Contingency Learning Effects Research Articles

Release from response interference in color-word contingency learning

In identifying the print colors of words when some combinations of color and word occur more frequently than others, people quickly show evidence of learning these associations. This contingency learning effect is evident in faster and more accurate responses to high-contingency combinations than to low-contingency combinations. Across four experiments, we systematically varied the number of response-irrelevant word stimuli connected to response-relevant colors. In each experiment, one group experienced the typical contingency learning paradigm with three colors linked to three words; other groups saw more words (six or twelve) linked to the same three colors. All four experiments disconfirmed a central prediction derived from the Parallel Episodic Processing (PEP 2.0) model (Schmidt et al., 2016)—that the magnitude of the contingency learning effect should remain stable as more words are added to the response-irrelevant dimension, as long as the color-word contingency ratios are maintained. Responses to high-contingency items did slow down numerically as the number of words increased between groups, consistent with the prediction from PEP 2.0, but these changes were unreliable. Inconsistent with PEP 2.0, however, overall response time did not slow down and responses to low-contingency items actually sped up as the number of words increased across groups. These findings suggest that the PEP 2.0 model should be modified to incorporate response interference caused by high-probability associations when responding to low-probability combinations.

Social norms shape visual appearance: Taking a closer look at the link between social norm learning and perceptual decision-making

One of the most fundamental questions in social psychology is whether norms can change individuals' minds by shaping the visual appearance of stimuli. This question was first raised by Muzafer Sherif (1935). Drawing on the extended social reinforcement account (Germar and Mojzisch, 2019), we aimed to provide a rigorous test of the hypothesis that norm learning leads to a persistent perceptual bias and, hence, to a change in the visual appearance of stimuli. From a methodological perspective, we used both a diffusion model approach and the method of adjustment, a well-established technique from psychophysics and vision research. The results of Experiments 1–3 show that norm effects on perceptual decision-making are robustly replicable, and are due to genuine social influence, that is, they cannot be explained by non-social priming, contingency learning effects (Experiments 1 and 2) or anchoring effects (Experiment 3). Most importantly, by using a psychophysical approach, Experiment 4 shows, for the first time, that social norm learning alters individuals' point of subjective equality and, hence, the visual appearance of stimuli.

Incidental learning in music reading: The music contingency learning task.

The present report investigated whether nonmusicians can incidentally learn musical skills needed for sight-reading. On each trial, participants identified a note name written inside of a note on the musical staff. In Experiment 1, each note was presented frequently with the congruent note name (e.g., "do" with the note for "do") and rarely with the incongruent names (e.g., "do" with the note for "fa"). With or without deliberate learning instructions, a robust contingency learning effect was observed: faster responses for congruent trials compared with incongruent trials. Participants also explicitly identified the meaning of the note positions more accurately than chance. Experiment 2 ruled out the potential influence of preexisting knowledge on the contingency learning effect by presenting notes most often with an incongruent note name. Robust learning was again observed, suggesting that participants acquired sufficient knowledge of musical notation to produce automatic influences on behaviour (e.g., akin to the interference effect previously found in skilled musicians). A congruency effect was additionally observed in Experiment 2, however. Experiment 3 further explored to what extent this congruency effect might be due to prior music knowledge and/or spatial stimulus-response compatibility between note and response locations (analogous to the SMARC effect). Overall, our results open up new avenues for investigating the incidental learning of complex material, musical or otherwise, and for reinforcing learning even further.

Contingency learning as binding? Testing an exemplar view of the colour-word contingency learning effect.

The learning of contingent regularities between events is fundamental for interacting with our world. We are also heavily influenced by recent experiences, as frequently studied in the stimulus-response binding literature. According to one view ("unitary view"), the learning of regularities across many events and the influence of recent events on current performance can coherently be explained with one high-learning rate memory mechanism. That is, contingency learning effects and binding effects are essentially the same thing, only studied at different timescales. On the other hand, there may be more to a contingency effect than just the summation of the influence of past events (e.g., an additional impact of learned regularities). To test these possibilities, the current report reanalyses a number of datasets from the colour-word contingency learning paradigm. It is shown that the weighted sum of binding effects accumulated across many previous trials (with especially strong influence of very recent events) does explain a large chunk of the contingency effect, but not all of it. In particular, the asymptote towards which the contingency effect decreases by accounting for an increasing number of previous-trial binding effects is robustly above zero. On the other hand, we also observe evidence for higher-order interactions between binding effects at differing lags, suggesting that a mere linear accumulation of binding episodes might underestimate their influence on contingency learning. Accordingly, focusing only on episodic stimulus-response binding effects that are due to the last occurrence of a stimulus rendered contingency learning effects non-significant. Implications for memory models are discussed.

