Once in contact always in contact: Evaluative conditioning is resistant to extinction

The effects of a retrieval cue on renewal of conditioned responses in human appetitive conditioning

Contextual renewal of reward anticipation may be one potential mechanism underlying relapse in eating and substance use disorders. We therefore tested retrieval cues, a method derived from an inhibitory retrieval-based model of extinction learning to attenuate contextual renewal using an appetitive conditioning paradigm. A pilot study was carried out in Experiment 1 to validate a differential chocolate conditioning paradigm, in which a specific tray was set up as a conditioned stimulus (CS) for eating chocolate (unconditioned stimulus, US). Using an ABA renewal design in Experiment 2, half of the participants were presented with a retrieval cue in the acquisition phase (group AC) and the other half in the extinction phase (group EC). Presentation of the retrieval cue in the EC was associated with reduced renewal of US-expectancy, while there was a clear renewal effect for US-expectancy in the AC. One limitation was the difference in cue presentations between both groups due to the number of trials in acquisition and extinction. Experiment 3 therefore aimed at replicating the results of Experiment 2, but with fewer cue presentations for the EC to match the AC. No significant group differences were observed indicating no effect of the retrieval cue. Theoretical and clinical implications in light of the differing results are discussed.

Evaluating the effects of counterconditioning, novelty-facilitated, and standard extinction on the spontaneous recovery of threat expectancy and conditioned stimulus valence

Extinction training has proved effective to diminish the expectancy of the aversive unconditioned stimulus (US). However, the negative valence of the conditioned stimulus (CS) may still stay intact. In fact, several studies have suggested that the CS negative valence may be a factor that promotes the return of fear. Our study focuses on the role of changes in the CS valence as a potential mechanism to reduce the spontaneous recovery of threat expectancies. To do that, we evaluated counterconditioning (CC), a technique aimed to reduce the CS negative valence by paring it with a positive stimulus and compared its efficacy to that of a novelty-facilitated extinction (NFE) and a standard extinction interventions. Using a 2-day protocol, participants first learned the relationship between a figure and an aversive sound, using a differential conditioning paradigm, and were then randomly assigned to one of three different groups. For the CC group, CS+ or cue A was paired with a positive US. The standard extinction group was exposed to cue A alone. For a third NFE group, cue A was followed by a neutral US. Finally, on the second day, spontaneous recovery was tested. Our findings did not provide evidence to suggest that CC could be more effective to prevent or reduce the return of threat expectancies or influence valence ratings when compared with NFE and standard extinction.

Attenuating experimentally acquired disgust: Comparing counterconditioning, exposure and unconditioned stimulus revaluation

BACKGROUND AND OBJECTIVES

Disgust is implicated in the aetiology and maintenance of various psychopathologies such as anxiety disorders and obsessive-compulsive disorders. Despite its prominent role in psychopathology, little is known about how to effectively attenuate disgust. The study examined strategies to modify an experimentally acquired disgust response in a sample of undergraduate students.

METHODS

A conditioning paradigm was used where participants (N = 175) first underwent acquisition of disgust via repeated presentations of a neutral picture (functioning as conditioned stimulus + [CS+]) paired with a disgusting picture (functioning as unconditioned stimulus [US]). Participants were then randomly assigned to either an exposure (repeated presentation of CS-only trials), counterconditioning (pairing CS+ with pleasant pictures), US revaluation (pairing disgusting US with pleasant pictures) or a control (filler task) condition. We hypothesised that counterconditioning would attenuate evaluative learned disgust to the greatest extent, relative to exposure and US revaluation. Participants' evaluations of the pictures were attained with a disgust-pleasantness visual analogue scale.

RESULTS

Exposure, counterconditioning and US revaluation reduced disgusting US expectancies. However, experimental and control conditions did not differ in terms of attenuating disgust towards CS+.

LIMITATIONS

Measures of psychopathology and implicit evaluations of disgust were not collected. Modest power might have limited significance of the results.

CONCLUSIONS

No statistical support for the effectiveness of disgust attenuation following exposure nor counterconditioning were found. Findings for US revaluation are inconclusive. Implications for future research are discussed.

