Protection from latent inhibition provided by a conditioned inhibitor.

Abstract

Two conditioned suppression experiments with rats investigated the influence on latent inhibition of compounding a Pavlovian conditioned inhibitor with the target cue during preexposure treatment.Results were compared to subjects that received conventional latent inhibition training, no preexposure, or preexposure to the target cue in compound with a neutral stimulus. In Experiment 1, greater attenuation of the latent inhibition effect was observed in subjects that received target preexposure in compound with a Pavlovian conditioned inhibitor relative to subjects that received preexposure with a neutral stimulus or to the target alone. In Experiment 2, this protection from latent inhibition was attenuated if the excitor that was used to train the conditioned inhibitor was extinguished between preexposure and target training. The results are consistent with an account offered by the extended comparator hypothesis.

Behavioral techniques for attenuating the expression of fear associations in an animal model of anxiety

“…2. As in Experiment 1, in this experiment relatively strong fear expression was expected in all subjects because they were trained in a design that encouraged the context specificity of the CS-preexposure effect; however, in three of the four groups we observed some attenuation of fear responding relative to equivalently treated subjects that received no CS-alone presentations (e.g., McConnell et al, 2009; Experiment 1; a group that yielded a mean of 2.0 log s). Subjects in Group MassTrials/MassSessions exhibited numerically the strongest fear across tests, followed by subjects in Group SpacTrials/MassSessions, Group MassTrials/SpacSessions, and Group Spac-Trials/SpacSessions, in that order.…”

Methods of comparing associative models and an application to retrospective revaluation

“…Lastly, the CEM explained almost all aspects of McConnell et al’s data. In fact, the largest difference between McConnell et al’s (2009) observations and the CEM’s predictions was in the group that received preexposures to the target stimulus in compound with a neutral stimulus. The CEM model predicted a larger protection effect by a neutral stimulus than was observed by McConnell et al Based on the CEM being able to explain both protection from LI effect and the reduced protection from LI achieved by extinction of A, the CEM provided a better fit to the data than the WCM and RWM.…”

“…That is, without any additional free parameters beyond those of the WCM, the CEM is able to explain both retrospective revaluation (including first- and second-order) and latent inhibition. More importantly, the higher-order retrospective revaluation effects observed by De Houwer and Beckers (2002) and McConnell et al (2009; 2010) can be explained by variants of the Van Hamme & Wasserman (1994) model (CEM and WCM), even though the associative literature universally claimed that the Van Hamme and Wasserman model could not explain higher-order retrospective revaluation. Thus, the present simulations highlight the importance of using actual simulations to support theoretical claims.…”

“…Moreover, the counterbalancing schemes used in empirical procedures were simulated by forcing counterbalanced cues to be represented by the same values for salience. The context was included as a cue in Pavlovian procedures that included a context change and one context extinction trial was interposed between each pair of trials except during extensive posttraining extinction treatments (e.g., McConnell et al, 2009). When multiple test cues were assessed in counterbalanced order, we disabled learning during the test phase so that test-order effects would not influence the predictions of the models.…”

“…McConnell et al (2009) identified the mechanisms underlying this effect by conducting the lick suppression experiments summarized in Table 7. In addition to observing both the basic LI effect and protection from LI effect (Experiment 1), McConnell et al (Experiment 2) observed a reduction in the strength of the protection effect as a result of associative deflation of the conditioned inhibitor’s training excitor.…”