Aware and (Dis)Liking: Item-Based Analyses Reveal That Valence Acquisition via Evaluative Conditioning Emerges Only When There Is Contingency Awareness.

Evaluative conditioning (EC) refers to changes in the liking of an affectively neutral stimulus (the conditioned stimulus, or CS) following the pairing of that stimulus with another stimulus of affective value (the unconditioned stimulus, or US). In 3 experiments, the authors assessed contingency awareness, that is, awareness of the CS-US associations, by relying on participants' responses to individual items rather than using a global method of assessment. They found that EC emerged on contingency aware CSs only. Of note, whether the CSs were evaluated explicitly (Experiments 1 and 2) or implicitly (Experiment 3) did not make a difference. This pattern supports the idea that awareness of the CS-US associations may be required for valence acquisition via EC. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of contingency violations on the extinction of a conditioned fear inhibitor and a conditioned fear excitor.

In 4 experiments, 192 male Holtzman and Sprague-Dawley rats were used in a conditioned-suppression paradigm to assess the effects of contingency variations on responding to a conditioned stimulus (CS) inhibitor (CS–) and a conditioned stimulus excitor (CS+). In Exp I, various unconditioned stimulus/stimuli (UCS) frequencies were equated across the presence and absence of a CS– in the context of either background cues (continuous-trial procedure) or an explicit neutral event (discrete-trial procedure). With both procedures, a CS-alone treatment enhanced inhibition, whereas treatments involving 50 or 100% reinforcement for the CS– eliminated inhibition without conditioning excitation to that CS. The latter outcome also occurred in Exp II, with discrete-trial training equating considerably reduced UCS frequencies for the presence and absence of the CS–. In further evidence that inhibition was eliminated without conditioning excitation to the CS–, Exp III showed that a novel CS did not acquire excitation when 25, 50, or 100% reinforcement was equated across the presence and absence of that CS in the context of a discrete-trial event. Using the procedures of Exp I, Exp IV showed that a CS+ was extinguished by a CS-alone treatment but was substantially maintained by treatments involving 50 or 100% uncorrelated reinforcement. These effects for a CS+ and a CS– implicate CS–UCS contiguity, rather than contingency, as the factor determining the extinction of a CS. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dissociation Between Judgments and Outcome-Expectancy Measures in Covariation Learning: A Signal Detection Theory Approach.

A number of studies using trial-by-trial learning tasks have shown that judgments of covariation between a cue c and an outcome o deviate from normative metrics. Parameters based on trial-by-trial predictions were estimated from signal detection theory (SDT) in a standard causal learning task. Results showed that manipulations of P(c) when contingency (ΔP) was held constant did not affect participants' ability to predict the appearance of the outcome (d') but had a significant effect on response criterion (c) and numerical causal judgments. The association between criterion c and judgment was further demonstrated in 2 experiments in which the criterion was directly manipulated by linking payoffs to the predictive responses made by learners. In all cases, the more liberal the criterion c was, the higher judgments were. The results imply that the mechanisms underlying the elaboration of judgments and those involved in the elaboration of predictive responses are partially dissociable. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluative conditioning and the awareness issue: Assessing contingency awareness with the Four-Picture Recognition Test.

An experiment is described that tested the moderating influence of contingency awareness on evaluative conditioning. After participants were conditioned within the picture-picture paradigm, contingency awareness was assessed by means of a recognition test (i.e., the 4-picture recognition test). Results indicate an inverse relationship between the conditioned affective reaction and contingency awareness: Only participants classified as unaware in the recognition test showed significant effects of evaluative learning. A closer inspection indicates that aware individuals stored not only the valence but also the nominal stimulus in mind. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Observational fear conditioning in the acquisition and extinction of attentional bias for threat: An experimental evaluation.

Anxious persons show automatic and strategic attentional biases for threatening information. Yet, the mechanisms and processes that underlie such biases remain unclear. The central aim of the present study was to elucidate the relation between observational threat learning and the acquisition and extinction of biased threat processing by integrating emotional Stroop color naming tasks within an observational differential fear conditioning procedure. Forty-three healthy female participants underwent several consecutive observational fear conditioning phases. During acquisition, participants watched a confederate displaying mock panic attacks (UCS) paired with a verbal stimulus (CS+), but not with a second nonreinforced verbal stimulus (CS-). As expected, participants showed greater magnitude electrodermal and verbal-evaluative (e.g., distress, fear) conditioned responses to the CS+ over the CS- word. Participants also demonstrated slower color-naming latencies to CS+ compared to the CS- word following acquisition and showed attenuation of this preferential processing bias for threat following extinction. Findings are discussed broadly in the context of the interplay between fear learning and processing biases for threat as observed in persons suffering from anxiety disorders. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging and integration of contingency evidence in causal judgment.

