Inference-based retrospective revaluation in human causal judgments requires knowledge of within-compound relationships

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.     

Within-compound associations in retrospective revaluation and in direct learning: A challenge for comparator theory

In three human causal learning experiments we investigated the role of within-compound associations in learning about absent cues versus learning about present cues. Different theoretical approaches agree that within-compound associations are essential for learning about absent cues-that is, for retrospective revaluation. They differ, however, with regard to the role of within-compound associations for learning about present cues-that is, for direct learning. A memory test was used to assess within-compound associations. Experiment 1 used a blocking/release from overshadowing design, Experiment 2 used a conditioned inhibition design, and Experiment 3 used a higher-order cue selection design. In all experiments, first-order retrospective revaluation was significantly correlated with within-compound associations, but no significant correlations were found for the direct learning conditions. In addition to this, second-order retrospective revaluation in Experiment 3 was positively correlated to joint knowledge of first-order and second-order within-compound associations. Furthermore, cue selection effects were stronger for direct learning conditions than for retrospective learning conditions. These results are at variance with the comparator hypothesis but are in agreement with a modified associative theory and with the suggestion that retrospective revaluation might be due to rehearsal processes.     

Associative history affects the associative change undergone by both presented and absent cues in human causal learning

R. A. Rescorla (2000) noted that a number of influential theories of associative learning do not take the associative history of cues (i.e., the prior training that they have received) into account when calculating the associative change undergone by those cues. The authors tested this assumption in a human causal learning paradigm and found associative history to be an important determinant of the learning undergone by cues that are presented on a trial. Moreover, associative history was also found to influence the amount of retrospective revaluation undergone by absent cues. These findings conflict with models of causal learning in which the associative change undergone by an element of a cue compound is governed by a summed error term (e.g., R. A. Rescorla & A. R. Wagner, 1972).     

Re-examination of the role of within-compound associations in the retrospective revaluation of causal judgements

We investigated blocking and retrospective revaluation of causal judgements using a scenario in which food cues acted as potential causes of an allergic reaction as the outcome. In the blocking contingency,the treatment cues were either paired or unpaired with the outcome prior to a second stage in which sequential compounds of treatment and target cues were paired with the outcome. The order of this compound and treatment training was reversed in retrospective revaluation contingencies. When the interstimulus interval between the treatment and target cues was unfilled on compound trials (Experiments 1 and 3), both blocking and retrospective revaluation were observed in that the target cue trained in compound with the paired treatment cue attracted lower causal ratings than the target cue trained in compound with the unpaired treatment cue. By contrast, performing a mental arithmetic task using numerals presented during the interstimulus interval had no effect on the magnitude of blocking but rendered retrospective revaluation unreliable (Experiments 2 and 3). These results provide further support for accounts of revaluation based upon within-compound associations.     

A comparison between elemental and compound training of cues in retrospective revaluation

Associative learning theories assume that cue interaction and, specifically, retrospective revaluation occur only when the target cue is previously trained in compound with the to-be-revalued cue. However, there are recent demonstrations of retrospective revaluation in the absence of compound training (e.g., Matute & Pine?o, 1998a, 1998b). Nevertheless, it seems reasonable to assume that cue interaction should be stronger when the cues are trained together than when they are trained apart. In two experiments with humans, we directly compared compound and elemental training of cues. The results showed that retrospective revaluation in the elemental condition can be as strong as and, sometimes, stronger than that in the compound condition. This suggests that within-compound associations are not necessary for retrospective revaluation to occur and that these effects can possibly be best understood in the framework of general interference theory.     

Causal Learning: Association Versus Computation

Causal learning enables humans and other animals not only to predict important events or outcomes, but also to control their occurrence in the service of needs and desires. Computational theories assume that causal judgments are based on an estimate of the contingency between a causal cue and an outcome. However, human causal learning exhibits many of the characteristics of the associative learning processes thought to underlie animal conditioning. One problem for associative theory arises from the finding that judgments of the causal power of a cue can be revalued retrospectively after learning episodes when that cue is not present. However, if retrieved representations of cues can support learning, retrospective revaluation is anticipated by modified versions of standard associative theories.     

Integrative and semantic relations equally alleviate age-related associative memory deficits

Two experiments compared effects of integrative and semantic relations between pairs of words on lexical and memory processes in old age. Integrative relations occur when two dissimilar and unassociated words are linked together to form a coherent phrase (e.g., horse-doctor). In Experiment 1, older adults completed a lexical-decision task where prime and target words were related either integratively or semantically. The two types of relation both facilitated responses compared to a baseline condition, demonstrating that priming can occur in older adults with minimal preexisting associations between primes and targets. In Experiment 2, young and older adults completed a cued recall task with integrative, semantic, and unrelated word pairs. Both integrative and semantic pairs showed significantly smaller age differences in associative memory compared to unrelated pairs. Integrative relations facilitated older adults' memory to a similar extent as semantic relations despite having few preexisting associations in memory. Integratability of stimuli is therefore a new factor that reduces associative deficits in older adults, most likely by supporting encoding and retrieval mechanisms.     

