Proportion Congruency Research Articles

Additive Effects of Item-Specific and Congruency Sequence Effects in the Vocal Stroop Task.

There is a growing interest in assessing how cognitive processes fluidly adjust across trials within a task. Dynamic adjustments of control are typically measured using the congruency sequence effect (CSE), which refers to the reduction in interference following an incongruent trial, relative to a congruent trial. However, it is unclear if this effect stems from a general control mechanism or a distinct process tied to cross-trial reengagement of the task set. We examine the relationship of the CSE with another measure of control referred to as the item-specific proportion congruency effect (ISPC), the finding that frequently occurring congruent items exhibit greater interference than items that are often incongruent. If the two effects reflect the same control mechanism, one should find interactive effects of CSE and ISPC. We report results from three experiments utilizing a vocal Stroop task that manipulated these two effects while controlling for variables that are often confounded in the literature. Across three experiments, we observed large CSE and ISPC effects. Importantly, these effects were robustly additive with one another (Bayes Factor for the null approaching 9). This finding indicates that the CSE and ISPC arise from independent mechanisms and suggests the CSE in Stroop may reflect a more general response adjustment process that is not directly tied to trial-by-trial changes in attentional control.

Contextual recruitment of cognitive control in preadolescent children and young adults

The ability to use contextual cues to adjust cognitive control according to situational demands is a hallmark of flexible and adaptive behavior. We investigated the development of three different types of contextual control recruitment in children (9- and 12-year-olds) and young adults. First, we implemented a list-wide proportion congruence manipulation in which conflict trials were frequently/infrequently presented within a list of trials. Second, we implemented a location-specific proportion congruence manipulation in which conflict trials were frequently/infrequently presented at one of two locations. Both types of contextual control recruitment are based on the formation of high-level associations between context features (lists and locations) and the respective cognitive control set. Contextual recruitment of control is observed in reduced interference at contexts with high conflict frequencies. Finally, we investigated a trial-by-trial, conflict-triggered recruitment of cognitive control. Here, the experience of a conflict in the previous trial is expected to reduce subsequent conflict. In all three forms of control recruitment, distinct contextual cues reveal information about the required extent of cognitive control. Young adults showed reliable adjustments of control for all types of contextual cues. Children were able to demonstrate contextual control recruitment based on stable context–control associations (lists and locations). However, using single conflict signals turned out to challenge children in that they were able to adapt control resources only for error reduction, not for reaction times. Altogether, the results indicated that children can learn and use high-level associations between context and control sets. Implications regarding proactive and reactive mechanisms of cognitive control are discussed.

When stimulus-driven control settings compete: On the dominance of categories as cues for control.

Stimulus-driven or reactive control refers to the modulation of attention poststimulus onset via retrieval of learned control settings associated with task stimuli. The present study asked which stimulus-driven control setting "wins" the competition when more than 1 is available to guide attention. Utilizing an item-specific proportion congruence manipulation in a picture-word Stroop task, 7 experiments examined competition between item-level and category-level control settings. In Experiment 1, category-level control dominated as evidenced by transfer of control to unique 50% congruent items (exemplars) from biased (33% or 67% congruent) animal categories. In Experiment 2, the dominance persisted-transfer was observed even for inconsistent transfer items (e.g., 83% congruent bird from a 33% congruent bird category). Recategorization of the exemplars prior to the Stroop task (Experiment 3a) successfully shifted the dominance to item-level control as did changing the Stroop task goal (Experiment 4a); however, exposure to the exemplars (Experiment 3b) and individuation training prior to the Stroop task did not (Experiments 3c and 4b). These novel findings suggest category-level control dominates in guiding attention poststimulus onset, but this dominance is dependent on contextual features (i.e., mutable). We propose a salience account of dominance and discuss implications for item-based computational models. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

The face-specific proportion congruency effect: social stimuli as contextual cues.

Previous research shows that larger interference is observed in contexts associated with a high proportion of congruent trials than in those associated with a low proportion of congruent trials. Given that one of the most relevant contexts for human beings is social context, researchers have recently explored the possibility that social stimuli could also work as contextual cues for the allocation of attentional control. In fact, it has been shown that individuals use social categories (i.e., men and women) as cues to allocate attentional control. In this work, we go further by showing that individual faces (instead of the social categories they belong to) associated with a high proportion of congruent trials can also lead to larger interference effects compared to individual faces predicting a relatively low proportion of congruent trials. Furthermore, we show that faces associated with a high proportion of congruent trials are more positively evaluated than faces associated with a high proportion of incongruent trials. These results demonstrate that unique human faces are potential contextual cues than can be employed to apply cognitive control when performing an automatic task.

Context-specific adjustment of cognitive control: Transfer of adaptive control sets.

