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Competition Between Outcomes
Abstract
In both Pavlovian conditioning and human causal judg- ment, competition between cues is well known to occur when multiple cues are presented in compound and followed by an outcome. More questionable is the occurrence of competition between outcomes when a single cue is followed by multiple outcomes presented in compound. In the experiment reported here, we demonstrated blocking (a type of stimulus competition) between outcomes. When the cue predicted one outcome, its ability to predict a second outcome that was presented in compound with the first outcome was reduced. The procedure mini- mized the likelihood that the observed competition between outcomes arose from selective attention. The competition between outcomes that we observed is problematic for contemporary theories of learning.
... Relative to MC-SO learning, where cues compete to predict a single outcome, MC-MO learning also provides an opportunity for outcomes to "compete" within or across learning trials. For example, a recent study by Miller and Matute (1998) finds that passive learning about the association between a cue (e.g., click) and an outcome (e.g., white noise) at time 1 (A r O1) can inhibit passive learning about the cue (e.g., click) and a second outcome (e.g., tone) at time 2 (A r O1, O2). If this is so, it is also possible that outcomes may compete in active learning situations as well. ...
... More specifically, when human subjects have to learn about meaningful outcomes (e.g., product benefits), it is possible that learning that a cue predicts a benefit at time 1 (A r O1) may inhibit learning that the cue predicts a second benefit at time 2 (A r O2). Whether Miller and Matute's (1998) outcome competition result will generalize to consumer learning contexts is an open question owing to different populations (e.g., rats vs. humans), learning goals (e.g., no goal vs. causal learning), and learning procedures (e.g., simultaneous vs. sequential presentation of competing outcomes). ...
... Research in associative learning has traditionally focused on how cues compete to become associated with an outcome, implying that outcomes cannot compete for associative strength with a cue. Recently, Miller and Matute (1998) have shown that outcomes can compete for associative strength with a cue during passive learning. We show that outcomes can compete for strength with a cue during active (i.e., motivated) learning. ...
As a product category evolves, consumers have the opportunity to learn a series of feature-benefit associations. Initially, consumers learn that some features predict a critical benefit, whereas other features do not. Subsequently, consumers have the opportunity to assess if previously predictive features, or novel features, predict new product benefits. Surprisingly, later learning is characterized by attenuated learning about previously predictive features relative to novel features. This tendency to ignore previously predictive features is consistent with a desire to protect prior learning. (c) 2007 by JOURNAL OF CONSUMER RESEARCH, Inc..
... These results therefore indicate an 'outcome blocking' effect -learning about the A-O1 association attenuated the formation of the A-O2 association. Miller and Matute (1998) have also provided a demonstration of "outcome blocking" in a series of sensory preconditioning experiments with rats. ...
... At test participants provided longer response times to the auditory element of the outcome compound relative to a control group that did not receive stage 1 training. Thus, demonstrating an outcome blocking effect comparable to that reported in animals (e.g., Miller and Matute, 1998;Rescorla, 1980). Flach et al. also reported an additional experiment, where the auditory stimuli were presented in stage 1, prior to being paired in compound with visual stimuli in stage 2. At test, the opposite effect was observed, that is, an outcome facilitation effect occurred where pretraining with an element of an outcome compound produced quicker response times to the added visual stimulus at test. ...
Overshadowing and relative validity constitute two phenomena that inspired the development of the Rescorla-Wagner model in 1972. They demonstrate that cues will interact with one another for an association with the presence or absence of an outcome. Here, three experiments sought to explore whether these two effects extended to outcomes using a food allergist paradigm with human participants. In Experiment 1 (overshadowing) participants received trials in which a cue was followed by a compound of two outcomes (A-O1O2). Test trials revealed that participants learned less about the A-O2 association than they did between a control cue C, which had been paired with O2 in isolation (C-O2) in training - thus demonstrating an outcome overshadowing effect. In Experiment 2 (relative validity) participants received true discrimination trials, in which A was paired with an O1O3 compound and B was paired with an O2O3 compound, and pseudo discrimination trials, in which C and D were paired on 50% of the trials with an O4O6 compound and on the remaining trials with an O5O6 compound. Consequently, O3 is less well predicted by A and B relative to O1 and O2, whereas O6 is equally well predicted by C and D relative to O4 and O5. Despite the relative validity of A and B for O3 being less than the relative validity of C and D for O6, the ratings of A and B for O3 were the same as C and D for O6. This failure to observe an outcome relative validity effect was reproduced in Experiment 3, which replicated Experiment 2, but with an adjustment made to the number of training trials given to participants. These results are discussed in terms of a real-time development of the Rescorla-Wagner model provided by Wagner (1981).
... The prediction that there will be cue competition or overshadowing between the capacities of two USs to become associated with a single CS has received empirical support (e.g., Miller & Matute, 1998). ...
... Because in typical Pavlovian conditioning procedures there is only one US (cf. Miller & Matute, 1998), the c.α CS value of each CS in a compound (e.g., A and B) sets the asymptote for the association from the US to that CS. This means that the US-CS associations will proceed independently for each of the components of a compound that is paired with a US. ...
Associative treatments of how Pavlovian conditioning affects conditioned behavior are rudimentary: A simple ordinal mapping is held to exist between the strength of an association (V) between a conditioned stimulus (CS) and an unconditioned stimulus (US; i.e., VCS-US) and conditioned behavior in a given experimental preparation. The inadequacy of this simplification is highlighted by recent studies that have taken multiple measures of conditioned behavior: Different measures of conditioned behavior provide the basis for drawing opposite conclusions about VCS-US. Here, we develop a simple model involving reciprocal associations between the CS and US (VCS-US and VUS-CS) that simulates these qualitative individual differences in conditioned behavior. The new model, HeiDI (How excitation and inhibition Determine Ideo-motion), enables a broad range of phenomena to be accommodated, which are either beyond the scope of extant models or require them to appeal to additional (learning) processes. It also provides an impetus for new lines of inquiry and generates novel predictions.
