Marianne Hammerl: "Differential effects of (un)awareness in evaluative conditioning" (cancelled)

Eva Walther: "Evaluative conditioning and the awareness issue: Assessing contingency awareness with the four-picture recognition test"

Michael Olson: "Implicit Evaluative Conditioning: Effects on Implicit Measures and in the Domain of Racial Prejudice"

Ap Dijksterhuis: "A subliminal road to happiness: Enhancing implicit self-esteem by subliminal evaluative conditioning"
 
 

Estrella Diaz: "Resistance to extinction on Human Evaluative Conditioning using between-subjects design"

Geert Francken: "Evaluative Conditioning is Resistant to Extinction in the Differential Fear Conditioning Paradigm"

Dirk Hermans: "Extinction, reinstatement, and counterconditioning of acquired stimulus valence: Their relation to mechanisms that drive/prevent return of fear after successful exposure therapy?"

Ottmar Lipp: "No support for Evaluative Learning Theory from studies using simple Pavlovian conditioning procedures"
 
 

Bob Boakes: "Changing hedonic responses to odours using explicit paired-associate learning procedures: A comparison between odour-picture and odour-taste learning"

Tom Meersmans: "Searching for non-evaluative referential learning"
 
 

Ingrid Johnsrude: "Learning to like: Investigating preference formation in humans"

Russ Fazio: "Attitude Formation through Associative Learning: Valence Asymmetries"

Dominic Dwyer: "Differences between learned flavour preferences based on nutrients and palatability: The effects of varying either nutrient content of the reinforcer or deprivation state on cue competition"
 
 

A long tradition of research shows that evaluations of social and nonsocial objects can be shaped or changed by evaluative conditioning. In a typical experiment, a target stimulus is paired a number of times with either a positive or a negative stimulus. After a few pairings, the evaluation of the target stimulus shifts towards the evaluation of the stimulus it was paired with. In the current work, the hypothesis was tested that evaluative conditioning techniques could be employed to enhance self-esteem. This hypothesis was based on a) the idea that self-esteem can be conceptualized as an evaluation of an "object", in this case the self; and on b) the notion that although most evaluative conditioning studies have shown shifts in evaluation of neutral and/or novel objects, a few experiments have shown that the evaluation of familiar and non-neutral objects can be influenced by evaluative conditioning as well.

In a series of experiments, it is indeed shown that implicit self-esteem can be enhanced with the help of subliminal evaluative conditioning techniques. Presenting participants with positive personality traits after subliminal activation of the self-concept (by subliminal presentation words such as "I" or "me") enhances self-esteem relative to control conditions in which participants are presented with neutral traits after self-concept activation or with positive traits without prior self-concept activation. Recent experiments speak to issues such as the consequences of the effect, the robustness of the effect and the potential moderating role of initial self-esteem.
 

Much controversy has surrounded the question of whether attitudes might develop implicitly via classical conditioning. Using a simultaneous conditioning procedure in the context of an unrelated task, we show that attitudes toward novel objects can develop through classical conditioning without explicit memory for the pairings. These attitudes were apparent on traditional explicit measures (experiment 1), as well as two different implicit measures of attitudes (experiments 2 and 3). Moreover, the same conditioning procedure was found to be effective in reducing Whites' automatically-activated negative attitudes toward Blacks (experiment 4). This reduction in prejudice was found even after a 2 day delay (experiment 5).
 

Recent studies have shown that the basic evaluative conditioning 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 unaware of the stimulus pairings (Fulcher & Hammerl, 2001; Hammerl & Grabitz, 2000). If participants are aware of the pairings, reactance effects occur (i.e., changes in the opposite direction of the valence of the affective stimulus). These effects occur when an awareness induction technique was used (by unveiling the stimulus pairings)  as well as when participants found the source of influence by themselves.

To examine whether these reactance effects are due to processes of  conscious countercontrol or whether the ratings reflect how the  participants intrinsically feel towards the stimuli, a new procedure was  developed that included a bogus pipeline condition known from attitude research in social psychology. The results show reactance effects also in  this procedure, suggesting that reactance is spontaneous and not due to  processes of conscious countercontrol. A replication study is currently  running.

