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Evaluative conditioning is one of the most widely studied procedures for establishing and changing attitudes. The surveillance task is a highly cited evaluative-conditioning paradigm and one that is claimed to generate attitudes without awareness. The potential for evaluative-conditioning effects to occur without awareness continues to fuel conceptual, theoretical, and applied developments. Yet few published studies have used this task, and most are characterized by small samples and small effect sizes. We conducted a high-powered ( N = 1,478 adult participants), preregistered close replication of the original surveillance-task study (Olson & Fazio, 2001). We obtained evidence for a small evaluative-conditioning effect when “aware” participants were excluded using the original criterion—therefore replicating the original effect. However, no such effect emerged when three other awareness criteria were used. We suggest that there is a need for caution when using evidence from the surveillance-task effect to make theoretical and practical claims about “unaware” evaluative-conditioning effects.

Evaluative conditioning (EC) refers to a modulation in the liking of a neutral stimulus after it has been paired with an unconditioned stimulus (US). Previous studies have uncovered some of the mec...

We investigate two questions, (1) the relevance of memory for evaluative conditioning (EC) effects based on smell-taste pairings, and (2) the potential preparedness of smell-taste combinations for yielding EC effects. The relevance of memory for EC effects is a subject of intense research. The majority of studies that investigate the memory-EC relation use visual stimuli and typically show no or relatively small EC effects without memory. For smell-taste combinations, only a few studies exist, with mixed results regarding the role of memory in EC. The idea that there might be a preparedness of smell and taste pairings comes from classical conditioning studies showing preparedness in food aversion and from research on joint processing of smells and tastes. In Experiment 1, we report a conceptual replication of previous studies with smell-taste and picture-taste pairings. In this experiment, we found no evidence for memory-independent EC overall. In a pre-registered Experiment 2, we used a design with smells, pictures, tastes, and sounds to test the role of memory more conclusively and test the preparedness hypothesis for smell-taste pairings. The results support the preparedness hypothesis for smell-taste pairings in EC. Furthermore, as in Experiment 1, we did not find evidence for memory-independent EC.

Evaluative conditioning (EC) changes the preference towards a formerly neutral stimulus (conditioned stimulus; CS), by pairing it with a valent stimulus (unconditioned stimulus; US), in the direction of the valence of the US. When the CS is presented suboptimally (i.e., too briefly to be consciously perceived), contingency awareness between CS and US can be ruled out. Hence, EC effects with suboptimally presented CSs would support theories claiming that contingency awareness is not necessary for EC effects to occur. Recent studies reported the absence of EC with briefly presented CSs when both CS and US were presented in the visual modality, even though the CSs were identified at above-chance levels. Challenging this finding, Heycke et al. (R Soc Open Sci 4(9):160935, 2017) found some evidence for an EC effect with briefly presented visual stimuli in a cross-modal paradigm with auditory USs, but that study did not assess CS visibility. The present study realized a close replication of this study, while deviated from it using different stimuli, introducing a brief practice phase, and adding a CS visibility check. Overall EC for briefly presented stimuli was absent, and results from the visibility check show that an EC effect with briefly presented CSs was only found, when the CSs were identified at above-chance levels.

I propose a Declarative Memory Model (DMM) of evaluative conditioning (EC). EC effects are changes in the valence of a conditioned stimulus (CS) due to previous pairings with a positive or negative unconditioned stimulus (US; e.g., De Houwer, 2007, https://doi.org/10.1017/S1138741600006491). According to the DMM, EC effects are found if (1) a memory trace is formed in the learning phase that links the CS to evaluative information from the US, if (2) this trace survives the retention interval, if (3) the trace or part of it is consciously retrieved when the CS is being evaluated, and if (4) the retrieved trace is used in the CS evaluation. For each of these stages, I make separate predictions about EC effects, many of which are based on empirical research on declarative memory. Where available, I report and discuss empirical evidence on EC that speaks to these hypotheses. The available empirical evidence is largely in line with the predictions of the DMM. Several predictions, however, have yet to be tested and some findings are ambiguous. While the DMM specifies conditions under which CS-US pairings should lead to a valence change, it does not deny the possibility that other processes might lead to a change in attitude as well. Advantages of the DMM are its foundation on declarative memory research, its applicability for attitude change effects in general, and its suitability for predictions of EC effects in the real world.

