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Augmentation in contingency learning under time pressure
Abstract
Recent research suggests that cue competition effects in human contingency learning, such as blocking, are due to higher-order cognitive processes. Moreover, some experimental reports suggest that the effect opposite to blocking, augmentation, could occur in experimental preparations that preclude the intervention of reasoning mechanisms. In the present research, we tested this hypothesis by investigating cue interaction effects in an experimental task in which participants had to enter their responses under time pressure. The results show that under these conditions, augmentation, instead of blocking, is observed.
Supplementary resource (1)
... mediated extinction versus release from overshadowing; [18]) and the evaluation of a redundant cue (e.g. blocking versus augmentation; [19]), which will be briefly discussed in relation to Experiment 2. However, by and large, studies rarely observe cue contingency effects of this nature occurring in both excitatory and inhibitory directions on the basis of a single manipulation. Karazinov and Boakes' [17] results constitute the best evidence for a non-rational second-order conditioning effect in human causal learning. ...
... Experiment 2 sought to replicate the dissociation found in Experiment 1, provide stronger evidence of second-order conditioning and conditioned inhibition using the same test measures, and examine whether other seemingly irrational learning effects could also be obtained using the speed manipulation. Recently, Vadillo and Matute [19] described such an effect using a blocking design. Blocking occurs when a target cue is paired with an outcome, but is always presented in compound with another cue that has previously been established as a strong predictor of that outcome. ...
... In Experiment 2, the same manipulation that produced the dissociation in the FN paradigm was not successful in dissociating retrospective revaluation effects (release from overshadowing versus mediated extinction) or learning about a redundant cue (blocking versus augmentation). Experiment 2 did not replicate Vadillo and Matute's [19] finding of time pressure producing augmentation. This might be due to differences in test procedures; causal ratings were used in Experiment 2 whereas an online response measure within a restricted time limit was used in Vadillo and Matute's study. ...
In human causal learning, excitatory and inhibitory learning effects can sometimes be found in the same paradigm by altering the learning conditions. This study aims to explore whether learning in the feature negative paradigm can be dissociated by emphasising speed over accuracy. In two causal learning experiments, participants were given a feature negative discrimination in which the outcome caused by one cue was prevented by the addition of another. Participants completed training trials either in a self-paced fashion with instructions emphasising accuracy, or under strict time constraints with instructions emphasising speed. Using summation tests in which the preventative cue was paired with another causal cue, participants in the accuracy groups correctly rated the preventative cue as if it reduced the probability of the outcome. However, participants in the speed groups rated the preventative cue as if it increased the probability of the outcome. In Experiment 1, both speed and accuracy groups later judged the same cue to be preventative in a reasoned inference task. Experiment 2 failed to find evidence of similar dissociations in retrospective revaluation (release from overshadowing vs. mediated extinction) or learning about a redundant cue (blocking vs. augmentation). However in the same experiment, the tendency for the accuracy group to show conditioned inhibition and the speed group to show second-order conditioning was consistent even across sub-sets of the speed and accuracy groups with equivalent accuracy in training, suggesting that second-order conditioning is not merely a consequence of poorer acquisition. This dissociation mirrors the trade-off between second-order conditioning and conditioned inhibition observed in animal conditioning when training is extended.
... Thus, simultaneous replication of augmentation in the laboratory and on the Internet would provide stronger support to the validity of Internet-based research than our previous studies on more solid and reliable learning effects. A recent experiment conducted by Vadillo and Matute (2010) showed that augmentation can be found in web-based studies. However, that experiment did not include a traditional laboratory sample and, therefore, did not allow a comparison of the relative effect sizes of the augmentation effect under both locations. ...
... Given that by the end of Phase 1 participants were responding at a relatively high and stable rate, these responses can be taken as a good baseline that can be used as a reference point on which to assess the number of responses at test. This dependent variable had already been analyzed in previous demonstrations of augmentation (Vadillo & Matute, 2010). The other dependent variable, R/Mean was computed by dividing the absolute level of responses to X and Y at test by the mean number of responses given during all training trials with Outcome1. ...
... However, these variables could be useful to predict other outcomes such as, for example, the failure or success to meet the data selection criteria. Finally, augmentation in human contingency learning has been observed only in a limited set of experimental tasks (Beesley & Shanks, submitted for publication; Mitchell et al., 2005; Vadillo & Matute, 2010). In order to better assess the reliability of the effect it would be necessary to prove not only that it can be observed under less controlled conditions (as shown by the present study), but also in completely different experimental settings. ...
Most demonstrations of the validity of Internet-based research methods are based on replications of well-known experimental phenomena on the Internet. However, in order to test whether the lack of control over the experimental conditions usually found in Internet studies has an effect on the quality of data, it would be more interesting to show that the Internet cannot only be used to replicate common and well-documented effects, but also less-known experimental findings or elusive phenomena that tend to occur only in very specific conditions. The present experiment explores one such effect, namely augmentation in associative learning, and shows that it can be readily found in the laboratory and on the Internet.
... Regardless, the very nature of the standard input-output paradigm clearly places an overwhelming emphasis on accurately predicting the transformation from covariation to judgment, with far less regard for the psychological mechanisms by which such a transformation comes about. More recently, researchers have started to investigate the trial-by-trial processing underlying learning, by employing nontraditional learning paradigms (De Houwer & Beckers, 2003;González-Martín, Cobos, Morís, & López, 2012;Le Pelley, Vadillo, & Luque, 2013;Vadillo & Matute, 2010;Waldmann & Walker, 2005), eyetracking Kruschke, Kappenman, & Hetrick, 2005;Le Pelley, Beesley, & Griffiths, 2011;Wills, Lavric, Croft, & Hodgson, 2007), and electroencephalography (Luque, López, Marco-Pallares, Càmara, & Rodríguez-Fornells, 2012;Morís, Luque, & Rodríquez-Fornells, 2013;Walsh & Anderson, 2011). These studies represent a refreshing alternative to the traditional input-output paradigm. ...
... One alternative approach for learning focuses on testing whether higher-order processes are critical to learning, by manipulating the availability of either time (González-Martín et al., 2012;Vadillo & Matute, 2010) or cognitive resources (De Houwer & Beckers, 2003;Waldmann & Walker, 2005). Though the introduction of such methodologies is refreshing, these specific findings yielded only ambiguous evidence for cognitively demanding processes in learning. ...