Age differences in causal judgment are consistently greater for preventative/negative relationships than for generative/positive relationships. In this study, a feature analytic procedure (Mandel & Lehman, 1998) was used to determine whether this effect might be due to differences in young and older adults’ integration of contingency evidence during causal induction. To reduce the impact of age-related changes in learning/memory, the authors presented contingency evidence for preventative, noncontingent, and generative relationships in summary form; the meaningfulness of causal context was varied to induce participants to integrate greater or lesser amounts of this evidence. Young adults showed greater flexibility in their integration processes than did older adults. In an abstract causal context, there were no age differences in causal judgment or integration, but in meaningful contexts, young adults’ judgments for preventative relationships were more accurate than older adults’ and young adults assigned more weight to the contingency evidence confirming these relationships. These differences were mediated by age-related changes in processing speed. The decline in this basic cognitive resource may place boundaries on the amount or type of evidence that older adults can integrate for causal judgment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fear conditioning in panic disorder: Enhanced resistance to extinction.

Enhanced conditionability has been proposed as a crucial factor in the etiology and maintenance of panic disorder (PD). To test this assumption, the authors of the current study examined the acquisition and extinction of conditioned responses to aversive stimuli in PD. Thirty-nine PD patients and 33 healthy control participants took part in a differential aversive conditioning experiment. A highly annoying but not painful electrical stimulus served as the unconditioned stimulus (US), and two neutral pictures were used as either the paired conditioned stimulus (CS+) or the unpaired conditioned stimulus (CS-). Results indicate that PD patients do not show larger conditioned responses during acquisition than control participants. However, in contrast to control participants, PD patients exhibited larger skin conductance responses to CS+ stimuli during extinction and maintained a more negative evaluation of them, as indicated by valence ratings obtained several times throughout the experiment. This suggests that PD patients show enhanced conditionability with respect to extinction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

étude du lien entre l'évaluation de la valence et les réponses verbales dans une tache de décision lexicale: Les réponses oui et non sont-elles des réponses affectives?

Evaluation of the positive or negative valence of a stimulus is an activity that is part of any emotional experience that has been mostly studied using the affective priming paradigm. In this study, we use the hypothesis that when a word leads to a positive valence evaluation, this favours a positive verbal response and inversely, a negative valence word favours a negative response. We are testing this hypothesis outside the affective priming paradigm to study to what extent evaluating a word, even when it is not primed, activates both motivational systems and consequently, positive verbal responses for approach and negative responses for avoidance. To validate this hypothesis, we are re-using both versions of the lexical decision task proposed by Wentura (2000). Results show an interaction between the type of response and word valence. It is temporally more onerous to give a no response to positive words than to negative words. This result confirms that there is a direct relation between the evaluation of a valence stimulus and the response to this stimulus, a relation that had up to now been essentially observed with motor behaviours, and more rarely with verbal responses. We propose integrating the existence of this link between evaluation and verbal response (yes and no) in interpreting the effects of affective priming. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conditioned stimulus familiarity determines effects of MK-801 on fear extinction.

Six experiments studied the role of conditioned stimulus (CS) familiarity in determining the effects of the N-methyl-d-aspartate (NMDA) receptor antagonist MK-801 on fear extinction. Systemic administration of MK-801 (0.1 mg/kg) impaired initial extinction but not reextinction learning. MK-801 impaired reextinction learning when the CS was relatively novel during reextinction training but not initial extinction learning when the CS was relatively familiar during initial extinction training. A context change failed to reinstate the sensitivity of initial fear extinction learning about a relatively familiar CS to MK-801. These experiments show that CS familiarity is an important determinant of effects of MK-801 on fear extinction learning: MK-801 impaired extinction learning about novel stimuli but spared extinction learning about familiar stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Responding to a conditioned stimulus depends on the current associative status of other cues present during training of that specific stimulus.

The comparator hypothesis is a response rule stating that responding to a Pavlovian conditioned stimulus/stimuli (CS) reflects the associative strength of the CS relative to that of other cues (comparator stimuli) that were present during CS training. Thus, modulation of the associative strength of a CS's comparator stimulus should alter responding to that CS. These studies examined the stimulus specificity of this effect using within-Ss designs. Rats were trained on 2 CSs, each with a unique comparator stimulus, to determine the degree to which posttraining extinction of the comparator stimulus for one CS influences responding to the other CS. Using negative contingency (Exps 1 and 2), overshadowing (Exp 3), and local context (Exp 4) preparations, stimulus specificity was observed. In each case, posttraining extinction of the comparator stimulus for one CS had greater impact on responding to that CS than on responding to the alternate CS. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluative learning with single versus multiple unconditioned stimuli: The role of contingency awareness.

