Extinction in multiple contexts reduces the return of extinguished responses: A multilevel meta-analysis.

Extinguished responses have been shown to reappear under several circumstances, and this reappearance is considered to model behaviors such as relapse after exposure therapy. Conducting extinction in multiple contexts has been explored as a technique to decrease the recovery of extinguished responses. The present meta-analysis aimed to examine whether extinction in multiple contexts can consistently reduce the recovery of extinguished responses. After searching in several databases, experiments were included in the analysis if they presented extinction in multiple contexts, an experimental design, and an adequate statistical report. Cohen's d was obtained for each critical comparison and weighted to obtain the sample's average weighted effect size. Analyses were then performed using a multilevel meta-analytic approach. Twenty-five studies were included, with a total sample of 37 experiments or critical comparisons. The analyses showed a large effect size for the sample, moderated by the length of conditioned stimulus exposure, type of experimental subject, and type of recovery. The robust effect of extinction in multiple contexts on relapse should encourage clinicians to consider extinction in multiple contexts as a useful technique in therapy and research.

Relation among, trait anxiety, intolerance to uncertainty and early maltreatment experiences on fear discrimination learning and avoidance generalization online task.

BACKGROUND AND OBJECTIVES: Early aversive experiences, which have been associated with elevated anxiety and intolerance of uncertainty (IUS), may contribute negatively to fear conditioning learning. The aim of the present study was to analyze the relation among individual differences in childhood maltreatment experiences, trait anxiety, and IUS in adulthood; and to determine how these variables could affect fear learning discrimination and avoidance generalization. METHODS: We adapted an avoidance procedure in an online fear learning task. Two pictures of different lamp colors (CS+) were first associated with two aversive images (US), while a third color was not (CS-). Next, clicking a button during one CS + could effectively avoid the US (CS + av), but not during the other (CS + unav). Finally, avoidance generalization was tested to lamp colors that were between CS- and CS + av (safety dimension) and CS + av and CS + unav (avoidability dimension). With a sample of 67 participants, we measured ratings of relief, expectancy, and anxiety, as well as button presses and individual differences (STAI, IUS and MAES). RESULTS: Aversive early experiences were positively related to trait anxiety and intolerance of uncertainty. The results of the task further suggested that maltreatment experience contributes to be more attentive to aversive signals, which could be implicated in leading to difficulties in discrimination learning. LIMITATIONS: Online experiments implies some loss of control over subjects and environment that can threaten internal validity. Likewise, the commitment of participants may be low. CONCLUSIONS: Results suggest that early aversive experience and anxiety could contribute to the development of IUS, which likely contributes to the development of avoidance behavior.

Behavioral effects on the offspring of rodent mothers exposed to Tetrahydrocannabinol (THC): A meta-analysis.

Pre and perinatal administration of Tetrahydrocannabinol (THC) in rodents and their offspring has many effects that have been studied using different methods that have not been integrated using quantitative methods. The effect of THC administration on behavior can be better understood by meta-analytic techniques. We examined whether there is an overall effect on the behavior of the offspring when THC is administered to mothers. Eligibility criteria included experiments using an experimental design with a control group without THC, in which THC is administered to mothers during pregnancy and lactation in rodents, and in which at least one type of behavioral (locomotor, emotional or cognitive) measurement in the offspring was implemented. Cohen's d was obtained for each study, then each individual study was weighted, and moderator analysis was performed. Analysis was performed using fixed and random effect models, and the heterogeneity was assessed by calculating Qb, I 2 and the prediction interval. Furthermore, 3 sub-meta-analyses were carried out according to the type of behavior. The general analysis determined a low weighted effect size of THC on the behavior of the offspring, moderated by type of rat strain. The sub-meta-analyses showed a medium effect for cognitive effects of THC in the offspring, and a low effect on locomotor activity and emotional behavior. In addition, publication bias was not detected. More research is needed to contribute to the understanding of the effect of THC exposure on offspring.

Blocking is not 'pure' cue competition: Renewal-like effects in forward and backward blocking indicate contributions by associative cue interference.