Conditioned inhibition produced by extinction-mediated recovery from the relative stimulus validity effect: a test of acquisition and performance models of empirical retrospective revaluation

Empirical retrospective revaluation is a phenomenon of Pavlovian conditioning and human causal judgment in which posttraining changes in the conditioned response (Pavlovian task) or causal rating (causal judgment task) of a cue occurs in the absence of further training with that cue. Two experiments tested the contrasting predictions made by 2 families of models concerning retrospective revaluation effects. In a conditioned lick-suppression task, rats were given relative stimulus validity training, consisting of reinforcing a compound of conditioned stimuli (CSs) A and X and nonreinforcement of a compound of CSs B and X, which resulted in low conditioned responding to CS X. Massive posttraining extinction of CS A not only enhanced excitatory responding to CS X, but caused CS B to pass both summation (Experiment 1) and retardation (Experiment 2) tests for conditioned inhibition. The inhibitory status of CS B is predicted by the performance-focused extended comparator hypothesis (J. C. Denniston, H. I. Savastano, & R. R. Miller, 2001), but not by acquisition-focused models of empirical retrospective revaluation (e.g., A. Dickinson & J. Burke, 1996; L. J. Van Hamme & E. A. Wasserman, 1994).     

The 28th Bartlett Memorial Lecture Causal learning: An associative analysis

The concordance between performance and judgements of the causal effectiveness of an instrumental action suggests that such actions are mediated by causal knowledge. Although causal learning exhibits many associative phenomena—blocking, inhibitory or preventative learning, and super-learning—judgements of the causal status of a cue can be changed retrospectively as a result of learning episodes that do not directly involve the cue. In order to explain retrospective revaluation, a modified associative theory is described in which the learning processes for retrieved cue representations are the opposite to those for presented cues, and this theory is evaluated by studies of the role of within-compound associations in retrospective revaluation and blocking. However, this modified theory only applies when the within-compound association represents a contiguous rather than a causal cue relationship.     

Within compound Associations Mediate the Retrospective Revaluation of Causality Judgements

The role of within-compound associations in the retrospective revaluation of causality judgements was investigated in a two-stage procedure in which the subjects were asked to learn whether or not different food stimuli caused an allergic reaction in hypothetical patients. In the compound-cue stage a number of compound cues, each consisting of a competing stimulus and a target stimulus, were associated with the reaction across a series of trials, whereas in the single-cue stage the subjects had the opportunity to learn which of the competing cues, when presented alone, caused the reaction. Each target stimulus was presented with the same competing cue across all compound trials in the consistent condition, but with a different competing cue on each trial in the varied condition. In a forward procedure, in which the single-cue stage preceded compound cue training, judgements of the causal effectiveness of the target stimuli were reduced or blocked by training them in compound with a competing cue that had been previously paired with the reaction. Moreover, the magnitude of this reduction was comparable in the consistent and varied conditions. This was not true, however, when the single- and compound-cue stages were reversed in the backward procedure. Judgements for target cues compounded with competing cues that were subsequently paired with the reaction were reduced only in the consistent condition. If it is assumed that stronger associations were formed between the competing and target stimuli during the compound-cue stage in the consistent condition than in the varied condition, this pattern suggests that the retrospective revaluation of causality judgements can be mediated by the formation of within-compound associations.     

Phonologically mediated priming of preexisting and new associations in young and older adults

In 2 experiments, the authors investigated phonologically mediated priming of preexisting and new associations in word retrieval. Young and older adults completed paired word stems with the first word that came to mind. Priming of preexisting associations occurred when word-stem pairs containing homophones (e.g., beech-s____) showed more completions with the target (e.g., sand) relative to unrelated pairs (e.g., batch-s____), with more priming for subordinate than for dominant homophones. Priming occurred for new associations independent of dominance such that word-stem pairs containing homophones (e.g., beech-l____ and beach-l____) were completed with the same word (e.g., laugh) more often than unrelated pairs (e.g., beech-l____ and batch-l____). No age differences in phonologically mediated priming were found for either type of association, suggesting age equivalence in the use of bottom-up phonological connections.     

