Contiguity and overshadowing interactions in the rapid-streaming procedure.

When multiple cues are associated with the same outcome, organisms tend to select between the cues, with one revealing greater behavioral control at the expense of the others (i.e., cue competition). However, non-human and human studies have not always observed this competition, creating a puzzling scenario in which the interaction between cues can result in competition, no interaction, or facilitation as a function of several learning parameters. In five experiments, we assessed whether temporal contiguity and overshadowing effects are reliably observed in the streamed-trial procedure, and whether there was an interaction between them. We anticipated that weakening temporal contiguity (ranging from 500 to 1,000 ms) should attenuate competition. Using within-subject designs, participants experienced independent series of rapid streams in which they had to learn the relationship between visual cues (presented either alone or with another cue) and an outcome, with the cue-outcome pairings being presented with either a delay or trace relationship. Across experiments, we observed overshadowing (Experiments 1, 2, 4, and 5) and temporal contiguity effects (Experiments 2, 3, and 4). Despite the frequent occurrence of both effects, we did not find that trace conditioning abolished competition between cues. Overall, these results suggest that the extent to which contiguity determines cue interactions depends on multiple variables, some of which we address in the General discussion.

Failures of memory and the fate of forgotten memories.

This review is intended primarily to provide cognitive benchmarks and perhaps a new mindset for behavioral neuroscientists who study memory. Forgetting, defined here broadly as all types of decreases in acquired responding to stimulus-specific eliciting cues, is commonly attributed to one or more of the following families of mechanisms: (1) (4) associative interference by information similar to, but different from the target information, (2) spontaneous decay of memory with increasing retention intervals, (3) displacement from short-term memory by irrelevant information, and (4) inadequate retrieval cues at test. I briefly review each of these families and discuss data suggesting that many apparent instances of spontaneous forgetting and displacement from short-term memory can be viewed as variants of inadequate retrieval cues and associative interference. The potential for recovery of target information from each of these families of forgetting without further relevant training is then reviewed, with a conclusion that most forgetting is due to retrieval failure as opposed to irreversible erasure of memory. The more general point is made that there are logical problems with ever talking about attenuating or erasing a memory as a consequence of conventional forgetting or disrupted consolidation/reconsolidation. Consideration is then given to the frequently overlooked but highly beneficial consequences of most forgetting. Lastly, the major variables that moderate forgetting are summarized, including (a) the similarities of the target information including training context to the explicit retrieval cues and context present at test, (b) the similarities of potentially interfering acquired information to the retrieval cues and context present at test, and (c) the retention interval for the target information relative to that for the potentially interfering information. Appropriate manipulation of these variables can reduce forgetting, and increase forgetting when desired.

Extinction of a Pavlovian-conditioned inhibitor leads to stimulus-specific inhibition.

Conditioned inhibitors have been shown to be largely unaffected by non-reinforced exposure (i.e., extinction treatment). Although excitatory associations are readily diminished by extinction treatment, so-called inhibitory associations appear to be largely immune to them. In two fear-conditioning experiments with rats, it was found that a decrease in inhibitory control can result from a massive number of extinction exposures to the inhibitor. Experiment 1 provided evidence that extinction treatment attenuated negative summation between the potential inhibitor and a transfer excitor. However, the extinction treatment had no influence on responding to the original training compound, indicating that some stimulus-specific inhibitory potential remained even after massive extinction. Experiment 2 indicated that retarded excitatory acquisition to the inhibitory stimulus observed after extinction treatment of the inhibitor is no greater than that following a similar amount of stimulus pre-exposure without prior inhibition training (i.e., latent inhibition). The findings indicate that inhibitory associations can be extinguished with large numbers of extinction trials, but they appear to be much more resistant to extinction than excitatory associations.

Patterns of care and outcomes in small cell carcinoma of the prostate: A national cancer database analysis.