... As a result of these trials, the pigeons demonstrated weak learning about the A-O2 association relative to a control group who received comparable treatment, but who had the A-O1 trials omitted. This led Rescorla to conclude that aspects of an outcome compete for associative strength in the same manner as cues (see also Miller & Matute, 1998, for a similar demonstration with rats). ...
... Thus, the current experiments, together with others Miller & Matute, 1998;Rescorla, 1980), suggest that a revision may be required to learning models which stipulate that β is a fixed learning-rate parameter. It is thus tempting to suggest that changes in attention/associability to both cues (α) and outcomes (β) are underpinned by comparable rules (see Griffiths & Thorwart, 2017;Thorwart, Livesey, Wilhelm, Liu & Lachnit, 2017, for further discussion). ...
When a cue reliably predicts an outcome, the associability of that cue will change. Associative theories of learning propose this change will persist even when the same cue is paired with a different outcome. These theories, however, do not extend the same privilege to an outcome; an outcome’s learning history is deemed to have no bearing on subsequent new learning involving that outcome. Two experiments were conducted which sought to investigate this assumption inherent in these theories using a serial letter-prediction task. In both experiments participants were exposed, in Stage 1, to a predictable outcome (‘X’) and an unpredictable outcome (‘Z’). In Stage 2 participants were exposed to the same outcomes preceded by novel cues which were equally predictive of both outcomes. Both experiments revealed that participants’ learning toward the previously predictable outcome was more rapid in Stage 2 than the previously unpredicted outcome. The implications of these results for theories of associative learning are discussed.
... In addition, the generality and validity of the findings were called into question (Matute et al., 1996;Shanks & Lopez, 1996), and it was suggested that the two-phase blocking paradigm used might favor nonassociative types of learning (Price & Yates, 1995). Finally, Waldmann and Holyoak's assumption that prior knowledge caused participants in their Experiment 2 to give low diagnostic ratings to an effect that suggests alternative causes (being underweight) was sometimes misinterpreted or ignored, which opened up the possibility of viewing the obtained low ratings of the redundant cue as evidence for blocking and the results of Experiment 3 (in which prior knowledge was excluded) as a mere failure to replicate (Matute et al., 1996;Miller & Matute, 1998). ...
... This learning input is clearly inconsistent with a common-cause model in which a common cause with stable properties independently generates three effects (see Waldmann & Holyoak, 1997, for a more detailed critique of Shanks & Lopez, 1996). Miller and Matute (1998) present a different example of this problem. In one condition of their experiment, a cause produced a specific effect Ol on the first five days, whereas on the sixth training day a second effect 02 suddenly appeared along with 01. ...
Causal asymmetry is one of the most fundamental features of the physical world: Causes produce effects, but not vice versa. This article is part of a debate between the view that, in principle, people are sensitive to causal directionality during learning (causal-model theory) and the view that learning primarily involves acquiring associations between cues and outcomes irrespective of their causal role (associative theories). Four experiments are presented that use asymmetries of cue competition to discriminate between these views. These experiments show that, contrary to associative accounts, cue competition interacts with causal status and that people are capable of differentiating between predictive and diagnostic inferences. Additional implications of causal-model theory are elaborated and empirically tested against alternative accounts. The results uniformly favor causal-model theory.
... Some researchers (e.g., Shanks, 1991; Shanks & Lopez, 1996; Price & Yates, 1995; Cobos, Lopez, Cano, Almaraz & Shanks, 2002) interpret the findings as consistent with associative learning theories. Others (e.g., Matute et al., 1996; Miller & Matute, 1998) assert that the findings are more consistent with contiguity theory, which assumes that associations are learned noncompetitively and bi-directionally through simple contiguity, and that cue competition takes place at judgment. ...
... Some researchers (e.g., Shanks, 1991; Shanks & Lopez, 1996; Price & Yates, 1995; Cobos, Lopez, Cano, Almaraz & Shanks, 2002 ) interpret the findings as consistent with associative learning theories. Others (e.g., Matute et al., 1996; Miller & Matute, 1998) assert that the findings are more consistent with contiguity theory, which assumes that associations are learned noncompetitively and bi-directionally through simple contiguity, and that cue competition takes place at judgment. In contrast, proponents of causal model theory (e.g., Waldmann & Holyoak 1992; Melz, Cheng, Holyoak & Waldmann, 1993; Waldmann, 2000) deny the evidence for cue competition for effects, suggesting that whereas causes compete, effects do not. ...
Two experiments using social stimuli tested a recurrent neural network model's predictions for cue competition for causes and effects. The delta-rule based model predicts the presence of cue competition for effects as well as for causes as a result of an asymmetry in the bidirectional associative strengths between the relevant cue-outcome pairs. This model can capture cue competition for effects when cues are encountered in the cause-effect direction, unlike associative and feed-forward models. Results support the model's prediction of cue competition for both effects and causes. The implications of these results for causal model theory and for various associative accounts of cue competition are discussed.
... By employing second-order conditioning, Rescorla avoided the use of simultaneous US presentations, and it is quite likely that the subjects were able to simultaneously perceive both the blocked and the blocking outcomes, especially because they were visual stimuli that appeared in close proximity. Similar evidence of blocking between outcomes, but with the blocking treatment embedded in a sensory preconditioning task instead of second-order conditioning, was reported by Esmoris-Arranz, Miller, and Matute (1997) and R. R. Miller and Matute (1998). ...
... Unlike in Burger et al. (2000), the subjects in this series were always tested on forward-trained associations. In order to test on forward-trained associations, we used a design similar to that used by R. R. Miller and Matute (1998). This design involved the use of sensory preconditioning so that our outcomes, like Rescorla's (1980) outcomes, were not different USs, making it more plausible to think that the subjects could simultaneously attend to two outcomes. ...
