Strength Of Aversion Research Articles

Alcohol-aversion therapy: Relation between strength of aversion and abstinence.

Cette experience montre que la therapie aversive des alcooliques a pour effet de diminuer leur consommation dans les tests gustatifs, de rendre plus negatives leurs evaluations, d'induire des indicateurs d'aversion (grimace, par exemple) et d'augmenter leurs reponses tachycardiques

Aversion conditioning and enhanced neophobia: role of test stimuli

In Experiment 1, 100 rats (Rattus norvegicus) received 10% sucrose or 5% casein hydrolysate followed, after 10 min, by a LiCl or saline injection or, after 12 h, by a LiCl injection. Subsequently, rats received aversion testing to the CS or neophobia testing to the opposite novel flavor. Aversion effects were reliably greater to casein than to sucrose. However, conditioning with sucrose yielded a reliably greater increase in neophobia to casein (relative to controls) than conditioning with casein yielded to sucrose. In Experiment 2, 60 rats received distilled water followed, after 10 min, by LiCl or saline injection or, after 12 h, by LiCl injection. Aversion effects occurred to distilled water. Neophobia testing to casein and sucrose showed that, relative to controls, neophobia increased reliably more to casein. The results of Experiments 1 and 2 were not attributable to differences in baseline intakes between casein and sucrose flavors. Together, these experiments indicated that the demonstration of conditioning-enhanced neophobia may depend more on the characteristics of the neophobia test flavor than on the strength of aversion established because of CS characteristics.

Effects of CS concentration in taste‐aversion learning: Problems in assessing aversion strength

The concentration of saccharin (CS) solutions was varied between groups of rats in four taste‐aversion learning experiments, using lithium chloride as the aversive agent (US). Saccharin intake was measured on four one‐bottle presentations yielding data on initial taste neophobia as well as postconditioning aversion strength. The results indicated that saccharin intake declined progressively with increasing concentrations on the first presentation, and that preconditioning intake to a large extent predicted postconditioning intake. In an attempt to correct postconditioning values for differences of saccharin intake on the preceding trial, a taste suppression ratio (TSR) was computed as the quotient of the amounts of saccharin consumed by individual rats on consecutive presentations. In general, the TSR was found to be too insensitive to detect differences of conditioning strength acquired by different saccharin concentrations. Alternative approaches to the CS‐concen‐tration problem in taste‐aversion learning are discussed.

Interfering with taste aversion learning in rats: The role of associative interference

Six experiments with rats investigated the conditions under which one flavor interferes with aversion conditioning to a second, familiar flavor. Conditioning to the familiar flavor was weakest when the interference flavor was contiguous to lithium-induced toxicosis, novel, more intense, and strongly associated with toxicosis. In addition, conditioning to the familiar flavor was weakened even if multiple conditioning trials were used. The repeated finding of an inverse relationship between strength of aversion to the target and interference flavors is interpreted as support for an associative competition hypothesis of the interference effect. The possible relevance of the interference effect to the attenuation of taste aversions in cancer patients is discussed.

Taste aversion proneness: A modulator of conditioned consummatory aversions in rats

Sprague-Dawley-derived rats were sequentially conditioned to avoid both anise- and saccharin-flavored solutions with counterbalanced orders of flavor exposures prior to cyclophosphamide-induced illness. The amounts of saccharin and anise solutions consumed during separate postconditioning single-bottle tests were correlated to determine if aversion strength was consistent across flavors. The saccharin-anise sequence revealed a positive and significant correlation, supporting the hypothesis that conditioned flavor aversions are modulated by some intrasubject factor or factors, a tendency designated as taste aversion proneness. However, a correlational coefficient of marginal significance was obtained from the anise-saccharin sequence, leaving unanswered questions concerning the salience and generality of taste aversion proneness. Despite this limitation, taste aversion proneness is viewed as having important applied implications for aversion therapy approaches to the treatment of human alcoholism.

Environment-dependent taste-aversion extinction: A question of stimulus novelty at conditioning

In Experiment 1, four groups of rats were exposed to two saccharin(Sac)-lithium chloride(LiCl) pairings in a novel animal compartment. In subsequent daily extinction trials, Sac (two groups) or water (H2O) (two groups) was presented either in the same (as conditioning) or a different compartment. There was no evidence that the presence or absence of the conditioning compartment influenced the amounts of Sac or H2O drunk. Postextinction preference tests (Sac vs. H2O), performed in the conditioning compartment, showed a compartment-dependent extinction effect: There was a significantly stronger aversion in the group drinking Sac during extinction in a different (from conditioning) compartment than in the group drinking Sac in the conditioning compartment. In Experiment 2, four groups were given two Sac-LiCl trials in a novel (2 groups) or a familiar (2 groups) compartment. One “novel compartment” group and one “familiar” group were offered Sac during daily Sac-aversion extinction trials in the conditioning compartment, and the remaining groups drank Sac in a different compartment. Again, intercompartment generalization of the Sac aversion was demonstrated: There was no evidence that the particular compartment present influenced the strength of aversion during extinction. Postextinction preference tests showed the previously observed compartment-dependent extinction effect only in the case of the “novel compartment” groups. Thus, in view of previously reported data, the number of conditioning trials and the novelty of the conditioning compartment were shown to be critical to compartment-dependent taste-aversion extinction.