Knowledge and competency standards for specialized cognitive behavior therapy for adult obsessive-compulsive disorder

Obsessive-Compulsive Disorder (OCD) is a leading cause of disability world-wide (World Health Organization, 2008). Treatment of OCD is a specialized field whose aim is recovery from illness for as many patients as possible. The evidence-based psychotherapeutic treatment for OCD is specialized cognitive behavior therapy (CBT, NICE, 2005, Koran and Simpson, 2013). However, these treatments are not accessible to many sufferers around the world. Currently available guidelines for care are deemed to be essential but insufficient because of highly variable clinician knowledge and competencies specific to OCD. The phase two mandate of the 14 nation International OCD Accreditation Task Force (ATF) created by the Canadian Institute for Obsessive Compulsive Disorders is development of knowledge and competency standards for specialized treatments for OCD through the lifespan deemed by experts to be foundational to transformative change in this field. This paper presents knowledge and competency standards for specialized CBT for adult OCD developed to inform, advance, and offer a model for clinical practice and training for OCD. During upcoming ATF phases three and four criteria and processes for training in specialized treatments for OCD through the lifespan for certification (individuals) and accreditation (sites) will be developed based on the ATF standards.

Another look at the extinction of conditioned flavor preferences: Amount of training and tests for spontaneous recovery

A conditioned flavor preference develops when hungry or thirsty rats experience a neutral flavor mixed in solution with a nutrient. In two sets of studies, we previously demonstrated that this learned preference is highly sensitive to flavor nonreinforcement (i.e., exposure to the flavor without the nutrient) either prior to (latent inhibition), during (partial reinforcement), or following (extinction) flavor-nutrient pairings. In each of these studies we employed a nutrient devaluation procedure to assess the integrity of specific flavor-nutrient associations following extinction, but more recently Gonzalez, Morillas, and Hall (Journal of Experimental Psychology: Animal Learning & Cognition, 42, 380-390, 2016) observed that sensitivity to extinction in thirsty rats in this preparation may depend upon use of a post-conditioning nutrient devaluation procedure. To assess the generality of our earlier results, but without including a post-conditioning nutrient devaluation phase, we assessed in three experiments the role of the number of flavor-nutrient pairings given prior to extinction and the possibility of spontaneous recovery following a 3-week delay. We observed that extinction consistently weakened the flavor preference in thirsty rats (in spite of the absence of a nutrient devaluation procedure) and also found no evidence for spontaneous recovery. These results establish that our prior findings that conditioned flavor preferences are weakened by extinction are quite robust in thirsty rats and that these extinction effects may be fairly permanent.

The influence of extinction and counterconditioning procedures on operant evaluative conditioning and intersecting regularity effects

One of the most effective methods of influencing what people like and dislike is to expose them to systematic patterns (or 'regularities') in the environment, such as the repeated presentation of a single stimulus (mere exposure), two or more stimuli (evaluative conditioning (EC)) or to relationships between stimuli and behaviour (approach/avoidance). Hughes et al. (2016) J. Exp. Psychol. Gen. 145, 731-754. (doi:10.1037/xge0000100) found that evaluations also emerge when regularities in the environment intersect with one another. In this paper, we examined if evaluations established via operant EC and intersecting regularities can be undermined via extinction or revised via counterconditioning. Across seven pre-registered studies (n = 1071), participants first completed a learning phase designed to establish novel evaluations followed by one of multiple forms of extinction or counterconditioning procedures designed to undo them. Results indicate that evaluations were-in general-resistant to extinction and counterconditioning. Theoretical and practical implications along with future directions are discussed.

Testing the judgment-related account for the extinction of evaluative conditioning

Evaluative conditioning (EC) effects refer to changes in the liking of a neutral (conditioned) stimulus (CS) due to pairing with an affective (unconditioned) stimulus (US). Some research found that EC effects are resistant to presentations of the CS without the US, whereas other studies found evidence for extinction effects. A recent study found extinction of EC only when participants rated the CS before and after the CS-only presentations, but not when CS evaluation was measured once or indirectly with the evaluative priming task. In two experiments (total N = 2,181), we found no evidence that indirectly measured evaluation is sensitive to extinction, using an indirect evaluation measure with high sensitivity - the Implicit Association Test. However, unlike previous research, we found that evaluation of any stimuli (and not only the CS) before the CS-only presentations decreases self-reported EC effects. Our results are compatible with the conclusion that the extinction of EC is limited to evaluation measured directly. We discuss the theoretical implications of these results, and conclude that the specific conditions (and mechanisms) that change the direct evaluative response are yet to be clarified.