Contemporary associative learning research largely focuses on cue competition phenomena that occur when 2 cues are paired with a common outcome. Little research has been conducted to investigate similar phenomena occurring when a single cue is trained with 2 outcomes. Three conditioned lick suppression experiments with rats assessed whether treatments known to alleviate blocking between cues would also attenuate blocking between outcomes. In Experiment 1, conditioned responding recovered from blocking between outcomes when a long retention interval was interposed between training and testing. Experiment 2 obtained recovery from blocking between outcomes when the blocking outcome was extinguished after the blocking treatment. In Experiment 3, a recovery from blocking between outcomes occurred when a reminder stimulus was presented in a novel context prior to testing. Collectively, these studies demonstrate that blocking of outcomes, like blocking of cues, appears to be caused by a deficit in the expression of an acquired association.
... Multiple USs) From a strict conditioning perspective, use of multiple, varied CSs or USs can impair CR acquisition (Escobar et al., 2001), sometimes through blocking (Miller & Matute, 1998), though this has not been studied in autoshaping. Moreover, this implication from respondent conditioning preparations is inconsistent with SSP outcomes. ...
Stimulus–stimulus pairing (SSP) is a procedure used by behavior analysis practitioners that capitalizes on respondent conditioning processes to elicit vocalizations. These procedures usually are implemented only after other, more customary methods (e.g., standard echoic training via modeling) have been exhausted. Unfortunately, SSP itself has mixed research support, probably because certain as-yet-unidentified procedural variations are more effective than others. Even when SSP produces (or increases) vocalizations, its effects can be short-lived. Although specific features of SSP differ across published accounts, fundamental characteristics include presentation of a vocal stimulus proximal with presentation of a preferred item. In the present article, we draw parallels between SSP procedures and autoshaping, review factors shown to affect autoshaping, and interpret autoshaping research for suggested SSP tests and applications. We then call for extended use and reporting of SSP in behavior-analytic treatments. Finally, three bridges created by this article are identified: basic-applied, respondent–operant, and behavior analysis with other sciences.
... On the other hand, interference effects in the A-B, A-C paradigm can be seen as analogous to interference effects between elementally trained outcomes, such as extinction and counterconditioning (e.g., Bouton, 1993;Pineño & Matute, 2000). Moreover, recent research has shown that interference between compounded elements does not only occur between cues trained in compound (e.g., blocking; Kamin, 1968), but also between outcomes trained in compound (e.g., Esmorís-Arranz, Miller & Matute, 1997;Miller & Matute, 1998). In summary, retroactive and proactive interference, both between compound or elemental cues and outcomes, can be observed in a variety of paradigms, and their common characteristics suggest the viability of a common explanation. ...
The impairment in responding to a secondly trained association because of the prior training of another (i.e., proactive interference) is a well-established effect in human and animal research, and it has been demonstrated in many paradigms. However, learning theories have been concerned with proactive interference only when the competing stimuli have been presented in compound at some moment of the training phase. In this experiment we investigated the possibility of proactive interference between elementally-trained stimuli at the acquisition and at the retrieval stages in a behav-ioral task with humans. After training a cue-outcome association we observed retardation in the acquisition of an association between another cue and the same outcome. Moreover, after asymptotic acquisition of the secondly trained association, impairment of retrieval of this secondly trained association was also observed. This finding of proactive interference between elementally-trained cues suggests that interference in predictive learning and other traditional interference effects could be integrated into a common framework.
... Notably, the prominence of learning models designed specifically to account for overshadowing and blocking (e.g., Rescorla & Wagner, 1972) led investigators to focus their research primarily on competition between cues. Nevertheless, decrements in responding produced by competition between outcomes (see Cell 2 of Figure 1) have been reported (Esmoriz-Arranz, Miller, & Matute, 1997;Miller & Matute, 1998;Rescorla, 1980) and challenge models based on total error reduction such as that of Rescorla and Wagner. To date, few associative models of learning have been designed to account for outcome competition (but see Stout & Miller, 2007). ...
Two fear-conditioning experiments with rats assessed whether retrospective revaluation, which has been observed in cue competition (i.e., when compounded cues are followed with an outcome), can also be observed in retroactive cue interference (i.e., when different cues are reinforced in separate phases with the same outcome). Experiment 1 found that after inducing retroactive cue interference (i.e., X-outcome followed by A-outcome), nonreinforced presentations of the interfering cue (A) decreases interference with responding to the target cue (X), just as has been observed in retrospective revaluation experiments in cue competition. Using the opposite manipulation (i.e., adding reinforced presentations of A), Experiment 2 demonstrated that after inducing retroactive cue interference, additional reinforced presentations of the interfering cue (A) increases interference with responding to the target cue (X); alternatively stated, the amount of interference increases with the amount of training with the interfering cue. Thus, both types of retrospective revaluation occur in retroactive cue competition. The results are discussed in terms of the possibility that similar associative mechanisms underlie cue competition and cue interference.
... competition is much scarcer (e.g., Esmoris-Arranz, Miller, & Matute, 1997; Miller & Matute, 1998; Rescorla, 1980). Few models have been developed in a Pavlovian framework to account for associative interference. ...
Two conditioned suppression experiments with rats were conducted to determine whether the spontaneous recovery and renewal that are commonly observed in retroactive outcome interference (e.g., extinction) also occur in retroactive cue interference. Experiment 1 showed that a long delay between Phase 2 (the interfering phase) and testing produces a recovery from the cue interference (i.e., the delay enhanced responding to the target cue trained in Phase 1), which is analogous to the spontaneous recovery effect observed in extinction and other retroactive outcome interference procedures. Experiment 2 showed that, when target and interfering cues are trained in separate contexts and testing occurs in a different but familiar context, a recovery from the cue interference is also observed (i.e., the context shift enhanced responding to the target), which is analogous to ABC renewal from extinction. The results are discussed in terms of the possibility that similar associative mechanisms underlie cue and outcome interference.