Fulcher, E. P., & Hammerl, M. (2001). When all is revealed: A dissociation  between evaluative learning and contingency awareness. Consciousness and Cognition, 10, 524-549.
Hammerl, M., & Grabitz, H. J. (2000). Affective evaluative learning in  humans: A form of associative learning or only an artifact? Learning and  Motivation, 31, 345-363.
 

A new measurement, the “Four-Picture Recognition Test,” was tested for its effectiveness in assessing contingency awareness in an evaluative conditioning paradigm. After conditioning participants within the picture-picture paradigm, we assessed contingency awareness with the four-picture test as well as with a conventional awareness questionnaire. Results indicated a strong dissociation between the tests. Whereas a majority of participants was able to identify the correct stimulus in the four-picture test, only a single participant was classified as aware in the questionnaire. Moreover, only participants classified as unaware in the recognition test showed significant effects of evaluative learning. The false alarms indicated that participants rely on highly systematic recognition strategies if they are not able to identify the correct stimulus.
 

Successful reduction of fear through exposure therapy is sometimes followed by a (partial) relapse.  This phenomenon is also known as Return of Fear (ROF).  From a learning psychology perspective, several possible mechanisms have been suggested to explain this sudden and seemingly unexpected return of anxiety symptomatology.  These include processes related to spontaneous recovery, context switches (renewal), confrontation with the original CS-US pair (reacquisition), and the mere confrontation with the US in the absence of the original CS (reinstatement).

We will focus on the possible impact of the latter mechanism.  Reinstatement was investigated in a differential fear conditioning paradigm.  Data from a first study demonstrate a significant impact of post-extinction US-only presentations on US-expectancy and fear ratings with respect to the relevant CS+.  Given that negative stimulus valence is rather insensitive to extinction, and given that this extinction-resistant stimulus valence might be a continuous source of response tendencies that are related to escape/avoidance, we hypothesised that negative stimulus valence of the CS+ might influence the extent of reinstatement after extinction.  In a second study we assessed the preventative influence of a counterconditioning procedure – that aimed at altering the extinction resistant stimulus valence of the CS+ -- on the extent of reinstatement (ROF).

Hermans, D., Crombez, G., Vansteenwegen, D., Baeyens, F., & Eelen, P. (2002). Expectancy-learning and evaluative learning in human classical conditioning: Differential effects of extinction.  In S.P. Shohov (Ed.). Advances in Psychology Research, Volume 12, pp. 21-45, NY: Nova Science Publishers.
Hermans, D., Vansteenwegen, D., Crombez, G., Baeyens, F., & Eelen, P. (2002). Expectancy- learning and evaluative learning in human classical conditioning: Affective priming as an indirect and unobtrusive measure of conditioned stimulus valence. Behaviour Research and Therapy. 40, 217-234.
 

Contrary to other forms of Pavlovian conditioning (PC), evaluative conditioning (EC) appears to be resistant to extinction. However, this functional difference might be due to procedural discrepancies between both lines of research. We present a series of extinction experiments that avoided this problem by using a differential fear conditioning paradigm with pictures of human faces as CSs and an electrocutaneous stimulus as US. We obtained both a typical PC measure (differential skin conductance responding) and a typical EC measure (response latency modulation in an affective priming task). Our results provide new support for the differential sensitivity of both forms of  Pavlovian conditioning to extinction. Some limitations of our findings are discussed.
 

In two experiments, the authors examined whether the resistance to extinction obtained in evaluative conditioning (EC) studies involves that EC is a qualitatively distinct form of classical conditioning (Baeyens, Eelen & Crombez, 1995) or it is the result of a non-associative artefact (Field & Davey, 1997, 1998, 1999). Both experiments included between- and within subjects control conditions. In Experiment 1, only verbal ratings were measured in order to evaluate the effect of CS-only exposures on EC whereas in Experiment 2, both verbal ratings and a post-extinction affective priming measure were used. The results showed that the EC effects are demonstrable in a between-subject design and that the extinction procedure did not have any influence on the acquired evaluative value of CSs regardless of whether the verbal ratings or the priming effects were used as dependent variables. The present results provide evidence that EC is resistant to extinction and suggest an interpretation of EC as a qualitatively distinct form of associative learning.
 