Behavioral and neural processes in counterconditioning: Past and future directions

Counterconditioning refers both to the technique and putative process by which behavior is modified through a new association with a stimulus of an opposite valence. Similar to extinction, counterconditioning is considered a form of inhibition that interferes with the expression of the originally learned response without erasing it. But whereas interest in extinction continues to rise, counterconditioning has received far less attention. Here, we provide an in-depth review of counterconditioning research and detail whether counterconditioning is any more effective than extinction at preventing relapse of the originally learned behavior. We consider the clinical implications of counterconditioning, describe recent neurobiological and neuroimaging research in this area, and consider future avenues in need of further investigation.

Evaluative conditioning affects the subsequent acquisition of differential fear conditioning as indexed by electrodermal responding and stimulus evaluations

It is currently unclear whether the acquisition of negative stimulus valence in evaluative and fear conditioning paradigms is interrelated or independent. The present study used a transfer paradigm to address this question. Three groups of participants were trained in a picture-picture evaluative conditioning paradigm before completing acquisition of differential fear conditioning using graphical shapes as conditional stimuli (CSs). In group congruent, the shape used as CS+ (paired with the US during fear conditioning) was paired with negative pictures, whereas the shape used as CS- (presented alone during fear conditioning) was paired with positive pictures. In group incongruent, the shape used as CS+ was paired with positive pictures, whereas the shape used as CS- was paired with negative pictures. In group different, different shapes were employed in evaluative and fear conditioning. Acquisition of differential electrodermal responses emerged within fewer acquisition trials in groups congruent and different than in group incongruent. Transfer of evaluative learning across paradigms was evident only after removal of participants who failed to display evaluative conditioning. The current research indicates that stimulus valence acquired during evaluative conditioning transfers to fear conditioning and will differentially affect the acquisition of fear learning as indexed by subjective evaluations and electrodermal responses. The findings suggest that evaluative and fear conditioning are not independent.

Effects of Nodal Distance on Conditioned Stimulus Valences Across Time

A meaningless symbol that repeatedly co-occurs with emotionally salient faces (US) can transform into a valenced symbol (CS). US-to-CS valence transformations have been observed for CS that have been directly (US→CS0) and indirectly (US→CS0→CS1→CS2) linked with face US. The structure of a US→CS0→CS1→CS2 series may be conceptualized in terms of “nodal distance,” where CS0, CS1, and CS2 are 0, 1, and 2 nodes from the US respectively. Increasing nodal distance between an evaluated CS and its linked US can reduce magnitude of observed CS valence transformations. We explored currently whether nodal distance can influence CS valence extinction, which describes reductions in CS valence following repeated exposures to CS without any accompanying US. In our study, faces with happy/neutral/sad expressions (US) were directly linked with nonsense words (US→CS0). The directly linked CS0 was concurrently linked with other words (CS0→CS1, CS1→CS2). Subjects evaluated all stimuli before and after conditioning, then continued to provide CS evaluations twice a week for 6 weeks. Bayesian factors provided credible evidence for the transformation and extinction of CS valences that were 0 and 1 nodes from US (all BF₁₀’s > 100). The variability across post-conditioning CS evaluations provides indirect evidence for context-sensitive/propositional and structural/associative operations during CS evaluations.