Blocking (i.e., reduced responding to cue X following YX-outcome pairings in Phase 2 as a consequence of cue Y having been paired with the outcome in Phase 1) is one of the signature phenomena in Pavlovian conditioning. Its discovery promoted the development of multiple associative models, most of which viewed blocking as an instance of pure cue competition (i.e., a decrease in responding attributable to training two conditioned stimuli in compound). Two experiments are reported in which rats were examined in a fear conditioning paradigm (i.e., lick suppression), and context dependency of retrieval at test was used as an index of associative cue interference (i.e., a decrease in responding to a target cue as a result of training a second cue with the same outcome but without concurrent presentation of the two cues). Specifically, we observed renewal of forward-blocking which parallels renewal of proactive interference, and renewal of backward-blocking which parallels renewal of retroactive interference. Thus, both backward-blocking (Experiment 1, embedded in a sensory preconditioning design) and forward-blocking (Experiment 2, conducted in first-order conditioning) appear to be influenced by retroactive and proactive interference, respectively, as well as cue competition. Consequently, blocking, long regarded as a benchmark example of pure cue competition, is sometimes a hybrid of cue competition and associative interference. Finally, the Discussion considers whether stimulus competition and associative interference are two independent phenomena or products of a single underlying process. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Why do people self-sacrifice for their country? The roles of identity fusion and empathic concern.

Identity fusion with a group, a feeling of connection with it, is a good predictor of extreme pro-group behavior, an action to favor or protect the group, including self-sacrifice. Relational ties and personal distress (self-oriented emotional reaction; e.g., anxiety, distress) toward ingroup members in need have been evaluated separately as mediators of the relationship between identity fusion and pro-group self-sacrifice. Another mediator could be empathic concern (other-oriented emotional reaction; e.g., compassion, sympathy), but it has not been considered in the literature. We related those three mediators in a model. The objective was to analyze whether relational ties mediate the relationship between identity fusion and pro-country self-sacrifice whereas both empathic concern and personal distress mediate the association between relational ties and pro-country self-sacrifice. We expected that identity fusion with the country leads to more relational ties, which in turn evokes both empathic concern and personal distress, and those emotional reactions promote more and less pro-country self-sacrifice, respectively, with more effect of empathic concern than personal distress. We considered the country as the group reference because it is the most used in identity fusion research. In a sample of university students (N = 539), the results supported this model: Identity fusion promoted relational ties, which in turn evoked empathic concern and personal distress. Then, the last two variables predicted more and less self-sacrifice, respectively, with more effect of empathic concern than personal distress. We discussed the theoretical implications of the model, especially the relationship of identity fusion with empathic concern and personal distress-traditional explanations for pro-group behavior-considering the different motivations associated to both emotional reactions. Despite the limitations associated with the measurements, the data supported the model that relates variables not previously explored jointly.

Alteraciones de la cognición social en síndromes de alto riesgo en psicosis / Social cognitive impairment in clinical high risk for psychos

Resumen La esquizofrenia es una enfermedad crónica, severa y que afecta aproximadamente al 1% de la población mundial. Pacientes con esta enfermedad presentan severos déficits en la cognición social (DCS). Estos déficits han sido observados en pacientes de primer episodio y familiares de primer grado. Los DCS determinan el pronóstico a largo plazo en esta enfermedad y son susceptibles de rehabilitación si es que se detectan precozmente. Solo recientemente se han caracterizado los déficits de la cognición social en sujetos de alto riesgo de desarrollar psicosis crónica. Estos sujetos presentan una oportunidad única para modificar la inserción social y modificar el pronóstico, pues no han sido afectados mayormente por la cronicidad de la enfermedad y presentan una sintomatología más leve que en etapas residuales. El presente trabajo pretende realizar una revisión de cómo los DCS están presentes desde etapas prodrómicas de la esquizofrenia y su importancia en la detección precoz de esta enfermedad.

Schizophrenia is a severe chronic disease that affects approximately 1 % of the world's population. Those who suffer this disease have serious deficits in social cognition (DSC), deficits that have been observed in first psychotic episode patients and first-degree relatives. The DSC determine the long-term prognosis in this disease and are susceptible to rehabilitation if they are detected early. Only recent studies have characterized deficits of social cognition in subjects with a high risk of developing chronic psychosis. These subjects present a unique opportunity to modify their social insertion and medical prognosis, as they have not been affected by the chronicity of the disease and present a milder symptomatology than in residual stages. This paper aims to make a review about how the DSC are present in schizophrenia from its prodromal stages and about its importance in the early detection of this disease.