Learning Habits: Does Overtraining Lead to Resistance to New Learning?

We explore the development of habitual responding within the colour-word contingency learning paradigm, in which participants respond to the colour of neutral words. Each word is most often presented in one colour. Learning is indicated by faster responses to the colour when the word is presented in the expected rather than in the unexpected colour. In Experiment 1, participants took part in two sessions, separated by one day. Critically, one set of words was trained across both days, and other new sets of words were introduced at various time points. Overall performance was faster on trials with overtrained words. Additionally, contingency effects were larger for overtrained words than for words introduced on Day 2. Removing the contingency had a similar impact on the learning effect for overtrained and new words. However, during a counterconditioning phase, where the words were made predictive of new colours, the previous contingency continued to influence performance for overtrained words but not for more recently introduced words. Relatedly, the new contingency was not acquired for the overtrained words. The reverse pattern was observed for recently-introduced words, with the newly-introduced contingency rapidly acquired and the influence of the old contingency quickly extinguished. In Experiments 2 and 3, however, both new and old learning effects were observed for both overtrained and recently-acquired contingencies. The net results suggest that while contingency learning effects are highly pliable during initial and subsequent learning, early-acquired contingency knowledge is maintained after removal of the contingency. Implications for models of learning are discussed.

Item-specific control of attention in the Stroop task: Contingency learning is not the whole story in the item-specific proportion-congruent effect.

A robust finding in the Stroop literature is that congruency effects (i.e., the color-naming latency difference between color words presented in incongruent vs. congruent colors) are larger for color words presented most often in their congruent color than for color words presented most often in incongruent colors. However, the cause of this item-specific proportion congruent (ISPC) effect is unclear, as it might be produced by either a conflict-adaptation strategy (e.g., prepare for conflict when the word RED appears) and/or a more general learning mechanism of stimulus-response contingencies (e.g., prepare to respond blue when the word RED appears). Thus far, attempts to directly dissociate the two processes appear to indicate no role for conflict adaptation, at least in situations in which contingency learning is also possible. We re-examined this conclusion in a Stroop task in which contingency learning and item-specific conflict frequency were manipulated partially independently. In addition to a contingency-learning effect emerging for stimuli matched on conflict frequency, a conflict-adaptation effect also emerged for stimuli matched on contingency. The two effects also had different time courses, with the contingency-learning effect emerging early and remaining stable throughout the experiment and the conflict-adaptation effect arising later in the experiment. These results challenge not only the contingency-learning account of the ISPC effect, an account that denies the existence of a conflict-adaptation process, but also control accounts that assume that, although conflict-adaptation processes do exist, they are not used when contingency learning is also possible.

Multiple expectancies underlie the congruency sequence effect in confound-minimized tasks

The congruency sequence effect (CSE) occurs when the congruency effect observed in tasks such as the Eriksen flanker task is smaller on trials preceded by an incongruent trial relative to trials preceded by a congruent trial. The CSE has been attributed to a range of factors including repetition expectancy, conflict monitoring, feature integration, and contingency learning. To clarify the debate surrounding the CSE and the mechanisms underlying its occurrence, researchers have developed confound-minimized congruency tasks designed to control for feature-integration and contingency-learning effects. A CSE is often observed in confound-minimized tasks, indicating that the effect is driven by repetition expectancy, conflict monitoring, or a combination of the two. Here, we propose and test a variant of the repetition expectancy account that emphasizes how multiple expectations can be formed simultaneously based upon the congruency type (congruent vs. incongruent) and the congruency repetition type (congruency repetition vs. congruency alternation) of the most recent trial. Data from confound-minimized versions of the prime-probe task were found to support this novel account. Data from confound-minimized versions of the Eriksen flanker, Simon, and Stroop tasks indicate that feature-integration confounds often remain in these tasks, potentially undermining the conclusions of previous work. We discuss the implications of these findings for ongoing theoretical debates surrounding the CSE.