... But beyond cue competition (i.e., competition between cues presented together), there is also published evidence of competition between outcomes presented together. For example, Esmoris-Arranz, Miller, and Matute (1997) and Miller and Matute (1998;also see Rescorla, 1980, for a variation on the same effect) reported that pairing a cue X (e.g., a tone) with a nontarget outcome (O1, e.g., a flashing light) followed by the tone being paired with a compound of the nontarget outcome and target outcome (O2, e.g., a white noise, that is X-[O1+O2] trials) attenuated responding to the tone after noise (O2) had been paired with a footshock, relative to subjects that had not the X-O1 pairings. Control groups in these studies determined that simultaneous presentation of innocuous stimuli O1 and O2 did not result in one outcome distracting the subjects from the other. ...
Despite the considerable success of contemporary associative models of learning in stimulating new behavioral research and modest success in providing direction to both neuroscience and psychotherapy, these models are confronted with at least three challenges. The first challenge is to the assumption that animals encode only one or a few summary statistics to capture what has been experienced over many training trials. This assumption is contrary to overwhelming evidence that the brain retains episodic information. The second challenge is that the learning-performance distinction has been largely ignored. Most models erroneously assume that behavior is a nearly perfect reflection of what has been encoded. The third challenge is to account for interactions between stimuli that have been presented separately (e.g., stimulus interference) as well as between stimuli that have been presented together (e.g., stimulus competition).
... Current models make no predictions regarding the strategic allocation of attention when learning occurs from a single cue to multiple outcomes. Our results indicate that people may allocate attention strategically across outcomes, ultimately implying outcome competition (Arcediano et al. 2005;Miller and Matute 1998). Second, the current research shows that such competition affects brand evaluations. ...
The highlighting effect occurs when the order in which consumers learn about brands determines the strength of association between these brands and their attributes. In four experiments, we find that consumers more strongly associate common attributes with early learned brands and unique attributes with late-learned brands. These findings imply an advantage for late entrants when unique attributes offer a higher value than attributes that are common to late and early entrants. We extend an attention-based model of associative learning to accommodate sequential learning of brand associations and predict when late versus early entrants will be able to sustain an advantage. (c) 2008 by JOURNAL OF CONSUMER RESEARCH, Inc..
... In addition, the generality and validity of the findings were called into question (Matute et al., 1996; Shanks & Lopez, 1996), and it was suggested that the two-phase blocking paradigm used might favor nonassociative types of learning (Price & Yates, 1995 ). Finally, Waldmann and Holyoak's assumption that prior knowledge caused participants in their Experiment 2 to give low diagnostic ratings to an effect that suggests alternative causes (being underweight) was sometimes misinterpreted or ignored, which opened up the possibility of viewing the obtained low ratings of the redundant cue as evidence for blocking and the results of Experiment 3 (in which prior knowledge was excluded) as a mere failure to replicate (Matute et al., 1996; Miller & Matute, 1998). Finally, a number of studies have been reported that exhibit competition among effects, a finding that contradicts the claim of causal-model theory that competition should be observed among alternative causes of a common effect but not among effects of a common cause (Matute et al., 1996; Price & Yates, 1995; Shanks & Lopez, 1996). ...
Causal asymmetry is one of the most fundamental features of the physical world: Causes produce effects, but not vice versa. This article is part of a debate between the view that, in principle, people are sensitive to causal directionality during learning (causal-model theory) and the view that learning primarily involves acquiring associations between cues and outcomes irrespective of their causal role (associative theories). Four experiments are presented that use asymmetries of cue competition to discriminate between these views. These experiments show that, contrary to associative accounts, cue competition interacts with causal status and that people are capable of differentiating between predictive and diagnostic inferences. Additional implications of causal-model theory are elaborated and empirically tested against alternative accounts. The results uniformly favor causal-model theory.
... Finally, our most surprising finding, competition between subsequent effects (i.e., effects presented with predictive training), is in strong contradiction to both families of accounts of causal judgment. However, this observation is consistent with prior evidence of competition in this situation (e.g., Esmoris-Arranz et al., 1997; Matute et al., 1996; Miller & Matute, 1998). In summary, the role of each of the variables investigated in the present research was not adequately isolated in previous research (i.e., they were not analyzed independent of the values of the other potential variables). ...
In the analysis of stimulus competition in causal judgment, 4 variables have been frequently confounded with respect to the conditions necessary for stimuli to compete: causal status of the competing stimuli (causes vs. effects), temporal order of the competing stimuli (antecedent vs. subsequent) relative to the noncompeting stimulus, directionality of training (predictive vs. diagnostic), and directionality of testing (predictive vs. diagnostic). In a factorial study using an overshadowing preparation, the authors isolated the role of each of these variables and their interactions. The results indicate that competition may be obtained in all conditions. Although some of the results are compatible with various theories of learning, the observation of stimulus competition in all conditions calls for a less restrictive reformulation of current learning theories that allows similar processing of antecedent and subsequent events, as well as of causes and effects.
... Consistent with the idea just described, we assume that the interference being produced in these studies is interference between conflicting associations controlled by a single cue and that it is this type of interference that leads to the use of context. In some situations (e.g., Esmoris-Arranz, Miller, & Matute, 1997;Miller & Matute, 1998), after a cue has signaled one outcome (i.e., O1) presenting the cue with two outcomes (X-O1,O2) produces some sort of interference whereby either the learning or expression of the cue-O2 relationship is impaired. It is unlikely that there was any interference of that type in the present studies. ...
In 2 experiments, participants completed a computer task in which they judged the probability of outcomes occurring (e.g., flowers growing, a bug infestation) given cues (e.g., treatment of soil with a fictitious garden product). In each 2-phase experiment, cue X was associated with 1 outcome in Phase 1 and with a 2nd outcome in Phase 2. When the outcome in Phase 1 (e.g., X led to a bug infestation) was replaced in Phase 2 (e.g., X led to flowers growing), contextual control was observed (Experiments 1 and 2). Information learned in each phase was less likely to be retrieved when the cue was tested in a context different from the 1 where training occurred. When the 2nd outcome did not conflict with information acquired in the 1st phase (e.g., X led to flowers and bugs), no contextual control was observed (Experiment 2). Acquiring a 2nd association to X resulted in contextual control only when it conflicted with an association learned earlier. The authors discuss the role of interference produced when conflicting information is acquired in establishing contextual control.