Evaluative conditioning (EC) is obtained when an initially neutral conditioned stimulus (CS) becomes evaluated positively (negatively) after being paired with an evaluatively positive (negative) unconditioned stimulus (US). Most EC studies have paired a given CS with a single US, but EC has also been obtained when a CS was paired with multiple USs of the same valence. This study compares how both variants of CS–US pairing affect awareness for CS–US pairings and ultimately EC effects. EC was assessed directly and indirectly, using evaluative ratings and the Extrinsic Affective Simon Task. Memory for US identity and US valence was assessed to investigate effects of awareness. The multiple-US condition showed attenuated EC effects compared with the single-US condition. The direct measure showed EC effects when awareness of US valence or US identity was present. The indirect measure showed EC effects only when awareness of US identity was present. Results are discussed with regard to the role of contingency awareness in EC. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparative electrophysiologic findings between responders and nonresponders to class III antiarrhythmic drugs among patients with ventricular tachyarrhythmia

Rabbits received conditional discrimination training using contextual stimuli to set the occasion for stimulus pairings during eyelid conditioning. Specifically, animals were exposed to either the presence or the absence of an oscillating chamber light throughout the intertrial interval (50 +/- 10 s). For half the animals, this light signaled paired presentations of a discrete tone conditioned stimulus (CS) and air puff unconditioned stimulus (US) while darkness signaled presentations of only the tone CS. The remaining animals experienced the opposite contextual relationship to the conditioning stimuli. These trial types occurred pseudo-randomly across a session, with all transitions between contextual settings (i.e., light or dark) taking place immediately at the CS-US offset. Under these conditions, animals successfully utilized the contextual stimuli as conditional cues for differential responding to the shared CS. Moreover, both light and dark were equally effective as discriminative stimuli. A subset of animals received further training in which the contextual contingency was removed by restricting all conditioning to the CS-alone context. Without the contingency in place, subsequent CS presentations (paired and CS-alone) evoked equivalent conditioned responding across three sessions of training. Following the reinstatement of the contextual contingencies, discriminatory responding was immediately observed and returned to previous levels within three sessions. Finally, animals appeared to use the static representation of the conditional cue, rather than the phasic transition between cues, for discriminatory responding. These findings are discussed in terms of current neurobiological models of eyelid conditioning.     

Facilitation of extinction by an increase or a decrease in trial duration.

Five experiments examined the effects of altering the duration of a conditioned stimulus (CS) for extinction. For the first 3 experiments, rats received conditioning with a 10-s CS before different groups received extinction with a CS that was either the same duration or longer than that used for conditioning. For the remaining 2 experiments, conditioning was conducted with a 60-s CS before different groups received extinction with a CS of either the same duration or a shorter duration than that used for conditioning. In all experiments, extinction progressed more readily when the CS duration was different for the 2 stages than when it was constant. The results are discussed in terms of rate expectancy theory and associative learning theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temporal Specificity of Extinction in Autoshaping.

Three experiments investigated the effects of varying the conditioned stimulus (CS) duration between training and extinction. Ring doves (Streptopelia risoria) were autoshaped on a fixed CS-unconditioned stimulus (US) interval and extinguished with CS presentations that were longer, shorter, or the same as the training duration. During a subsequent test session, the training CS duration was reintroduced. Results suggest that the cessation of responding during an extinction session is controlled by generalization of excitation between the training and extinction CSs and by the number of nonreinforced CS presentations. Transfer of extinction to the training CS is controlled by the similarity between the extinction and training CSs. Extinction learning is temporally specific. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Making causal judgments from the proportion of confirming instances: The pCI rule.

It is proposed that causal judgments about contingency information are derived from the proportion of confirmatory instances (pCI) that are evaluated as confirmatory for the causal candidate. In 6 experiments, pCI values were manipulated independently of objective contingencies assessed by the ΔP rule. Significant effects of the pCI manipulations were found in all cases, but causal judgments did not vary significantly with objective contingencies when pCI was held constant. The experiments used a variety of stimulus presentation procedures and different dependent measures. The power PC theory, a weighted version of the ΔP rule, the Rescorla-Wagner associative learning model (R. A. Rescorla & A. R. Wagner, 1972), and the ΔD rule, which is the frequency-based version of the pCI rule, were unable to account for the significant effects of the pCI manipulations. These results are consistent with a general explanatory approach to causal judgment involving the evaluation of evidence and updating of beliefs with regard to causal hypotheses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Genetic variation among Trypanosoma cruzi populations

