experiments examined the habituation of rats’ neophobia to novel flavors, and the disruption of that habituation by presentation of a distractor flavor either immediately before or immediately after the target flavor. Habituation of neophobia to lemon solution was more seriously disrupted by presentation of saline as a distractor than by presentation of coffee as a distractor, and this was true whether the distractor was presented before or after the target on each habituation trial. Two further experiments established that the relative ineffectiveness of coffee as a distractor could not be attributed to its lack of salience, and was probably related to its greater similarity to the target lemon flavor. These results do not fully accord with those reported by Robertson and Garrud (1983), but are readily explained in terms of generalization of habituation between distractor and target flavors. 相似文献
11.
J. E. Sherman C. F. Hickis A. G. Rice K. W. Rusiniak J. Garcia 《Learning & behavior》1983,11(1):101-106
Two experiments explored the reinforcing effect of ethanol on conditioned location and flavor preferences in hungry rats. In Experiment 1, rats were administered ethanol (.5, 1.0, or 2.0 g/kg, ig) prior to confinement in one side of a shuttlebox with access to a flavored solution. On control trials, H2O was administered prior to confinement to the opposite side with a different flavored solution. Location choice tests revealed an overall aversion for the ethanol-associated side that was largest at the 2.0-g/kg dose. Flavor choice tests revealed an aversion for the ethanol-associated flavor at the 2.0-g/kg dose, no reliable difference at the 1.0-g/kg dose, and, of particular interest, a preference at the .5-g/kg dose. The results of Experiment 2 suggest that caloric restoration served as the reinforcing mechanism for the conditioned flavor preference. An isocaloric glucose solution conditioned a flavor preference of the same magnitude as that obtained with ethanol. Moreover, when ethanol provided no caloric advantage, the associated flavor was less preferred than a flavor associated with an isocaloric glucose solution. 相似文献
12.
In two experiments, rats (n = 228) received pretraining access to a distinctive novel flavor (saline) followed by aversion conditioning to a different novel conditioned stimulus (CS) (saccharin). Then the rats were tested for aversion to the CS (saccharin) or for conditioning-enhanced neophobia to a third novel flavor (casein hydrolysate). Pretraining access to a distinctive novel flavor that differed from the CS reliably reduced the magnitude of conditioning-enhanced neophobia to casein, but did not reliably affect conditioned aversion effects to the CS. Pretraining access to the CS reduced aversion effects to the CS and reduced postconditioning neophobia to casein to the performance level shown by ingestion-toxin controls. Results were consistent with the view (Braveman & Jarvis, 1978) that conditioned aversion and neophobia may be independent phenomena with separable underlying mechanisms. 相似文献
13.
Alexander F. Luongo 《Learning & behavior》1976,4(3):225-230
In three experiments, rats were presented compound solutions consisting of a common element, saccharin, mixed with one of two different flavor elements, cinnamon and wintergreen. Rats in the experimental groups consistently received a toxicosis-inducing injection following one compound solution but not following the other compound solution. Rats in the control groups received toxicosis-inducing injections half the time following each of the compound solutions. After training in each experiment, there were tests for conditioning to the saccharin alone. The experimental groups drank significantly more than the control groups, indicating that the aversion to the partially reinforced saccharin in isolation was less when the different flavor cues were more highly correlated with reinforcement. In Experiment III, there was also a test for conditioning to the cinnamon or wintergreen flavor alone. The experimental group drank significantly less of the continuously reinforced flavor than the control group did of the partially reinforced flavor. These results are similar to those reported within more traditional conditioning paradigms. 相似文献
14.
It has been reported previously that rats prefer a flavor they consumed under high deprivation to a flavor they consumed under low deprivation (Revusky, 1967). Here it was found that this preference occurs only if nutritive solutions are used and the flavors are given preceding and following eating. If flavors are given separately from the daily feeding, rats prefer the flavor given under low deprivation, whether or not a nutritive solution is used (Experiment 3). If flavors are given before and after the daily feeding, rats prefer the flavor they had under high deprivation (before feeding) more if sucrose solutions are used than if saccharin solutions are used and more on a high-deprivation test than on a low-deprivation test (Experiments 1 and 2). It was concluded that the “incentive value” of consumption is not necessarily higher under high deprivation than under low deprivation. The preference for the low-deprivation flavor obtained here may reflect a greater proportional rewarding effect of consumption under low deprivation or may reflect an aversion to the flavor consumed under high deprivation. Perhaps a small taste of flavor under high deprivation initiates responses of digestion that are unsatisfied and thus aversive, and the more so the higher the deprivation level. 相似文献
15.