... For instance, overshadowing of outcomes is evidenced when cue X in training is paired with two outcomes (O1 and O2 presented simultaneously), and the resultant stimulus control indicative of the X-O1 association is found to be attenuated relative to when cue X is paired with O1 in the absence of O2 (Rescorla, 1980). In addition, blocking of outcomes is evidenced in attenuated stimulus control indicative of an X-O1 association when cue X is initially paired with O2 before cue X is paired with a simultaneous compound of O1 and O2, relative to a group lacking the initial X-O2 pairings (Esmoris-Arranz, Miller, & Matute, 1997;Miller & Matute, 1998). It is notable that this sort of overshadowing and blocking of outcomes is observed, even when measures have been taken to preclude response competition (i.e., the observed competition between outcomes is not simply a matter of a subject not being able to do two things at once) or competition for attention (i.e., the competition is not due to O2 distracting the subject from O1). ...
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 human fear-conditioning paradigm is a widely used procedure to study anxiety. However, merely thinking about the aversive outcome is typically not measured in this procedure. This is surprising because thinking of an aversive event is of clinical relevance (e.g., in the form of intrusions) and theoretical interest. We present two preregistered studies that (a) included thinking of an aversive outcome as an additional dependent variable and (b) compared several interventions to reduce it. We found that mere thinking of an aversive outcome could be successfully conditioned. Among the participants who showed successful acquisition, extinction training was less successful in reducing it than counterconditioning. Presenting new additional outcomes also proved effective to reduce thoughts about the initial outcome when the new outcomes were positive stimuli. Including thinking of the aversive outcome as an additional dependent variable may serve to enhance the understanding of anxiety-related disorders and inform their treatment.
A basic assumption of most researchers is that behavior is generally functional, and indeed, in most instances the function is obvious. But in a number of cases, some behaviors of neurophysiologically 'normal' organisms appear to be maladaptive. Considerable research has been conducted to understand the basis of such behavior as well as how the frequency of such behavior can be reduced. Here we provide a brief panoramic review of the major sources of maladaptive behavior in neurophysiologically 'normal' organisms: a) altered environmental contingencies relative to those faced by ancestral generations in their environment of evolutionary adaptation, b) altered environmental contingencies within the lifespan of the animal, c) linked behaviors in which the dysfunctional behavior is a linked companion of a more valuable beneficial trait, and d) the labeling of some behaviors as 'maladaptive' when more careful examination finds that they provide net benefit. Most of our attention is on the consequences of altered contingencies across and within a generation, with altered contingencies within a generation constituting a form of associative interference. The central issue in these two cases can be framed in terms of insufficient or excessive transfer of training resulting in maladaptive behavior. We discuss the functional basis of successful and unsuccessful near transfer (i.e., stimulus and response generalization) and far transfer (including rule learning and abstraction).
The weight loss during evaporation from an aqueous and nonaqueous microemulsion with limonene was followed gravimetrically at two different humidities. Result showed that at lower humidity the weight loss is greater for both of the systems. The weight loss is a however, higher for the aqueous counterpart.
The nature of interference between cues (X, A) trained apart with a common outcome (O; an unconditioned stimulus) was explored by assessing proactive interference in first-order Pavlovian conditioning (i.e., A-O, X-O, resulting in attenuated responding to X). Three lick-suppression studies were conducted with water-deprived rats. Posttraining extinction of the interfering cue (A) attenuated proactive interference (Experiment 1), which mirrors the observation that extinction of the competing cue can reduce competition between cues trained together (e.g., recovery from overshadowing). Proactive interference was also attenuated with manipulations known to attenuate interference between outcomes trained apart (e.g., counterconditioning), namely reminder cues (Experiment 2) and renewal (Experiment 3). The findings suggest that similar processes underlie interference between cues trained apart, between cues trained together, and between outcomes trained apart.
The development of the real educational contents and customized virtual education satisfying the needs of specific engineering education domain is getting more and more research attention in this area of Web and virtual technologies. By analyzing the characteristics of computer-based educational methods and using the rapidly changing Internet and object technologies, we developed a Web-based, interactive virtual laboratory system of unit operations and process systems engineering education. The proposed system is expected to overcome many obstacles in performing the unit operations laboratory at the current setting. More teachwares and experiments suites are being added for the extensive, quantitative evaluation on educational efficiency of the proposed system, and the result will be reported at the conference.
Four experiments using a conditioned lick suppression preparation with rats were conducted to examine whether overshadowing of subsequent events could be obtained in Pavlovian backward conditioning (i.e. unconditioned stimulus [US] before conditioned stimulus [CS]), and to determine whether such overshadowing could be reversed without further training with the overshadowed CS, as has been reported in overshadowing of antecedent events. In Experiment 1, a backward-conditioned CS overshadowed a second backward-conditioned CS. Two posttraining manipulations, extinction of the overshadowing CS (Experiment 2) and shifting of the temporal relationship of the overshadowing CS to the US (Experiment 3), increased responding to the overshadowed CS. These results constitute the first unambiguous demonstration of stimulus competition between subsequent events using first-order conditioning, and they show that, like overshadowing with forward conditioning, such overshadowing is due, at least in part if not completely, to a failure to express information that had been acquired.
Contemporary theories of associative learning require cues be trained in compound for cue competition (interference) to occur. That is, Cues A and X should compete for behavioral control only if training consists of AX-outcome (O) trials and not if each cue is separately paired with O (i.e., X-O and A-O). Research with humans challenges this view by showing that A-O trials interpolated between training and testing of a X-O association impair responding to X (i.e., retroactive interference). In six conditioned suppression studies with rats, the authors demonstrate that two cues trained apart can each interfere with the potential of the other to predict the outcome. The authors conclude that this type of interference (a) reflects a failure to retrieve the target association due to priming at test of the interfering association and (b) is attenuated if the outcome is of high biological significance. These findings parallel previous reports in verbal learning research and suggest that a similar associative structure underlies some types of associations in nonverbal subjects.