Four experiments examined the effect of naloxone pretreatment on the expression and extinction of ethanol-induced conditioned place preference (experiments 1, 2, 4) or conditioned place aversion (experiments 1, 3). DBA/2 J mice received four pairings of a distinctive tactile (floor) stimulus (CS) with injection of ethanol (2 g/kg) given either immediately before or after 5-min exposure to the CS. A different stimulus was paired with injection of saline. Pre-CS injection of ethanol produced conditioned place preference, whereas post-CS injection of ethanol produced conditioned place aversion. Both behaviors extinguished partially during repeated choice testing after vehicle injection. Naloxone (10 mg/kg) had little effect on the initial expression of conditioned place preference, but facilitated its extinction. Moreover, repeated naloxone testing resulted in the expression of a weak conditioned place aversion to the CS that initially elicited a place preference. In contrast, naloxone (1.5 or 10 mg/kg) enhanced expression of conditioned place aversion, thereby increasing its resistance to extinction. A control experiment (experiment 4) indicated that repeated testing with a different aversive drug, lithium chloride, did not affect rate of extinction or produce an aversion to the CS previously paired with ethanol. These findings do not support the suggestion that naloxone facilitates the general processes that underlie extinction of associative learning. Also, these data are not readily explained by the conditioning of place aversion at the time of testing. Rather, naloxone's effects appear to reflect a selective influence on maintenance of ethanol's conditioned rewarding effect, an effect that may be mediated by release of endogenous opioids. Overall, these findings encourage further consideration of the use of opiate antagonists in the treatment of alcoholism.     

Under what conditions can human affective conditioning occur without contingency awareness? Test of the evaluative conditioning paradigm.

The role of conscious cognitive processes in human affective conditioning remains controversial, with several theories arguing that such conditioning can occur without awareness of the conditioned stimulus (CS)-unconditioned stimulus (UCS) contingency. One specific type of affective conditioning in which unaware conditioning is said to occur is "evaluative conditioning." The present experiment tested the role of contingency awareness by embedding an evaluative conditioning paradigm in a distracting masking task while obtaining, in addition to subjective ratings of affect, both psychophysiological (skin conductance and startle eyeblink) and indirect behavioral (affective priming) measures of conditioning, along with a trial-by-trial measure of awareness from 55 college student participants. Aware participants showed conditioning with all of the measures; unaware participants failed to show conditioning with all measures. The behavioral, neurophysiological, and therapeutic implications of these findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of context on performance to conditioned stimuli with mixed histories of reinforcement and nonreinforcement.

Five conditioned suppression experiments, with 160 Wistar rats, explored the role of the conditioning history of the conditioned stimulus (CS) in determining the effects of contextual fear on performance to the CS. Contextual fear was produced by postconditioning exposure to unconditioned stimulus/stimuli (UCS) alone in the context of conditioning; it was independently assessed with context-preference tests. When the number of reinforced and nonreinforced trials was equated across extinction, partial reinforcement, and latent inhibition procedures, only the extinction procedure produced a CS whose performance was subsequently affected (i.e., augmented) by contextual fear. Contextual fear's relatively unique augmenting effect on fear of an extinguished CS was abolished by extensive, but not by less extensive, reacquisition training. Results indicate that, depending on the CS's conditioning history, contextual fear either augments or has little effect on fear of the CS. It is suggested that augmentation by context should be viewed as the restoration of fear that is otherwise depressed by extinction. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

I like it because I said that I like it: Evaluative conditioning effects can be based on stimulus-response learning.

Evaluative conditioning (EC) effects are often assumed to be based on a learned mental link between the CS (conditioned stimulus) and the US (unconditioned stimulus). We demonstrate that this link is not the only one that can underlie EC effects, but that if evaluative responses are actually given during the learning phase also a direct link between the CS and an evaluative response—a CS-ER link—can be learned and lead to EC effects. In Experiment 1, CSs were paired with USs and participants were asked to evaluate the pairs during the conditioning phase. Resulting EC effects were unaffected by a later revaluation of the USs, suggesting that these EC effects can be attributed to CS-ER learning rather than to CS-US learning. Experiment 2 replicated Experiment 1 with the difference that no evaluative responses were given during the learning phase. EC effects in this study were influenced by US revaluation, suggesting that these EC effects are mainly based on CS-US learning. In Experiment 3, it was shown that EC effects can be found even if the USs are entirely removed from the procedure and the CSs are only paired with enforced evaluative responses. Together the experiments show that the valence of a stimulus can change because of a contingency with an evaluative response. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Timed excitatory conditioning under zero and negative contingencies.

Rats (rattus norvegicus) anticipated the arrival of a food pellet unconditioned stimulus (US) even when the conditioned stimulus (CS) signaled no overall change or a substantial decrease in the overall rate of US occurrence. Pellet USs were scheduled probabilistically in the intertrial interval at either an equivalent rate (Experiment 1) or a four times higher rate (Experiments 2 and 3) than in the CS, which included one fixed-time target US. Conditioning has been said to involve learning "whether" (contingency) the CS signals a change in the US, and if so, "when" (contiguity) the US is scheduled to arrive. Our results suggest that "when" trumps "whether," challenging the received view that a positive CS-US contingency is necessary for successful conditioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)