Response production during extinction training is not sufficient for extinction of evaluative conditioning

Two high-powered experiments examined the role of evaluative response production in the extinction of evaluative conditioning (EC) by positioning EC in the procedural and conceptual framework of classical conditioning (CC). According to Rescorla's response inhibition hypothesis, more frequent responding during extinction training results in larger extinction during testing. Experiment 1 used three extinction conditions following response acquisition in an EC procedure: evaluative responses were measured only after extinction; after acquisition and after extinction; or were continuously measured after acquisition, during extinction and after extinction. Based on Rescorla's response inhibition hypothesis, we predicted that extinction of EC would be the highest in the third condition. Experiment 2 was aimed at further facilitating extinction of EC by encouraging participants to experience that their evaluation may change over the course of the experiment. To this end, half of the participants completed pre- and post-acquisition ratings prior to practicing continuous response expression in the extinction phase. Contrary to our predictions, no extinction of EC was observed in either of these experiments. We conclude that Rescorla's inhibition response hypothesis may not apply to EC and discuss the theoretical implications of this finding.

Evaluative Conditioning as Memory-Based Judgment

The article proposes a view of evaluative conditioning (EC) as resulting from judgments based on learning instances stored in memory. It is based on the formal episodic memory model MINERVA 2. Additional assumptions specify how the information retrieved from memory is used to inform specific evaluative dependent measures. The present approach goes beyond previous accounts in that it uses a well-specified formal model of episodic memory; it is however more limited in scope as it aims to explain EC phenomena that do not involve reasoning processes. The article illustrates how the memory-based-judgment view accounts for several empirical findings in the EC literature that are often discussed as evidence for dual-process models of attitude learning. It sketches novel predictions, discusses limitations of the present approach, and identifies challenges and opportunities for its future development.

Simple First: A Skeleton for an Evaluative Learning Model

Simple firstis our name for a set of hypotheses that we have found useful in our research on evaluative learning. The hypotheses are: (1) It is easier to encode and retrieve information that two concepts are linked than information about how they are linked; (2) It is easier to store and retrieve information than to make an inference based on that information; (3) When people encounter an object and memory activates valence that is mentally linked to that object, they consider the activation valid evidence that the activated valence characterizes the object. We demonstrate how these hypotheses generate useful assumptions about Evaluative Conditioning, and open paths for further research on evaluative learning and evaluation.

Flavour Liking and Preference Conditioned by Caffeine in Humans

When caffeine consumers repeatedly experience a novel flavoured drink containing caffeine, the rated pleasantness of the drink flavour increases progressively. These results could be interpreted in terms of the flavour acting as a Pavlovian conditioned stimulus (CS) predicting the consequences of caffeine ingestion. However, all studies of this phenomenon to date have used between-subjects designs, and one criticism of this is that changes in pleasantness might have arisen from nonspecific effects. A more rigorous test is to examine changes in pleasantness for two drinks, a CS+ flavour paired with caffeine and CS− paired with placebo. Accordingly, 20 moderate caffeine consumers consumed both CS+ and CS− drinks in counterbalanced order over eight conditioning trials at breakfast, with hedonic and sensory characteristics evaluated on each trial. As predicted, the rated pleasantness of the CS+ drink increased whereas pleasantness of the CS− drink did not change. Despite this, participants did not have an overall preference for the CS+ flavour posttraining. However, both those who chose the CS+ and those who chose the CS− at the end showed the same direction and rate of change in pleasantness for the two drinks during training, but spurious differences in baseline preference obscured this effect in terms of an overall change in preference. Overall these data suggest that changes in pleasantness of drinks paired with caffeine delivery are best explained in terms of Pavlovian associations between drink flavour and the postingestive effects of caffeine.

Successful differential evaluative conditioning using simultaneous and trace conditioning procedures in the picture–picture paradigm

This paper describes a study designed to investigate the efficacy of two traditional classical conditioning procedures in generating evaluative conditioning (EC) in the picture–picture paradigm in human participants. Differential EC was found using both simultaneous and trace conditioning procedures. In addition, the use of a block–subblock (BSB) nonpaired control condition and full counterbalancing of conditioned stimulus–unconditioned stimulus (CS–UCS) pairings across participants indicated that the observed EC effects were the result of associative learning. Examination of whether successful conditioning could take place with or without conscious awareness of CS–UCS contingencies was inconclusive. The results provide evidence for EC as an associative process and also provide some insight into the possible conditioning parameters that might successfully generate EC.