IntroductionThe recognition of the conditioned-unconditioned stimulus (CS-US) association in classical conditioning is referred to as contingency awareness. The neural underpinnings of contingency awareness in human fear conditioning are poorly understood.ObjectivesWe aimed to explore the EEG correlates of contingency awareness.MethodsHere, we recorded electroencephalography (EEG) from a sample of 20 participants in a semantic conditioning experiment. In the acquisition phase the participants were presented with sequences of words from two semantic categories paired with tactile stimulation followed by presentation of a neutral sound (US-) ((e.g., animals -> left hand vibration -> US-, clothes -> right hand vibration -> US-). In the test phase the association violated in 50% of trials which followed by a presentation of a loud noise (US+). The participants were only instructed to listen carefully. On the basis of self-reported contingency awareness, twenty participants were divided in aware (N=12) and unaware (N=8) group.ResultsThe aware group expressed a non-lateralized effect of alpha-beta (12-23 Hz) suppression along with a more negative CNV at central channels preceding presentation of the vibration (main effect of Group). Also, CNV was more negative in expectation of US+ comparing with expectation of US- in the aware group but not in the unaware group.ConclusionsThe results indicate that contingency awareness is accompanied by neural patterns reflecting expectation as can be seen in the suppression of somatosensory alpha-beta activity before expected presentation of the vibration as well as in CNV in expectation of an aversive event.

Consumer research can benefit greatly from more insight into unconscious processes underlying behavior. Williams and Poehlman’s effort at more clearly conceptualizing consciousness and call for more research provides a welcome stimulus in this regard. At the same time, providing evidence for unconscious causation is fraught with methodological difficulties. We outline why it is vital to uphold standards of evidence for claims regarding unconscious processes, as it is precisely a lack of rigor on this front that has generated a countermovement by researchers skeptical of dual-process models in general and unconscious processes in particular. We contend that the skeptics have offered valid causes for concern, which we leverage to formulate six concrete recommendations for future research on consciousness. Researchers should (1) specify the process level at which they claim evidence for unconscious processes, (2) not confuse unconscious influences with unconscious processes, (3) carefully choose between different operational definitions of awareness, (4) maximally satisfy four criteria for awareness measures, and (5) complement measurement with experimental manipulations of awareness. Finally, we recommend to (6) refrain from hard claims about unconscious causation that transcend the limitations of the evidence, recognizing that consciousness is a continuous construct.

It is easier to indicate the ink color of a color-neutral noun when it is presented in the color in which it had been shown frequently before, relative to print colors in which it had been shown less often. This phenomenon is known as color-word-contingency learning. It remains unclear whether participants actually learn semantic (word-color) associations or/and response (word-button) associations. We here present a novel variant of the paradigm that can disentangle semantic and response learning, because word-color and word-button associations are manipulated independently. In four experiments, each involving four daily sessions, novel words (pseudowords such as enas, fatu or imot) were probabilistically associated either with a particular color, a particular response-button position, or with both. Neutral trials were also included, and participants’ awareness of the contingencies was manipulated. The data showed no impact of explicit contingency awareness, but clear evidence both for response learning and for semantic learning, with effects emerging swiftly. Deeper processing of color information, with color words presented in black instead of color patches to indicate response-button positions, resulted in stronger effects, both for semantic and response learning. Our data add a crucial piece of evidence lacking so far in color-word contingency learning studies: Semantic learning effectively takes place even when associations are learned in an incidental way.

The evaluative conditioning (EC) effect refers to the change in the liking of a neutral stimulus (conditioned stimulus, CS) due to its pairing with another stimulus (unconditioned stimulus, US). We examined whether the extinction rate of the EC effect is moderated by feature-specific attention allocation. In two experiments, CSs were abstract Gabor patches varying along two orthogonal, perceptual dimensions (i.e. spatial frequency and orientation). During the acquisition phase, one of these dimensions was predictive of the valence of the USs. During the extinction phase, CSs were presented alone and participants were asked to categorise the CSs either according to their valence, the perceptual dimension that was task-relevant during the acquisition phase, or a perceptual dimension that was task-irrelevant during the acquisition phase. As predicted, explicit valence measures revealed a linear increase in the extinction rate of the EC effect as participants were encouraged to assign attention to non-evaluative stimulus information during the extinction phase. In Experiment 1, Affect Misattribution Paradigm (AMP) data mimicked this pattern of results, although the effect just missed conventional levels of significance. In Experiment 2, the AMP data revealed an increase of the EC effect if attention was focused on evaluative stimulus information. Potential mechanisms to explain these findings are discussed.

Background Transcranial direct current stimulation (tDCS) is a neuromodulation method that has been used to modulate learning. We tested whether anodal tDCS targeted at the left DLPFC could enhance learning in a semantic variant of discrimination eyeblink conditioning, i.e., whether the stimulation would have a specific effect on the discrimination ability, rate of acquisition, amplitude of the conditioned response (CR), or all of these. Methods Immediately prior to the eyeblink conditioning, the participants received either active stimulation of 1 mA for 10 min or sham stimulation. The anode was placed over F3 and the cathode over the right supraorbital area. The conditioned stimuli (CSs) were common Finnish male and female names that were presented as text. Male names were reinforced with an unconditioned stimulus. Results Stimulation had no effect on the learning rate or discrimination ratio, but the stimulated participants showed steeper CR acquisition in the initial phase of the experiment. Nevertheless, the participants in the stimulation group showed greater eyeblink CRs to the non-reinforced CS. Discussion Contrary to our initial hypothesis, the magnitude and rate of CRs to non-reinforced CS was higher in the active stimulation group than in the sham stimulation group, which may suggest deterioration of discrimination and contingency awareness in the used task. Our observations may suggest a lack of effect on the participants’ ability to discriminate between two different types of CS. Furthermore, cathodal modulation of the right prefrontal cortex may explain the change in magnitude and rate of CRs to non-reinforced CS.