Over the last 10 years our research group at the University of Queensland has conducted a number of experiments aimed at testing predictions derived from Evaluative Learning Theory.  These experiments employed the standard procedures used in studies of human Pavlovian conditioning as indexed by autonomic responses.  Neutral visual, pictures of geometric shapes, or tactile stimuli served as conditional stimuli (CS) and aversive electric stimuli, set to an intensity that is ‘unpleasant, but not painful’, served as unconditional stimuli (US).  The studies employed a small number of different CSs in delay conditioning procedures at an 8 s ISI.  Dependent measures were physiological (skin conductance, blink startle), behavioural (RT in affective priming), or verbal (US expectance, ratings of CS pleasantness taken during or before and after conditioning).  Different combinations of these DVs were employed across different experiments in an attempt to assess affective and relational learning simultaneously.  Changes in CS pleasantness as indexed by ratings, affective priming or blink startle modulation were readily observed.  However, contrary to the predictions from Evaluative Learning Theory, our findings indicated that acquired CS unpleasantness is subject to Extinction, as indexed by blink startle modulation (Lipp et al., 1997), online ratings of CS pleasantness (Lipp et al., 2001) or affective priming (Purkis & Lipp, in preparation). Occasion setting, as indexed by blink startle modulation (Hardwick & Lipp, 2000). Stimulus competition, as indexed by pre/post ratings (Lipp et al., 2001). Manipulations of CS_US contingencies, as indexed by blink startle (Lipp et al., 1998). Awareness of the CS_US contingencies, as indexed by blink startle and pre/post ratings (Purkis & Lipp, 2001). Taken together the results suggest that the changes in CS valence observed in simple conditioning procedures that involve a small number of long lasting CSs and an aversive US do not conform to the predictions of Evaluative Learning Theory.  Rather, dislikes acquired in these procedures are subject to the same variables known to affect relational learning.
 

In three recent experiments we have asked participants to learn both odour-picture and odour-taste pairings.  For the odour-picture task they sniff an odour before turning the page of a booklet to look at the next picture. The design is such that odour, O1, is always paired with a neutral picture and O3 with an unpleasant picture.  For the interpolated odour-taste task they sniff the liquid in a container before drinking it.  Odour, O2, is always mixed into a low concentration sucrose solution and O4 into an unpleasant and bitter tasting solution of sucrose-octa-acetate (SOA).  After the initial block of training trials, participants are asked, on sniffing the odour at the start of each trial, to predict the pleasantness, or otherwise, of the picture or taste that will follow.  The test phase starts with a rating test in which each odour is rated for, bitterness, liking (pleasantness), intensity (strength), bitterness and sweetness, always in that order.  This is followed by a recall test for explicit memory for the stimuli paired with the odours during training.

The main aim of this project is to test whether odour-taste associations generate changes in odour liking that are (a) more independent of explicit memory and (b) more resistant to extinction than those generated by odour-picture memory.  Progress so far in detecting such differences has been slow.  The main outcome to date has to been to confirm yet again that the conditioned change in the perceptual properties of an odour, e.g. sweetness, resulting from experience of odour-taste combinations is a robust effect.  Liking ratings show highly variable results and are related in these experiments to explicit recall of the pairings.
 

Evaluative conditioning refers to the changes in liking of a neutral stimulus (the CS or Conditional Stimulus) as a result of merely pairing it with another already liked or disliked stimulus (the US or Unconditional Stimulus). This type of learning can be seen as a form of referential learning: as a consequence of repeatedly pairing the CS with a US, the CS in itself will activate the representation of the (valence of the) US, thereby changing the perceived valence of the CS.

We examined whether other, non-evaluative stimulus properties of a US can also be activated by the CS. A series of experiments will be discussed in which we tried to condition/transfer the age of people, the gender of children, the gender of surnames and the direction from which an aversive US came.
 