Is the devil in the detail? Evidence for S-S learning after unconditional stimulus revaluation in human evaluative conditioning under a broader set of experimental conditions

Whether valence change during evaluative conditioning is mediated by a link between the conditional stimulus (CS) and the unconditional stimulus (US; S-S learning) or between the CS and the unconditional response (S-R learning) is a matter of continued debate. Changing the valence of the US after conditioning, known as US revaluation, can be used to dissociate these accounts. Changes in CS valence after US revaluation provide evidence for S-S learning but if CS valence does not change, evidence for S-R learning is found. Support for S-S learning has been provided by most past revaluation studies, but typically the CS and US have been from the same stimulus category, the task instructions have suggested that judgements of the CS should be based on the US, and USs have been mildly valenced stimuli. These factors may bias the results in favour of S-S learning. We examined whether S-R learning would be evident when CSs and USs were taken from different categories, the task instructions were removed, and more salient USs were used. US revaluation was found to influence explicit US evaluations and explicit and implicit CS evaluations, supporting an S-S learning account and suggesting that past results are stable across procedural changes.

Subjective, physiological, and behavioural responses towards evaluatively conditioned stimuli

Evaluative Conditioning (EC) is commonly defined as the change in liking of a stimulus (conditioned stimulus, CS) due to its pairings with an affective unconditioned stimulus (US). In Experiment 1, we investigated effects of repeated stimulus pairings on affective responses, i.e. valence and arousal ratings, pupil size, and duration estimation. After repeatedly pairing the CSs with affective USs, a consistent pattern of affective responses emerged: The CS_negative was rated as being more negative and more arousing, resulted in larger pupils, and was temporally overestimated compared to the CS_neutral. In Experiment 2, the influence of a mere instruction about the contingency between a CS and US on affective responses was examined. After mere instruction about upcoming pairings between the CS and US, subjective ratings also changed, but there was neither evidence for differential pupillary responses nor for differential temporal processing. The results indicate that EC via pairings or instructions can change the affective responses towards formerly neutral stimuli and introduce pupil size as a physiological measure in EC research. However, Experiment 2 suggests that there might be moderating factors based on the type of EC procedure involved.

Negativity Bias, Negativity Dominance, and Contagion

We hypothesize that there is a general bias, based on both innatepredispositions and experience, in animals and humans, to give greater weight to negative entities (e.g., events, objects, personal traits). This is manifested in 4 ways: (a) negative potency (negative entities are stronger than the equivalent positive entities), (b) steeper negative gradients (the negativity of negative events grows more rapidly with approach to them in space or time than does the positivity of positive events, (c) negativity dominance (combinations of negative and positive entities yield evaluations that are more negative than the algebraic sum of individual subjective valences would predict), and (d) negative differentiation (negative entities are more varied, yield more complex conceptual representations, and engage a wider response repertoire). We review evidence for this taxonomy, with emphasis on negativity dominance, including literary, historical, religious, and cultural sources, as well as the psychological literatures on learning, attention, impression formation, contagion, moral judgment, development, and memory. We then consider a variety of theoretical accounts for negativity bias. We suggest that 1 feature of negative events that make them dominant is that negative entities are more contagious than positive entities.

Evaluative conditioning increases with temporal contiguity. The influence of stimulus order and stimulus interval on evaluative conditioning

Evaluative conditioning (EC) is a change in valence that is due to pairing a conditioned stimulus (CS) with another, typically valent, unconditioned stimulus (US). This paper investigates how basic presentation parameters moderate EC effects. In two studies we tested the effectiveness of different temporal relations of the CS and the US, that is, the order in which the stimuli were presented and the temporal distance between them. Both studies showed that the size of EC effects was independent of the presentation order of CS and US within a stimulus pair. Contrary to classical conditioning effects, EC effects are thus not most pronounced after CS-first presentations. Furthermore, as shown in Experiment 2, EC effects increased in magnitude as the temporal interval between CS and US presentations decreased. Experiment 1 showed largest EC effects in the condition with simultaneous presentations - which can be seen as the condition with the temporally closest presentation. In this Experiment stimuli were presented in two different modalities, which might have facilitated simultaneous processing. In Experiment 2, in which all stimuli were presented visually, this advantage of simultaneous presentation was not found. We discuss practical and theoretical implications of our findings.