Humans responded on multiple random-ratio (RR) random-interval (RI) schedules, and their verbalized performance awareness (PA; i.e., their ability to accurately describe what they did) was measured in three experiments. In Experiment 1, instructions informed participants that to earn points, either sometimes rapid responding and sometimes slow responding would work best (accurate instructions); rapid responding would work best (go fast instructions); spaced responding would work best (go slow instructions); or no advice was provided (minimal instructions). In Experiments 2 and 3, participants received either accurate or minimal instructions and were subject to extinction after a multiple RR-RI schedule. In all experiments, both performance awareness, and receiving accurate instructions, were related to schedule-sensitive responding, but were unrelated to one another - participants receiving accurate-rate instructions were not more likely to show performance awareness than those exposed to minimal instructions. Both higher performance awareness and exposure to accurate instructions predicted faster extinction in Experiment 2 but not in Experiment 3. The current results suggest that performance awareness rather than contingency awareness is more strongly related to humans displaying schedule-typical behavior and that this is not strongly related to any explicit verbal instructions that are given.

In the field of evaluative conditioning (EC), two opposing theories—propositional single-process theory versus dual-process theory—are currently being discussed in the literature. The present set of experiments test a crucial prediction to adjudicate between these two theories: Dual-process theory postulates that evaluative conditioning can occur without awareness of the contingency between conditioned stimulus (CS) and unconditioned stimulus (US); in contrast, single-process propositional theory postulates that EC requires CS-US contingency awareness. In a set of three studies, we experimentally manipulate contingency awareness by presenting the CSs very briefly, thereby rendering it unlikely to be processed consciously. We address potential issues with previous studies on EC with subliminal or near-threshold CSs that limited their interpretation. Across two experiments, we consistently found an EC effect for CSs presented for 1000 ms and consistently failed to find an EC effect for briefly presented CSs. In a third pre-registered experiment, we again found evidence for an EC effect with CSs presented for 1000 ms, and we found some indication for an EC effect for CSs presented for 20 ms.

Attitudes are a core construct of social psychology, and research showed that attitudes can be acquired by merely pairing neutral stimuli with other liked or disliked stimuli (i.e., evaluative conditioning, EC). In this research we address the role of different memory processes contributing to EC. Although it is commonly found that memory for the pairings increases EC, we argue that memory performance data obtained in the standard paradigm remain ambiguous. We hypothesize that memory for stimulus pairings may moderate EC by means of an intentional use of conscious recollection as well as through unintended effects of memory. In two experiments we used modified memory tests that distinguish between these different memory processes on an item-level by identifying recollection as the participant's ability to control memory performance. The analyses of the experiments showed that both intended and unintended influences independently moderate EC. Based on these results we discuss the role of different memory processes in EC, and how memory and learning processes may be related.

We examined whether the generalization of recently acquired likes and dislikes depends on feature-specific attention allocation. Likes and dislikes were established by means of an evaluative-conditioning procedure in which participants were presented with several exemplars of two subordinate categories (e.g., young men vs. old women). Whereas exemplars of one category were consistently paired with negative stimuli, exemplars of the second category were consistently paired with positive stimuli. In addition, we manipulated feature-specific attention allocation for specific stimulus dimensions (e.g., gender vs. age), either during (Experiments 1 and 2) or before the acquisition phase of the experiment (Experiment 3). Both direct and indirect attitude measures revealed a clear impact of this manipulation on attitude generalization. More specifically, only generalization stimuli that were similar to the CSs in terms of the stimulus dimension that was selectively attended to were evaluated in a manner that was congruent with the acquired liking of those CSs.

In three experiments, we tested the influence of instructions about an allegedly upcoming extinction or counterconditioning phase on evaluative conditioning (EC) effects. After an acquisition phase in which neutral stimuli were related to positive or negative stimuli via instructions (Experiments 1 and 2a) or actual pairings (Experiment 2b), three different groups of participants were either informed that in the next phase the neutral stimuli would be presented without positive or negative stimuli (extinction instruction), that the neutral stimuli in the next phase would be paired with stimuli of the opposite valence than before (counterconditioning instruction), or received no further instructions. Afterwards, liking of the originally neutral stimuli was measured either with an evaluative rating (Experiment 1) or with an Implicit Association Test (IAT; Experiments 2a and 2b). EC was reduced in the counterconditioning condition of Experiment 1 and in the joint analysis of Experiments 2a and 2b. The extinction instruction led to a reduction of EC only in Experiment 1. Finally, whether the acquisition phase consisted of instructions about CS–US pairings (Experiment 2a) or the actual experience of CS–US pairings (Experiment 2b) did not significantly impact the observed changes in liking. Overall, our results suggest that similar mechanisms might mediate instruction- and experienced-based EC. Our results are in line with propositional models of EC but can be explained also by association formation models and dual process models of EC, provided that certain auxiliary assumptions are made.

