Color-word Contingency Learning Research Articles

Two sources of color-word contingency learning: Episodic retrieval of stimulus-response bindings and propositional knowledge.

There is an ongoing debate about the cognitive mechanisms behind human contingency learning (CL). Although, in some studies, episodic retrieval of previous responses fully explained the observed CL effects (C. G. Giesen et al., 2020; Schmidt et al., 2020), other findings suggest that global contingencies have an additional effect on behavior (Xu & Mordkoff, 2020). In a high-powered (N = 500), preregistered study, we investigated CL effects after controlling for episodic retrieval of distractor-target (S-S) and distractor-response (S-R) bindings. Retrieval explained a large part of the CL effect. However, we still found a reliable residual CL effect even after controlling for retrieval. Notably, the residual CL effect depended on contingency awareness: The residual CL effect only occurred for trials for which participants correctly detected the respective color-word contingency, whereas for trials without contingency awareness, there was no residual CL effect. Collectively, our findings suggest that human CL is driven by two independent sources: (a) episodic retrieval of S-S and S-R bindings and (b) propositional knowledge of the contingencies. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Supplemental Material for Two Sources of Color–Word Contingency Learning: Episodic Retrieval of Stimulus-Response Bindings and Propositional Knowledge

Supplemental Material for Two Sources of Color–Word Contingency Learning: Episodic Retrieval of Stimulus-Response Bindings and Propositional Knowledge

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.

EXPRESS: Contingency learning and episodic contributions to the Item-Specific Proportion Congruent Effect.

Several studies have challenged the conflict adaptation account of cognitive control effects, suggesting that they are the result of learning/memory processes independent from control modulation. Some authors have suggested that the Item-Specific Proportion Congruent (ISPC) effect (i.e., the smaller congruency effect on items presented frequently in an incongruent combination) is driven by color-word contingency learning (CL). However, it has recently been suggested that CL can be explained in terms of episodic retrieval of the response given to the last encounter with the same stimulus, with no role of associative learning. The present study aims to analyze the independent role of CL and episodic retrieval on the ISPC effect. Experiment 1 showed no effect of control modulation and indicated that, when manipulated independently, learning-driven contingency is modulated by the episodic factor, but it remains significant. Experiments 2 and 3 extended the study of the interplay between learning and recency to the color-word CL paradigm, finding larger contingency effects on color words compared to neutral ones and replicating the interaction between CL and episodic retrieval from Experiment 1. Surprisingly, these two experiments also showed control modulation apart from contingency and recency effects in color words. In sum, our study reveals that the ISPC effect results from the joint contribution of cognitive control, associative learning, and episodic effects.

Simultaneous Engagement of Top-Down and Bottom-Up Control in the Stroop Task

Abstract: In this study, with three Stroop task experiments, we investigated simultaneous engagement of list-wide and item-specific control mechanisms and their potential interaction. By using list-wide proportion congruency (LWPC), item-specific proportion congruency (ISPC)-transfer, and unbiased-transfer sets that were made up of distinct color-word pairings, we were able to observe both LWPC and ISPC effects. By comparing the LWPC effects that were observed with the ISPC-transfer sets and the unbiased-transfer sets, we investigated the relationship between item-specific control and list-wide control. By comparing the findings from Experiments 1 and 2 with the findings of Experiment 3, we observed the possible mediating role of contingency learning in the ISPC-transfer sets on the generalizability of list-wide control. Across all experiments, we consistently observed item-specific control, with the ISPC effect. Although we did not find evidence for list-wide control in the first two experiments, in the third experiment, where color-word contingency learning was minimal for ISPC-transfer items, we observed a significant LWPC effect. Our findings indicate that the introduction of contingency learning in the ISPC-transfer items may reduce top-down control. Importantly, none of the experiments revealed an interaction between item-specific control and list-wide control, suggesting that these two control mechanisms operated independently.

The Law of Recency: An Episodic Stimulus-Response Retrieval Account of Habit Acquisition.

