Revisiting the relation between contingency awareness and attention: evaluative conditioning relies on a contingency focus

Although evaluative conditioning has occasionally been demonstrated in the absence of contingency awareness, many recent studies imply that its acquisition depends on the availability of attentional resources during conditioning. In previous experiments attention has typically been manipulated in a general way rather than looking at the particular focus of attention. The present study investigated the role of a focus on the CS-US contingency. Two separate distraction tasks were designed that either diverted attention from the stimuli or directed it to the stimuli while drawing attention away from the contingency between the stimuli. Both types of distraction were shown to eliminate evaluative conditioning. Significant evaluative conditioning was observed in a third group of participants who were required to attend the contingencies. A mediation analysis showed that the observed discrepancy in evaluative conditioning effects between groups was mediated by contingency awareness. The results imply that attention in terms of a stimulus focus is not sufficient for evaluative conditioning to occur. Rather, attention to the contingencies between stimuli appears to be crucial in evaluative conditioning, because it is supposed to foster the acquisition of contingency awareness.     

Revisiting the relation between contingency awareness and attention: Evaluative conditioning relies on a contingency focus

Although evaluative conditioning has occasionally been demonstrated in the absence of contingency awareness, many recent studies imply that its acquisition depends on the availability of attentional resources during conditioning. In previous experiments attention has typically been manipulated in a general way rather than looking at the particular focus of attention. The present study investigated the role of a focus on the CS–US contingency. Two separate distraction tasks were designed that either diverted attention from the stimuli or directed it to the stimuli while drawing attention away from the contingency between the stimuli. Both types of distraction were shown to eliminate evaluative conditioning. Significant evaluative conditioning was observed in a third group of participants who were required to attend the contingencies. A mediation analysis showed that the observed discrepancy in evaluative conditioning effects between groups was mediated by contingency awareness. The results imply that attention in terms of a stimulus focus is not sufficient for evaluative conditioning to occur. Rather, attention to the contingencies between stimuli appears to be crucial in evaluative conditioning, because it is supposed to foster the acquisition of contingency awareness.     

Human evaluative conditioning: Order of stimulus presentation

In an experiment designed to demonstrate evaluative conditioning, subjects were shown 48 pictures of sculptures that they rated on a scale with 21 categories (?10 to +10). Then, the two most liked pictures (L) were paired with pictures from the categories ?1, 0, or +1 (N). In contrast to prior experiments, subjects were given either forward conditioning (N-L) or backward conditioning (L-N) trials but not both. Four other neutral stimuli were paired with each other (N-N) and acted as control stimulus pairs. After conditioning, the stimuli were rated a second time. There was a statistically significant difference in evaluative ratings showing a change of the evaluative tone of the previously neutral stimuli in a positive direction only after forward conditioning. This finding is inconsistent with results of prior experiments and challenges the assumption of Martin and Levey (1987) that evaluative conditioning is different from human classical conditioning.     

Measuring evaluative conditioning using the Implicit Association Test

When a neutral stimulus is paired with a stimulus that has strong affective properties, these properties often appear to be transferred to the neutral stimulus. This learning has been termed evaluative conditioning. In two experiments, participants first learned the ‘meanings’ of four non-words. Two of these meanings were affectively positive, and two were affectively negative. Transfer of affect was measured in the Implicit Association Test (IAT). In the IAT, a participant’s affective response to an item is inferred from his or her ability to categorise that item with other pleasant and unpleasant stimuli. An item easily categorised with other liked stimuli is deemed to be liked itself. In both experiments, evidence for transfer of affect was observed in the IAT. Thus, non-words given pleasant meanings in training (evaluative conditioning) were more easily categorised with pleasant than unpleasant personality characteristics, compared to non-words given unpleasant meanings. The results suggest that the IAT is a useful way to test for evaluative conditioning. It is both sensitive to the transfer of affective properties from one stimulus to another, and, because affect is measured indirectly, the results are unlikely to be due to the demand characteristics of the experiment.     

The Effect of Counterconditioning on Evaluative Responses and Harm Expectancy in a Fear Conditioning Paradigm

In fear conditioning, extinction targets harm expectancy as well as the fear response, but it often fails to eradicate the negative affective value that is associated with the conditioned stimulus. In the present study, we examined whether counterconditioning can serve to reduce evaluative responses within fear conditioning. The sample consisted of 70 nonselected students, 12 of whom were men. All participants received acquisition with human face stimuli as the conditioned stimuli and an unpleasant white noise as the unconditioned stimulus. After acquisition, one third of the sample was allocated to an extinction procedure. The other participants received counterconditioning with either a neutral stimulus (neutral tone) or a positive stimulus (baby laugh). Results showed that counterconditioning (with both neutral and positive stimuli), in contrast to extinction, successfully reduced evaluative responses. This effect was found on an indirect measure (affective priming task), but not on self-report. Counterconditioning with a positive stimulus also tended to enhance the reduction of conditioned skin conductance reactivity. The present data suggest that counterconditioning procedures might be a promising approach in diminishing evaluative learning and even expectancy learning in the context of fear conditioning.     