When presenting a neutral stimulus (CS) in close temporal and spatial proximity to a positive or negative stimulus (US) the former is often observed to adopt the valence of the latter, a phenomenon named evaluative conditioning (EC). It is already well established that under most conditions, contingency awareness is important for an EC effect to occur. In addition to that, some findings suggest that awareness of the stimulus pairs is not only relevant during the learning phase, but that it is also relevant whether memory for the pairings is still available during the measurement phase. As previous research has shown that memory is better after temporally distributed than after contiguous (massed) repetitions, it seems plausible that also EC effects are moderated by distributed practice manipulations. This was tested in the current studies. In two experiments with successful distributed practice manipulations on memory, we show that also the magnitude of the EC effect was larger for pairs learned under spaced compared to massed conditions. Both effects, on memory and on EC, are found after a within-participant and after a between-participant manipulation. However, we did not find significant differences in the EC effect for different conditions of spaced practice. These findings are in line with the assumption that EC is based on similar processes as memory for the pairings.

Evaluative conditioning (EC) is the valence change of a (typically neutral) stimulus (CS) that is due to the previous pairing with another (typically valent) stimulus (US). It has been repeatedly shown that EC effects are stronger or existent only if participants know which US was paired with which CS. Knowledge of the CS–US pairings is usually measured temporally close to both the conditioning phase and the CS valence measurement phase. Hence, the relation between EC and knowledge about the pairings could indicate either that participants need to become aware of the pairings at some point or that they need to remember them during the CS valence test. We isolated the impact of memory during the CS valence test in a study that encompassed two sessions. During the first session, participants were presented with CS–US pairings. The valence of the CSs was measured in a second session several days later using both a rating scale and an affective priming procedure. Memory for the pairings was measured both during the first and the second session. Using item-based multilevel analysis, we found that EC in the second session was related to memory for the pairings during the second session, but not to the memory for the pairings measured immediately after the learning phase. For the pairs that were remembered during the first session, but not during the second session, no EC effect was found. These results suggest that memory for CS–US pairings during valence measurement can be relevant for EC effects to occur.

Evaluative conditioning (EC) is generally considered to be one of the routes via which likes and dislikes are acquired. We identify recent trends in EC research and speculate about the topics that will dominate future research on EC. Many of the recent developments in EC research were shaped by functional definitions of EC that refer only to environmental conditions, but not to mental processes and representations. These functional definitions stimulated the development of and debates between theories about the mental processes that mediate EC. These trends, as well as greater methodological and conceptual sophistication, inspired meta-conditional studies that aim at determining the conditions under which EC is characterized by certain properties. The question of whether EC depends on contingency awareness remains a central topic, albeit with a stronger link to theorizing about underlying mental processes. Other automaticity features have gained enhanced interest, as can for example be seen in research investigating whether EC is goal-independent and whether EC is resource-independent. We argue that future research would benefit from a sharper distinction between processes that operate during acquisition (i.e., when CS–US pairs are presented) and processes that operate during measurement (i.e., when the effects of CS–US pairings are assessed). We conclude with a short summary of all articles in this Special Issue, relating them to the identified trends in EC research.

Evaluative conditioning (EC) refers to changes in the evaluation of a conditioned stimulus (CS) due to its repeated pairing with an unconditioned stimulus (US). One of the most debated topics in EC research is whether or not EC is dependent on contingency awareness. In this study, we go beyond this debate by examining whether contingency awareness mediates the impact of attentional resources and goal-directed attention on EC. Attentional resources were manipulated by presenting CSs and USs either within the same modality or in different modalities. Goal-directed attention was manipulated by asking participants to respond to the CSs or to the USs. Results indicate that the effect of goal-directed attention on EC is mediated by contingency awareness, whereas the effect of attentional resources on EC is not.

In two experiments, we tested the generality of the learning effects in the recently-introduced color-word contingency learning paradigm. Participants made speeded evaluative judgments to valenced target words. Each of a set of distracting nonwords was presented most often with either positive or negative target words. We observed that participants responded faster on trials that respected these contingencies than on trials that contradicted the contingencies. The contingencies also produced changes in liking: in a subsequent explicit evaluative rating task, participants rated positively-conditioned nonwords more positively than negatively-conditioned nonwords. Interestingly, contingency effects in the performance task correlated with this explicit rating effect in both experiments. In Experiment 2, all effects reported were independent of subjective and objective contingency awareness (which was completely lacking), even when awareness was measured at the item level. Our results reveal that learning in this type of performance task extends to nonword-valence contingencies and to responses different from those emitted during the performance task. We discuss the implications of these findings for theories about the processes that underlie contingency learning in performance tasks and for research on evaluative conditioning.