Many models of learning describe both the end product of learning (e.g., causal judgments) and the cognitive mechanisms that unfold on a trial-by-trial basis. However, the methods employed in the literature typically provide only indirect evidence about the unfolding cognitive processes. Here, we utilized a simultaneous secondary task to measure cognitive processing during a straightforward causal-learning task. The results from three experiments demonstrated that covariation information is not subject to uniform cognitive processing. Instead, we observed systematic variation in the processing dedicated to individual pieces of covariation information. In particular, observations that are inconsistent with previously presented covariation information appear to elicit greater cognitive processing than do observations that are consistent with previously presented covariation information. In addition, the degree of cognitive processing appears to be driven by learning per se, rather than by nonlearning processes such as memory and attention. Overall, these findings suggest that monitoring learning processes at a finer level may provide useful psychological insights into the nature of learning.
... Hence, we concluded that more empirical research is needed to reveal the moderators of this important effect. Notwithstanding that others before us had also hinted at the unreliability of blocking (e.g., Batson & Batsell, 2000;Beesley & Shanks, 2012;Blaser, Couvillon, & Bitterman, 2006;Guerrieri, Lachnit, Gerber, & Giurfa, 2005;LoLordo, Jacobs, & Foree, 1982;Taylor, Joseph, Balsam, & Bitterman, 2008;Vadillo & Matute, 2010;Yamada, 2010), our article spurred discussions on the status of the blocking effect (Skibba, 2016;Soto, in press;Urcelay, in press). ...
... Even though little work examined within-compound associations in the blocking design shortly after this work, other work has questioned the ubiquity of the blocking effect and revitalized this area of study. Although the blocking design is commonly thought to yield only cue competition, in some circumstances, the exact opposite result is possible (e.g., Batson & Batsell, 2000;Couvillon, Klosterhalfen, & Bitterman, 1983;Dickinson, Nicholas, & Mackintosh, 1983;Vadillo & Matute, 2010). For example, using flavor-aversion experiments, our laboratory has shown preconditioning one flavor (CS1) before compound conditioning of that CS1 along with a novel flavor (CS2) results in a significantly stronger aversion to CS2; an outcome that is the opposite of blocking and one that we have termed augmentation (e.g., Batsell & Batson, 1999). ...
In 3 experiments with rat subjects, we explored flavor-aversion learning across multiple conditioning stages. Experiment 1 was the first demonstration of taste-taste augmentation: Saccharin (SAC) preconditioning followed by compound conditioning of SAC + saline produced a significantly stronger saline aversion. Notably, taste-taste augmentation was recorded both when the 2 tastes were mixed together or presented separately during compound conditioning. Experiments 2A and 2B involved 3 conditioning phases to determine if an augmented flavor could subsequently augment a third flavor. Specifically, after Flavor 1 preconditioning, Flavors 1 and 2 were conditioned in compound, and then, Flavors 2 and 3 were conditioned in compound. This conditioning regimen yielded a significantly stronger aversion to Flavor 3, and this stronger aversion was not attributable to direct generalization from either Flavor 1 or Flavor 2. It appears that a given flavor can have multiple within-compound associations, and these associations can summate to produce a stronger conditioned response to a third taste.
... However, blocking is not always observed with this design. Furthermore, absence of blocking in humans is particularly likely when the humans are engaged in a cognitively demanding secondary task (DeHower and Beckers 2003;Vadillo and Matute 2010). For this reason, it is perhaps more prudent to conclude that both Hebbian and error-driven mechanisms are involved in associative learning and that prediction-making or learning from prediction error can be inhibited by placing demands on the relevant areas of the brain. ...
The great variability of morphological structure across languages makes it uncontroversial that morphology is learned. Yet, morphology presents formidable learning challenges, on par with those of syntax. This article takes a constructionist perspective in assuming that morphological constructions are a major outcome of the learning process. However, the existence of morphological paradigms in many languages suggests that they are often not the only outcome. The article reviews domain-general approaches to achieving this outcome. The primary focus is on mechanisms proposed within the associative/connectionist tradition, which are compared with Bayesian approaches. The issues discussed include the role of prediction and prediction error in learning, generative vs. discriminative learning models, directionality of associations, the roles of (unexpectedly) present vs. absent stimuli, general-to-specific vs. specific-to-general learning, and the roles of type and token frequency. In the process, the notion of a construction itself is shown to be more complicated that it first appears.
... Hence, we concluded that more empirical research is needed to reveal the moderators of this important effect. Notwithstanding that others before us had also hinted at the unreliability of blocking (e.g., Batson & Batsell, 2000;Beesley & Shanks, 2012;Blaser, Couvillon, & Bitterman, 2006;Guerrieri, Lachnit, Gerber, & Giurfa, 2005;LoLordo, Jacobs, & Foree, 1982;Taylor, Joseph, Balsam, & Bitterman, 2008;Vadillo & Matute, 2010;Yamada, 2010), our article spurred discussions on the status of the blocking effect (Skibba, 2016;Soto, in press;Urcelay, in press). ...
The blocking effect has inspired numerous associative learning theories and is widely cited in the literature. We recently reported a series of 15 experiments that failed to obtain a blocking effect in rodents. Based on those consistent failures, we claimed that there is a lack of insight into the boundary conditions for blocking. In his commentary, Soto (in press) argues that contemporary associative learning theory does provide a specific boundary condition for the occurrence of blocking, namely the use of same- versus different-modality stimuli. Given that in ten of our 15 experiments same-modality stimuli were used, he claims that our failure to observe a blocking effect is unsurprising. We cannot but disagree with that claim, because of theoretical, empirical, and statistical problems with his analysis. We also address two other possible reasons for a lack of blocking that are referred to in Soto’s (in press) analysis, related to generalization and salience, and dissect the potential importance of both. While Soto’s (in press) analyses raises a number of interesting points, we see more merit in an empirically guided analysis and call for empirical testing of boundary conditions on blocking.
... Lamentablemente el único estudio hasta la fecha que ha puesto a prueba esta predicción no ha conseguido encontrar este efecto (Beesley & Shanks, 2012). De hecho, estos experimentos sugieren que en la señalización contextual se puede encontrar lo contrario al efecto de bloqueo, un fenómeno poco habitual al que generalmente se conoce como aumentación (Batsell & Batson, 1999;Vadillo & Matute, 2010. Utilizando la nomenclatura anterior, este fenómeno tiene lugar cuando la presencia de los distractores A favorece (en lugar de impedir) que se aprenda sobre los distractores X. O dicho de otra manera, las diferentes claves que predicen dónde aparecerá el estímulo diana no compiten entre sí, sino que en realidad, cuanto más se aprende sobre algunas de ellas, más se aprende también sobre las otras. ...