The Influence of Facial Feedback on Race Bias

Two studies were conducted to examine whether facial feedback can modulate implicit racial bias as assessed by the Implicit Association Test (IAT). Participants were surreptitiously induced to smile through holding a pencil in their mouth while viewing photographs of unfamiliar Black or White males or performed no somatic configuration while viewing the photographs (Study 1 only). All participants then completed the IAT with no facial manipulation. Results revealed a spreading attitude effect, with significantly less racial bias against Blacks among participants surreptitiously induced to smile during prior viewing of Black faces than among participants surreptitiously induced to smile during prior viewing of White faces.

An Initial Test of Reconsolidation in Disgust-Related Learning and Extinction

This study examines whether the spacing of a single unreinforced retrieval trial relative to extinction learning allows for "rewriting" the original disgust association, thereby preventing the return of disgust using a paradigm that employs disgust-relevant unconditioned stimuli (US). During conditioning, disgusting US were paired with a color square that served as the conditioned stimuli (CS). Participants (n = 54) then returned to the lab 24 hours later and received a "reactivation" intervention which consisted of one unpaired presentation of the CS+. Participants were then randomized to receive extinction trials either 10 min (Group A) or 6 hours (Group B) after reactivation. A third control group (Group C) did not receive the reactivation manipulation before extinction. Participants returned 24 hours later for additional extinction trials and at a 1-month follow-up for disgust reinstatement. Although the paradigm resulted in participants evaluating the CS+ as significantly more unpleasant after being associated with a disgust-relevant US, extinction learning within the reconsolidation window did not influence self-reported reduction or return of disgust. However, there was some evidence suggesting that those who received reactivation (Groups A and B), regardless of timing, evaluated the CS+ as less unpleasant after extinction relative to acquisition, whereas this pattern was not observed among those who did not receive reactivation (Group C). The implications of these findings for anxiety-related disorders in which disgust has been implicated will be discussed.

Cue competition in evaluative conditioning as a function of the learning process

Evaluative conditioning (EC) is the change in the valence of a stimulus resulting from pairings with an affective (unconditioned) stimulus (US). With some exceptions, previous work has indicated that this form of conditioning might be insensitive to cue competition effects such as blocking and overshadowing. Here we assessed whether the extent of cue competition in EC depends upon the type of contingency learning during conditioning. Specifically, we contrasted a learning task that biased participants toward cognitive/inferential learning (i.e., predicting the US) with a learning task that prevented prolonged introspection (i.e., a rapid response made to the US). In all cases, standard EC effects were observed, with the subjective liking of stimuli changed in the direction of the valence of the US. More importantly, when inferential learning was likely, larger EC effects occurred for isolated stimuli than for compounds (indicating overshadowing). No blocking effects on explicit evaluations were observed for either learning task. Contingency judgments and implicit evaluations, however, were sensitive to blocking, indicating that the absence of a blocking effect on explicit evaluations might be due to inferences that occur during testing.

Effective behavioural strategies for reducing disgust in contamination-related OCD: A review

Disgust is an understudied but important emotion in various psychological disorders. Over the last decade, increasing evidence suggests that disgust is also present in various subtypes of obsessive-compulsive disorder (OCD), especially in contamination-related OCD (C-OCD). The treatment of choice for C-OCD is exposure with response prevention, originally designed to reduce fear-associated emotions thought to be acquired through Pavlovian conditioning (PC). However, disgust has been proposed to be acquired through evaluative conditioning (EC) and according to the referential model of this form of learning, there are functional differences between PC and EC that need to be considered in the treatment of disgust-related responses. Alternative strategies suggested by EC-based models include counterconditioning (contingent presentation of the CS with a US of opposite valence) and US revaluation (contingent presentation of the US with US of opposite valence). Drawing on the referential model, this paper reviews evidence for the effectiveness of each strategy to identify the most theoretically sound and empirically valid intervention to reduce disgust in C-OCD.