A habit is a regularity in automatic responding to a specific situation. Classical learning psychology explains the emergence of habits by an extended learning history during which the response becomes associated to the situation (learning of stimulus-response associations) as a function of practice (“law of exercise”) and/or reinforcement (“law of effect”). In this paper, we propose the “law of recency” as another route to habit acquisition that draws on episodic memory models of automatic response regulation. According to this account, habitual responding results from (a) storing stimulus-response episodes in memory, and (b) retrieving these episodes when encountering the stimulus again. This leads to a reactivation of the response that was bound to the stimulus (c) even in the absence of extended practice and reinforcement. As a measure of habit formation, we used a modified color-word contingency learning (CL) paradigm, in which irrelevant stimulus features (i.e., word meaning) were predictive of the to-be-executed color categorization response. The paradigm we developed allowed us to assess effects of global CL and of an instance-based episodic response retrieval simultaneously within the same experiment. Two experiments revealed robust CL as well as episodic response retrieval effects. Importantly, these effects were not independent: Controlling for response retrieval effects eliminated effects of CL, which supports the claim that habit formation can be mediated by episodic retrieval processes, and that short-term binding effects are not fundamentally separate from long-term learning processes. Our findings have theoretical and practical implications regarding (a) models of long-term learning, and (b) the emergence and change of habitual responding.

Disentangling semantic and response learning effects in color-word contingency learning.

It is easier to indicate the ink color of a color-neutral noun when it is presented in the color in which it has frequently been shown before, relative to print colors in which it has been shown less often. This phenomenon is known as color-word contingency learning. It remains unclear whether participants actually learn semantic (word-color) associations and/or response (word-button) associations. We present a novel variant of the paradigm that can disentangle semantic and response learning, because word-color and word-button associations are manipulated independently. In four experiments, each involving four daily sessions, pseudowords—such as enas, fatu or imot—were probabilistically associated with either a particular color, a particular response-button position, or both. Neutral trials without color-pseudoword association were also included, and participants’ awareness of the contingencies was manipulated. The data showed no influence of explicit contingency awareness, but clear evidence both for response learning and for semantic learning, with effects emerging swiftly. Deeper processing of color information, with color words presented in black instead of color patches to indicate response-button positions, resulted in stronger effects, both for semantic and response learning. Our data add a crucial piece of evidence lacking so far in color-word contingency learning studies: Semantic learning effectively takes place even when associations are learned in an incidental way.

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.

Contingency Learning With Evaluative Stimuli

In two experiments, we tested the generality of the learning effects in the recently-introduced color-word contingency learning paradigm. Participants made speeded evaluative judgments to valenced target words. Each of a set of distracting nonwords was presented most often with either positive or negative target words. We observed that participants responded faster on trials that respected these contingencies than on trials that contradicted the contingencies. The contingencies also produced changes in liking: in a subsequent explicit evaluative rating task, participants rated positively-conditioned nonwords more positively than negatively-conditioned nonwords. Interestingly, contingency effects in the performance task correlated with this explicit rating effect in both experiments. In Experiment 2, all effects reported were independent of subjective and objective contingency awareness (which was completely lacking), even when awareness was measured at the item level. Our results reveal that learning in this type of performance task extends to nonword-valence contingencies and to responses different from those emitted during the performance task. We discuss the implications of these findings for theories about the processes that underlie contingency learning in performance tasks and for research on evaluative conditioning.

Adding the goal to learn strengthens learning in an unintentional learning task

Previous research has demonstrated that contingency learning can take place in the absence of the intention to learn. For instance, in the color-word contingency learning task, each distracting word is presented most often in a given target color (e.g., "month" in red and "plate" in green), and less often in the other colors. Participants respond more quickly and accurately when the word is presented in the expected rather than an unexpected color, even though there is no reason why they would have the intention to learn the contingencies between the words and the colors. It remains to be determined, however, whether learning in such situations would benefit or suffer from adding the goal to learn contingencies. In the reported experiment, half of the participants were informed that each word was presented most often in a certain color, and they were instructed to try to learn these contingencies. The other half of the participants were not informed that contingencies would be present. The participants given the learning goal produced a larger response time contingency effect than did the control participants. In contrast to some results from other learning paradigms, these results suggest that intentional learning adds to, rather than interferes with, unintentional learning, and we propose an explanation for some of the conflicting results.