... By a similar argument, if blocking occurred then we expect that the compound b2 & c1 should be seen as more likely to predict up than down. This second, compound measure increases the sensitivity of the experiment for detecting blocking (a sometimes elusive phenomenon; see Beesley & Shanks, 2012;Maes et al., 2016;Vadillo & Matute, 2010. ...
Blocking refers to the finding that less is learned about the relationship between a stimulus and an outcome if pairings are conducted in the presence of a second stimulus that has previously been established (via pretraining) as a reliable predictor of that outcome. Attentional models of associative learning suggest that blocking reflects a reduction in the attention paid to the blocked cue. We tested this idea in three experiments in which participants were trained in an associative learning task using a blocking procedure. Attention to stimuli was measured 250 ms after onset using an adapted version of the dot probe task. This task was presented at the beginning of each associative learning trial (Experiments 1 & 2) or in independent trials (Experiment 3). Each experiment found evidence of reduced attention to blocked stimuli as compared to pretrained stimuli, but no evidence of a corresponding difference in a control condition. In addition, this attentional bias correlated positively with the magnitude of blocking in associative learning, as measured by predictive-value judgments. Moreover, Experiments 2 and 3 found evidence of an influence of learning about predictiveness on memory for episodes involving stimuli. These findings are consistent with a central role of learned attentional biases in producing the blocking effect, and in the encoding of new memories. Although these attentional biases were likely created in an effortful way during learning, they exerted an influence on learning and memory very rapidly and independently of participants’ ongoing task goals.
... Similarly, rats tasked with predicting foot shocks became more responsive to a low salience auditory cue when it was presented together with a high salience auditory cue (Urcelay and Miller 2009). Similar cue facilitation effects have been found for humans when their cognitive resources are restricted (Vadillo and Matute 2010). All of these results suggest that the presence of salient cue can actually increase response to low salience cues, a cue facilitation effect. ...
New brands often partner with well-known brands under the assumption that they will benefit from the awareness and positive associations that well-known brands yield. However, this associations-transfer explanation may not predict co-branding results when the expected benefits of the co-branded product are presented simultaneously with the co-branding information. In this case, the results of co-branding instead follow the predictions of adaptive-learning theory which posits that consumers may differentially associate each brand with the outcome as a result of cue interaction effects. Three experiments show that the presence of a well-known brand can weaken or strengthen the association between the less-known brand and the co-branding outcome depending on the timing of the presentation of product benefit information. When this information was presented simultaneously with co-branding information (at a delay after co-branding information), the presence of a well-known brand weakened (strengthened) the association of the less-known brand with the outcome and thereby lowered (improved) evaluation of the less-known brand.
A fundamental assumption of learning theories is that the credit assigned to predictive cues is not simply determined by their probability of reinforcement, but by their ability to compete with other cues present during learning. This assumption has guided behavioral and neural science research for decades, and tremendous empirical and theoretical advances have been made identifying the mechanisms of cue competition. However, when learning conditions are not optimal (e.g., when training is massed), credit assignment is no longer competitive. This is a catastrophic failure of the learning system that exposes the individual's vulnerability to form spurious associations in the real world. Here, we uncover that cue competition can be rescued when conditions are suboptimal provided that the individual has agency over the learning experience. Our findings reveal a new connection between agency over learning and credit assignment to cues, and open new avenues of investigation into the underlying mechanisms.
Previous research on causal learning has usually made strong claims about the relative complexity and temporal priority of some processes over others based on evidence about dissociations between several types of judgments. In particular, it has been argued that the dissociation between causal judgments and trial-type frequency information is incompatible with the general cognitive architecture proposed by associative models. In contrast with this view, we conduct an associative analysis of this process showing that this need not be the case. We conclude that any attempt to gain a better insight on the cognitive architecture involved in contingency learning cannot rely solely on data about these dissociations. (PsycINFO Database Record (c) 2012 APA, all rights reserved).
A fundamental principle of learning is that predictive cues or signals compete with each other to gain control over behavior. Associative and propositional reasoning theories of learning provide radically different accounts of cue competition. Propositional accounts predict that under conditions that do not afford or warrant the use of higher order reasoning processes, cue competition should not be observed. We tested this prediction in 2 contextual cuing experiments, using a visual search task in which patterns of distractor elements predict the location of a target object. Blocking designs were used in which 2 sets of predictive distractors were trained in compound, with 1 set trained independently. There was no evidence of cue competition in either experiment. In fact, in Experiment 2, we found evidence for augmentation of learning. The findings are contrasted with the predictions of an error-driven associative model of contextual cuing (Brady & Chun, 2007).
We hypothesized that attitudes characterized by a strong association between the attitude object and an evaluation of that object are capable of being activated from memory automatically upon mere presentation of the attitude object. We used a priming procedure to examine the extent to which the mere presentation of an attitude object would facilitate the latency with which subjects could indicate whether a subsequently presented target adjective had a positive or a negative connotation. Across three experiments, facilitation was observed on trials involving evaluatively congruent primes (attitude objects) and targets, provided that the attitude object possessed a strong evaluative association. In Experiments 1 and 2, preexperimentally strong and weak associations were identified via a measurement procedure. In Experiment 3, the strength of the object-evaluation association was manipulated. The results indicated that attitudes can be automatically activated and that the strength of the objectevaluation association determines the likelihood of such automatic activation. The implications of these findings for a variety of issues regarding attitudes—including their functional value, stability, effects on later behavior, and measurement—are discussed.