BACKGROUND: Small cell carcinoma (SCC) of the prostate is a rare, aggressive disease. Evidence is limited; however, the current standard of care is chemotherapy. The benefit of local treatment modalities is unknown. METHODS: We queried the National Cancer Database identifying all SCC/neuroendocrine cases of the prostate, excluding those with unknown nodal or metastatic status, unknown treatment, or those not receiving chemotherapy. Overall survival (OS) was calculated using Kaplan-Meier curves. Multivariable Cox proportional hazards model was used to identify factors associated with survival. A further subgroup analysis was performed on the utility of local therapy on survival in the nonmetastatic setting. RESULTS: Our final cohort included 657 patients with a median age of 68. Most patients had positive lymph nodes (60.1%) and metastatic disease (70.0%). Median survival was 12 months (95% confidence interval [95% CI], 11.1-13.3 months) with a median follow-up of 11.8 months. Metastatic disease, age greater than or equal to 70, omission of androgen deprivation therapy (ADT), and lower income (P < .05 for all) were all associated with reduced OS. Patients with prostate-specific antigen (PSA) greater than or equal to 33 ng/mL and those receiving ADT had better survival (P < .05). Those with nonmetastatic disease were more likely to undergo prostatectomy and/or prostatic/pelvic radiation (P < .0001). Prostatic/pelvic radiation in the nonmetastatic setting was associated with longer survival (P = .02). Though well powered, our study is limited by the selection bias inherent to all observational studies, despite the statistical methods utilized to reduce this effect. CONCLUSIONS: Although chemotherapy is the mainstay of treatment, radiation to the prostate/pelvis may be beneficial in the nonmetastatic setting. In addition to chemotherapy, ADT may benefit patients with an elevated PSA.

Associative structure of conditioned inhibition produced by inhibitory perceptual learning treatment.

Exposure to a set of complex stimuli yields an enhanced ability to discriminate between these stimuli. In previous experimental studies, two distinguishable stimuli, X and A, were each repeatedly paired with a common Stimulus B to create compound Stimuli XB and AB. Prior evidence suggests that unique Features X and A form mutually inhibitory associations. This was evidenced by pairing Feature A with a biologically relevant stimulus (i.e., an unconditioned stimulus [US]) and observing that Stimulus X alone later serves to inhibit anticipatory behaviors for that US. These observations may reflect the mutually inhibitory nature of the two Features X and A. However, by assessing the influence of X on behavior that anticipates the US rather than Feature A, these experiments tested inhibition only indirectly. In the present experiments, a more direct measure of inhibition is proposed and tested with rats. We found evidence of retardation and negative summation of associations between unique Features X and A in their capacity to serve as competing cues during overshadowing treatments. Stimulus X was less susceptible to overshadowing by A (which is indicative of retardation of the establishment of an X-A within-compound association) and was able to suppress overshadowing by A of another stimulus (Y) when X was presented with Y at test (which is indicative of negative summation of the representation of A by X). Thus, XB/AB trials were seen to establish an inhibitory relationship between X and A.

Facilitated Extinction Training to Improve Pharmacotherapy for Smoking Cessation: A Pilot Feasibility Trial.