Assessing the blocking of occasion setting.

An occasion setter (OS) is a stimulus or context with the capacity to disambiguate an ambiguous conditioned stimulus (CS). Previous research has shown that OSs share some features with regular Pavlovian CSs. Amongst them, research has shown that OSs are subject to blocking; that is, a new OS exerts reduced behavioral control after training in compound with a previously established OS. Of additional interest, in Pavlovian blocking, it has been reported that a blocked CS comes to elicit conditioned responding after the extinction of the blocking CS. This is an example of retrospective revaluation, a family of phenomena in which the response to a specific stimulus is modified by training a related cue. Here, three experiments sought to extend the analogies between OS and Pavlovian conditioning by examining the blocking of OSs and its retrospective revaluation. In all experiments, an OS was established by pairing a CS with food in the presence of the OS, but not in its absence (i.e., positive OS). Blocking was then trained by presenting the OS in compound with a novel OS. Experiment 1 showed blocking of the second OS, but direct exposure to the blocking OS did not enhance responding to the second OS. Experiment 2 replicated the blocking effect but subsequent training of the blocking OS with a reversed contingency showed no retrospective revaluation. Experiment 3 examined whether blocking of the OS occurred with a novel CS during the compound phase. In this experiment blocking was again observed, but only when subjects were tested with the original CS. These results are discussed focusing on the underlying links at work in occasion setting.

Proactive interference by cues presented without outcomes: Differences in context specificity of latent inhibition and conditioned inhibition.

This report is part of a larger project examining associative interference as a function of the nature of the interfering and target associations. Lick suppression experiments with rats assessed the effects of context shifts on proactive outcome interference by latent inhibition (LI) and Pavlovian conditioned inhibition (CI) treatments on subsequently trained Pavlovian conditioned excitation treatment. LI and CI were trained in Context A during Phase 1, and then excitation treatment was administered in Context B during Phase 2, followed by tests for conditioned excitation in Contexts A, B, or C. Experiment 1 preliminarily established our LI and CI treatments and resulted in equally retarded acquisition of behavioral control when the target cue was subsequently trained as a conditioned excitor and tested in Context A. However, only CI treatment caused the target to pass a summation test for inhibition. Centrally, Experiment 2 consisted of LI and CI treatments in Context A followed by excitatory training in Context B. Testing found low excitatory control by both LI and CI cues in Context A relative to strong excitatory control in Context B, but CI treatment transferred to Context C more strongly than LI treatment. Experiment 3 determined that LI treatment failed to transfer to Context C even when the number of LI trials was greatly increased. Thus, first-learned LI appears to be relatively context specific, whereas first-learned CI generalizes to a neutral context. These observations add to existing evidence that LI and CI treatments result in different types of learning that diverge sharply in transfer to a novel test context.

Preventing the recovery of extinguished ethanol tolerance.

There is substantial evidence that drug-paired cues become associated with drug effects. From a Pavlovian perspective, these cues act as conditioned stimuli and elicit conditioned compensatory responses that contribute to drug tolerance. Here we report two experiments with rats in which we studied the extinction of the associative tolerance to the ataxic effect of ethanol. Experiment 1 evaluated whether changes in the temporal and physical contexts after extinction training provoke recovery of the extinguished tolerance. The results showed successful extinction, spontaneous recovery and renewal of the extinguished tolerance, but no summation of renewal and spontaneous recovery. Experiment 2 evaluated whether using massive extinction trials and delivering extinction in multiple contexts attenuates the renewal effect. The results showed that both manipulations reduced renewal of the extinguished tolerance to the ataxic effect of ethanol; however, these manipulations used in combination did not appear to be more effective in reducing recovery than each by itself. The present results may help guide further research that evaluates behavioral ploys to prevent the recovery of extinguished responses.

Attenuating social affective learning effects with Memory Suppression manipulations.

People can form opinions of other individuals based on information about their good or bad behavior. The present study investigated whether this affective learning might depend on memory links formed between initially neutral people and valenced information. First, participants viewed neutral faces paired with sentences describing prosocial or antisocial behaviors. Second, memory suppression manipulations with the potential to aid in the forgetting of valenced information were administered. Using the Think/No think paradigm, the effectiveness of four different suppression instructions was compared: Unguided Suppression, Guided Suppression, Distraction, and Thought Substitution. Overall, all the tasks appreciably reduced affective learning based on prosocial information, but only the Guided Suppression and Thought Substitution tasks reduced affective learning based on antisocial information. These results suggest that weakening the putative memory link between initially neutral people and valenced information can decrease the effect of learned associations on the evaluation of other people. We interpreted this as indicative that social affective learning may rely on declarative memories.