Review of the literature indicates that, according to theories of selective attention, learning about a stimulus depends on attending to that stimulus; this is represented in 2-stage models by saying that Ss switch in analyzers as well as learning stimulus-response associations. It is argued that this assumption, however, is equally well represented in a formal model by the incorporation of a stimulus-specific learning-rate parameter, a, into the equations describing changes in the associative strength of stimuli. Previous theories of selective attention have also assumed that (a) Ss learn to attend to and ignore relevant and irrelevant stimuli (i.e., that a may increase or decrease depending on the correlation of a stimulus with reinforcement); and (b) there is an inverse relationship between the probabilities of attending to different stimuli (i.e., that an increase in a to one stimulus is accompanied by a decrease in a to others). The first assumption has been used to explain the phenomena of acquired distinctiveness and dimensional transfer, the second to explain those of overshadowing and blocking. It is argued that although the first assumption is justified by the data, the second is not: Overshadowing and blocking are better explained by the choice of an appropriate rule for changing a, such that a decreases to stimuli that signal no change from the probability of reinforcement predicted by other stimuli. (65 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)
The present experiments addressed a fundamental discrepancy in the Pavlovian conditioning literature concerning responding to a target cue following compound reinforced training with another cue of higher salience. Experiment 1 identified one determinant of whether the target cue will be overshadowed or potentiated by the more salient cue, namely contiguity between compound CS termination and US presentation. Overshadowing and potentiation were observed with delay and trace procedures, respectively. Experiments 2 and 3 contrasted elemental and configural explanations of potentiation. Both experiments supported a configural account. Experiments 3 and 4, by manipulating prior learning experiences to bias subjects to encode the same compound elementally or configurally, demonstrated decreased potentiation and overshadowing, respectively. Overall, these experiments demonstrate potentiation with nontaste stimuli and identify one variable that determines whether overshadowing or potentiation will occur. Moreover, they show that prior experiences can determine how a compound is encoded and are compatible with the idea of flexible encoding as a principle of information processing.
Associative learning effects can be defined as changes in behavior that are due to relations between events in the world. Most often, these effects are explained in terms of the formation of unqualified associations in memory. I describe an alternative theoretical explanation, according to which associative learning effects are the result of the nonautomatic generation and evaluation of propositions about relations between events. This idea is supported by many studies showing that associative learning effects are determined not only by the direct experience of events but also by prior knowledge, instructions, intervention, and deductive reasoning. Moreover, evidence supports the assumption that associative learning effects depend on nonautomatic processes. Whereas a propositional approach thus offers many new insights, questions can be raised about what the idea of association formation adds to our understanding of associative learning.
Most studies of human contingency judgment have been based on the assumption that frequency information about one predictor is assessed in isolation of information about other predictors. Recent evidence, however, suggests that the judged predictive strength of one cue is influenced by the predictive strengths of other copresent cues. Two experiments demonstrate that stimuli with the same outcome contingencies may nonetheless have different predictive strengths as the result of cue interaction. The first experiment, in which a within-subject design was used, provides a demonstration of blocking. A stimulus presented in compound with a strong predictor was rated as less predictive than another stimulus that was presented in compound with a nonpredictive cue. In the second experiment, cue interactions in conditioned inhibition were examined. A stimulus gained negative predictive strength as the result of compound presentations with a positive predictor when the outcome was not presented. This negative predictor was compared with an otherwise analogous stimulus that was not presented in compound with a positive predictor. These results support the use of animal-conditioning models as accounts of human contingency learning.
We hypothesized that attitudes characterized by a strong association between the attitude object and an evaluation of that object are capable of being activated from memory automatically upon mere presentation of the attitude object. We used a priming procedure to examine the extent to which the mere presentation of an attitude object would facilitate the latency with which subjects could indicate whether a subsequently presented target adjective had a positive or a negative connotation. Across three experiments, facilitation was observed on trials involving evaluatively congruent primes (attitude objects) and targets, provided that the attitude object possessed a strong evaluative association. In Experiments 1 and 2, preexperimentally strong and weak associations were identified via a measurement procedure. In Experiment 3, the strength of the object-evaluation association was manipulated. The results indicated that attitudes can be automatically activated and that the strength of the object-evaluation association determines the likelihood of such automatic activation. The implications of these findings for a variety of issues regarding attitudes--including their functional value, stability, effects on later behavior, and measurement--are discussed.
REPORTS 3 EXPERIMENTS, INVOLVING BOTH INSTRUMENTAL AND CLASSICAL CONDITIONING PROCEDURES IN RATS AND RABBITS. IN EACH CASE A PARTIALLY REINFORCED CUE WAS FOUND TO BE A LESS EFFECTIVE STIMULUS IN ISOLATION WHEN IT HAD BEEN EXPERIENCED AS A COMMON CUE IN COMPOUNDS CONTAINING ELEMENTS MORE HIGHLY CORRELATED WITH REINFORCEMENT, THAN WHEN IT HAD BEEN EXPERIENCED IN SIMILAR COMPOUNDS WHICH DID NOT CONTAIN SUCH ELEMENTS. THE FINDINGS ARE MORE READILY INTERPRETABLE IN TERMS OF THOSE THEORIES WHICH INCORPORATE A BASIC STIMULUS-SELECTION PROCESS, THAN IN TERMS OF SIMPLE CONDITIONING-EXTINCTION THEORY. (17 REF.) (PsycINFO Database Record (c) 2006 APA, all rights reserved).
We investigated a phenomenon called judgmental overshadowing. Subjects predicted whether each of several patients had a disease on the basis of whether or not the patient had each of two symptoms. For all the subjects, the presence of the disease was moderately contingent on the presence of one of the symptoms (S1). In Condition 1 of our first experiment, the presence of the disease was highly contingent on the presence of the other symptom (S2). In Condition 2, the presence of the disease was independent of S2. Judgmental overshadowing occurred in that the S1-disease contingency was judged to be stronger in Condition 2 than in Condition 1. Subsequent experiments showed that judgmental overshadowing depends little on the form of the judgment, is not due to a response bias or contrast effect, and does not depend on subjects' actively diagnosing each patient. These results are consistent with, and are generally predicted by, an associative-learning model of contingency judgment.
The research reported in this article replicated the well-established phenomenon of competition between causes (C) as well as the more controversial presence and absence of competition between effects (E). The test question was identified as a crucial factor leading to each outcome. Competition between causes was obtained when the test question asked about the probability of E given C, p(E/C), implicitly compared with the probability of E given some alternative cause, p(E/C'). competition between effects was obtained when the test question asked about p(C/E) implicitly compared with p(C/E'). Under these conditions, effects competed for diagnostic value just as causes competed for predictive value. Additionally, some conditions in which neither causes nor effects competed were identified. These results suggest a bidirectional and noncompetitive learning process, the contents of which can be used in different ways (competitively or noncompetitively and forward or backward) as a function of test demands.