Experiments with different temporal relations between the conditioned stimulus (CS) and the unconditioned stimulus (US) in conditioning assessed whether US devaluation effects can be obtained after nutrient-conditioned flavor preference learning. One flavor (CScarb) was paired with a carbohydrate, Polycose; a 2nd flavor (CSprot) was paired with a protein, casein; and a 3rd flavor (CS-) was presented by itself. Following conditioning, one of the nutrients was devalued through pairings with lithium chloride in the absence of the CS flavors. In a subsequent 2-bottle test, rats preferred CScarb over CSprot; however, this preference was smaller when the carbohydrate was devalued than when the protein was devalued. Results suggest that CS flavors are able to form associations with the sensory features of nutrient USs under a wide variety of circumstances.
In this article I review research and theory on the "interference paradigms" in Pavlovian learning. In these situations (e.g., extinction, counterconditioning, and latent inhibition), a conditioned stimulus (CS) is associated with different unconditioned stimuli (USs) or outcomes in different phases of the experiment; retroactive interference, proactive interference, or both are often observed. In all of the paradigms, contextual stimuli influence performance, and when information is available, so does the passage of time. Memories of both phases are retained, and performance may depend on which is retrieved. Despite the similarity of the paradigms, conditioning theories tend to explain them with separate mechanisms. They also do not provide an adequate account of the context's role, fail to predict the effects of time, and overemphasize the role of learning or storage deficits. By accepting 4 propositions about animal memory (i.e., contextual stimuli guide retrieval, time is a context, different memories are differentially dependent on context, and interference occurs at performance output), a memory retrieval framework can provide an integrated account of context, time, and performance in the various paradigms.
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)
This study examined how people detect and assess the strength of contingent relationships between pairs of events. Some researchers have suggested that contingency learning is analogous to classical conditioning and that contingency judgment is based on psychological associations formed during learning. Others have rejected the associative account in favor of a rule-based account involving higher level statistical and causal reasoning. The results of 4 experiments in which college-student participants performed a simulated medical-judgment task, showed that the rule-based account does not provide a sufficient explanation of cue-interaction effects in contingency learning and judgment. Elements of the associative account are needed to explain the entire range of contingency judgment phenomena. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Examined the ability of CS-evoked representations of flavored substances to modulate the conditioning of LiCl-based aversions to simultaneously presented flavors or odors. In Exps I–III, 156 thirsty Sprague-Dawley rats first received pairings of an auditory CS with a flavored-water UCS; they then received pairings of a compound stimulus with a toxin. Exp IV examined the potentiation of aversion conditioning to a novel odor using 32 Ss. In Exp I, conditioning of a flavor was partially overshadowed when it was presented in compound with a tone that had been previously paired with another flavor. Exp II replicated that result and also found that conditioning to a flavor was not overshadowed when the flavor was presented in compound with a tone that had been paired with that same flavored substance. In Exps III and IV, conditioning to an odor stimulus was potentiated when it was presented in compound with either a tone or another odor that had been previously paired with a flavor stimulus. Results suggest that evoked representations of stimuli may substitute for those events themselves in a variety of associative functions. (36 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)
In Experiments 1 and 2, rats received initial training in which two neutral events were presented as a serial compound (A → X). Subsequent training with A as a signal for shock was found to endow X with the ability to evoke the conditioned response of suppression. Experiment 2 also showed that responding to X was diminished if, prior to testing, Stimulus A underwent extinction. Two possible mechanisms for these findings are considered: (a) that X elicits responding through the associative chain X-A-shock, and (b) that A activates a representation of X that gains direct associative strength during conditioning with A and loses it during extinction of A. Experiment 3 demonstrated that an X-shock association established after initial A → X training can be extinguished by nonreinforced presentations of A. These results suggest that associatively evoked representations of stimuli can enter into associations. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Three experiments tested a simple connectionist network approach to human categorization. The specific network considered consists of a layer of input nodes, each representing a feature of the exemplar to be categorized, connected in parallel to a layer of output nodes representing the categories. Learning to categorize examplars consists of adjusting the weights in the network so as to increase the probability of making correct categorizations; weight changes are determined by the R. A. Rescorla and A. R. Wagner (1972) learning rule. The experiments used a simulated medical diagnosis procedure in which Ss have to decide which disease (the category) each of a series of patients is suffering from on the basis of the patients' symptoms (the features). After a series of trials, the Ss rated the extent to which particular symptoms were associated with particular diseases. It is shown that a process of selective learning occurs in this categorization task and that selection depends on the relative predictiveness of the symptom for the disease. Such effects parallel results found in animal conditioning experiments and are readily reproduced by the connectionist network model. Results are discussed in terms of a variety of traditional theories of categorization. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Conducted 3 experiments with a total of 80 homing pigeons and 10 hybrid cock pigeons to investigate selective discrimination learning during acquisition training. A 2-key autoshaping procedure was used in which Ss' responses to the common and distinctive elements of 2 successively presented compound visual stimuli were recorded separately. The difference between the correlations with reinforcement of the compound stimuli influenced between- and within-trial discrimination learning. The methods and findings of these experiments are discussed in terms of several views of stimulus selection in animal discrimination learning. (23 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)
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.
ALCOVE (attention learning covering map) is a connectionist model of category learning that incorporates an exemplar-based representation (Medin & Schaffer, 1978; Nosofsky, 1986) with error-driven learning (Gluck & Bower, 1988; Rumelhart, Hinton, & Williams, 1986). Alcove selectively attends to relevant stimulus dimensions, is sensitive to correlated dimensions, can account for a form of base-rate neglect, does not suffer catastrophic forgetting, and can exhibit 3-stage (U-shaped) learning of high-frequency exceptions to rules, whereas such effects are not easily accounted for by models using other combinations of representation and learning method.
Recent research on contingency judgment indicates that the judged predictiveness of a cue is dependent on the predictive strengths of other cues. Two classes of models correctly predict such cue interaction: associative models and statistical models. However, these models differ in their predictions about the effect of trial order on cue interaction. In five experiments reported here, college students viewed trial-by-trial data regarding several medical symptoms and a disease, judging the predictive strength of each symptom with respect to the disease. The results indicate that trial order influences the manner in which cues interact, but that neither the associative nor the statistical models can fully account for the data pattern. A possible variation of an associative account is discussed.