Whereas previous evaluative conditioning (EC) studies produced inconsistent results concerning the role of contingency knowledge, there are classical eye-blink conditioning studies suggesting that declarative processes are involved in trace conditioning but not in delay conditioning. In two EC experiments pairing neutral sounds (conditioned stimuli; CSs) with affective pictures (unconditioned stimuli; USs), we tested whether the type of conditioning procedure affects the relationship between awareness and EC. Auditory CSs and visual USs were either overlapping and co-terminating (Delay Conditioning Group), or they were separated by a short temporal gap (Trace Conditioning Group). In both groups, contingency awareness was manipulated by varying the duration at which the US was presented during conditioning. Furthermore, in addition to a post-conditioning measure of awareness, US detectability was measured concurrently during the learning phase in Experiment 2. US exposure duration affected both measures of awareness. The data of both experiments demonstrate that EC does not occur if the USs are presented at very brief durations, but reliable EC effects can be observed at longer US exposure durations. As there were no differences between trace and delay conditioning, the data suggest that contingency awareness plays a crucial role in trace and in delay conditioning of evaluative responses. These results challenge automatic association-formation accounts of EC, but they are in line with ‘single-process’ accounts assuming EC to be dependent on conscious declarative knowledge about CS–US contingencies.

There is considerable debate about whether differential delay eyeblink conditioning can be acquired without awareness of the stimulus contingencies. Previous investigations of the relationship between differential-delay eyeblink conditioning and awareness of the stimulus contingencies have assessed awareness after the conditioning session was finished using a post-experimental questionnaire. In two experiments, the point at which contingency awareness developed during the conditioning session was estimated from a button-press measure of expectancy of the unconditioned stimulus (US). In both experiments, knowledge of the stimulus contingencies and acquisition of differential delay eyeblink conditioning developed approximately in parallel. In Experiment 1 it was shown that predicting the US facilitated eyeblink conditioning compared with predicting the eyeblink response. In Experiment 2, a masking task was used that slowed down the emergence of awareness, and it was shown that differential conditioning only occurred in participants who were able to predict the US. The current findings challenge the hypothesis that differential delay eyeblink conditioning is entirely mediated by a functionally and neurally distinct nondeclarative learning system.

Whether human evaluative conditioning can occur without contingency awareness has been the subject of an intense and ongoing debate for decades, troubled by a wide array of methodological difficulties. Following recent methodological innovations, the available evidence currently points to the conclusion that evaluative conditioning effects do not occur without contingency awareness. In a simulation, we demonstrate, however, that these innovations are strongly biased toward the conclusion that evaluative conditioning requires contingency awareness, confounding the measurement of contingency memory with conditioned attitudes. We adopt a process-dissociation procedure to separate the memory and attitude components. In 4 studies, the attitude parameter is validated using existing attitudes and applied to probe for contingency-unaware evaluative conditioning. A fifth experiment incorporates a time-delay manipulation confirming the dissociability of the attitude and memory components. The results indicate that evaluative conditioning can produce attitudes without conscious awareness of the contingencies. Implications for theories of evaluative conditioning and associative learning are discussed.

Emotionally significant objects and events in our environment attract attention based on their motivational relevance for survival. Such kind of emotional attention is thought to lead to affect-specific amplified processing that closely resembles effects of directed attention. Although there has been extensive research on prioritized processing of visual emotional stimuli, the spatio-temporal dynamics of motivated attention mechanisms in auditory processing are less clearly understood. We investigated modulatory effects of emotional attention at early auditory processing stages using time-sensitive whole-head magnetoencephalography. A novel associative learning procedure involving multiple conditioned stimuli (CSs) per affective category was introduced to specifically test whether affect-specific modulation can proceed in a rapid and highly differentiating fashion in humans. Auditory evoked fields (AEFs) were recorded in response to 42 different ultrashort, click-like sounds before and after affective conditioning with pleasant, unpleasant, or neutral auditory scenes. As hypothesized, emotional attention affected neural click tone processing at time intervals of the P20-50m (20–50 ms) and the N1m (100–130 ms), two early AEF components sensitive to directed selective attention (Woldorff et al., 1993). Distributed source localization revealed amplified processing of tones associated with aversive or pleasant compared with neutral auditory scenes at auditory sensory, frontal and parietal cortex regions. Behavioral tests did not indicate any awareness for the contingent CS–UCS (unconditioned stimulus) relationships in the participants, suggesting affective associative learning in absence of contingency awareness. Our findings imply early and highly differentiating affect-specific modulation of auditory stimulus processing supported by neural mechanisms and circuitry comparable with those reported for directed auditory attention.