When two causes for a given effect are simultaneously presented, it is natural to expect an effect of greater magnitude. However many laboratory tasks preclude such an additivity rule by imposing a ceiling on effect magnitude-for example, by using a binary outcome. Under these conditions, a compound of two causal cues cannot be distinguished from a compound of one causal cue and one noncausal cue. Two experiments tested the effect of additivity on cue competition. Significant but weak forward blocking and no backward blocking were observed in a conventional "allergy" causal judgment task. Explicit pretraining of magnitude additivity produced strong and significant forward and backward blocking. Additivity pretraining was found to be unnecessary for another cue competition effect, release from overshadowing, which does not logically depend on additivity. The results confirm that blocking is constrained when effect magnitude is constrained and provide support for an inferential account of cue competition.
Three experiments sought to develop the suggestion that, under some circumstances, common associative learning mechanisms might underlie animal conditioning and human causal learning, by demonstrating, in humans, an effect analogous to the unblocking by reinforcer omission observed in animal conditioning. Experiment 1 found no such effect. Experiment 2, designed to prevent inhibitory influences that might have masked excitatory unblocking in Experiment 1, demonstrated unblocking, indicating common human-animal associative learning mechanisms in which the associability of a stimulus varies as a function of its predictive history. Experiment 3, using a similar design but with a procedure promoting application of rational inference processes, failed to detect the same unblocking effect, indicating that associative and cognitive mechanisms may influence human causal learning.
When people judge the contingency between atarget cue and an outcome, they also take into account the contingency between the outcome and other cues with which the target cue co-occurred. Several authors have argued that such cue competition effects are due to higher order reasoning processes. We review the evidence that supports this hypothesis and discuss whether higher order reasoning might also play a role in other learning phenomena.
The dominant theoretical approach to causal learning postulates the acquisition of associative weights between cues and outcomes. This reduction of causal induction to associative learning implies that learners are insensitive to important characteristics of causality, such as the inherent directionality between causes and effects. An ongoing debate centers on the question of whether causal learning is sensitive to causal directionality (as is postulated by causal-model theory) or whether it neglects this important feature of the physical world (as implied by associationist theories). Three experiments using different cue competition paradigms are reported that demonstrate the competence of human learners to differentiate between predictive and diagnostic learning. However, the experiments also show that this competence displays itself best in learning situations with few processing demands and with convincingly conveyed causal structures. The study provides evidence for the necessity to distinguish between competence and performance in causal learning.
Three experiments examined human processing of stimuli as predictors and causes. In Experiments 1A and 1B, two serial events that both preceded a third were assessed as predictors and as causes of the third event. Instructions successfully provided scenarios in which one of the serial (target) stimuli was viewed as a strong predictor but as a weak cause of the third event. In Experiment 2, participants' preexperimental knowledge was drawn upon in such a way that two simultaneous antecedent events were processed as predictors or causes, which strongly influenced the occurrence of overshadowing between the antecedent events. Although a tendency toward overshadowing was found between predictors, reliable overshadowing was observed only between causes, and then only when the test question was causal. Together with other evidence in the human learning literature, the present results suggest that predictive and causal learning obey similar laws, but there is a greater susceptibility to cue competition in causal than predictive attribution.
In three experiments, we show that people respond differently when they make predictions as opposed to when they are asked to estimate the causal or the predictive value of cues: Their response to each of those three questions is based on different sets of information. More specifically, we show that prediction judgments depend on the probability of the outcome given the cue, whereas causal and predictive-value judgments depend on the cue-outcome contingency. Although these results might seem problematic for most associative models in their present form, they can be explained by explicitly assuming the existence of postacquisition processes that modulate participants' responses in a flexible way.
Associative and causal reasoning accounts are probably the two most influential types of accounts of causal reasoning processes. Only causal reasoning accounts predict certain asymmetries between predictive (i.e., reasoning from causes to effects) and diagnostic (i.e., reasoning from effects to causes) inferences regarding cue-interaction phenomena (e.g., the overshadowing effect). In the experiments reported here, we attempted to delimit the conditions under which these asymmetries occur. The results show that unless participants perceived the relevance of causal information to solving the task, predictive and diagnostic inferences were symmetrical. Specifically, Experiments 1A and 1B showed that implicitly stressing the relevance of causal information by having participants review the instructions favored the presence of asymmetries between predictive and diagnostic situations. In addition, Experiment 2 showed that explicitly stressing the relevance of causal information by stating the importance of the causal role of events after the instructions were given also favored the asymmetry.
Studies performed by different researchers have shown that judgements about cue-outcome relationships are systematically influenced by the type of question used to request those judgements. It is now recognized that judgements about the strength of the causal link between a cue and an outcome are mostly determined by the cue-outcome contingency, whereas predictions of the outcome are more influenced by the probability of the outcome given the cue. Although these results make clear that those different types of judgement are mediated by some knowledge of the normative differences between causal estimations and outcome predictions, they do not speak to the underlying processes of these effects. The experiment presented here reveals an interaction between the type of question and the order of trials that challenges standard models of causal and predictive learning that are framed exclusively in associative terms or exclusively in higher order reasoning terms. However, this evidence could be easily explained by assuming the combined intervention of both types of process.
When people try to obtain a desired event and this outcome occurs independently of their behavior, they often think that they are controlling its occurrence. This is known as the illusion of control, and it is the basis for most superstitions and pseudosciences. However, most experiments demonstrating this effect had been conducted many years ago and almost always in the controlled environment of the psychology laboratory and with psychology students as subjects. Here, we explore the generality of this effect and show that it is still today a robust phenomenon that can be observed even in the context of a very simple computer program that users try to control (and believe that they are controlling) over the Internet. Understanding how robust and general this effect is, is a first step towards eradicating irrational and pseudoscientific thinking.
The inverse base-rate effect in categorization (Medin & Edelson, 1988) arises when participants assign an ambiguous stimulus to a category that occurred less frequently than an alternative category, against the principles of Bayesian decision making. In the experiment reported in this article, rule-based and attention-shifting accounts of the inverse base-rate effect were evaluated. Participants completed a categorization task, known to produce the inverse base-rate effect, under standard conditions, under time pressure, and with a secondary task load. The inverse base-rate effect persisted under severe time pressure and under secondary task load. The results provided no evidence for the role of rule-based processes in producing the inverse base-rate effect. The data from the experiment are compatible with an attention-shifting account.
