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).

Associative interference and nonreinforcement in human contingency learning.

This article reports three experiments comparing the impact on contingency assessment of associative cue interference (proactive, interspersed, and retroactive) and nonreinforcement (latent inhibition, partial reinforcement, and extinction). All three experiments used variants of the rapid trial streaming procedure developed by Allan and collaborators. Participants were exposed to stimulus streams and then asked how likely it was for a target cue to be accompanied (Experiment 1) or to be followed (Experiments 2 and 3) by a target outcome. Experiments 1 and 2 looked at interference and found that when the objective target cue-outcome contingency is positive, interspersed interference is more effective than either proactive or retroactive interference. Experiment 2 additionally showed that this conclusion was a function of the target cue-outcome contingency: when the number of cue-outcome pairings was low, retroactive interference was more efficient than interspersed interference. Experiment 3 examined nonreinforcement and found that the efficacies of latent inhibition, partial reinforcement, and extinction are also a function of the target cue-outcome contingency, but the pattern differed greatly from what was observed in Experiment 2. When the number of cue-outcome pairings was high, there was no difference between latent inhibition, partial reinforcement, and extinction. When the number of cue-outcome pairings was low, extinction did not lower the contingency judgement, whereas latent inhibition and partial reinforcement did.

Error monitoring in rats? We need models.

Kononowicz et al. (2022, Proceedings of the National Academy of Sciences of the United States of America, 119, Article e2108850119) claims that rats monitor their errors in a timing task and can use this information to guide their behavior. The present outlook paper examines whether this conclusion is warranted by their data.

Signal detection analysis of contingency assessment: Associative interference and nonreinforcement impact cue-outcome contingency sensitivity, whereas cue density affects bias.

In a signal detection theory approach to associative learning, the perceived (i.e., subjective) contingency between a cue and an outcome is a random variable drawn from a Gaussian distribution. At the end of the sequence, participants report a positive cue-outcome contingency provided the subjective contingency is above some threshold. Some researchers have suggested that the mean of the subjective contingency distributions and the threshold are controlled by different variables. The present data provide empirical support for this claim. In three experiments, participants were exposed to rapid streams of trials at the end of which they had to indicate whether a target outcome O1 was more likely following a target cue X. Interfering treatments were incorporated in some streams to impend participants' ability to identify the objective X-O1 contingency: interference trials (X was paired with an irrelevant outcome O2), nonreinforced trials (X was presented alone), plus control trials (an irrelevant cue W was paired with O2). Overall, both interference and nonreinforced trials impaired participants' sensitivity to the contingencies as measured by signal detection theory's d', but they also enhanced detection of positive contingencies through a cue density effect, with nonreinforced trials being more susceptible to this effect than interference trials. These results are explicable if one assumes interference and nonreinforced trials impact the mean of the associative strength distribution, while the cue density influences the threshold. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Base rates bias performance in a temporal bisection task.

We investigated how base rates affect temporal discrimination. In a temporal bisection task, pigeons learned to choose one key after a short sample and another key after a long sample. When presented with a range of intermediate samples they produced a psychometric function characterized by a bias and a scale parameter. When one of the trained samples was more frequent than the other, only the location parameter changed, with the pigeons biasing their choices toward the key associated with the most frequent sample. We then reproduced the bisection task in a long operant chamber, with choice keys far apart, and tracked the pigeons' motion patterns during the sample. Pigeons learned to approach the short key following sample onset, wait on the "short side" for a few seconds, and then, when the sample continued, depart toward the long key. This time-place curve was affected by sample base rate: The probability of pigeons going directly to the long side after sample onset increased when long samples were more frequent than short samples, indicating a decrease of temporal control. We found no evidence of changes in temporal sensitivity. The results are most consistent with models of timing that take into account biasing effects and competition for stimulus control. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Individual differences in the perception of cue-outcome contingencies: A signal detection analysis.

