Extinction of the overshadowing CS after overshadowing in conditioned taste aversion

Abstract

Using a conditioned taste aversion preparation, overshadowing of flavor-illness association was produced through the presentation of a second flavor during the interval between the fIrst flavor and illness. The modulatory effects of extinguishing the association between the second (overshadowing) flavor and illness on conditioned responding to the target flavor was investigated.In Experiment 1, we found that, following one-trial overshadowing, extinction of the overshadowing flavor had no effect on conditioned responding to the target flavor. In Experiment 2, we found a similar absence of an effect of extinction of the overshadowing stimulus in a multitrial overshadowing paradigm. Experiment 3 conflrmed the results of Experiments 1 and 2 using conditioning parameters that were designed to weaken the association between the overshadowed flavor and illness. In Experiments 4 and, 5, we used simultaneous presentation of the flavors during conditioning and obtained a weakened aversion to the overshadowed flavor when the overshadowing CS was extinguished. These findings are inconsistent with previous observations in conditioned fear preparations that suggest that extinction of the association between the overshadowing stimulus and the unconditioned stimulus attenuates overshadowing. Possible reasons for the discrepant results are discussed.

Second-order conditioning detects unexpressed morphine-induced salt aversion

“…It may be that the salt concentration was not high (salient) enough to be conditioned (Kalat & Rozin, 1970;Rescorla & Wagner, 1972). This account seems unlikely given the extent of the literature demonstrating conditioned taste aversion when a salt solution of 1% or less is paired with other USs such as LiCl (see, e.g., Bouton, Dunlap, & Swartzentruber, 1987;Kalat & Rozin, 1970;Schachtman, Kasprow, Meyer, Bourne, & Hart, 1992;Yamamoto, Shimura, Sako, Yasoshima, & Sakai, 1994b ). Drugs of abuse like morphine are thought to induce taste aversion through different neural mechanisms than predominantly emetic drugs such as LiCl (see, e.g., Hunt & Amit, 1987;Riley, Jacobs, & LoLordo, 1978;Swank, Schafe, & Bernstein, 1995;Yamamoto, Shimura, Sako, Yasoshima, & Sakai, 1994a).…”

Overshadowing and CS duration: counteraction and a reexamination of the role of within-compound associations in cue competition

“…We addressed this problem by first examining the interaction of the overshadowing treatment and long CS duration with the intent of illuminating sources of previous discrepant reports concerning posttraining extinction of an overshadowing cue. Prior reports in the literature have often reported increases in responding to the overshadowed target after extinguishing the overshadowing cue (retrospective revaluation; e.g., Kaufman & Bolles, 1981; Matzel et al, 1985; Matzel et al, 1987), but some studies reported the opposite (mediated extinction; e.g., Schachtman et al, 1992; Shevill & Hall, 2004; Exp 1c), and other studies have found no effect (Holland, 1999; Revusky, Parker, & Coombes, 1977). Experiment 1 found that, with elemental training, conditioned suppression to the target stimulus decreased as the duration of the CS increased, and that, with compound cue training, the opposite pattern of responding was observed.…”

“…In other words, they observed mediated extinction with long duration cues. A further instance of mediated extinction within a taste aversion preparation was reported by Schachtman, Kasprow, Meyer, Bourne, and Hart (1992). They administered two flavors followed by LiCl injection, and observed overshadowing.…”

The effect of stimulus duration on over-selectivity: Evidence for the role of within-compound associations.

“…Research using rats in a conditioned flavour aversion paradigm has demonstrated that short duration CSs result in weak odours being overshadowed by salient tastes but potentiate odours with long CS durations and that post-training extinction of the salient taste following long CS durations results in mediated extinction (Westbrook, Homewood, Horn, & Clarke, 1983). Crucially, following simultaneous, rather than serial, CS presentation, post-training extinction following an overshadowing preparation has been shown to result in mediated extinction (Schachtman, Kasprow, Meyer, Bourne, & Hart, 1992;Shevill & Hall, 2004),…”