We used adaptive network theory to extend the Rescorla-Wagner (1972) least mean squares (LMS) model of associative learning to phenomena of human learning and judgment. In three experiments subjects learned to categorize hypothetical patients with particular symptom patterns as having certain diseases. When one disease is far more likely than another, the model predicts that subjects will substantially overestimate the diagnosticity of the more valid symptom for the rare disease. The results of Experiments 1 and 2 provide clear support for this prediction in contradistinction to predictions from probability matching, exemplar retrieval, or simple prototype learning models. Experiment 3 contrasted the adaptive network model with one predicting pattern-probability matching when patients always had four symptoms (chosen from four opponent pairs) rather than the presence or absence of each of four symptoms, as in Experiment 1. The results again support the Rescorla-Wagner LMS learning rule as embedded within an adaptive network model.
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).
Four experiments used a novel stimulus sequence to compare simultaneous and sequential associations among neutral stimuli in a sensory preconditioning procedure. In Experiments 1, 2, and 4, rats received a sequence of the form AB-B' in which A was simultaneous with B but sequential with B'. Subsequently, either B or B' was conditioned, and the response to A assessed. This procedure matches the context of A's presentation in comparing its sequential association with B' and its simultaneous association with B, something that prior paradigms have neglected. Experiment 3 used an analogous B'-AB procedure to compare simultaneous and backward associations. Experiments 1-3 used a flavor-aversion procedure in which A, B, and B' were flavors and lithium chloride was the reinforcer. Experiment 4 used conditioned suppression with auditory and visual stimuli and shock reinforcer. All four experiments found simultaneous associations between A and B to be substantial. Moreover, in all cases, conditioning of B produced a greater response to A than did conditioning to B', which suggests that simultaneous associations are stronger than are sequential ones when this paradigm is employed.
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.
Differences in processing representations of conditioned and unconditioned stimuli (CSs and USs) may result from either their temporal order in training (i.e., CSs precede USs) or the greater biological significance of USs. The CS- and US-preexposure effects were used to probe this question. These effects are similar except that context extinction between preexposure and training more readily attenuates the US- than the CS-preexposure effect. In Experiments 1, 2, and 5, context extinction following preexposure to the stimulus that later served as Event 1 in Event 1-->Event 2 pairings alleviated the response deficit due to Event 1 preexposure if Event 1 was biologically significant. In Experiments 3 and 4, context extinction alleviated the response deficit due to Event 2 preexposure if Event 2 was biologically significant. Thus, biological significance and not temporal order determines how a representation will be processed.
Stimulus competition (e.g., blocking) has been observed between antecedent events (i.e., conditioned stimuli or potential causes), but recent evidence within the human causal learning literature suggests that it could also be obtained between subsequent events (i.e., unconditioned stimuli or potential effects). The present research tested this hypothesis with rat subjects. To avoid confounding the antecedent versus subsequent variable with the affective value of the events involved (i.e., unconditioned stimuli are ordinarily of greater affective value than conditioned stimuli), a preparation was used in which antecedent and subsequent events all lacked affective value during the blocking phases of the study. This was achieved through the use of sensory preconditioning. Blocking of subsequent events as well as antecedent events was observed. The challenge to most associative theories that is provided by blocking of subsequent events is discussed.
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.
Three experiments tested a simple connectionist network approach to human categorization. The specific network considered consists of a layer of input nodes, each representing a feature of the exemplar to be categorized, connected in parallel to a layer of output nodes representing the categories. Learning to categorize exemplars consists of adjusting the weights in the network so as to increase the probability of making correct categorizations; weight changes are determined by the Rescorla-Wagner (1972) learning rule. The experiments used a simulated medical diagnosis procedure in which subjects have to decide which disease (the category) each of a series of patients is suffering from on the basis of the patients' symptoms (the features). After a series of trials, the subjects rated the extent to which particular symptoms were associated with particular diseases. In each of the experiments, it is shown that a process of selective learning occurs in this categorization task and that selection in turn depends on the relative predictiveness of the symptom for the disease. Such effects parallel results found in animal conditioning experiments and are readily reproduced by the connectionist network model. The results are also discussed in terms of a variety of traditional theories of categorization.
College students rated the causal efficacy of Elements X, A, and B of food compounds AX and BX in producing the allergic reaction of a hypothetical patient. The results of a 16-day allergy test were presented to subjects in a serial, trial-by-trial manner. The response format used was a running estimate, in which subjects were asked to rate all of the three foods after each of the 16 trials. Ratings of distinctive Elements A and B diverged and ratings of common Element X decreased as the difference in the correlation of AX and BX with the occurrence and nonoccurrence of the allergic reaction increased. These human causal judgments closely correspond with stimulus selection effects observed in the conditioned responses of animals in associative learning studies. The experiment also directly demonstrated the fact that significant changes in the causal ratings of a stimulus occur on trials in which the cue is not presented. Associative theories such as that of Rescorla and Wagner (1972) predict changes in associative strength only for those stimulus elements that are presented on a particular trial. A modification of the Rescorla-Wagner model is described that correctly predicts immediate changes in the associative strengths of all relevant cues on each trial—whether presented or not.
Three experiments investigated whether a process akin to L. J. Kamin's (1969) blocking effect would occur with human contingency judgments in the context of a video game. 102 students were presented with sets of trials on each of which they could perform a particular action and observe whether the action produced a particular outcome in a situation in which there was an alternative potential cause of the outcome. Exp I showed that prior observation of the relationship between the alternative cause and the outcome did indeed block or reduce learning about the subsequent action-outcome relationship. However, exposure to the relationship between the alternative cause and the outcome after observing the association between the action and the outcome also reduced judgments of the action-outcome contingency (backward blocking), a finding at variance with conditioning theory. In Exp II, it was found that the degree of backward blocking depended on the predictive value of the alternative cause. Finally, Exp III showed that the backward blocking effect was not the result of greater forgetting about the action-outcome relationship in the experimental than in the control condition. Results cast doubt upon the applicability of contemporary theories of conditioning to human contingency judgment.