Cue Competition and Incidental Learning: No Blocking or Overshadowing in the Colour-Word Contingency Learning Procedure Without Instructions to Learn

Overshadowing and blocking are two important findings that are frequently used to constrain models of associative learning. Overshadowing is the finding that learning about a cue (referred to as X) is reduced when that cue is always accompanied by a second cue (referred to as A) during the learning phase (AX). Blocking is the finding that after learning a stimulus-outcome relation for one stimulus (A), learning about a second stimulus (X) is reduced when the second stimulus is always accompanied by the first stimulus (AX). It remains unclear whether overshadowing and blocking result from explicit decision processes (e.g., “I know that A predicts the outcome, so I am not sure whether X does, too”), or whether cue competition is built directly into low-level association formation processes. In that vein, the present work examined whether overshadowing and/or blocking are present in an incidental learning procedure, where the predictive stimuli (words or shapes) are irrelevant to the cover task and merely correlated with the task-relevant stimulus dimension (colour). In two large online studies, we observed no evidence for overshadowing or blocking in this setup: (a) no evidence for an overshadowing cost was observed with compound (word-shape) cues relative to single cue learning conditions, and (b) contingency learning effects for blocked stimuli did not differ from those for blocking stimuli. However, when participants were given the explicit instructions to learn contingencies, evidence for blocking and overshadowing was observed. Together, these results suggest that contingencies of blocked/overshadowed stimuli are learned incidentally, but are suppressed by explicit decision processes due to knowledge of the contingencies for the blocking/overshadowing stimuli.

Context-specific proportion congruent effects: Compound-cue contingency learning in disguise.

Conflict between task-relevant and task-irrelevant stimulus information leads to impairment in response speed and accuracy. For instance, in the colour-word Stroop paradigm, participants respond slower and less accurately to the print colour of incongruent colour words (e.g., "red" printed in green) than to congruent colour words (e.g., "green" in green). Importantly, this congruency effect is diminished when the trials in an experiment are mostly incongruent, relative to mostly congruent, termed a proportion congruent effect. When distracting stimuli are mostly congruent in one context (e.g., location or font) but mostly incongruent in another context (e.g., another location or font), the congruency effect is still diminished in the mostly incongruent context, termed a context-specific proportion congruent (CSPC) effect. Both the standard proportion congruent and CSPC effects are typically interpreted in terms of conflict-driven attentional control, frequently termed conflict adaptation or conflict monitoring. However, in two experiments, we investigated contingency learning confounds in context-specific proportion congruent effects. In particular, two variants of a dissociation procedure are presented with the font variant of the CSPC procedure. In both, robust contingency learning effects were observed. No evidence for context-specific control was observed. In fact, results trended in the wrong direction. In all, the results suggest that CSPC effects may not be a useful way of studying attentional control.

Category learning in the color-word contingency learning paradigm.

In the typical color-word contingency learning paradigm, participants respond to the print color of words where each word is presented most often in one color. Learning is indicated by faster and more accurate responses when a word is presented in its usual color, relative to another color. To eliminate the possibility that this effect is driven exclusively by the familiarity of item-specific word-color pairings, we examine whether contingency learning effects can be observed also when colors are related to categories of words rather than to individual words. To this end, the reported experiments used three categories of words (animals, verbs, and professions) that were each predictive of one color. Importantly, each individual word was presented only once, thus eliminating individual color-word contingencies. Nevertheless, for the first time, a category-based contingency effect was observed, with faster and more accurate responses when a category item was presented in the color in which most of the other items of that category were presented. This finding helps to constrain episodic learning models and sets the stage for new research on category-based contingency learning.

The acquisition of simple associations as observed in color-word contingency learning.