The role of memory for compounds in cue competition

Revisions of common associative learning models incorporate a within-compound association mechanism in order to explain retrospective cue competition effects (e.g., [Dickinson, A., & Burke, J. (1996). Within-compound associations mediate the retrospective revaluation of causality judgements. Quarterly Journal of Experimental Psychology, 49B, pp. 60-80.]). These models predict a correlation between memory for compounds (as a measure for the strength of within-compound associations) and retrospective cue competition but not forward cue competition. This was indeed found in a study of [Melchers, K. G., Lachnit, H., & Shanks, D. (2004). Within-compound associations in retrospective revaluation and in direct learning: A challenge for comparator theory. Quarterly Journal of Experimental Psychology, 57B, pp. 25-54.]. We argue that a higher-order reasoning account of causal learning can also explain the evidence for the role of within-compound associations in cue competition. Moreover, this account predicts that if making inferences during the learning stage is impeded, a correlation between memory for compounds and forward cue competition should be found as well. The results of a new study confirmed this prediction.     

An inhibitory within-compound association attenuates overshadowing

According to the comparator hypothesis (Miller & Matzel, 1988), cue competition depends on the association between a target stimulus (X) and a competing cue (e.g., an overshadowing cue [A]). Thus, it was expected that overshadowing would be reduced by establishing an inhibitory-like relationship between X and A before compound conditioning. In three lever press suppression experiments with rats, this expectation was supported. Experiment 1 showed that establishing an inhibitory X-A relationship reduced overshadowing. In Experiment 2, degrading the inhibitory-like relationship before conditioning allowed reinforced AX compound trials to result in overshadowing. Experiment 3 replicated the results of Experiment 2 when the inhibitory relationship was degraded after compound conditioning. The results support the view that within-compound associations are necessary not only for retrospective revaluation, but also for conventional cue competition.     

Does causal knowledge help us be faster and more frugal in our decisions?

One challenge that has to be addressed by the fast and frugal heuristics program is how people manage to select, from the abundance of cues that exist in the environment, those to rely on when making decisions. We hypothesize that causal knowledge helps people target particular cues and estimate their validities. This hypothesis was tested in three experiments. Results show that when causal information about some cues was available (Experiment 1), participants preferred to search for these cues first and to base their decisions on them. When allowed to learn cue validities in addition to causal information (Experiment 2), participants also became more frugal (i.e., they searched fewer of the available cues), made more accurate decisions, and were more precise in estimating cue validities than was a control group that did not receive causal information. These results can be attributed to the causal relation between the cues and the criterion, rather than to greater saliency of the causal cues (Experiment 3). Overall, our results support the hypothesis that causal knowledge aids in the learning of cue validities and is treated as a meta-cue for identifying highly valid cues.     

Multiple imitation mechanisms in children

Four studies using a computerized paradigm investigated whether children's imitation performance is content-specific and to what extent dependent on other cognitive processes such as trial-and-error learning, recall, and observational learning. Experiment 1 showed that 3-year-olds could successfully imitate what we call novel cognitive rules (e.g., first → second → third), which involved responding to 3 different pictures whose spatial configuration varied randomly from trial to trial. However, these same children failed to imitate what we call novel motor-spatial rules (e.g., up → down → right), which involved responding to 3 identical pictures that remained in a fixed spatial configuration from trial to trial. Experiment 2 showed that this dissociation was not due to a general difficulty in encoding motor-spatial content, as children successfully recalled, following a 30-s delay, a new motor-spatial sequence that had been learned by trial and error. Experiment 3 replicated these results and further demonstrated that 3-year-olds can infer a novel motor-spatial sequence following observation of a partially correct and partially incorrect response-a dissociation between imitation and observational learning (or emulation learning). Finally, Experiment 4 presented 3-year-olds with "familiar" motor-spatial sequences that involved making a linear response (e.g., left → middle → right) as well as "novel" motor-spatial sequences (e.g., right → up → down) used in Experiments 1-3 that were nonlinear and always involved a change in direction. Children had no difficulty imitating familiar motor-spatial sequences but again failed to imitate novel motor-spatial sequences. These results suggest that there may be multiple, dissociable imitation learning mechanisms that are content-specific. More importantly, the development of these imitation systems appears to be independent of the operations of other cognitive systems, including trial and error learning, recall, and observational learning.     