Introduction: Varenicline reduces smoking satisfaction during the pre-cessation run-in period, which may contribute to extinction of cravings and smoking behavior. Research indicates that efficacy is enhanced when the run-in period is increased from 1 to 4 weeks, providing a longer extinction opportunity. We hypothesized that efficacy could be further enhanced by harnessing basic and applied research on extinction. We developed a pre-cessation extinction-facilitating intervention and tested its feasibility in a pilot trial. Methods: The facilitated extinction (FE) intervention comprised brief counseling and workbook-recommending strategies to maximize extinction processes during the run-in, including instructions to smoke at a normal rate across contexts and cues, and use of an extinction cue to enhance generalization. Participants were randomly assigned to one of three varenicline interventions: standard (1-week run-in), extended (4-week run-in), and extended + FE. Interventions were delivered prior to the target quit date (TQD). Assessments were conducted in weeks 1 and 4 pre-TQD and 1 and 3 months post-TQD, with focus on feasibility indices. Results: Recruitment and retention goals were met (N = 58). Treatment satisfaction was high across groups. The majority of FE participants adhered to instructions and maintained their usual smoking rate during the run-in period. Greater decreases in craving and smoking satisfaction were observed among participants in both extended groups versus the standard group (p < .005). Conclusions: Feasibility was demonstrated. Participants adhered to the FE intervention, thereby optimizing the number and variety of extinction trials. Findings support testing the novel FE smoking cessation intervention in a fully powered trial. Implications: This study expands the research on the clinical benefits of extending the pre-cessation run-in period of varenicline. It introduces the hypothesis that further benefit might be achieved by translating basic behavioral research, as well as cue-exposure research and therapy for other disorders, to improve the extinction and generalization processes thought to underlie much of varenicline's effect. A FE intervention was developed and found acceptable to smokers and feasible to implement in a research setting. The study sets the stage for a subsequent randomized controlled trial.

Proactive interference by cues presented without outcomes: Differences in context specificity of latent inhibition and conditioned inhibition.

This report is part of a larger project examining associative interference as a function of the nature of the interfering and target associations. Lick suppression experiments with rats assessed the effects of context shifts on proactive outcome interference by latent inhibition (LI) and Pavlovian conditioned inhibition (CI) treatments on subsequently trained Pavlovian conditioned excitation treatment. LI and CI were trained in Context A during Phase 1, and then excitation treatment was administered in Context B during Phase 2, followed by tests for conditioned excitation in Contexts A, B, or C. Experiment 1 preliminarily established our LI and CI treatments and resulted in equally retarded acquisition of behavioral control when the target cue was subsequently trained as a conditioned excitor and tested in Context A. However, only CI treatment caused the target to pass a summation test for inhibition. Centrally, Experiment 2 consisted of LI and CI treatments in Context A followed by excitatory training in Context B. Testing found low excitatory control by both LI and CI cues in Context A relative to strong excitatory control in Context B, but CI treatment transferred to Context C more strongly than LI treatment. Experiment 3 determined that LI treatment failed to transfer to Context C even when the number of LI trials was greatly increased. Thus, first-learned LI appears to be relatively context specific, whereas first-learned CI generalizes to a neutral context. These observations add to existing evidence that LI and CI treatments result in different types of learning that diverge sharply in transfer to a novel test context.

Associative structure of second-order conditioning in humans.

Second-order conditioning (SOC; i.e., conditioned responding to S2 as a result of S1-US pairings followed by S2-S1 pairings) is generally explained by either a direct S2→US association or by an associative chain (i.e., S2→S1→US). Previous research found that differences in responses to S2 after S1 was extinguished often depended on the nature of the S2-S1 pairings (i.e., sequential or simultaneous). In two experiments with human participants, we examined the possibility that such differences result from S1 evoking S2 during extinction of S1 following simultaneous but not sequential S2-S1 pairings. This evocation of S2 by S1 following simultaneous pairings may have paired the evoked representation of S2 with absence of the outcome, thereby facilitating mediated extinction of S2. Using sequential S2-S1 pairings, both Experiments 1 and 2 failed to support this account of how extinction of S1 reduced responding to S2. Experiment 1 found that extinguishing S1 reduced responding to S2, while extinguishing S2 had little effect on responses to S1, although forward evocation of S1 during extinction of S2 paired the evoked representation of S1 with absence of the outcome. In Experiment 2, evocation of S2 during S1 nonreinforced trials was prevented because S2-S1 pairings followed (rather than proceeded) S1-alone exposures. Nevertheless, responding to S2 at test mimicked S1 responding. Responding to S2 was high in the context in which S1 had been reinforced and low in the context in which S1 had been nonreinforced. Collectively, these experiments provide additional support for the associative-chain account of SOC.