Comparing the context specificity of extinction and latent inhibition.

Exposure to a cue alone either before (i.e., latent inhibition treatment) or after (i.e., extinction) the cue is paired with an unconditioned stimulus results in attenuated conditioned responding to the cue. Here we report two experiments in which potential parallels between the context specificity of the effects of extinction and latent inhibition treatments were directly compared in a lick suppression preparation with rats. The reversed ordering of conditioning and nonreinforcement in extinction and latent inhibition designs allowed us to examine the effect of training order on the context specificity of what is learned given phasic reinforcement and nonreinforcement of a target cue. Experiment 1 revealed that when conditioned-stimulus (CS) conditioning and CS nonreinforcement were administered in the same context, both extinction and latent inhibition treatments had reduced impacts on test performance, relative to excitatory conditioning when testing occurred outside the treatment context. Similarly, Experiment 2 showed that when conditioning was administered in one context and nonreinforcement was administered in a second context, the effects of both extinction and latent inhibition treatments were attenuated when testing occurred in a neutral context, relative to the context in which the CS was nonreinforced. The observed context specificity of extinction and latent inhibition treatments has been previously reported in both cases, but not in a single experiment under otherwise identical conditions. The results of the two experiments convergently suggest that memory of nonreinforcement becomes context dependent after a cue is both reinforced and nonreinforced, independent of the order of training.

The role of test context in latent inhibition of conditioned inhibition: Part of a search for general principles of associative interference.

In two lick suppression experiments with rats, we assessed interference with behavior indicative of conditioned inhibition by a latent inhibition treatment as a function of test context. We asked what effect the test context has, given identical latent inhibition treatments in Phase 1 and identical conditioned inhibition trainings in Phase 2. In Experiment 1, an AAA versus AAB context-shift design determined that the latent inhibition treatment in Phase 1 attenuated behavior indicative of the conditioned inhibition training administered in Phase 2, regardless of the test context, which could reflect a failure to either acquire or express conditioned inhibition. In Experiment 2, an ABA versus ABB design showed that test performance in Contexts A and B reflected the treatments that had been administered in those contexts (i.e., conditioned inhibition was observed in Context B but not A), which could reflect either the context specificity of either latent inhibition or conditioned inhibition. In either case, latent inhibition of conditioned inhibition training in at least some situations was seen to reflect an expression deficit rather than an acquisition deficit. These data, in conjunction with prior reports, suggest that latent inhibition is relatively specific to the context in which it was administered, whereas conditioned inhibition is specific to its training context only when it is the second-learned relationship concerning the target cue. These experiments are part of a larger effort to delineate control by the test context of two-phase associative interference, as a function of the nature of target training and the nature of interference training.

Enhancement and reduction of associative retroactive cue interference by training in multiple contexts.

Retroactive cue interference refers to situations in which a target cue X is paired with an outcome in phase 1 and a nontarget cue Z is paired with the same outcome in phase 2, with less subsequent responding to X being seen as a result of the phase 2 training. Two conditioned suppression experiments with rats were conducted to determine whether retroactive cue interference is similarly modulated by a manipulation that influences retroactive outcome interference (e.g., extinction). Both experiments used an ABC renewal-like design in which phase 1 training, phase 2 training, and testing each occurred in different contexts. Experiment 1 found that training the target association in multiple contexts without altering the number of training trials during phase 1 decreased retroactive cue interference (i.e., increased responding consistent with the target association). Experiment 2 found that training the interfering association in multiple contexts without altering the number of interference trials during phase 2 increased retroactive cue interference (i.e., decreased responding consistent with the target association). The possibility of similar mechanisms underlying cue interference and outcome interference is discussed.