Extinction Can Reduce the Impact of Reward Cues on Reward-Seeking Behavior

Reward-associated cues are thought to promote relapse after treatment of appetitive disorders such as drug-taking, binge eating, and gambling. This process has been modelled in the laboratory using a Pavlovian-instrumental transfer (PIT) design in which Pavlovian cues facilitate instrumental reward-directed action. Attempts to reduce facilitation by cue exposure (extinction) have produced mixed results. We tested the effect of extinction in a recently developed PIT procedure using a natural reward, chocolate, in human participants. Facilitation of instrumental responding was only observed in participants who were aware of the Pavlovian contingencies. Pavlovian extinction successfully reduced, but did not completely eliminate, expectancy of reward and facilitation of instrumental responding. The results indicate that exposure can reduce the ability of cues to promote reward-directed behavior in the laboratory. However, the residual potency of extinguished cues means that additional active strategies may be needed in clinical practice to train patients to resist the impact of these cues in their environment.

Unconscious learning of likes and dislikes is persistent, resilient, and reconsolidates

Preferences profoundly influence decision-making and are often acquired through experience, yet it is unclear what role conscious awareness plays in the formation and persistence of long-term preferences and to what extent they can be altered by new experiences. We paired visually masked cues with monetary gains or losses during a decision-making task. Despite being unaware of the cues, subjects were influenced by their predictive values over successive trials of the task, and also revealed a strong preference for the appetitive over the aversive cues in supraliminal choices made days after learning. Moreover, the preferences were resistant to an intervening procedure designed to abolish them by a change in reinforcement contingencies, revealing a surprising resilience once formed. Despite their power however, the preferences were abolished when this procedure took place shortly after reactivating the memories, indicating that the underlying affective associations undergo reconsolidation. These findings highlight the importance of initial experiences in the formation of long-lasting preferences even in the absence of consciousness, while suggesting a way to overcome them in spite of their resiliency.

Is evaluative conditioning really resistant to extinction? Evidence for changes in evaluative judgements without changes in evaluative representations

Evaluative conditioning (EC) is defined as the change in the evaluation of a conditioned stimulus (CS) due to its pairing with a positive or negative unconditioned stimulus (US). Although several individual studies suggest that EC is unaffected by unreinforced presentations of the CS without the US, a recent meta-analysis indicates that EC effects are less pronounced for post-extinction measurements than post-acquisition measurements. The disparity in research findings suggests that extinction of EC may depend on yet unidentified conditions. In an attempt to uncover these conditions, three experiments (N = 784) investigated the influence of unreinforced post-acquisition CS presentations on EC effects resulting from simultaneous versus sequential pairings and pairings with single versus multiple USs. For all four types of CS-US pairings, EC effects on self-reported evaluations were reduced by unreinforced CS presentations, but only when the CSs had been rated after the initial presentation of CS-US pairings. EC effects on an evaluative priming measure remained unaffected by unreinforced CS presentations regardless of whether the CSs had been rated after acquisition. The results suggest that reduced EC effects resulting from unreinforced CS presentations are due to judgement-related processes during the verbal expression of CS evaluations rather than genuine changes in the underlying evaluative representations.

Alleviation of Moral Disgust, Shame, and Guilt in Posttraumatic Stress Reactions

Research suggests that moral disgust, shame, and guilt are present in posttraumatic psychopathology. However, it is unclear that these emotional states are responsive to empirically supported interventions for posttraumatic stress symptoms (PTSS). This study explored the relations among moral disgust, shame, guilt, and PTSS, and examined comprehensive distancing (CD) as a novel intervention for these emotional states in undergraduates with elevated PTSS. Participants were randomly assigned to use a CD or a cognitive challenge task in response to personalized scripts of a traumatic event. Both interventions were associated with decreases in disgust, moral disgust, shame, and guilt. Contrary to predictions, there were no significant differences between the exercises in the reduction of negative emotions. In addition, PTSS severity was correlated with trauma-related guilt as well as state guilt and shame, but not trait or state measures of disgust or moral disgust. This proof of concept project sets the stage for further research examining CD as an alternative or adjunctive intervention for posttraumatic stress reactions with strong features of moral disgust, shame, and guilt.