Destination memory: the relationship between memory and social cognition.

Destination memory refers to the ability to remember to whom one has sent information (e.g., "did I tell my colleague X or Y about the conference?", "did I send that email to my colleague X or Y?"). This review describes empirical studies demonstrating how normal aging and neurological disorders compromise destination memory. Centrally, we propose a comprehensive framework, destination memory framework (DMF), in which destination memory contributes to the uniqueness of a communications episode by creating an association between the content of a communications event and the context of its transmission. The DMF also focuses on how the association between communicated information and its destination, an association mainly supported by binding, can be related to the subjective experience of an episode. Additionally, the DMF emphasizes how destination recall can be influenced by social processing, specifically by familiarity of interlocutors, stereotypes that are associated with interlocutors, and the perceived emotional and cognitive states of interlocutors. By so doing, we highlight how destination memory can be intertwined with not only basic cognition but social cognition as well.

The communicative function of destination memory.

Mahr & Csibra's (M&C's) proposal that episodic memory has a role in communicative interaction is innovative. However, the model would be strengthened by the inclusion of the construct of destination memory. Destination memory refers to the ability to remember to whom one has sent information. Research has demonstrated that this ability is essential for communicative efficacy and daily interactions with others.

The role of test context in latent inhibition of conditioned inhibition: Part of a search for general principles of associative interference.

In two lick suppression experiments with rats, we assessed interference with behavior indicative of conditioned inhibition by a latent inhibition treatment as a function of test context. We asked what effect the test context has, given identical latent inhibition treatments in Phase 1 and identical conditioned inhibition trainings in Phase 2. In Experiment 1, an AAA versus AAB context-shift design determined that the latent inhibition treatment in Phase 1 attenuated behavior indicative of the conditioned inhibition training administered in Phase 2, regardless of the test context, which could reflect a failure to either acquire or express conditioned inhibition. In Experiment 2, an ABA versus ABB design showed that test performance in Contexts A and B reflected the treatments that had been administered in those contexts (i.e., conditioned inhibition was observed in Context B but not A), which could reflect either the context specificity of either latent inhibition or conditioned inhibition. In either case, latent inhibition of conditioned inhibition training in at least some situations was seen to reflect an expression deficit rather than an acquisition deficit. These data, in conjunction with prior reports, suggest that latent inhibition is relatively specific to the context in which it was administered, whereas conditioned inhibition is specific to its training context only when it is the second-learned relationship concerning the target cue. These experiments are part of a larger effort to delineate control by the test context of two-phase associative interference, as a function of the nature of target training and the nature of interference training.

Comparing the context specificity of extinction and latent inhibition.

Exposure to a cue alone either before (i.e., latent inhibition treatment) or after (i.e., extinction) the cue is paired with an unconditioned stimulus results in attenuated conditioned responding to the cue. Here we report two experiments in which potential parallels between the context specificity of the effects of extinction and latent inhibition treatments were directly compared in a lick suppression preparation with rats. The reversed ordering of conditioning and nonreinforcement in extinction and latent inhibition designs allowed us to examine the effect of training order on the context specificity of what is learned given phasic reinforcement and nonreinforcement of a target cue. Experiment 1 revealed that when conditioned-stimulus (CS) conditioning and CS nonreinforcement were administered in the same context, both extinction and latent inhibition treatments had reduced impacts on test performance, relative to excitatory conditioning when testing occurred outside the treatment context. Similarly, Experiment 2 showed that when conditioning was administered in one context and nonreinforcement was administered in a second context, the effects of both extinction and latent inhibition treatments were attenuated when testing occurred in a neutral context, relative to the context in which the CS was nonreinforced. The observed context specificity of extinction and latent inhibition treatments has been previously reported in both cases, but not in a single experiment under otherwise identical conditions. The results of the two experiments convergently suggest that memory of nonreinforcement becomes context dependent after a cue is both reinforced and nonreinforced, independent of the order of training.