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

BACKGROUND AND OBJECTIVES: Recent data indicate that extinguished fear often returns when the testing conditions differ from those of treatment. Several manipulations including extensive extinction training, extinction in multiple contexts, and spacing the extinction trials and sessions reduce the return of fear. Moreover, extensive extinction and extinction in multiple contexts summate in reducing return of fear, and the spacing of the extinction trials and the spacing of extinction sessions summate in reducing return of fear. Here we evaluated whether these techniques also attenuate the context specificity of latent inhibition, and whether they summate to further decrease fear responding at test. METHODS: In two experiments, with rats as subjects in a lick suppression preparation, we assessed the effects of massive CS preexposure, CS preexposure in multiple contexts, and of spacing the CS-preexposure trials and sessions, in reducing the context specificity of latent inhibition. RESULTS: Fear responding was attenuated by all four manipulations. Moreover, extensive CS preexposure in multiple contexts, and conjoint spacing of the CS-preexposure trials and sessions, were more effective in reducing the context specificity of latent inhibition than each manipulation alone. LIMITATIONS: Our experimental designs evaluated degrees of context specificity of latent inhibition but omitted groups in which latent inhibition was assessed without a context shift away from the context of latent inhibition treatment. This precluded us from drawing conclusions concerning absolute (as opposed to relative) levels of recovery from latent inhibition. CONCLUSIONS: Techniques effective in decreasing the return of conditioned fear following extinction are also effective in decreasing the context specificity of latent inhibition in an animal model of anxiety. Fear and anxiety disorders might be prevented in anxious human participants with the same techniques used here, but that is still an empirical question.

Classical conditioning and pain: conditioned analgesia and hyperalgesia.

This article reviews situations in which stimuli produce an increase or a decrease in nociceptive responses through basic associative processes and provides an associative account of such changes. Specifically, the literature suggests that cues associated with stress can produce conditioned analgesia or conditioned hyperalgesia, depending on the properties of the conditioned stimulus (e.g., contextual cues and audiovisual cues vs. gustatory and olfactory cues, respectively) and the proprieties of the unconditioned stimulus (e.g., appetitive, aversive, or analgesic, respectively). When such cues are associated with reducers of exogenous pain (e.g., opiates), they typically increase sensitivity to pain. Overall, the evidence concerning conditioned stress-induced analgesia, conditioned hyperalagesia, conditioned tolerance to morphine, and conditioned reduction of morphine analgesia suggests that selective associations between stimuli underlie changes in pain sensitivity.

Failure to observe renewal following retrieval-induced forgetting.

Recent studies have pursued the nature of inhibition observed in retrieval-induced forgetting (RIF) tasks. In a RIF paradigm, participants are trained on category-exemplar pairs in Phase 1. Then, some exemplars from select categories (Rp+ items) receive further practice in Phase 2. At test, impaired recall for non-practiced exemplars of the practiced categories (Rp- items) is observed relative to exemplars from non-practiced categories (Nrp items). This difference constitutes RIF. Prior reports of spontaneous recovery from RIF indicate that RIF represents a lapse rather than a loss of memory. Empirical analogs and theoretical considerations suggest that RIF should also be reversible through a change of context between Phase 2 and testing (i.e., renewal). We conducted two experiments using human participants to evaluate the context dependency of RIF. In both experiments, Phases 1 and 2 occurred in distinctly different contexts with subsequent testing occurring in either the Phase 1 context or the Phase 2 context. RIF was observed in both experiments. Experiment 1 additionally found that the magnitude of RIF was not reduced by testing in the Phase 1 context relative to testing in the Phase 2 context. Experiment 2 further tested context dependency of RIF by (1) increasing the dissimilarity between the two contexts and (2) inserting a retention interval between Phase 2 and test for half of the participants in each test context condition. The data again indicated no effect of the context manipulation. Thus, no renewal from RIF was observed in either experiment; moreover, these null findings were supported by Bayesian analyses. These results are compared with analogous inhibitory processes in the animal memory literature that typically show both physical and temporal context dependency.

Retrospective revaluation of associative retroactive cue interference.