When a caloric substance is followed by a flavored substance, preference for the flavor that followed the calories can increase because of a flavor-nutrient association. We showed here that this effect is opposed by a fullness effect: consuming the caloric substance itselfreduces-consuniption of the flavor that follows. Because consumption of this flavor was less than consumption of a flavor that was given alone, there was a reduced preference for the flavor that followed the calories—an effect opposing flavor-nutrient learning. The preference for the flavor that was given alone and consumed in greater amounts seems to be due to exposure per se and is not a result of contrast. When the amount of the flavor given alone was directly controlled so that it was one half the amount of the flavor that followed the calories, preference for the flavor following the calories was no higher than when consumption of the two flavors was equal. Thus, exposure can interfere with flavor-nutrient learning, but does not enhance it. 相似文献
16.
The relationship between flavor evaluative conditioning and contingency awareness was examined in two experiments using flavored
drinks. In Experiment 1, one flavor was always paired with sugar and the other with bitter tween (polysorbate20) during conditioning. In a subsequent test phase, participants tasted the two flavors, and their evaluative ratings indicated
an overall preference for the sugar-paired flavor. Moreover, participants were generally able to report which flavor had been
paired with sugar and which with tween. This finding was replicated and confirmed in Experiment 2A. Furthermore, in both experiments,
evaluative conditioning was seen only in those participants who were aware of the contingencies. Experiment 2B demonstrated
that evaluative conditioning does not occur to colors, although participants are contingency aware. The differences between
the present findings and prior studies, in which apparently unaware flavor conditioning has been found, are discussed. 相似文献
17.
In two experiments, experimental rats were trained to have strong aversions to one of 10 novel-flavored solutions through contingent lithium injections; control rats were injected with lithium in the absence of prior consumption. Each animal was then tested with each of the 10 solutions, and the preferences of the experimental rats and the control rats were compared. A generalization gradient of the aversion to each conditioned aversive flavor was obtained for each test flavor. 相似文献
18.
When the first presentation of a neophobic flavor is immediately followed by a distractor flavor, habituation of the neophobic response is typically attenuated. This is manifested by the fact that neophobia is still shown to the target flavor on its second presentation. Three experiments investigated the prediction that this effect will occur only for novel, but not familiar, distractor solutions. Experiments 1 and 2 found that, contrary to this prediction, both novel and familiar distractors can attenuate the habituation of a neophobic response. In Experiment 3, however, when the distractor was made very much more familiar, it lost its ability to interfere with the habituation of neophobia to the target solution. These results are discussed in terms of Wagner’s (1981) theory of habituation. 相似文献
19.
Rats tend to prefer flavors previously consumed under low deprivation to flavors previously consumed under high deprivation (Capaldi & Myers, 1982). We attempted to distinguish among possible associative explanations by determining whether this conditioning phenomenon was based upon conditioned preferences, conditioned aversions, or both. We compared preference for flavors presented exclusively under either high or low deprivation with preference for a neutral flavor. In Experiments 1A and 1B the neutral flavor was one that had been randomly paired with both high and low deprivation, whereas in Experiments 2 and 3 the neutral flavors had not been associated with either high or low deprivation. Our results strongly suggest that this conditioning phenomenon is based upon an actual increase in preference for the flavor consumed under low deprivation rather than on any form of aversion conditioning. 相似文献
20.
Two experiments allowed rats to drink freely two neutral flavors (almond and vanilla) in simultaneous compound with two hedonically valued flavors (quinine and saccharin). The neutral flavor previously paired with saccharin was subsequently preferred. The neutral flavor that had been paired with quinine was subsequently avoided. Experiment 3 found similar results when the animals were hand-fed a preset amount of the solution. Preference shifts were not obtained when differential amounts of the neutral flavors were consumed in isolation. The data indicate that flavor-flavor associations can shift taste preferences. 相似文献