All in its proper time: monitoring the emergence of a memory bias for novel, arousing-negative words in individuals with high and low trait anxiety

The well-established memory bias for arousing-negative stimuli seems to be enhanced in high trait-anxious persons and persons suffering from anxiety disorders. We monitored the emergence and development of such a bias during and after learning, in high and low trait anxious participants. A word-learning paradigm was applied, consisting of spoken pseudowords paired either with arousing-negative or neutral pictures. Learning performance during training evidenced a short-lived advantage for arousing-negative associated words, which was not present at the end of training. Cued recall and valence ratings revealed a memory bias for pseudowords that had been paired with arousing-negative pictures, immediately after learning and two weeks later. This held even for items that were not explicitly remembered. High anxious individuals evidenced a stronger memory bias in the cued-recall test, and their ratings were also more negative overall compared to low anxious persons. Both effects were evident, even when explicit recall was controlled for. Regarding the memory bias in anxiety prone persons, explicit memory seems to play a more crucial role than implicit memory. The study stresses the need for several time points of bias measurement during the course of learning and retrieval, as well as the employment of different measures for learning success.

Analysis of blocking of flavor-preference conditioning based on nutrients and palatable tastes in rats

In Experiment 1 rats were given training in which a mixture of two flavors was paired with sucrose. This established a substantial preference for each of the flavors; however, when rats were given prior experience with just one of the flavors paired with sucrose, training with the compound produced only a weak preference for the other - an example of the blocking effect, well known in other associative learning paradigms. Both the palatable taste of sucrose and its nutrient properties contribute to its ability to reinforce preference acquisition. The role of these two forms of learning was examined in two further experiments in which the reinforcer used was fructose (which is considered to support preference learning because it is palatable but not through its nutrient properties) or maltodextrin (thought to support preference learning by way of its nutrient properties). In neither case was blocking observed. At the theoretical level, this outcome constitutes a challenge to the attempt to explain flavor-preference learning in terms of the standard principles of associative learning theory. Its implication at the level of application is that the potential of the blocking procedure as a technique for preventing the development of unwanted flavor preferences may be limited.

The role of awareness in attitude formation through evaluative conditioning

This article provides a review of past and contemporary debates regarding the role of awareness in attitude formation through evaluative conditioning (EC), that is, by repeatedly pairing a stimulus with other stimuli of positive or negative valence. Because EC is considered the most prototypical method to form and change the network of evaluative associations in memory, the role of awareness in this effect is critical to the question of whether attitudes may be formed and changed through dual processes. We analyze the reasons why there has been so much discussion and disagreement regarding the role of awareness, review past and contemporary methodologies and their limitations, discuss the role of mental processes and conditioning procedures, and identify promising directions for future research in this area.

Relationship between fear conditionability and aversive memories: evidence from a novel conditioned-intrusion paradigm

Intrusive memories – a hallmark symptom of posttraumatic stress disorder (PTSD) – are often triggered by stimuli possessing similarity with cues that predicted or accompanied the traumatic event. According to learning theories, intrusive memories can be seen as a conditioned response to trauma reminders. However, direct laboratory evidence for the link between fear conditionability and intrusive memories is missing. Furthermore, fear conditioning studies have predominantly relied on standardized aversive stimuli (e.g. electric stimulation) that bear little resemblance to typical traumatic events. To investigate the general relationship between fear conditionability and aversive memories, we tested 66 mentally healthy females in a novel conditioned-intrusion paradigm designed to model real-life traumatic experiences. The paradigm included a differential fear conditioning procedure with neutral sounds as conditioned stimuli and short violent film clips as unconditioned stimuli. Subsequent aversive memories were assessed through a memory triggering task (within 30 minutes, in the laboratory) and ambulatory assessment (involuntary aversive memories in the 2 days following the experiment). Skin conductance responses and subjective ratings demonstrated successful differential conditioning indicating that naturalistic aversive film stimuli can be used in a fear conditioning experiment. Furthermore, aversive memories were elicited in response to the conditioned stimuli during the memory triggering task and also occurred in the 2 days following the experiment. Importantly, participants who displayed higher conditionability showed more aversive memories during the memory triggering task and during ambulatory assessment. This suggests that fear conditioning constitutes an important source of persistent aversive memories. Implications for PTSD and its treatment are discussed.