Three experiments investigated the learning of simple associations in a color-word contingency task. Participants responded manually to the print colors of 3 words, with each word associated strongly to 1 of the 3 colors and weakly to the other 2 colors. Despite the words being irrelevant, response times to high-contingency stimuli and to low-contingency stimuli quickly diverged. This high-low difference remained quite constant over successive blocks of trials, evidence of stable contingency learning. Inclusion of a baseline condition-an item having no color-word contingency-permitted separation of the contingency learning effect into 2 components: a cost due to low contingency and a benefit due to high contingency. Both cost and benefit were quick to acquire, quick to extinguish, and quick to reacquire. The color-word contingency task provides a simple way to directly study the learning of associations. (PsycINFO Database Record

Contingency proportion systematically influences contingency learning

In the color-word contingency learning paradigm, each word appears more often in one color (high contingency) than in the other colors (low contingency). Shortly after beginning the task, color identification responses become faster on the high-contingency trials than on the low-contingency trials-the contingency learning effect. Across five groups, we varied the high-contingency proportion in 10% steps, from 80% to 40%. The size of the contingency learning effect was positively related to high-contingency proportion, with the effect disappearing when high contingency was reduced to 40%. At the two highest contingency proportions, the magnitude of the effect increased over trials, the pattern suggesting that there was an increasing cost for the low-contingency trials rather than an increasing benefit for the high-contingency trials. Overall, the results fit a modified version of Schmidt's (2013, Acta Psychologica, 142, 119-126) parallel episodic processing account in which prior trial instances are routinely retrieved from memory and influence current trial performance.

Relative speed of processing determines color-word contingency learning.

In three experiments, we tested a relative-speed-of-processing account of color-word contingency learning, a phenomenon in which color identification responses to high-contingency stimuli (words that appear most often in particular colors) are faster than those to low-contingency stimuli. Experiment 1 showed equally large contingency-learning effects whether responding was to the colors or to the words, likely due to slow responding to both dimensions because of the unfamiliar mapping required by the key press responses. For Experiment 2, participants switched to vocal responding, in which reading words is considerably faster than naming colors, and we obtained a contingency-learning effect only for color naming, the slower dimension. In Experiment 3, previewing the color information resulted in a reduced contingency-learning effect for color naming, but it enhanced the contingency-learning effect for word reading. These results are all consistent with contingency learning influencing performance only when the nominally irrelevant feature is faster to process than the relevant feature, and therefore are entirely in accord with a relative-speed-of-processing explanation.

The Parallel Episodic Processing (PEP) model 2.0: A single computational model of stimulus-response binding, contingency learning, power curves, and mixing costs

The current paper presents an extension of the Parallel Episodic Processing model. The model is developed for simulating behaviour in performance (i.e., speeded response time) tasks and learns to anticipate both how and when to respond based on retrieval of memories of previous trials. With one fixed parameter set, the model is shown to successfully simulate a wide range of different findings. These include: practice curves in the Stroop paradigm, contingency learning effects, learning acquisition curves, stimulus-response binding effects, mixing costs, and various findings from the attentional control domain. The results demonstrate several important points. First, the same retrieval mechanism parsimoniously explains stimulus-response binding, contingency learning, and practice effects. Second, as performance improves with practice, any effects will shrink with it. Third, a model of simple learning processes is sufficient to explain phenomena that are typically (but perhaps incorrectly) interpreted in terms of higher-order control processes. More generally, we argue that computational models with a fixed parameter set and wider breadth should be preferred over those that are restricted to a narrow set of phenomena.

Contingency learning is reduced for high conflict stimuli

Recent theories have proposed that contingency learning occurs independent of control processes. These parallel processing accounts propose that behavioral effects originally thought to be products of control processes are in fact products solely of contingency learning. This view runs contrary to conflict-mediated Hebbian-learning models that posit control and contingency learning are parts of an interactive system. In this study we replicate the contingency learning effect and modify it to further test the veracity of the parallel processing accounts in comparison to conflict-mediated Hebbian-learning models. This is accomplished by manipulating conflict to test for an interaction, or lack thereof, between conflict and contingency learning. The results are consistent with conflict-mediated Hebbian-learning in that the addition of conflict reduces the magnitude of the contingency learning effect.