Two fear-conditioning experiments with rats assessed whether retrospective revaluation, which has been observed in cue competition (i.e., when compounded cues are followed with an outcome), can also be observed in retroactive cue interference (i.e., when different cues are reinforced in separate phases with the same outcome). Experiment 1 found that after inducing retroactive cue interference (i.e., X-outcome followed by A-outcome), nonreinforced presentations of the interfering cue (A) decreases interference with responding to the target cue (X), just as has been observed in retrospective revaluation experiments in cue competition. Using the opposite manipulation (i.e., adding reinforced presentations of A), Experiment 2 demonstrated that after inducing retroactive cue interference, additional reinforced presentations of the interfering cue (A) increases interference with responding to the target cue (X); alternatively stated, the amount of interference increases with the amount of training with the interfering cue. Thus, both types of retrospective revaluation occur in retroactive cue competition. The results are discussed in terms of the possibility that similar associative mechanisms underlie cue competition and cue interference.

Trial spacing during extinction: the role of context-US associations.

Studies of extinction in Pavlovian preparations can identify conditions that make extinction more enduring and increase the benefits of exposure-based behavior therapy. One such potential condition is the use of spaced extinction trials. Nevertheless, contradictory results of spacing extinction trials are found in the existing literature. Here we examine the strength of the association between the extinction context and the unconditioned stimulus as a variable that reconciles the seemingly contradictory prior reports. To assess the role of this variable, we evaluated the effects of extinction trial spacing as a function of the associative status of the extinction context in three lick suppression experiments with rats. In Experiment 1, the associative status of the extinction context was manipulated by giving extinction treatment in either the same context as acquisition or a different context. In Experiment 2, the associative status of the extinction context was initially high as a result of the acquisition context being used for extinction and then it was manipulated through postacquisition context exposure. In Experiment 3, extinction was administered in a context different from that of acquisition and the associative status of the extinction context was manipulated by delivering unsignaled footshock (i.e., the unconditioned stimuli) in the extinction context between acquisition and extinction. In all three experiments, consistently less conditioned suppression was observed with spaced extinction trials relative to massed extinction trials when the associative value of the extinction context was relatively low. In contrast, massed extinction trials produced less conditioned suppression when the associative status of the extinction context was high. Thus, stimulus control after extinction is influenced by an interaction between the intertrial interval during extinction and the associative status of the extinction context.

Associative structure of integrated temporal relationships.

According to the temporal-coding hypothesis (TCH; Savastano & Miller, Behavioural Processes 44:147-162, 1998), acquired associations include temporal information concerning the interval between the associated elements. Moreover, the TCH posits that subjects can integrate two independently acquired associations that share a common element (e.g., S2-S1 and S1-US), which results in the creation of a third association with its own temporal relationship (S2-US). Some evidence has suggested that such temporal integration occurs at the time of testing (Molet, Miguez, Cham, & Miller, Journal of Experimental Psychology: Animal Behavior Processes 38:369-380, 2012). Here we report two fear-conditioning experiments with rats conducted to identify the associative structure of the integrated temporal relationship. The goal was to distinguish between two possible associative structures that could exist following an initial test on which temporal integration occurs: (1) Conditioned responding to S2 on subsequent tests could be the result of recurring successive activation of two independently learned temporal maps that remain independently stored in memory (i.e., S2-S1 plus S1-US). (2) Temporal integration at the moment of initial testing could result in the formation of a direct S2-US (or S2-response) temporal map. Integration was found to occur at test and to produce a new association that was independent of associations with the common element (S1). However, the associative status of S1 appeared to modulate whether or not the new association with S2 was US-specific (S2-US) or directly activated a fear response (S2-response).

Extinction with multiple excitors.

Four conditioned suppression experiments with rats, using an ABC renewal design, investigated the effects of compounding the target conditioned excitor with additional, nontarget conditioned excitors during extinction. Experiment 1 showed stronger extinction, as evidenced by less renewal, when the target excitor was extinguished in compound with a second excitor, relative to when it was extinguished with associatively neutral stimuli. Critically, this deepened extinction effect was attenuated (i.e., more renewal occurred) when a third excitor was added during extinction training. This novel demonstration contradicts the predictions of associative learning models based on total error reduction, but it is explicable in terms of a counteraction effect within the framework of the extended comparator hypothesis. The attenuated deepened extinction effect was replicated in Experiments 2a and 3, which also showed that pretraining consisting of weakening the association between the two additional excitors (Experiments 2a and 2b) or weakening the association between one of the additional excitors and the unconditioned stimulus (Experiment 3) attenuated the counteraction effect, thereby resulting in a decrease in responding to the target excitor. These results suggest that more than simple total error reduction determines responding after extinction.