A conceptual and theoretical analysis of evaluative conditioning

Evaluative conditioning is best defined as an effect, that is, as a change in the valence of a stimulus that results from pairing the stimulus with another stimulus. This definition has several advantages that are made explicit in this paper. One of the advantages is that it clarifies that evaluative conditioning can be due to multiple processes. Therefore, the conditions under which evaluative conditioning is observed can depend on the processes that underlie a particular manifestation of evaluative conditioning. This could explain why there are so many conflicting results about the conditions under which evaluative conditioning can be found. Future research should adopt a meta-conditional approach that focuses not only on whether a certain condition is crucial for obtaining evaluative conditioning but should also examine when a certain condition is crucial.     

Expectancy-learning and evaluative learning in human classical conditioning: affective priming as an indirect and unobtrusive measure of conditioned stimulus valence

It has been argued that in classical conditioning two processes might be operative. First, one may learn that the conditioned stimulus (CS+) is a valid predictor for the occurrence of the biologically negative or positive event (US; expectancy-learning). Second, one may learn to perceive the conditioned stimulus itself as a negative or positive stimulus, depending on the valence of the event it has been associated with (evaluative learning). Until the present, however, both forms of learning have been investigated using rather different conditioning procedures. Using a differential aversive conditioning preparation with pictures of human faces as CSs and an electrocutaneous stimulus as US, we were able to demonstrate that both forms of learning can co-occur. Moreover, the extent of evaluative learning in this aversive conditioning procedure did not significantly differ from the amount of evaluative learning in an evaluative conditioning procedure with positive and negative adjectives as USs, which was administered to the same participants. In the present study evaluative learning was not only indexed by direct evaluative ratings, but we introduced affective priming as an indirect and unobtrusive, reaction time based measure of stimulus valence. Finally, imagery instructions during acquisition did not facilitate expectancy-learning nor evaluative learning.     

Changing CS features alters evaluative responses in evaluative conditioning

Evaluative conditioning (EC) refers to changes in people's evaluative responses toward initially neutral stimuli (CSs) by mere spatial and temporal contiguity with other positive or negative stimuli (USs). We investigate whether changing CS features from conditioning to evaluation also changes people's evaluative response toward these CSs. We used computer-generated male faces as CSs and paired them with other positively or negatively evaluated faces. When participants evaluated the CS faces, they either appeared unchanged, with glasses, with beards, or glasses and beards. Unchanged faces showed a clear conditioning effect, while all other face versions showed no significant conditioning effects. The conditioning effect also depended on participants’ awareness of a CS's respective US. These results mirror configural explanations of stimulus generalization in classical conditioning, with implications for EC as explanation for attitude acquisition and learning of likes and dislikes in everyday life.     

The effect of comparative context on evaluative conditioning

Evaluative conditioning (EC) is a change in the evaluation of a stimulus after the stimulus co-occurred with affective stimuli. The present research examined whether EC of one stimulus depends also on the co-occurrence of another stimulus with positive or negative stimuli. We paired two target people with affective stimuli. We found that a person who appeared eight times with positive stimuli and eight times with negative stimuli was liked more when the other person appeared always (16 times) with negative stimuli than when the other person appeared always with positive stimuli. The manipulation did not change the US evaluation or the general standard on the value dimension of what a positive or negative stimulus is. We suggest that like other evaluative traits (e.g., evil, pretty) co-occurrence with affective stimuli is sensitive to temporary standards. The manipulation changed the standard of what co-occurrence with affective stimuli is considered positive versus negative.     