In a signal detection theory (SDT) approach to associative learning, one assumes that, when a subject is exposed to a flow of stimuli, an association is created between the internal representations of a cue and of an outcome, allowing the representation of the cue to activate the representation of the outcome. The outcome activation is a random variable drawn from a Gaussian distribution with mean m (sensitivity to the contingency) and standard deviation d (variability in outcome activation). Depending on whether the outcome activation is above or below various decision thresholds, the participant perceives either a negative, a null, or a positive contingency between the cue and the outcome. This study presents a detailed SDT analysis of the performance of four participants on whom data in a contingency assessment task were collected almost daily during several months. Parameters from the SDT model proved relatively stable over time, except if feedback was provided to the subject. In that case, for some participants but not all, the sensitivity increased. The decision criteria were also affected. Some of these changes endured despite the discontinuation of feedback. The variability in outcome activation was not affected by the feedback.

Retroactive interference: Counterconditioning and extinction with and without biologically significant outcomes.

Following cue-outcome (X-O) pairings, 2 procedures that reduce conditioned responses to X are extinction, in which X is presented by itself, and counterconditioning, in which X is paired with a different outcome typically of valence opposite that of training. Although studies with animals have generally found counterconditioning more efficient than extinction in reducing responding, data from humans are less clear. They suggest counterconditioning is more efficient than extinction at interfering with emotional processing, but there is little difference between the two procedures regarding their impact on the verbal assessment of the probability of the outcome given the cue. However, issues of statistical power leave conclusions ambiguous. We compared counterconditioning and extinction in highly powered experiments that exploited a novel procedure. A rapid streamed-trial procedure was used in which participants were asked to rate how likely a target outcome was to accompany a target cue after being exposed to acquisition trials followed by extinction, counterconditioning, or neither. In Experiments 1 and 2, evaluative conditioning was assessed by asking participants to rate the pleasantness of the cues after treatment. These studies found counterconditioning more efficient than extinction at reducing evaluative conditioning but less efficient at decreasing the assessment of the conditional probability of the outcome given the cue. The latter effect was replicated with neutral outcomes in Experiments 3 and 4, but the effect was inverted in Experiment 4 in conditions designed to preclude reinstatement of initial training by the question probing the conditional probability of the outcome given the cue. Effect sizes were small (Cohen's d of 0.2 for effect on evaluative conditioning, Cohen's d of 0.3 for effect on the outcome expectancy). If representative, this poses a serious constraint in terms of statistical power for further investigations of differential efficiency of extinction and counterconditioning in humans. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Perception and the metaphysics of information.

Sims (Science, 360, 652-656, 2018) aimed to apply tools from information theory (rate-distortion theory) to perception. Here I provide an overview of rate-estimation theory and the way Sims applies to it to psychological issues before briefly discussing the implications of such applications.

Biasing performance through differential payoff in a temporal bisection task.

We investigated how differential payoffs affect temporal discrimination. In a temporal bisection task, pigeons learned to choose one key after a short sample and another key after a long sample. When presented with a range of intermediate samples they produced a Gaussian psychometric function characterized by a location (bias) parameter and a scale (sensitivity) parameter. When one key yielded more reinforcers than the other, the location parameter changed, with the pigeons biasing their choices toward the richer key. We then reproduced the bisection task in a long operant chamber, with choice keys far apart, and tracked the pigeons' motion patterns during the sample. These patterns were highly stereotypical-on the long sample trials, the pigeons approached the short key at sample onset, stayed there for a while, and then departed to the long key. The distribution of departure times also was biased when the payoff probabilities differed. Moreover, it is likely that temporal control decreased while control by location increased. No evidence was found of changes in temporal sensitivity. The results are consistent with models of timing that take into account bias effects and competition of stimulus control. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Log versus linear timing in human temporal bisection: A signal detection theory study.

Using signal detection theory, we investigated whether human participants represent time linearly or logarithmically in a bisection task. Participants saw a stimulus 1.0 to 1.5 s in duration, and then judged whether the stimulus duration was closer to 1.0 s or to 1.5 s, and how sure they were of their response. Whereas the mean of the subjective stimulus duration was a linear function of the objective stimulus duration, participants produced remarkably different psychophysical functions-linear for some participants, concave for others, and convex for still others. Hence, the appropriate question might not be whether humans encode time linearly or logarithmically, but for which participants and under which conditions is time encoded linearly, logarithmically, or even exponentially. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Associative versus predictive processes in Pavlovian conditioning.