The error in total error reduction.

Most models of human and animal learning assume that learning is proportional to the discrepancy between a delivered outcome and the outcome predicted by all cues present during that trial (i.e., total error across a stimulus compound). This total error reduction (TER) view has been implemented in connectionist and artificial neural network models to describe the conditions under which weights between units change. Electrophysiological work has revealed that the activity of dopamine neurons is correlated with the total error signal in models of reward learning. Similar neural mechanisms presumably support fear conditioning, human contingency learning, and other types of learning. Using a computational modeling approach, we compared several TER models of associative learning to an alternative model that rejects the TER assumption in favor of local error reduction (LER), which assumes that learning about each cue is proportional to the discrepancy between the delivered outcome and the outcome predicted by that specific cue on that trial. The LER model provided a better fit to the reviewed data than the TER models. Given the superiority of the LER model with the present data sets, acceptance of TER should be tempered.

Decline in cue-provoked craving during cue exposure therapy for smoking cessation.

INTRODUCTION: Based on the principles of Pavlovian learning and extinction, cue exposure therapy (CET) involves repeated exposure to substance-associated cues to extinguish conditioned cravings and reduce the likelihood of relapse. The efficacy of CET is predicated on successful extinction, yet the process of extinction in CET trials has rarely been demonstrated. This study explored the extinction process using a cue-reactivity paradigm in smokers undergoing multiple CET sessions as part of a comprehensive smoking cessation treatment. METHODS: The sample comprised 76 moderately dependent, treatment-seeking smokers who completed at least 4 CET sessions and 6 counseling sessions. The CET and counseling sessions were scheduled twice weekly, and participants began using transdermal nicotine replacement therapy on their quit day, which occurred prior to initiation of CET. Each CET session consisted of presentation of 140 images on a computer screen, with self-reported craving as the primary measure of cue reactivity. RESULTS: Mixed-model analyses revealed a progressive decline in cue-provoked craving both within and across 6 sessions of CET. Moderator analyses showed that the decline in craving was greatest among those who displayed initial cue reactivity. CONCLUSIONS: These data are consistent with the premise that CET can produce extinction of laboratory-based cue-provoked smoking cravings and highlight important individual differences that may influence extinction. Implications for conducting cue exposure research and interventions are discussed.

Attention as an acquisition and performance variable (AAPV).

This article introduces a new model of Pavlovian conditioning, attention as an acquisition and performance variable (AAPV), which, like several other so-called attentional models, emphasizes the role of variation of cue salience, together with associative strength, in accounting for conditioning phenomena. AAPV is primarily (but not exclusively) a performance-focused model in that it assumes not only that both the saliences and associative strengths of cue representations change during acquisition, but also that they are both influential at the time of test in determining responding. Different weights are given to the representations' associative strengths according to the representations' respective saliences at test. The model also treats the representation of a stimulus that is directly activated by presentation of that stimulus as distinct from the representation of the same stimulus that is activated by presenting a companion of the stimulus. Additionally, extinction is viewed as resulting from a decrease in the salience of the cue's representation, rather than a decrease in associative strength. Simulations of several Pavlovian phenomena are presented in order to illustrate the model and assess its robustness.

Enhancement and reduction of associative retroactive cue interference by training in multiple contexts.

Retroactive cue interference refers to situations in which a target cue X is paired with an outcome in phase 1 and a nontarget cue Z is paired with the same outcome in phase 2, with less subsequent responding to X being seen as a result of the phase 2 training. Two conditioned suppression experiments with rats were conducted to determine whether retroactive cue interference is similarly modulated by a manipulation that influences retroactive outcome interference (e.g., extinction). Both experiments used an ABC renewal-like design in which phase 1 training, phase 2 training, and testing each occurred in different contexts. Experiment 1 found that training the target association in multiple contexts without altering the number of training trials during phase 1 decreased retroactive cue interference (i.e., increased responding consistent with the target association). Experiment 2 found that training the interfering association in multiple contexts without altering the number of interference trials during phase 2 increased retroactive cue interference (i.e., decreased responding consistent with the target association). The possibility of similar mechanisms underlying cue interference and outcome interference is discussed.