Sex affects the initial strength but not the extinction of poison-based taste aversions in deer mice ( Peromyscus maniculatus bairdi)

An examination of the effect of sex upon taste-aversion learning in deer mice ( Peromyscus maniculatus bairdi ) found that (a) sex has no apparent effect upon either the acquisition or the extinction of a LiCl-induced aversion to sucrose solution if the animals are tested while fluid deprived, but that (b) if the animals are tested under nondeprived conditions, males exhibit a greater initial aversion than females but both sexes seem to extinguish their aversions at similar rates. These findings differ from those previously reported for laboratory rats, in which it has been found that sex affects the extinction but not the acquisition of poison-induced taste aversions. It was suggested that either (a) sex interacts with taste-aversion learning via different mechanisms in deer mice and in rats, or (b) the apparent differences in extinction rates reported for rats might conceivably reflect differences in initial aversion strength which were undetected due to the use of high doses of toxin.

Plasma corticosterone levels as an index of the strength of illness induced taste aversions

Data are presented which demonstrate the task generality of pituitary-adrenal changes that accompany avoidance conditioning. In two experiments a conditioned aversion to milk was established by pairing it with lithium chloride (LiCl). In Experiment 1 conditioned pituitary-adrenal activation occurred when, in a conflict situation, animals reexperienced milk that had earlier been paired with LiCl. The relationship between the strength of aversion and corticosterone levels was such that animals showing the greatest avoidance showed the largest elevations in plasma corticosterone. In Experiment 2 this behavior/steroid relationship was manipulated. Dexamethasone (DEX) pretreatment on the day of conditioning was used to attenuate the conditioned aversion. Compared to saline (SAL) controls when reexposed to milk, DEX animals showed an attenuated aversion (i.e., drank more) and a smaller conditioned response (i.e., less adrenocortical activity). The reduction of conditioned elevation in corticosterone was not due to any residual effects of DEX at the time of testing (Experiment 3). Plasma levels of corticosterone represent an index for assessing the strength of illness induced conditioned taste aversions.

Variations in the strength of conditioned taste aversion in rats as a function of time of inducement

In an experiment to determine the optimal time of day for the establishment of taste-aversion learning, 24 male albino rats were divided into four equal groups. Following 14 days of ad-lib water and food, Group 1 animals were water deprived beginning at 4 a.m. on Day 15. Group 2 was also introduced to water deprivation on Day 15 beginning at 10 a.m.; likewise, Group 3 began at 4 p.m. and Group 4 started at 10 p.m. After 24 h of deprivation, the taste cues (1.5 grains of saccharin in 600 cc of tap water) were made available to each group at 4 a.m., 10 a.m., 4 p.m., or 10 p.m., respectively. After allowing the animals to drink the taste cue for 1 h, the drinking tubes were removed, and, subsequent to a 30-min interval, each animal was injected with cyclophosphamide, an illness-inducing drug. The subjects were then given 4 days to recover from the ensuing illness with water available ad lib. Upon recovery, the animals in each group were again water deprived for 24 h using the same times as on Day 15. The next day, all groups were tested for aversions at 4 a.m., 10 a.m., 4 p.m., or 10 p.m., respectively, by giving each animal in each group access for 1 h to two bottles: one filled with tap water and the other filled with the taste cue. Results indicated that aversions were strongest for the 4 p.m. animals and weakest for the 10 p.m. group. The 4 a.m. and 10 a.m. animals fell between the other two groups in terms of aversion strength.

Bait-shyness acquisition and resistance to extinction as functions of US exposure prior to conditioning

Cyclophosphamide-induced aversions to saccharin-flavored tap water were observed in normal control rats, in rats subjected to varying numbers of cyclophosphamide injections prior to conditioning, and in rats similarly subjected to preconditioning saline injections. Both initial magnitude and resistance to extinction of a conditioned flavor aversion were found to be inverse functions of preconditioning familiarity with drug-induced illness. Six preconditioning cyclophosphamide injections markedly reduced both initial aversion magnitude and resistance to extinction. In contrast, three such injections failed to affect initial aversion magnitude and resulted in a small acceleration of extinction rate, while one preconditioning cyclophosphamide injection produced no observable effects. These findings depict preconditioning familiarity with illness as one important variable modulating the strength of conditioned flavor aversions and emphasize the importance of viewing resistance to extinction as one indicator of aversion strength.

Role of drug novelty and metabolism in the aversive effects of hashish injections in rats

Water-deprived rats learned in one trial to avoid fluids whose tastes were paired with an intraperitoneal injection of a potent hashish extract. Aversions of similar strength were conditioned to different novel tastes on successive pairing sessions in the same animals, suggesting that the aversive effects of the drug are not a function solely of the novelty of the drugged state. Pretreatment with an inhibitor of drug-metabolizing hepatic enzyme systems greatly reduced the strength of hashish-induced learned taste aversions; thus the metabolites of cannabis underlie its noxious effects on the molecular level.

An effect of flavors on strength of conditioned aversions

Attempts to condition aversions to nonpreferred flavors have not been as consistently successful as when preferred flavors were used. To find if the problem is one of method of measurement or if it is a general characteristic in the conditioning of aversions, the present experiment used several measurement procedures to compare aversions formed by rats to one preferred and one nonpreferred flavor. On all measures, whether relative (decreases in intake) or absolute (final amount consumed), aversions for the preferred flavor were greater than for the nonpreferred flavor.