Learning and memory are so obviously related that it is hard to see how the understanding of one could proceed without an understanding of the other. Yet, in psychology, they are studied by two different research communities. The concept of association, which is central both to the field of conditioning and to that of retrieval and forgetting, could be used to bridge the gap between the two concepts. However, the concept is quite different in the fields of learning and memory, a situation for which this article argues that the Rescorla-Wagner model is mainly to blame. By viewing Pavlovian conditioning as the outcome of a predictive process but using the traditional associative language developed in memory studies to describe this process, it has introduced an unnecessary confusion between memory and prediction within the field of learning. This confusion needs to be acknowledged so that the concepts of associations and predictions can again be differentiated. This would allow for better integration of the fields of learning and memory.

Psychophysics of associative learning: Quantitative properties of subjective contingency.

Allan and collaborators (Allan, Hannah, Crump, & Siegel, 2008; Allan, Siegel, & Tangen, 2005; Siegel, Allan, Hannah, & Crump, 2009) recently proposed to apply signal detection theory to the analysis of contingency judgment tasks. When exposed to a flow of stimuli, participants are asked to judge whether there is a contingent relation between a cue and an outcome, that is, whether the subjective cue-outcome contingency exceeds a decision threshold. In this context, we tested the following hypotheses regarding the relation between objective and subjective cue-outcome contingency: (a) The underlying distributions of subjective cue-outcome contingency are Gaussian; (b) The mean distribution of subjective contingency is a linear function of objective cue-outcome contingency; and (c) The variance in the distribution of subjective contingency is constant. The hypotheses were tested by combining a streamed-trial contingency assessment task with a confidence rating procedure. Participants were exposed to rapid flows of stimuli at the end of which they had to judge whether an outcome was more (Experiment 1) or less (Experiment 2) likely to appear following a cue and how sure they were of their judgment. We found that although Hypothesis A seems reasonable, Hypotheses B and C were not. Regarding Hypothesis B, participants were more sensitive to positive than to negative contingencies. Regarding Hypothesis C, the perceived cue-outcome contingency became more variable when the contingency became more positive or negative, but only to a slight extent. (PsycINFO Database Record

Stepping back from 'persistence and relapse' to see the forest: Associative interference.

Historically, there has been considerable interest in a large variety of forms of associative interference. However, various factors including interest in clinical application and perhaps recent funding priorities have resulted in a narrowed focus on one particular instance of interference, extinction, with relative neglect of other types of interference. We have been using the existing literature and conducting new experiments to determine whether there is a consistent set of rules governing the occurrence and persistence of two-phase associative interference across (a) proactive and retroactive interference, (b) cue and outcome interference, (c) the type of training in phase 1 (excitatory, inhibitory, or simple nonreinforcement), and (d) the type of training in phase 2 (excitatory, inhibitory, or simple nonreinforcement). Our hope is that a return to more general questions concerning associative interference might reveal broad truths concerning the nature of forgetting. Identifying global principles of associative interference may also help us better appreciate the nature of extinction, including how it can be enhanced and made more enduring, as well as how it can be minimized and made more fleeting.

Trial frequency effects in human temporal bisection: implications for theories of timing.

To contrast the classic version of the Scalar Expectancy Theory (SET) with the Behavioral Economic Model (BEM), we examined the effects of trial frequency on human temporal judgments. Mathematical analysis showed that, in a temporal bisection task, SET predicts that participants should show almost exclusive preference for the response associated with the most frequent duration, whereas BEM predicts that, even though participants will be biased, they will still display temporal control. Participants learned to emit one response (R[S]) after a 1.0-s stimulus and another (R[L]) after a 1.5-s stimulus. Then the effects of varying the frequencies of the 1.0-s and 1.5-s stimuli were assessed. Results were more consistent with BEM than with SET. Overall, this research illustrates how the impact of non-temporal factors on temporal discrimination may help us to contrast associative models such as BEM with cognitive models such as SET. Deciding between these two classes of models has important implications regarding the relations between associative learning and timing. This article is part of a Special Issue entitled: Associative and Temporal Learning.

On the content of learning in interval timing: representations or associations?