One way to learn to like or dislike a neutral target stimulus is through associations with positive or negative context stimuli. The present research investigates whether people need to be aware of the association between a target and a context stimulus (i.e., contingency aware) in order for associative learning of likes and dislikes to occur. We predicted that awareness of the association between context and target is necessary when target novelty is low, but not when target novelty is high. We conducted two experiments in which we varied target novelty and measured contingency awareness using a picture-bound recognition task. This allowed us to separately investigate evaluative conditioning for “contingency awareness” and “contingency unawareness” context–target pairs. The results show, as predicted, that awareness of the association between context and target is needed for low-novelty targets but not needed for high-novelty targets.

I present an overview of emotion theories, organised around the question of emotion causation. I argue that theories of emotion causation should ideally address the problems of elicitation, intensity, and differentiation. Each of these problems can be divided into a subquestion that asks about the relation between stimuli and emotions (i.e., the functional level of process description, cf. Marr, 1982) and a subquestion that asks about the mechanism and representations that intervene (i.e., the algorithmic level of process description). The overview reveals that theories of emotion causation sometimes differ with regard to the kind of process that they hold responsible for emotion causation. More precisely, they hold different assumptions regarding the conditions under which the process is supposed to operate (optimal versus suboptimal), the format of the representations involved (propositional versus perceptual), and the object or input of the central process (stimulus versus responses/experience). Further, the overview reveals that theories of emotion causation sometimes differ with regard to the level of process description that they focus on. Finally, the overview brings to light several similarities among the theories discussed.

Previous research has indicated that conditioning depends on contingency awareness (CA). However, we argue that these studies have examined this issue under methodological conditions that might be insensitive to associative learning without CA. In the present study we examined the effect of an experimental manipulation of CA on attentive processing of classically conditioned stimuli, which is sensitive to associative learning with and without CA. We found that aversive conditioning with additional contingency instructions modulated visual attention, in the sense that the conditioned cues captured and held attention more strongly than the non-conditioned cues. Surprisingly, conditioning under conditions of restricted CA yielded a response pattern that was different from that under full CA. These findings suggest that conditioning with full and restricted CA can lead to qualitatively different effects on attention.

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.

Episodic stimulus-response (S-R) bindings emerge whenever a response is executed in temporal proximity to a stimulus and they are retrieved from memory by repeating the stimulus on a later occasion. To examine whether retrieval of S-R bindings is sensitive to contextual influences, we manipulated contingencies between stimulus repetitions and response repetitions. In a sequential priming paradigm, stimulus repetitions were either predictive of response repetitions (positive contingency) or response changes (negative contingency) or were orthogonal to the response relation (no contingency). Results revealed that compared to the orthogonal condition, S-R binding and retrieval effects were larger under positive contingency but were reduced under negative contingency. The modulating effect of contingency on the strength of S-R binding and retrieval processes was not mediated by contingency awareness. These findings implicate that S-R binding and retrieval processes are implicitly tuned to adapt to contextual affordances that either promote or hinder the use of S-R bindings for efficient action regulation.

Can conditioning occur without conscious awareness of the contingency between the stimuli? We trained participants on two separate reaction time tasks that ensured attention to the experimental stimuli. The tasks were then interleaved to create a differential Pavlovian contingency between visual stimuli from one task and an airpuff stimulus from the other. Many participants were unaware of the contingency and failed to show differential eyeblink conditioning, despite attending to a salient stimulus that was contingently and contiguously related to the airpuff stimulus over many trials. Manipulation of awareness by verbal instruction dramatically increased awareness and differential eyeblink responding. These findings cast doubt on dual-system theories, which propose an automatic associative system independent of cognition, and provide strong evidence that cognitive processes associated with awareness play a causal role in learning.

Fear-potentiated startle is defined as an increase in the magnitude of the startle reflex in the presence of a stimulus that was previously paired with an aversive event. It has been proposed that a subject's awareness of the contingencies in the experiment may affect fear-potentiated startle. The authors adapted a conditional discrimination procedure (AX+/BX-), previously validated in animals, to a human fear-potentiated startle paradigm in 50 healthy volunteers. This paradigm allows for an assessment of fear-potentiated startle during threat conditions as well as inhibition of fear-potentiated startle during safety conditions. A response keypad was used to assess contingency awareness on a trial-by-trial basis. Both aware and unaware subjects showed fear-potentiated startle. However, awareness was related to stimulus discrimination and fear inhibition.

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.

Two experiments are described that investigate the effects of attention in moderating evaluative conditioning (EC) effects in a picture‐picture paradigm in which previously discovered experimental artifacts (e.g., Field & Davey, 1999) were overcome by counterbalancing conditioned stimuli (CSs) and unconditioned stimuli (USs) across participants. Conditioned responses for individuals who had attention enhanced were compared against a control group and groups for whom attention was impeded using a distracter task. In a second experiment the effects of attention were dissociated from those of contingency awareness by using backward‐masked US presentations. The results of these experiments indicate that although associative EC effects may not be disrupted by a lack of contingency awareness, attention is an important factor in establishing conditioning. These results shed some light onto the possible boundary conditions that could explain past inconsistencies in obtaining EC effects in the visual paradigm.