Time course of colour-word contingency learning: Practice curves, pre-exposure benefits, unlearning, and relearning

In performance-based measures of implicit contingency learning, learning effects have been observed very early in the task (e.g., within a few trials) and remain stable throughout the experiment. This has been taken to suggest that the contingency knowledge underlying the learning effects is formed almost instantly and does not develop further across trials. One potential concern with the available evidence is that response times are overall much slower early on in an experiment and speed up over practice in a decelerating function. If learning effects scale with overall response time, then learning effects observed early on in an experiment might be artificially inflated. In the current report with the colour-word contingency learning paradigm, participants were given an extended practice phase before introducing predictive stimuli (words). Thus, learning could be assessed after the large practice speedup in performance had already occurred. In one experiment, the contingency learning effect was found to again be fairly stable, but with a hint of an increasing effect with time. In a second experiment, words were pre-exposed in a neutral hue before being coloured. This increased the magnitude of the learning effect, suggesting a preparation time benefit. More importantly, the contingency learning effect was observed to increase over time. In a third experiment, we assessed unlearning rates when the contingency was removed, and relearning when the contingencies were reintroduced. The results revealed a cumulative effect of contingencies acquired across multiple blocks. In sum, the evidence reported in this paper shows that, contrary to previous claims, implicit contingency learning is cumulative.

Contingency learning is not affected by conflict experience: Evidence from a task conflict-free, item-specific Stroop paradigm

A contingency learning account of the item-specific proportion congruent effect has been described as an associative stimulus–response learning process that has nothing to do with controlling the Stroop conflict. As supportive evidence, contingency learning has been demonstrated with response conflict-free stimuli, such as neutral words. However, what gives rise to response conflict and to Stroop interference in general is task conflict. The present study investigated whether task conflict can constitute a trigger or, alternatively, a booster to the contingency learning process. This was done by employing a “task conflict-free” condition (i.e., geometric shapes) and comparing it with a “task conflict” condition (i.e., neutral words). The results showed a significant contingency learning effect in both conditions, refuting the possibility that contingency learning is triggered by the presence of a task conflict. Contingency learning was also not enhanced by the task conflict experience, indicating its complete insensitivity to Stroop conflict(s). Thus, the results showed no evidence that performance optimization as a result of contingency learning is greater under conflict, implying that contingency learning is not recruited to assist the control system to overcome conflict.

Emotional reactivity during anticipation and perception of affective pictures.

The focus of the present study was on further exploring anticipatory responses to emotional stimuli by measuring the eyeblink startle reflex in a variation of the picture-picture affective learning procedure. Participants (113 undergraduate women) were not explicitly instructed before the experiment began. Instead, they had to learn the specific relations between cues (geometrical shapes) and emotional pictures based on pairings during the first part of the task. Plausible contingency learning effects were tested afterwards, in a parallel sequence of trials including auditory probes during cues and pictures processing during the second part of the task. Results did show the typical affective startle modulation pattern during perception, linear F(1, 200) = 52.67, p < .0001, but unexpected inhibition for both pleasant and unpleasant, compared to neutral cues, during anticipation, quadratic F(1, 200) = 7.07, p < .009. All patterns of startle modulation were independent of cue-picture contingency awareness (all interactions Fs < 1). Skin conductance changes showed the predictable quadratic trend either during picture perception or anticipatory periods (greater activity for emotional vs. neutral; overall quadratic F(1, 224) = 7.04, p < .01), only for participants fully aware of the cue-picture contingency, quadratic F(1, 158) = 5.86, p < .02. Overall, our results during anticipation (cues processing) seem to suggest that more resources were allocated to highly arousing pictures that engage attention. Differences between the present results and prior research may be attributed to procedural variations in the sample, cues, or instructions. Future studies should also explore in more detail the role of the contingency awareness during anticipation.

Contingency learning and unlearning in the blink of an eye: A resource dependent process

Recent studies show that when words are correlated with the colours they are printed in (e.g., MOVE is presented 75% of the time in blue), colour identification is faster when the word is presented in its correlated colour (MOVE in blue) than in an uncorrelated colour (MOVE in green). The present series of experiments explored the possible mechanisms involved in this colour-word contingency learning effect. Experiment 1 demonstrated that the effect is already present after 18 learning trials. During subsequent unlearning, the effect extinguished equally rapidly. Two reanalyses of data from Schmidt, Crump, Cheesman, and Besner (2007) ruled out an account of the effect in terms of stimulus repetitions. Experiment 2 demonstrated that participants who carry a memory load do not show a contingency effect, supporting the hypothesis that limited-capacity resources are required for learning. Experiment 3 demonstrated that memory resources are required for both storage and retrieval processes.