Re-assessing causal accounts of learnt behavior in rats

Rats received either a common-cause (i.e., A→B, A→food) or a causal-chain training scenario (i.e., B→A, A→food) before their tendency to approach the food magazine during the presentation of B was assessed as a function of whether it was preceded by a potential alternative cause. Causal model theory predicts that the influence of an alternative cause should be restricted to the common-cause scenario. In Experiment 1, responding to B was reduced when it occurred after pressing a novel lever during the test phase. This effect was not influenced by the type of training scenario. In Experiment 2, rats were familiarized with the lever prior to test by training it as a potential cause of B. After this treatment, the lever now failed to influence test responding to B. In Experiment 3, rats given common-cause training responded more to B when it followed a cue that had previously been trained as a predictor of B, than when it followed another stimulus. This effect was not apparent in rats that received causal-chain training. This pattern of results is the opposite of that predicted by causal model theory. Thus, in three experiments, the presence of an alternative cause failed to influence test responding in manner consistent with causal model theory. These results undermine the application of causal model theory to rats, but are consistent with associative analyses.     

Causal learning about tolerance and sensitization

We introduce two abstract, causal schemata used during causal learning. (1) Tolerance is when an effect diminishes over time, as an entity is repeatedly exposed to the cause (e.g., a person becoming tolerant to caffeine). (2) Sensitization is when an effect intensifies over time, as an entity is repeatedly exposed to the cause (e.g., an antidepressant becoming more effective through repeated use). In Experiment 1, participants observed either of these cause—effect data patterns unfolding over time and exhibiting the tolerance or sensitization schemata. Participants inferred stronger causal efficacy and made more confident and more extreme predictions about novel cases than in a condition with the same data appearing in a random order over time. In Experiment 2, the same tolerance/sensitization scenarios occurred either within one entity or across many entities. In the manyentity conditions, when the schemata were violated, participants made much weaker inferences. Implications for causal learning are discussed.     

I see what you’re saying: Voice signals influence children’s judgments of direct and averted gaze

Adults use gaze and voice signals as cues to the mental and emotional states of others. We examined the influence of voice cues on children’s judgments of gaze. In Experiment 1, 6-year-olds, 8-year-olds, and adults viewed photographs of faces fixating the center of the camera lens and a series of positions to the left and right and judged whether gaze was direct or averted. On each trial, participants heard the participant-directed voice cue (e.g., “I see you”), an object-directed voice cue (e.g., “I see that”), or no voice. In 6-year-olds, the range of directions of gaze leading to the perception of eye contact (the cone of gaze) was narrower for trials with object-directed voice cues than for trials with participant-directed voice cues or no voice. This effect was absent in 8-year-olds and adults, both of whom had a narrower cone of gaze than 6-year-olds. In Experiment 2, we investigated whether voice cues would influence adults’ judgments of gaze when the task was made more difficult by limiting the duration of exposure to the face. Adults’ cone of gaze was wider than in Experiment 1, and the effect of voice cues was similar to that observed in 6-year-olds in Experiment 1. Together, the results indicate that object-directed voice cues can decrease the width of the cone of gaze, allowing more adult-like judgments of gaze in young children, and that voice cues may be especially effective when the cone of gaze is wider because of immaturity (Experiment 1) or limited exposure (Experiment 2).     

Retrospective revaluation in humans: Learning or memory?

The phenomenon of retrospective revaluation has posed considerable problems for many associative learning theories as it involves a change in the associative strength of a cue on trials on which that cue is absent. The present series of experiments pursues this idea of changes in associative strength between evoked representations of cues, in an effort to establish, de novo, an excitatory connection between two cues simultaneously activated in memory. Given the finding of Dwyer, Mackintosh, and Boakes (1998) that simultaneous activation of absent cues in the memory of rats resulted in learning comparable to that seen inretrospective revaluation, we expected that if retrospective revaluation was found in humans, then excitatory learning due to simultaneous activation would also be seen. This was not the case. The implications of our results are discussed in terms of Dickinson and Burke's (1996) modified SOP model and a version of McLaren's (1993) APECS network. We conclude that many of the effects attributed to learning in retrospective revaluation studies are better thought of as due to changes in the retrievability of items in memory.     

Backward Blocking and Recovery from Overshadowing in Human Causal Judgement: The Role of Within-compound Associations

We replicated and extended a project by Dickinson and Burke (1996) that concerned human causal judgement. In a medical diagnostic setting, college students' ratings of the causal efficacy of target cues showed retrospective revaluation: relative to a proper control condition, ratings of target cues both increased ('recovery from overshadowing') and decreased ('backward blocking') during a second stage of training in which competing cues, but not target cues, were presented. These changes in causal judgements were exhibited only by subjects who had learned which target and competing cues were paired with one another during the first stage of training. These results cannot be explained by the Rescorla-Wagner (1972) model of associative learning, but they can be explained by the revised model of Van Hamme and Wasserman (1994); the revised model assigns non-zero salience to nonpresented target stimuli whose memories or representations are retrieved by competing stimuli that had previously been paired with those target stimuli.