Are human contingency judgments based on associationistic principles such as cue competition or on normative principles as specified by rational-cognitive models? In this study, participants learned to predict an outcome from several simultaneously presented cues. They were asked to judge the cues in regard to causal power or statistical concepts such as probability or relative frequency. Uniform application of associationistic principles implies cue-interaction effects of blocking (Experiment 1) and conditioned inhibition (Experiment 2) for all judgments. A rational-cognitive framework predicts cueinteraction effects for causality judgments, but not for probability and relative frequency judgments. The results support the rational-cognitive framework on all accounts.
Ciiven the task of di the source of a patient's aUer^'ic reav-tion. college students jiuigcii the causal efficacy of common (A') and distinctive (A and Bj elements of compound stimuli: AX and BX. As the differential correlation of AX and BX with the occurrence and nonoccurrence ofthe allergic reaction rose from .00 to 1.00. ratings of ihe distinctive A and B elements diverged; most importantly, ratings ofthe common X element fell. These causal judgments of humans closely parallel the conditioned responses of animals in associa-tive learning studies, and clearly disclose that stimuli compete with one another for control over behavior.
In the first experiment subjects were presented with a number of sets of trials on each of which they could perform a particular action and observe the occurrence of an outcome in the context of a video game. The contingency between the action and outcome was varied across the different sets of trials. When required to judge the effectiveness of the action in controlling the outcome during a set of trials, subjects assigned positive ratings for a positive contingency and negative ratings for a negative contingency. Furthermore, the magnitude of the ratings was related systematically to the strength of the actual contingency. With a fixed probability of an outcome given the action, judgements of positive contingencies decreased as the likelihood that the outcome would occur without the action was raised. Correspondingly, the absolute value of ratings of negative contingencies was increased both by an increment in the probability of the outcome in the absence of the action and by a decrement in the probability of the outcome following the action. A systematic bias was observed, however, in that positive judgements were given under a non-contingent relationship when the outcome frequency was relatively high. However, this bias could be reduced by giving extended exposure to the non-contingent schedule (Experiment 2).
This pattern of contingency judgements can be explained if it is assumed that a process of selective attribution operates, whereby people are less likely to attribute an outcome to some potential target cause if another effective cause is present. Experiments 2 and 3 demonstrated the operation of this process by showing that initially establishing another agent as an effective cause of the outcome subsequently reduced or blocked the extent to which the subjects attributed the outcome to the action.
Finally, we argue that the pattern and bias in contingency judgements based upon interactions with a causal process can be explained in terms of contemporary conditioning models of associative learning.
Despite the many demonstrations of blocking in animals, there is still little evidence of blocking with human subjects, which is problematic for general learning and behavior theory. The purpose of this research was to examine blocking with human subjects using a design and behavioral procedure (conditioned suppression) similar to those commonly used in animal research. First, subjects learned an operant task. Later, they were instructed to suppress responding when a visual US was presented. Two Pavlovian acquisition phases and a test phase occurred while the subjects were performing the operant task. In the first Pavlovian phase, CS A predicted the US for the experimental group, but was uncorrelated with the US for the control group. In the second Pavlovian phase, a compound CS AX predicted the US for both groups. At test, CS X was presented to all subjects and suppression ratios were assessed. Experimental subjects suppressed responding in the presence of CS X less than did control subjects, thereby demonstrating a blocking effect. This research, in demonstrating blocking in humans, adds to the known similarities in animal and human behavior.
The influence of a secondary task on forward blocking of human contingency ratings was examined. A smaller blocking effect was found when participants performed a highly demanding secondary task than when they performed a less demanding secondary task. The modulatory effect of secondary task difficulty was significant only when the secondary task was administered during both the learning and the test phase of the contingency judgement task. The results suggest that forward blocking in human contingency learning cannot be fully accounted for by associative processes. Instead, forward blocking seems to depend at least partially on deliberate deductive reasoning processes.
Several researchers have recently claimed that higher order types of learning, such as categorization and causal induction, can be reduced to lower order associative learning. These claims are based in part on reports of cue competition in higher order learning, apparently analogous to blocking in classical conditioning. Three experiments are reported in which subjects had to learn to respond on the basis of cues that were defined either as possible causes of a common effect (predictive learning) or as possible effects of a common cause (diagnostic learning). The results indicate that diagnostic and predictive reasoning, far from being identical as predicted by associationistic models, are not even symmetrical. Although cue competition occurs among multiple possible causes during predictive learning, multiple possible effects need not compete during diagnostic learning. The results favor a causal-model theory.
Five experiments investigated the development of aversions to stimuli with strong odor components. Those odors were presented simultaneously with tastes are followed by lithium chloride. Contrary to expectations derived from previous investigations of compound conditioning, the presence of a taste stimulus at the time of conditioning was found to potentiate rather than overshadow the resulting odor aversions. Explanations in terms of either the taste's unconditioned aversiveness or nonassociative effects were found to be inadequate. An alternative interpretation attributing potentiation to the summed effects of within-compound odor-taste associations and odor-unconditioned stimulus associations was suggested. In agreement with such an interpretation, evidence of odor-taste associations was found in this situation. Furthermore, continued aversiveness of the taste was necessary for potentiation of the odor aversion to occur. An account of potentiation in terms of within-compound associations makes the phenomenon compatible with modern theories of Pavlovian associations.
The 1st part of this article evaluates the extent to which 2 elemental theories of conditioning, stimulus sampling theory and the Rescorla-Wagner (1972) theory, are able to account for the influence of similarity on discrimination learning. A number of findings are reviewed that are inconsistent with predictions derived from these theories, either in their present form or in various modified forms. The 2nd part of the article is concerned with developing an alternative, configural account for discrimination learning. In contrast to previous configural theories, the present version is set within the framework of a connectionist network.
Five experiments explored facilitated taste-aversion conditioning (odor-mediated taste augmentation), using rats that experienced odor (A) and taste (X) in an A+/AX+ design. Augmentation occurred when the stimuli were presented simultaneously during AX+ conditioning, and significantly weaker conditioning occurred after a sequential presentation (Experiment 1). Experiments 2 and 3 demonstrated that augmented conditioning decreased if the odor aversion was reduced through preexposure or extinction following A+ conditioning. A second-order conditioning explanation was not supported by the results of Experiment 4. Experiment 5 showed that extinction of the odor aversion after AX+ conditioning did not alter the strength of the augmented taste aversion. Odor-mediated taste augmentation is similar to potentiation, in which odor and taste cues operate in a synergistic, not competitive, manner.