This research investigates the role of involvement and need for cognition in influencing contingency awareness in attitude formation. Two experiments examine the nature of favorable attitudes formulated through established classical conditioning procedures. The results of Experiment 1 indicate that awareness influences attitudes toward a conditioned stimulus, particularly under conditions of high involvement and high need for cognition. Experiment 2 suggests that contingency awareness mediates the relationship between inferential belief formation and attitudes and that this effect is stronger under high involvement and high need for cognition. Implications for understanding the role of classical conditioning procedures in advertising are discussed.

S. Wiens and A. Ohman (2002) disputed the conclusion that Pavlovian conditioning is strongly related to contingency awareness (P. F. Lovibond & D. R. Shanks, 2002) on the basis that an inappropriate definition of awareness was used. J. R. Manns, R. E. Clark, and L. R. Squire (2002) contended that delay eyeblink conditioning is independent of awareness. The authors of the present article consider these arguments, highlight several problems in the new studies described by the commentators, and conclude that there is still little evidence for unconscious conditioning in either subliminal autonomic conditioning or eyeblink conditioning. The most parsimonious account of existing data is that a single learning process gives rise to both awareness and conditioned responding. Further progress in evaluating the possibility of unconscious conditioning would be facilitated by the development of more completely specified and testable dual-process models.

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.

The focus of the present study was on further exploring anticipatory responses to emotional stimuli by measuring the eyeblink startle reflex in a variation of the picture-picture affective learning procedure. Participants (113 undergraduate women) were not explicitly instructed before the experiment began. Instead, they had to learn the specific relations between cues (geometrical shapes) and emotional pictures based on pairings during the first part of the task. Plausible contingency learning effects were tested afterwards, in a parallel sequence of trials including auditory probes during cues and pictures processing during the second part of the task. Results did show the typical affective startle modulation pattern during perception, linear F(1, 200) = 52.67, p < .0001, but unexpected inhibition for both pleasant and unpleasant, compared to neutral cues, during anticipation, quadratic F(1, 200) = 7.07, p < .009. All patterns of startle modulation were independent of cue-picture contingency awareness (all interactions Fs < 1). Skin conductance changes showed the predictable quadratic trend either during picture perception or anticipatory periods (greater activity for emotional vs. neutral; overall quadratic F(1, 224) = 7.04, p < .01), only for participants fully aware of the cue-picture contingency, quadratic F(1, 158) = 5.86, p < .02. Overall, our results during anticipation (cues processing) seem to suggest that more resources were allocated to highly arousing pictures that engage attention. Differences between the present results and prior research may be attributed to procedural variations in the sample, cues, or instructions. Future studies should also explore in more detail the role of the contingency awareness during anticipation.

We argue that the effects of evaluative learning may occur (a) without conscious perception of the affective stimuli, (b) without awareness of the stimulus contingencies, and (c) without any awareness that learning has occurred at all. Whether the three experiments reported in our target article provide conclusive evidence for either or any of these assertions is discussed in the commentaries of De Houwer and Field. We respond with the argument that when considered alongside other studies carried out over the past few decades, our experiments provide compelling evidence for a theory that posits a dissociation between evaluative learning and contingency awareness.

The role of contingency awareness in evaluative conditioning has been a contentious issue for quite some time now. Several papers provide a review of the relevant evidence (De Houwer, Baeyens, & Hendrickx, 1997a; De Houwer, Thomas, & Baeyens, in press; Field, 2000; Lovibond & Shanks, in press; Shanks & St. John, 1994), but the conclusions that are reached differ markedly. For instance, whereas De Houwer et al. (in press) concluded that evaluative conditioning is largely independent of contingency awareness, Field (2000, p. 32) argued that there is little unequivocal evidence that evaluative conditioning without contingency awareness is a robust finding. The results of Fulcher and Hammerl provide another interesting contribution to the debate. The aim of this commentary is to illustrate how even a single series of studies such as those of Fulcher and Hammerl can be interpreted in different ways depending on one’s perspective. I will first adopt a sceptical point of view and will try to argue that the evidence presented by Fulcher and Hammerl does not provide conclusive evidence for unconscious evaluative conditioning. Afterward, I will look at the same studies from a more open, broader point of view and argue that the reported results are important and that they are in line with the results of many previous results which also support the hypothesis that, in comparison to other forms of Pavlovian conditioning, evaluative conditioning is largely independent of contingency awareness

Fulcher and Hammerl's (2001) important exploration of the role of contingency awareness in evaluative conditioning (EC) raises a lot of issues for discussion: (1) what boundaries, if any, exist between EC and affective learning paradigms?; (2) if EC does occur without awareness does this mean it is nonpropositional learning?; (3) is EC driven by stimulus–response (S–R), rather than stimulus–stimulus (S–S), associations and if so should it then surprise us that contingency awareness is not important?; and (4) if S–R associations are at the heart of EC, should we automatically assume EC is part of a different learning mechanism to autonomic Pavlovian conditioning (Field, 2000a, 2000b)? This article, after a critical review of Fulcher and Hammerl's work, discusses these issues with reference to what can be realistically inferred about the mechanisms underlying EC.