Retrospective revaluation of associative retroactive cue interference.

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.

Cue duration and trial spacing effects in contingency assessment in the streaming procedure with humans.

According to the cycle/trial (C/T) rule, the rate of associative learning is a function of the ratio between the overall rate of U.S. presentation (C) and its rate in the presence of the conditioned stimulus (CS; [T]). This rule is well supported in studies with nonhumans. The present study was conducted to test whether it also applies to human contingency learning. In Experiment 1, participants were exposed to rapid streams of trials. Sensitivity to the cue-outcome contingency varied with both intertrial interval (ITI, which captures C) and cue duration, but the C/T rule was not respected, notably because the effect of ITI was much larger than the effect of cue duration. Experiment 2 showed that mere suppression of verbal strategies did not alter the magnitude of the ITI effect. Experiment 3 replicated Experiment 1 but with cue duration and ITI varied between 1,000 and 3,000 ms instead of between 100 and 1,000 ms. Performance was insensitive to both cue duration and ITI. This was not the consequence of Experiment 3 only varying the cue duration to ITI ratio by a factor of 3; in Experiment 4 where the cue duration was 100 ms, a 300-ms ITI was sufficient to observe an ITI effect. The lack of an ITI effect with a 1,000-ms cue and an ITI varying between 1,000 and 3,000 ms was replicated in Experiment 5. These results are discussed in light of how processes underlying associative learning might break down when events occur very rapidly. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Conditioned suppression is an inverted-U function of footshock intensity.

Most theories of associative learning assert that conditioned responding to a target cue is a monotonically increasing function of unconditioned-stimulus (US) intensity. In a lick suppression preparation with rats, a cue was paired with a 0.4-, 0.6-, 0.8-, 1.0-, 1.2-, or 1.4-mA footshock in Experiment 1a, and with a 0.3-, 0.8-, 1.3-, or 1.8-mA footshock in Experiment 1b. Subsequent suppression in response to the cue was an inverted-U function of the US intensity. In Experiment 2, we demonstrated that massive extinction of the training context and compound conditioning can each attenuate the response decrement caused by training with a high-intensity US. The sometimes-competing-retrieval model (Stout & Miller, Psychological Review 114:759-783, 2007) provides a better fit to these data than do several other models of associative learning.

Associative foundation of causal learning in rats.

Are humans unique in their ability to interpret exogenous events as causes? We addressed this question by observing the behavior of rats for indications of causal learning. Within an operant motor-sensory preconditioning paradigm, associative surgical techniques revealed that rats attempted to control an outcome (i.e., a potential effect) by manipulating a potential exogenous cause (i.e., an intervention). Rats were able to generate an innocuous auditory stimulus. This stimulus was then paired with an aversive stimulus. The animals subsequently avoided potential generation of the predictive cue, but not if the aversive stimulus was subsequently devalued or the predictive cue was extinguished (Exp. 1). In Experiment 2, we demonstrated that the aversive stimulus we used was in fact aversive, that it was subject to devaluation, that the cue-aversive stimulus pairings did make the cue a conditioned stimulus, and that the cue was subject to extinction. In Experiments 3 and 4, we established that the decrease in leverpressing observed in Experiment 1 was goal-directed instrumental behavior rather than purely a product of Pavlovian conditioning. To the extent that interventions suggest causal reasoning, it appears that causal reasoning can be based on associations between contiguous exogenous events. Thus, contiguity appears capable of establishing causal relationships between exogenous events. Our results challenge the widely held view that causal learning is uniquely human, and suggest that causal learning is explicable in an associative framework.