An A+/AX+ Pavlovian conditioning design typically produces weakened or blocked conditioning to stimulus X. Two experiments were conducted in which rats first received an odor (A+) paired with an emetic US, and then received odor and taste (AX+) paired with the US. In both experiments, the preconditioned odor facilitated conditioning to the taste. In Experiment 1, a group that received two odor-illness pairings in A+ conditioning had a stronger taste aversion than a group that only had a single odor-illness pairing. Experiment 2 demonstrated that the strengthened taste aversion in the A+/AX+ condition was not due to stimulus generalization. The results represent a unique outcome in the flavor-aversion literature that is similar to potentiation. We propose that this facilitated conditioning to X in the A+/AX+ design be termed augmentation.
On the basis of previous work that has shown a taste can potentiate odor-aversion conditioning in AX+ conditioning, 6 experiments used rats to examine the effects of pairing a preconditioned taste (A) with a novel odor cue (X) in an A+/AX+ aversion conditioning design. Experiments 1A and 1B demonstrated that a preconditioned taste produced a robust odor aversion that was significantly stronger than a potentiated odor aversion. The results of Experiment 2 showed that the robust odor aversion produced by A+/AX+ conditioning was not the result of the potentiated odor aversion summating with generalization from the taste aversion. The augmented odor aversion was produced only when the taste and odor stimuli were presented simultaneously (Experiment 3) and the preconditioned taste aversion was intact at compound conditioning (Experiment 4). Pairing a novel odor with a preconditioned taste was not sufficient to condition an aversion to odor (Experiment 5), although other results implicated a role for an association between odor and taste in the odor augmentation effect (Experiment 6). The present results have implications for current models of taste + odor interactions in flavor-aversion conditioning.
A configural theory of associative learning is described that is based on the assumption that conditioning results in associations between the unconditioned stimulus and a representation of the entire pattern of stimulation that was present prior to its delivery. Configural theory was formulated originally to account for generalization and discrimination in Pavlovian conditioning. The first part of the article demonstrates how this theory can be used to explain results from studies of overshadowing, blocking, summation, and discrimination learning. The second part of the article shows how the theory can be developed to explain a broader range of phenomena, including mediated conditioning, reinforcer devaluation effects, the differential outcomes effect, acquired equivalence, sensory preconditioning, and structural discriminations.
Participants saw a series of situations in which a cue (a light appearing at a certain position) could be followed by an outcome (a drawing of a tank that exploded) and were afterwards asked to rate the likelihood of the outcome in the presence of the cue. In Experiments 1 and 2, the compound cues AT and KL were always followed by the outcome (AT+, KL+). During an elemental phase that either preceded or followed the compound phase, Cue A was also paired with the outcome (A+). Cue T elicited a lower rating than Cues K and L when cues were described as being weapons but not when the cues were said to be indicators. The magnitude of this blocking effect was also influenced by whether the outcome occurred to a maximal or submaximal extent. Experiment 3 replicated the effect of cue instructions on blocking (A+, AT+) but showed that cue instructions had no impact on reduced overshadowing (B-, BT+). The results shed new light on previous findings and support probabilistic contrast models of human contingency judgements.
In an allergist causal-judgment task, food compounds were followed by an allergic reaction (e.g., AB+), and then 1 cue (A) was revalued. Experiment 1, in which participants who were instructed that whatever was true about one element of a causal compound was also true of the other, showed a reverse of the standard retrospective revaluation effect. That is, ratings of B were higher when A was causal (A+) than when A was safe (A-). This effect was taken to reflect inferential reasoning, not an associative mechanism. In Experiment 2, within-compound associations were found to be necessary to produce this inference-based revaluation. Therefore, evidence that within-compound associations are necessary for retrospective revaluation is consistent with the inferential account of causal judgments.
In a contingency learning task, 4-year-old and 8-year-old children had to predict the outcome displayed on the back of a card on the basis of cues presented on the front. The task was embedded in either a causal or a merely predictive scenario. Within this task, either a forward blocking or a backward blocking procedure was implemented. Blocking occurred in the causal but not in the predictive scenario. Moreover, blocking was affected by the scenario to the same extent in both age groups. The pattern of results was similar for forward and backward blocking. These results suggest that even young children are sensitive to the causal structure of a contingency learning task and that the occurrence of blocking in such a task defies an explanation in terms of associative learning theory.
The present study aimed to replicate an associative learning effect, overshadowing, both in the traditional laboratory conditions and over the internet. The experimental task required participants to predict an outcome based on the presence of several cues. When a cue that was always trained together with a second cue was presented on isolation at test, the expectancy of the outcome was impaired, which revealed overshadowing. This experimental task was performed by undergraduate students (N=106) in the laboratory and by a different set of anonymous participants over the internet (N=91). Similar levels of overshadowing were obtained in both locations. These similarities show that web-delivered experiments can be used as a complement of traditional experiments.
It has been suggested that causal learning in humans is similar to Pavlovian conditioning in animals. According to this view, judgments of cause reflect the degree to which an association exists between the cause and the effect. Inferential accounts, by contrast, suggest that causal judgments are reasoning based rather than associative in nature. We used a direct measure of associative strength, identification of the outcome with which a cause was paired (cued recall), to see whether associative strength translated directly into causal ratings. Causal compounds AB+ and CD+ were intermixed withA+ and C- training. Cued-recall performance was better for cue B than for cue D; thus, associative strength was inherited by cue B from the strongly associated cue A (augmentation). However, the reverse was observed on the causal judgment measure: Cue B was judged to be less causal than D (cue competition). These results support an inferential over an associative account of causal judgments.
In two "allergist" causal judgement experiments, participants were trained with a blocking design (A+|AB+). The procedure allowed different food cues to be paired with different fictitious allergic reactions. On test, participants were asked to rate the causal efficacy of the target cues and to recall the particular allergic reaction (outcome) that had followed each cue during training. Forward blocking was observed on the causal judgement measure and on the outcome recall measure in both Experiment 1 and Experiment 2. A backward blocking contingency was also trained in Experiment 2 (AB+|A+). Backward blocking was not observed either on the causal judgement or on the outcome recall measure. The evidence from the recall measure suggests that forward blocking in this task results from a failure to encode the B-outcome relationship during training. Associative and nonassociative mechanisms of forward blocking are discussed.
