Effects of extinction and US reinstatement of a blocking CS-US association

Abstract

Rats were used in a conditioned taste-aversion procedure to examine the effects of extinction of a blocking CS-US association prior to the compound conditioning trials. Rats were initially given a pairing of a vinegar flavor with LiC!. Some subjects then received three extinction trials with the vinegar flavor, and other subjects were given water. Subjects were then given compound stimulus conditioning trials in which a novel sucrose flavor, the target stimulus, was followed by vinegar and then a LiCI i~ection. The test on sucrose revealed a blocking effect for the subjects that did not receive the extinction trials, and blocking was attenuated for subjects that received extinction with vinegar. Also, prior to compound conditioning, some animals received a presentation of LiCI in the absence of any flavor-that is, US reinstatement. The results stemming from this treatment replicated a previous finding that US reinstatement treatment alters the ability of an extinguished CS to limit manifest learning about another association.

Dorsal hippocampal lesions impair blocking but not latent inhibition of taste aversion learning in rats.

“…The procedure used to produce blocking involved only one conditioning session in each stage. Although most previous studies have used several conditioning sessions to the taste during the first stage (Batson & Best, 1979), and although the use of only one conditioning session to the compound during the second stage has not been frequent in previous studies, a procedure similar to ours has been demonstrated to be effective by Gustavson et al (1992). Thus, our results confirm the possibility of obtaining blocking with only one conditioning session in each stage.…”

“…Blocking has been demonstrated in taste aversion learning (Revusky, 1977). It appears even with only one compound-aversive stimulus pairing (Batson & Best, 1979; Gustavson, Hart, Calton, & Schachtman, 1992).…”

Conditioning and Cognitive-Behaviour Therapy

“…Firstly, there is little human research explicitly assessing the role of awareness in such learning. Secondly, taste aversion learning in animals has been shown to obey essentially the same laws as other forms of Pavlovian conditioning, and is subject to informational manipulations such as blocking (Westbrook & Brookes, 1988), context specificity (Bonardi, Honey, & Hall, 1990) and reinstatement (Gustavson, Hart, Calton, & Schachtman, 1992). Finally, expectancy and placebo effects are well established with drug stimuli.…”

Increasing trial number produces augmentation, not blocking, in flavor-aversion conditioning

“…We reviewed the flavor-aversion experiments that reported significant flavor-flavor blocking effects, and interestingly, although we found a number of studies that reported significant blocking effects using flavors as A and X, all of these experiments employed a sequential presentation of the flavors during AX+ conditioning (e.g., Bonardi, Honey, & Hall, 1990;Gallo & Candido, 1995;Gallo, Valouskova, & Candido, 1997;Gillan & Domjan, 1977;Gustavson, Hart, Calton, & Schachtman, 1992;Moron, Ballesteros, Valouskova, & Gallo, 2001;Parker, 1986;Reilly, Bornovalova, Dengler, & Trifunovic, 2003;Willner, 1978; however, see Pierce & Heth, 2010 2 ). We posit the weakened flavor aversion following sequential compound conditioning in the A+ → AX+ design may represent a different form of the blocking effect than that observed following simultaneous compound conditioning in the AX+ phase.…”