The proposal that affective learning, the learning of likes and dislikes, can exist in the absence of contingency awareness, whereas signal learning, the learning of stimulus relationships, cannot, was investigated in a differential conditioning paradigm that was embedded in a visual masking task. Startle magnitude modulation and changes in verbal ratings served as measures of affective learning, whereas skin conductance was taken to reflect signal learning. Awareness was assessed online with an expectancy dial and in a postexperimental questionnaire. Both between-subject comparisons of verbalizers and nonverbalizers and within-subject comparisons of verbalizers before and after verbalization failed to reveal any evidence for learning, whether affective or otherwise, in the absence of knowledge of the stimulus contingencies.

Evaluative conditioning refers to changes in the liking of a stimulus that are due to the fact that the stimulus has been paired with other, positive or negative stimuli. Although evaluative conditioning appears to be subjected to certain boundary conditions, significant evaluative conditioning effects have been obtained using a large variety of stimuli and procedures. Some data suggest that evaluative conditioning can occur under conditions that do not support other forms of Pavlovian conditioning, and several models have been proposed to account for these differences. In the present article, the authors summarize the available literature, draw conclusions where possible, and provide suggestions for future research.

Two experiments assessed whether human affective learning is sensitive to occasion setting. The first experiment (N 5 18) employed a within-subjects, sequential feature positive design (X φι A1/A2). Modulation of blink startle, an index of affective learning, was larger during A1 than during A2, suggesting that participants had learned a modulatory relationship. Experiment 2 (N 5 32) assessed whether the feature also acquired conditioned valence in a between-subjects design. One group received sequential feature positive training (X φι A1/A2), and a second group was trained in a sequential feature negative design (X φι A2/A1). Startle modulation during the feature was larger in the sequential feature positive group than in the sequential feature negative group. The results are interpreted to suggest the presence of modulated affective learning to the target concurrent with simple affective learning to the feature. ≈ 2000 Academic Press

Field and Davey (1997) claimed that evaluative conditioning (EC), rather than being a genuine type of Pavlovian associative learning, represents nothing but an experimental artifact. They come to this conclusion by first identifying the prototypical experimental procedure of EC research, by next pointing to the potential methodological shortcomings of this prototypical procedure in order to infer associative learning, and by finally demonstrating that when the appropriate controls are added to this prototypical procedure, it becomes clear that apparent EC results represent nothing but an experimental artifact. In this paper, we first demonstrate that what Field and Davey identify as the “prototypical procedure” is, as a matter of fact, the exception rather than the rule in EC research, such that the potential scope of their criticism is rather limited. Next, we show how the results of their own experiment are actually due to an artifact that is not present in any EC study. Finally, we discuss how Field and Davey's criticism of EC research has its roots in a misconception of the appropriate within or between subject controls for Pavlovian associative learning.

In three experiments, each of a set colour-unrelated distracting words was presented most often in a particular target print colour (e.g., “month” most often in red). In Experiment 1, half of the participants were told the word-colour contingencies in advance (instructed) and half were not (control). The instructed group showed a larger learning effect. This instruction effect was fully explained by increases in subjective awareness with instruction. In Experiment 2, contingency instructions were again given, but no contingencies were actually present. Although many participants claimed to be aware of these (non-existent) contingencies, they did not produce an instructed contingency effect. In Experiment 3, half of the participants were given contingency instructions that did not correspond to the correct contingencies. Participants with these false instructions learned the actual contingencies worse than controls. Collectively, our results suggest that conscious contingency knowledge might play a moderating role in the strength of implicit learning.

Evidence from hemodynamic and electrophysiological measures suggests that the processing of emotionally relevant information occurs in a spatially and temporally distributed affective network. ERP studies of emotional stimulus processing frequently report differential responses to emotional stimuli starting around 120 msec. However, the involvement of structures that seem to become activated at earlier latencies (i.e., amygdala and OFC) would allow for more rapid modulations, even in distant cortical areas. Consistent with this notion, recent ERP studies investigating associative learning have provided evidence for rapid modulations in sensory areas earlier than 120 msec, but these studies either used simple and/or very few stimuli. The present study used high-density whole-head magneto-encephalography to measure brain responses to a multitude of neutral facial stimuli, which were associated with an aversive or neutral odor. Significant emotional modulations were observed at intervals of 50–80 and 130–190 msec in frontal and occipito-temporal regions, respectively. In the absence of contingency awareness and with only two learning instances, a remarkable capacity for emotional learning is observed.

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.

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.