Models of timing differ on two fundamental issues, the form of the representation and the content of learning. First, regarding the representation of time some models assume a linear encoding, others a logarithmic encoding. Second, regarding the content of learning cognitive models assume that the animal learns explicit representations of the intervals relevant to the task and that their behavior is based on a comparison of those representations, whereas associative models assume that the animal learns associations between its representations of time and responding, which then drive performance. In this paper, we show that some key empirical findings (timescale invariant psychometric curves, bisection point at the geometric mean of the trained durations in the bisection procedure, and location of the indifference point in the time-left procedure) seem to make these two issues interdependent. That is, cognitive models seem to entail a linear representation of time, and at least a certain class of associative models seem to entail a log representation of time. These interdependencies suggest new ways to compare and contrast timing models.

The temporal pattern of responding in conditioned bar-press suppression: the role of the context switch and training mode.

The present study examined the temporal pattern of responding in a conditioned bar-press suppression task in rats. Rats were exposed to either a 30-s or a 120-s conditioned stimulus (CS) followed by a footshock. Training took place either while the rats were lever-pressing for water (online), or with the lever removed from the box (offline). They were then exposed to the CS while they were lever-pressing for water, either in the training context or in a different context. Bar-press suppression during the CS was constant across the duration of the CS during training, but was restricted to the initial portion of the CS at the time of testing, especially when subjects were tested in a different context. Those results replicate the reactive (as opposed to anticipatory) pattern observed in a lick suppression procedure by Jozefowiez et al. (2011) and indicate that a change in context at the time of testing might be critical for its expression.

Two components of responding in Pavlovian lick suppression.

The present research examined the temporal distribution of responding in a lick suppression paradigm. In Experiment 1, rats were trained with either a 30- or a 120-s conditioned stimulus (CS), which was followed either by a footshock (unconditioned stimulus [US]) or nothing. Licking during the CS was suppressed only in the former condition. Suppression was more pronounced early in the CS. In Experiment 2, rats were exposed to two 30-s or two 120-s CSs, with delivery of the shock being contingent on CS1 for half of the animals and on CS2 for the other half. For both the paired and the unpaired conditions, suppression at the beginning of CS1 was observed for all the groups. By discounting the possibility of generalization between CS1 and CS2, it appears that this initial suppression was not a conditioned response to the CS, but an unconditioned one due to mere exposure to the shock US.

Integration of spatial relationships and temporal relationships in humans.

Three experiments tested human participants on a two-dimensional, computer, landmark-based search task to assess the integration of independently acquired spatial and temporal relationships. Experiment 1 showed that A-B spatial training followed by B-outcome spatial training resulted in spatial integration in such a way that A was effectively associated with the outcome. Experiment 2 showed that A-B spatial and temporal training followed by B-outcome spatial and temporal training resulted in integration that created both spatial and temporal relationships between A and the outcome. Experiment 3 refuted an alternative explanation, one that is based on decision-making speed, to the temporal-integration strategy that was suggested by Experiment 2. These results replicate in humans the observations regarding spatial integration made by Sawa, Leising, and Blaisdell (2005) using a spatial-search task with pigeons, and they extend those observations to temporal integration.

Timescale invariance and Weber's law in choice.

Pigeons were exposed to concurrent schedules for which reinforcement was alternately available at different times for each of two choices. In Experiment 1 (in which reinforcement times progressed arithmetically), overall, but not relative, response rate was timescale invariant. In Experiment 2 (in which reinforcement times progressed geometrically and were more spaced out), there was temporal control at all reinforcement times, but the amplitude of left-right response alternation decreased as time in the trial increased. These results indicate that the temporal regulation of both overall and relative response rates conforms to Weber's law although relative rate is heavily influenced by processes other than timing. It also adds support to the idea that overall and relative response rate reflects the operation of two independent processes.

Timing in choice experiments.

In Experiment 1, pigeons chose between variable- and fixed-interval schedules. The timer for 1 schedule was reset by a reinforcement on that schedule or on either schedule. In both cases, the pigeons timed reinforcement on each schedule from trial onset. The data further suggest that their behavior reflects 2 independent processes: 1 deciding when a response should be emitted and responsible for the timing of the overall activity, and the other determining what this response should be and responsible for the allocation of behavior between the 2 response keys. Results from Experiment 2, which studied choice between 2 fixed-interval schedules, support those 2 conclusions. These results have implications for the study of operant choice in general.