The study of reward learning in animals has revealed an interrelated set of limbic and cortical structures involved in reinforcement and motivation, and recent work is exploring how these systems exert effects on behaviour. Emotional associative learning has not yet been much investigated in humans from a similar neuroscientific perspective. Conditioned place preference is one of the most common procedures for assessing conditioned reward associations in animals, and we have developed an analogous procedure for use with people. We have used this procedure with several neuropsychological patient populations: the results of these studies are consistent with what has been reported in the animal literature about the brain substrates of reward learning. Our studies also provide new information regarding multiple, partially redundant, mechanisms of preference formation in humans, and suggest that there may be differences in the relative importance of these mechanisms, both from individual to individual and over the life span.
 

As a whole, the field has devoted more attention to questions regarding attitude change, attitude structure and function, and the influence of attitudes on judgments and behavior than it has to the issue of attitude formation.  Although it has long been known that attitudes can develop on the basis of the positive or negativity of one’s experiences with the attitude objects, little is known about the associative learning process per se.  A new line of research concerning the development of attitudes through exploratory behavior and associative learning aims to redress this imbalance.  The research involves the formation of attitudes toward novel objects as a consequence of learning the outcomes that accrue from interaction with the object, with the goal of illuminating and testing some fundamental principles regarding the development of evaluative associations.
An experiment that illustrates the basic paradigm will be presented.  The procedure is essentially a computer game, affectionately known as “BeanFest”- a simulated world, consisting only of beans.  The participant’s goal is to survive in this world.  Survival is represented by one’s current energy level, which can range from 0 to 100, with 0 signifying “death.”  When eaten, some beans provide energy, whereas others deplete energy. Visually, the beans vary along two dimensions-shape and number of speckles.  Different types of beans are associated with different outcomes.  Participants showed evidence of learning, with their performance improving steadily across the blocks.  Moreover, the attitudes that participants developed toward different types of beans generalized to new beans that had not been presented earlier.  Two intriguing asymmetries  emerged, however.  Negatively-valenced beans were learned better than positively-valenced beans, and negative attitudes influenced generalization to novel beans more strongly than positive attitudes did.
Subsequent experiments that have focused on the interpretation of these asymmetries will be summarized.  The learning asymmetry appears to stem from the basic principle that avoidance behavior provides no information about the actual value of the object.  Invalid assumptions that a bean is positive promote approach behavior and, hence, are corrected.  However, invalid assumptions that a bean is negative persist, because these expectancies promote avoidance. The generalization asymmetry reflects a general tendency to weigh resemblance to a known negative more heavily than resemblance to a known positive.
 

The examination of learned flavour preferences in animals has led to the suggestion that preference based on nutrients differ from those based on palatability alone. A comparison of preferences based on nutrient (maltodextrin) and non-nutrient (saccharine) reinforcers found that the former were more sensitive to cue-competition effects than the latter. This not only supports the idea that flavour nutrient and flavour flavour learning differ but also suggests that this difference might include them obeying different learning rules. This possibility was examined further by comparing learned flavour preferences in animals trained with or without food deprivation using a single reinforcer that is both palatable and nutritious.
 

Although research into Evaluative Conditioning has progressed considerably over the past 25 years, there has been a worrying undercurrent of doubt about the strength and reliability of conditioning effects. Partly this has been due to well-documented methodological debates and the discoveries of experimental artifacts that cast a cloud over some of the research. However, the seeds of doubts have undoubtedly been nurtured even more by the numerous informal (and not so informal) reports of researchers failing to obtain EC effects—even when replicating previously successful paradigms. This has led some to talk of boundary conditions that could enhance or eliminate the effects in EC experiments. This paper briefly reviews some of the known failures to obtain EC, or replicate past experiments before describing 11 new experiments that have explored various possible boundary conditions in the visual domain (such as attention, contingency awareness and relevance of CS-UCS pairings). These various experiments are a catalogue of weird and wonderful results that highlight the problems that we face in EC research.