Associative accounts uniquely predict that second-order conditioning might be observed in human predictive judgements. Such an effect was found for cue X in two experiments in which participants were required to predict the outcomes of a series of training trials that included P + and PX-, but only when training was paced by requiring participants to make a prediction within 3 s on each trial. In Experiment 1 training on P + ended before training was given on PX - . In Experiment 2 trials with P+, PX-, T + and other cues were intermixed. In the unpaced group inhibitory learning was revealed by a summation test, TX versus TM, where M was a control stimulus. These results suggest either that pacing interferes with learning successive associations more than with learning simultaneous associations or that lack of time to think interferes with inferential processes required for this type of inhibitory learning.
The associative view of human causal learning argues that causation is attributed to the extent that the putative cause activates, via an association, a mental representation of the effect. That is, causal learning is a human analogue of animal conditioning. We tested this associative theory using a task in which a fictitious character suffered from two allergic reactions, rash (O1) and headache (O2). In a conditioned inhibition design with each of these two outcomes (A-O1/AX- and B-O2/BY-), participants were trained that one herbal remedy (X) prevented O1 and that the other (Y) prevented O2. These inhibitory properties were revealed in a causal judgement summation test. In a subsequent categorization task, X was most easily categorized with O1, and Y with O2. Thus, the categorization data indicated an excitatory X-O1 and Y-O2 association, the reverse of the inhibitory relationship observed on the causal judgement measure. A second experiment showed that this pattern of excitation and inhibition is dependent on intermixed A-O1 and AX- trials. These results are problematic for the standard application of associative activation theories to causal judgement. We argue instead that the inhibition revealed in the causal judgement task reflects inferential reasoning, which relies, in part, on the ability of the cue in question to excite a representation of the outcome, as revealed in the categorization test.
Cue competition is one of the most studied phenomena in associative learning. However, a theoretical disagreement has long stood over whether it reflects a learning or performance deficit. The comparator hypothesis, a model of expression of Pavlovian associations, posits that learning is not subject to competition but that performance reflects a complex interaction of encoded associative strengths. That is, subjects respond to a cue to the degree that it signals a change in the likelihood or magnitude of reinforcement relative to that in the cue's absence. Initially, this performance-focused view was supported by studies showing that posttraining revaluation of a competing cue often influences responding to the target cue. However, recently developed learning-focused accounts of retrospective revaluation have revitalized the debate concerning cue competition. Further complicating the picture are phenomena of cue facilitation, which have been addressed less frequently than cue competition by formal models of conditioning of either class. The authors present a formalization and extension of the comparator hypothesis, which results in sharpened differentiation between it and the new learning-focused models.
The present article presents a response rule developed to account for both positive and negative stimulus interaction. In the response rule proposed here, positive interaction phenomena (e.g., second-order conditioning) and negative interaction phenomena (e.g., Pavlovian conditioned inhibition) are presumed to occur during performance and acquisition, respectively. Also, in this rule the novelty of the test stimulus determines the expression of positive interaction on responding. As the stimulus loses its novelty over training, positive interaction effects will wane, which will allow negative interaction effects to emerge in responding elicited by the stimulus. It is proposed that this response rule can be adopted by acquisition-focused associative models (e.g., Rescorla & Wagner, 1972) in order to account for contrary associative phenomena in the literature. The simulation program used in this study is available for download from the author's website and from the Psychonomic Society website at www.psychonomic.org/archive.
Taste preconditioning augments odor-aversion learning Augmentation under time pressure 587 rBatson Augmentation, not blocking, in an A þ /AX þ flavour-conditioning procedure
- W R Batsell
- Jr
- G Y Paschall
- D I Gleason
- J D Batson
Batsell, W. R., Jr., Paschall, G. Y., Gleason, D. I., & Batson, J. D. (2001). Taste preconditioning augments odor-aversion learning. Journal of Experimental Psychology: Animal Behavior Processes, 27, 30–47. Augmentation under time pressure 587 rBatson, J. D., & Batsell, W. R., Jr. (2000). Augmentation, not blocking, in an A þ /AX þ flavour-conditioning procedure. Psychonomic Bulletin and Review, 7, 466–471
Outcome and cue properties modulate blocking rAugmentation under time-pressure 17 De Houwer Evidence for the role of higher order reasoning processes in cue competition and other learning phenomena
- De Houwer
- J Beckers
- T Glautier
De Houwer, J., Beckers, T., & Glautier, S. (2002). Outcome and cue properties modulate blocking. Quarterly Journal of Experimental Psychology, 55A, 965-985. rAugmentation under time-pressure 17 De Houwer, J., Beckers, T., & Vandorpe, S. (2005). Evidence for the role of higher order reasoning processes in cue competition and other learning phenomena. Learning & Behavior, 33, 239-249
Reproduction in any form (including the internet) is prohibited without prior permission from the Society Augmentation, not blocking, in an A þ /AX þ flavour-conditioning procedure
- J D Batson
- W R Batsell
- Jr
Copyright © The British Psychological Society Reproduction in any form (including the internet) is prohibited without prior permission from the Society Batson, J. D., & Batsell, W. R., Jr. (2000). Augmentation, not blocking, in an A þ /AX þ flavour-conditioning procedure. Psychonomic Bulletin and Review, 7, 466–471.
Cue-interaction effects in human contingency learning are modulated by the availability of time to think
- M A Vadillo
- H Matute
Vadillo, M. A., & Matute, H. (2007a, July). Cue-interaction effects in human contingency learning are modulated by the availability of time to think. Joint Meeting of the Experimental Psychology Society and the Psychonomic Society, Edinburgh.
Reproduction in any form (including the internet) is prohibited without prior permission from the Society Mitchell, C A dissociation between causal judgement and the ease with which a cause is categorized with its effect
- E J Livesey
- P F Lovibond
Copyright © The British Psychological Society Reproduction in any form (including the internet) is prohibited without prior permission from the Society Mitchell, C. J., Livesey, E., & Lovibond, P. F. (2007). A dissociation between causal judgement and the ease with which a cause is categorized with its effect. Quarterly Journal of Experimental Psychology, 60, 400–417.
The implicit association test as a measure of acquired associative strength between cause and effect in human causal learning. Paper presented at the XVIII Annual Meeting of the Spanish Society for Comparative Psychology
- S Vandorpe
- J Houwer
Vandorpe, S., & De Houwer, J. (2006, September). The implicit association test as a measure of acquired associative strength between cause and effect in human causal learning. Paper presented at the XVIII Annual Meeting of the Spanish Society for Comparative Psychology, Má, Spain.