Search

The return of fear following exposure therapy suggests that extinction does not result in a permanent unlearning of the association between a conditional stimulus (CS) and an unconditional stimulus (US). One proposed mechanism of return of fear is ABA renewal in which a CS is paired with a US in context A, presented alone in context B, and followed by test trials in context A. The current study examined the effects of extended extinction and multiple extinction contexts on ABA renewal in 121 first year psychology students. Using a fear conditioning procedure, renewal of shock expectancy during test was observed when extinction was presented for 12 extinction trials in a single context. In addition, renewal was attenuated when extinction was extended to 36 extinction trials or conducted in multiple contexts with 12 extinction trials. Combining extended extinction with multiple contexts resulted in the greatest attenuation of renewal. The results suggest that prolonged exposure treatment in multiple contexts may enhance the cross-contextual generalizability of extinction learning and reduce the likelihood of renewal of fear. [ABSTRACT FROM AUTHOR]

Abstract: The present human fear conditioning study examined whether the valence of an extinction cue has a differential effect on attenuating renewal that is induced by removal of the extinction context. Additionally, the study aimed to assess whether such attenuating effect is based on a modulatory or safety-signal role of the cue. In acquisition, extinction, and test stages of the experiment, human participants received pairings of human faces, presented against a particular background color, with the presence or absence of an aversive auditory stimulus. Experimental groups differed in the valence of a cue that was presented during extinction, in whether or not extinction took place against a different background color than present during acquisition and testing, and in whether the extinction cue was present or absent at test. The conditioned response consisted of auditory-stimulus expectancy ratings. It was hypothesized that a positively valued extinction cue yields faster extinction, stronger attenuation of renewal, and better transfer of its inhibitory power to non-extinguished stimuli than a negatively valued cue. All three hypotheses were confirmed, suggesting that the positive, but not the negative, cue had become a safety signal. The results were discussed in the framework of extinction-based exposure treatments. [Copyright &y& Elsevier]

Abstract: This paper presents evidence of extinction, spontaneous recovery and renewal in a conditioned preferences paradigm based on taste–taste associations. More specifically, in three experiments rats exposed to a simultaneous compound of citric acid–saccharin solution showed a preference for the citric solution when the preference was measured with a two-bottle test (citric vs. water). Experiment 1 revealed that conditioned preferences were extinguished by repeated presentations of the citric acid solution without the saccharin. In Experiment 2, an additional test trial was introduced 21 days after the extinction treatment. Delayed testing resulted in the recovery of the extinguished preference for the citric, reflecting a spontaneous recovery effect. Experiment 3 revealed a preference renewal effect that was obtained when the extinction was conducted in a context different from that of the remaining experimental stages. The implications of these results are analyzed with attention paid to the mechanisms underlying learning of flavor preferences. [ABSTRACT FROM AUTHOR]

Abstract: The ABA renewal procedure involves pairing a conditional stimulus (CS) and an unconditional stimulus (US) in one context (A), presenting extinction trials of the CS alone in a second context (B), and nonreinforced test trials of the CS in the acquisition context (A). The renewal of extinguished conditioned behaviour is observed during test. The current study tested the effects of multiple extinction contexts and context similarity in attenuating renewal. Participants (N =99) took part in a fear conditioning ABA renewal procedure. Using a measure of self-reported expectancy of the US, ABA renewal was observed when a single extinction context that was dissimilar to the test context was used. Renewal was attenuated, though still present, when extinction occurred in multiple dissimilar extinction contexts or in a single extinction context that was similar to the test context. Renewal was completely abolished when multiple extinction contexts that were similar to the test context were combined. Multiple extinction contexts and context similarity act additively in their effect on attenuating renewal. The results are discussed in relation to the design of exposure therapy programs that seek to reduce relapse that can occur via renewal. [ABSTRACT FROM AUTHOR]

Abstract: Just as fear can be learned, it can also be inhibited. The most common way of reducing learned fear is through extinction, where the conditioned stimulus (CS) previously paired with an aversive unconditioned stimulus (US) is repeatedly presented on its own. Another, much less commonly studied, way to inhibit learned fear is by habituating, or devaluing, the US. In this procedure, fear responding to a CS is reduced by repeatedly presenting the US in the absence of the CS following the conditioning phase. The purpose of the present study was to directly compare the effects of US habituation and CS extinction on a learned fear response (freezing). Experiment 1 demonstrated that US habituation given either after (Experiment 1A) or before (Experiment 1B) fear conditioning reduced freezing to the CS at test. We then showed that the reduction in freezing resulting from either US habituation or CS extinction was context-specific (i.e., a change in context led to a renewal of the learned fear response; Experiment 2) and, furthermore, was attenuated when a pre-test shock was given (i.e., reinstatement of fear was observed in both cases; Experiment 3). Finally, Experiment 4 demonstrated that an injection of the NMDA antagonist MK-801 prior to US habituation impaired long-term retention of the learning that takes place during this procedure. Together, these results suggest that the decrement in conditioned fear responses produced by US habituation and CS extinction could rely on overlapping processes. [Copyright &y& Elsevier]

Abstract: The renewal of extinguished conditioned behaviour appears to reflect context-dependent learning. The present research used a conditioned suppression task with humans to examine whether instructions concerning the context could influence renewal. Pairings of a conditional stimulus (CS) and unconditional stimulus (US) were made in one context, followed by extinction trials of CS alone in a second context, and test trials of CS alone upon return to the original learning context. Four experiments tested whether the renewal of conditioned suppression observed during test would be attenuated if participants were instructed that the context changes were irrelevant to the predictive relationship between the CS and US. Using a differential conditioning design, no attenuation was found when the instructions were given prior to conditioning (Experiment 1) or immediately prior to the test trials (Experiment 2). The latter result was replicated with a single-cue conditioning design and further controls for exposure to the extinction contexts (Experiment 3). The collection of on-line ratings about the relationship between the contextual changes and the predictive nature of the CS indicated that participants did attend to and believe the instructions (Experiment 4). The results point to the resistance of renewal to explicit instructions that attempt to devalue the role of the contextual cues. [Copyright &y& Elsevier]