The role of CS-US contingency in human evaluative conditioning

Recent studies suggest that in Pavlovian conditioning, two different processes may be operative: signal learning and evaluative learning, resulting in two qualitatively different associative structures. Signal-learning is hypothesized to be responsible for providing us with genuine predictors (CS) for significant events (US). This proposition logically entails that the statistical-correlational relation, i.e. the contingency between CS and US should be a crucial determinant of signal learning. Evaluative conditioning, on the other hand, refers to the observation that the mere pairing of neutral with (dis)liked stimuli changes the valence of the originally neutral stimuli in a (negative) positive direction. As argued elsewhere, evaluative conditioning is probably based on the CS acquiring a mere referential value to the US, without any genuine CS-US expectancy being involved. From this, it was hypothesized that evaluative conditioning might not be dependent on CS-US contingency. Using the standard evaluative conditioning paradigm, four different levels of CS-US contingency were created on a between-subject base. The overall effect of evaluative conditioning was strongly significant, and was not mediated by awareness of the CS-US relation. Of crucial importance, this conditioning effect did not interact with the level of contingency, supporting the hypothesis that CS-US contingency is not a crucial determinant of evaluative conditioning. Moreover, this effect was obtained in a situation in which Ss simultaneously evidenced to have consciously registered quite accurately the different levels of CS-US contingency.     

Boundary conditions for the influence of unfamiliar non-target primes in unconscious evaluative priming: The moderating role of attentional task sets

Evaluative priming by masked emotional stimuli that are not consciously perceived has been taken as evidence that affective stimulus evaluation can also occur unconsciously. However, as masked priming effects were small and frequently observed only for familiar primes that there also presented as visible targets in an evaluative decision task, priming was thought to reflect primarily response activation based on acquired S–R associations and not evaluative semantic stimulus analysis. The present study therefore assessed across three experiments boundary conditions for the emergence of masked evaluative priming effects with unfamiliar primes in an evaluative decision task and investigated the role of the frequency of target repetition on priming with pictorial and verbal stimuli. While familiar primes elicited robust priming effects in all conditions, priming effects by unfamiliar primes were reliably obtained for low repetition (pictures) or unrepeated targets (words), but not for targets repeated at a high frequency. This suggests that unfamiliar masked stimuli only elicit evaluative priming effects when the task set associated with the visible target involves evaluative semantic analysis and is not based on S–R triggered responding as for high repetition targets. The present results therefore converge with the growing body of evidence demonstrating attentional control influences on unconscious processing.     

Transfer of newly acquired stimulus valence between identities in dissociative identity disorder (DID)

Patients with Dissociative Identity Disorder (DID) frequently report episodes of interidentity amnesia, that is amnesia for events experienced by other identities. The goal of the present experiment was to test the implicit transfer of trauma-related information between identities in DID. We hypothesized that whereas declarative information may transfer from one identity to another, the emotional connotation of the memory may be dissociated, especially in the case of negative, trauma-related emotional valence. An evaluative conditioning procedure was combined with an affective priming procedure, both performed by different identities. In the evaluative conditioning procedure, previously neutral stimuli come to refer to a negative or positive connotation. The affective priming procedure was used to test the transfer of this acquired valence to an identity reporting interidentity amnesia. Results indicated activation of stimulus valence in the affective priming task, that is transfer of emotional material between identities.     

Effects of US-Alone Presentations on Human Evaluative Conditioning

In the context of evaluative conditioning, the effects of additional presentations of the unconditioned stimulus (US) prior to conditioning (US preexposure) or after conditioning (US postexposure) were examined using between- and within-subjects control conditions. Two experiments that differed with respect to the nationality of the subjects were conducted. In both experiments, US-alone presentations reduced the magnitude of the evaluative response. The US pre- and postexposure effects were observed in subjects classified as aware as well as in subjects classified as unaware of the experimental contingencies. Another finding is that the evaluative conditioning procedure described by Martin and Levey (1978; Levey & Martin, 1975) resulted in reliable conditioning effects also in an American sample, thus extending the scope of that special evaluative conditioning paradigm. The findings are discussed in the context of recent models of classical and evaluative conditioning. Especially, the unexpected US postexposure effect gives rise to speculations concerning the learning process underlying evaluative conditioning.     

Self‐esteem as a source of evaluative conditioning

This study was designed to examine whether self‐esteem can be used as a source of evaluative conditioning, and whether implicit or explicit self‐esteem was more predictive of the evaluative conditioning effect. Moreover, the role of contingency awareness in the acquisition of the evaluative conditioning effect was also examined. Words related to the self and a general other were served as unconditioned stimuli (USs) in the evaluative conditioning process in order to see whether the evaluation could be transferred to neutral, abstract paintings after 10 times of pairing. An evaluative conditioning effect was demonstrated in that the evaluation of the paintings became more positive after repeatedly paired with words about the self but not words about general others. Implicit self‐esteem predicted the magnitude of the evaluative conditioning effect, while the association between explicit self‐esteem and the evaluative conditioning effect was nonsignificant, both with and without the effect of contingency awareness being controlled for. Copyright © 2009 John Wiley & Sons, Ltd.     