Conditioned flavor aversions were extinguished by presenting without consequence auditory stimuli that had been previously paired with the aversive flavor. In Experiment 1, rats that received tone-sucrose pairings, then sucrose-lithium chloride (LiCl) pairings, and finally repeated tone-alone presentations showed greater sucrose consumption in subsequent testing than rats that received similar sucrose-LiCl pairings and tone-alone presentations but no initial tone-sucrose pairings. Experiment 2 demonstrated the stimulus specificity of the mediated extinction observed in Experiment 1. In Experiment 3, rats that received first-order light-food and second-order tone-light pairings prior to sucrose-LiCl pairings did not show greater subsequent sucrose consumption when extinction of the second-order tone intervened. These results suggest that conditioned stimulus (CS)-evoked representations of events can substitute for those events themselves in the extinction of previously established associations.
Two experiments are reported which investigated the conditioning of inhibition to a neutral stimulus as a result of its repeated pairing with a previouslyconditioned inhibitor. Both experiments employed a conditioned suppression technique with rat subjects. Experiment 1 detected the second-order inhibition through the retarded acquisition of concurrently administered excitatory conditioning. Experiment 2 found similar retardation in the acquisition of excitatory fear conditioning following previous second-order conditioning of inhibition to the stimulus. Implications are discussed for theories of the nature of inhibition and for second-order conditioning as an assessment technique.
Food aversions were established in rats by administering lithium chloride (LiCl) immediately after the presentation of an exteroceptive conditioned stimulus (CS) which previously had been paired with a food substance. In Experiment 1, rats which received first tone-food and then tone-LiCl pairings showed less food consumption in subsequent testing than rats which received only tone-food or tone-LiCl pairings. Experiments 2 and 3 demonstrated the stimulus specificity of aversions established in this manner. Rats which first received pairings of light and tone CSs with two different food substances and then received pairings of one of those CSs with LiCl showed greater aversion to the food previously associated with the LiCl-paired CS than to the other food substance. Experiment 3 also showed that specific aversions were not acquired if rats received CS-shock rather than CS-LiCl pairings. These results suggest that CS-evoked representations of events can substitute for those events themselves in the formation of new associations.
Conditioned lick suppression in rats was used to examine the effectiveness of three different “reminder” treatments in reactivating associations to a blocked stimulus in a Kamin blocking paradigm. Experiment I indicated that with our parameters prior tone-footshock pairings could block manifestation of a light-footshock association that would otherwise be evident following pairings of a light-tone compound stimulus with footshock. In Experiment II, exposure to either the US, the blocked stimulus (light), or the apparatus cues between the compound conditioning trials and testing decreased blocking. Experiments III(a) and III(b) replicated the unblocking effects seen in Experiment II and included control groups that received the identical training and reminder treatments except for the omission of the light from the compound stimulus. These latter animals failed to display behaviour comparable to the blocked and reminded subjects, thereby establishing the associative basis of suppression to the light in the animals reminded following treatment known to produce blocking. Experiment IV also replicated the results of Experiment II and included control groups that received identical light-tone compound trials and reminder treatments without prior conditioning to the tone alone. In these control groups, reminder treatments tended to disrupt rather than increase evidence of conditioning to the light. The results suggest that associations are formed to the added element of a compound despite prior conditioning to the initial element, and that failure on the test trial to retrieve these associations to the blocked CS, rather than a failure to attend to or learn about the added element, is at least in part responsible the Kamin blocking effect.
In this article I review research and theory on the "interference paradigms" in Pavlovian learning. In these situations (e.g., extinction, counterconditioning, and latent inhibition), a conditioned stimulus (CS) is associated with different unconditioned stimuli (USs) or outcomes in different phases of the experiment; retroactive interference, proactive interference, or both are often observed. In all of the paradigms, contextual stimuli influence performance, and when information is available, so does the passage of time. Memories of both phases are retained, and performance may depend on which is retrieved. Despite the similarity of the paradigms, conditioning theories tend to explain them with separate mechanisms. They also do not provide an adequate account of the context's role, fail to predict the effects of time, and overemphasize the role of learning or storage deficits. By accepting 4 propositions about animal memory (i.e., contextual stimuli guide retrieval, time is a context, different memories are differentially dependent on context, and interference occurs at performance output), a memory retrieval framework can provide an integrated account of context, time, and performance in the various paradigms.
Waldmann and Holyoak (1992) presented evidence in support of the claim that cue selection does not emerge in "diagnostic" human learning tasks in which the cues are interpretable as effects and the outcomes as the causes of those effects. Waldmann and Holyoak argued that this evidence presents a major difficulty for associationist theories of learning and instead supports a "causal model" theory. We identify a number of flaws in Waldmann and Holyoak's experimental procedures and report three new experiments designed to test their claim. In Experiment 1, cue selection was observed regardless of causal order and regardless of whether the cues were abstractly or concretely specified. In Experiments 2 and 3, cue selection was again observed when subjects predicted causes from effects. We conclude that our results are consistent with simple associationist theories of learning but contradict Waldmann and Holyoak's causal model theory.
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.
Recovery from blocking by extinguishing the blocking stimulus
- A P Blaisdell
- L M Gunther
- R R Miller
Blaisdell, A.P., Gunther, L.M., & Miller, R.R. (1997). Recovery from blocking by extinguishing the blocking stimulus. Manuscript submitted for publication.
Blocking of antecedent and subsequent events: Implications for cue competition in causal judgment
- F J Esmoris-Arranz
- R R Miller
- H Matute
Esmoris-Arranz, F.J., Miller, R.R., & Matute, H. (1997). Blocking of antecedent and subsequent events: Implications for cue competition in causal judgment. Journal of
Experimental Psychology: Animal Behavior Processes, 23, 145-156.