Evaluative conditioning in the picture-picture paradigm with random assignment of conditioned stimuli to unconditioned stimuli

Human participants were allocated to 1 of 3 groups. In the conditioning group, each conditioned stimulus (CS)-unconditioned stimulus (US) pair was presented 7 times during the acquisition phase. Participants who were assigned to the extinction group saw 5 additional presentations of each CS in isolation after the 7 presentations of each CS-US pair. In the latent inhibition group, the CS-only trials were presented before the CS-US trials. Overall, a significant evaluative conditioning effect was observed. This effect cannot be dismissed on the basis of the arguments developed by A. P. Field and G. C. L. Davey (1997, 1998, 1999), and the results thus provide strong evidence for the associative nature of evaluative conditioning. The results are also in line with other findings, which showed that evaluative conditioning is resistant to extinction.     

Context effects in evaluative conditioning of implicit evaluations

Propositional models of evaluative conditioning postulate that the impact of stimulus pairings on liking should depend not on the pairings themselves but on what the pairings imply about the relation between stimuli. Hence, context manipulations that change the implications of stimulus pairings should moderate evaluative conditioning. We manipulated context by varying the way in which context cues were paired with affective outcomes while keeping the pairings between target cues and affective outcomes constant. All participants saw one target cue compound that was followed by a positive outcome (XF+) and another target cue compound that was followed by a negative outcome (YG?). In condition Same, each context cue was consistently paired with a positive or negative outcome, regardless of whether it was presented alone or in compound with another cue (A+, B+, AB+; C?, D?, CD?). In condition Opposite, however, a context cue was paired with a certain outcome when presented alone and with an outcome of the opposite valence when presented in a compound with another cue (A+, B+, AB?; C?, D?, CD+). Employing several implicit measures, we assessed the implicit evaluations of the target cues X and Y. In all three studies, the outcome of the measurement procedure differed between conditions. In condition Same, the positively paired cue X was evaluated more positively than the negatively paired cue Y. In condition Opposite, however, this preference was not present. This pattern of results suggests that EC is determined not only by the objective pairings but also by the context in which these pairings occur. Implications for models of evaluative conditioning are discussed.     

Recent books

Recent studies have shown that the basic evaluative conditioning (EC) effect (originally neutral stimuli acquiring an affective value congruent with the valence of the affective stimulus they were paired with) seems to be limited to participants who are unaware of the stimulus pairings. If participants are aware of the pairings, reactance effects occur (i.e., changes in the opposite direction of the valence of the affective stimulus). To examine whether these reactance effects are due to processes of conscious countercontrol or whether the ratings reflect intrinsic feelings towards the stimuli, a new procedure was developed that included a bogus‐pipeline condition. In this procedure, which was adapted from attitude research, participants were connected to bogus lie detector equipment leading them to believe that their “true” affective‐evaluative responses were being observed. In Experiment 1, reactance effects occurred also in this procedure, suggesting that the effect is spontaneous and not due to processes of conscious countercontrol. In Experiment 2, these effects were replicated using a between‐subjects design in addition to the standard within‐subjects control condition.     

情绪词对新异刺激喜好度变化的调节机制

通过三个实验探讨了情绪词的情绪信息对新异刺激喜好度变化的调节机制。实验采用评价条件化(Evaluative Conditioning)范式, 将新异刺激(相当于条件刺激, CS)与情绪词(相当于无条件刺激, US)配对呈现, 最后测量被试对新异刺激的喜好程度。三个实验通过设置表面故事, 控制新异刺激与情绪词间的配对关系, 并改变任务的加工深度, 揭示了情绪词调节新异刺激喜好度变化的机制。研究结果表明, 情绪词对新异刺激喜好度的调节不依赖于对刺激间偶联关系的意识以及被试的任务状态, 是一种自下而上的自动化的联想学习过程。     

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.     

Goal relevance moderates evaluative conditioning effects

An important process by which preferences emerge is evaluative conditioning, defined as a change in the evaluation of a stimulus by pairing it repeatedly and consistently with an affective stimulus. The current research focuses on the role of motivation in this learning process. Specifically, it was investigated whether a conditioning procedure that is relevant to an individual's current goals is more effective than an irrelevant procedure. To this end, beverages were conditioned with either disgusted faces (relevant) or fearful faces (irrelevant). The results showed that thirsty(rather than non-thirsty) participants’ choice and evaluation of beverages were influenced by pairing beverages with disgust but not with fear. As similar results were obtained under optimal and suboptimal presentation of the conditioned stimuli, it is suggested that goals can affect automatic, associative learning, adding to the emerging body of research demonstrating that goals unconsciously affect evaluative processes.