Cognitive control protects processing of relevant information from interference by irrelevant information. The level of this processing selectivity can be flexibly adjusted to different control demands (e.g., frequency of conflict) associated with a certain context, leading to the formation of specific context-control associations. In the present study we investigated the robustness and transferability of the acquired context-control demands to new situations. In three experiments, we used a version of the context-specific proportion congruence (CSPC) paradigm, in which each context (e.g., location) is associated with a specific conflict frequency, determining high and low control demands. In a learning phase, associations between context and control demands were established. In a subsequent transfer block, stimulus-response mappings, whole task sets, or context-control demands changed. Results showed an impressive robustness of context-control associations, as context-specific adjustments of control from the learning phase were virtually unaffected by new stimuli and tasks in the transfer block. Only a change of the context-control demand eliminated the context-specific adjustment of control. These findings suggest that context-control associations that have proven to be adaptive in the past are continuously applied despite major changes in the task structure as long as the context-control associations remain the same.

The effect of dopaminergic medication on conflict adaptation in Parkinson's disease.

Parkinson's disease (PD) is a neurological disorder associated primarily with motor symptoms such as tremor, slowness of movement, and difficulties with gait and balance. Most patients take dopaminergic medication to improve their motor functions. Previous studies reported indications that such medication can impair higher cognitive functions (cf. dopamine overdose hypothesis). In the present study, we examined the effect of medication status on conflict adaptation. PD patients performed a Stroop task in which we manipulated the proportion of congruent and incongruent items, thereby allowing us to explore conflict adaptation. The use of mouse movements allowed us to examine the action dynamics of conflict adaptation in PD, and their sensitivity to dopaminergic medication. Each patient performed the same task twice: once without making changes to their regular medication regime, and once after overnight withdrawal from their medication. Results showed that medication improved mouse movements and alleviated motor symptoms. Moreover, patients' mouse movements were modulated as a function of the proportion congruency manipulation, revealing conflict adaptation in PD, which was unaffected by medication status. The present study extends earlier work on conflict adaptation in PD where reduced transient (trial-by-trial) conflict adaptation was observed ON compared to OFF medication (Duthoo etal., 2013, Neuropsychology, 27, 556). Our findings suggest that more sustained cognitive control processes may not be sensitive to dopamine overdose effects.

Different mechanisms can account for the instruction induced proportion congruency effect

When performing a conflict task, performance is typically worse on trials with conflict between two responses (i.e., incongruent trials) compared to when there is no conflict (i.e., congruent trials), a finding known as the congruency effect. The congruency effect is reduced when the proportion of incongruent trials is high, relative to when most of the trials are congruent (i.e., the proportion congruency effect). In the current work, it was tested whether different kinds of instructions can be used to induce a proportion congruency effect, while holding the actual proportion of congruent trials constant. Participants were instructed to strategically use the (invalid) information that most of the trials would be congruent versus incongruent, or they were told to adopt a liberal versus a conservative response threshold. All strategies effectively altered the size of the congruency effect relative to baseline, although in terms of statistical significance the effect was mostly limited to the error rates. A diffusion-model analysis of the data was partially consistent with the hypothesis that both types of instructions induced a proportion congruency effect by means of different underlying mechanisms.

ERP evidence for conflict in contingency learning.

The proportion congruency effect refers to the observation that the magnitude of the Stroop effect increases as the proportion of congruent trials in a block increases. Contemporary work shows that proportion effects can be driven by both context and individual items, and are referred to as context-specific proportion congruency (CSPC) and item-specific proportion congruency (ISPC) effects, respectively. The conflict-modulated Hebbian learning account posits that these effects manifest from the same mechanism, while the parallel episodic processing model posits that the ISPC can occur by simple associative learning. Our prior work showed that the neural correlates of the CSPC is an N2 over frontocentral electrode sites approximately 300 ms after stimulus onset that predicts behavioral performance. There is strong consensus in the field that this N2 signal is associated with conflict detection in the medial frontal cortex. The experiment reported here assesses whether the same qualitative electrophysiological pattern of results holds for the ISPC. We find that the spatial topography of the N2 is similar but slightly delayed with a peak onset of approximately 300 ms after stimulus onset. We argue that this provides strong evidence that a single common mechanism-conflict-modulated Hebbian learning-drives both the ISPC and CSPC.

Time-out for conflict monitoring theory: Preventing rhythmic biases eliminates the list-level proportion congruent effect.

The proportion congruent (PC) effect is the observation that congruency effects are smaller when most trials are incongruent rather than congruent. The list-level PC (LLPC) effect is the finding that a PC effect can transfer from biased inducer items to unbiased diagnostic items. Such effects are generally interpreted as resulting from conflict monitoring and attentional adaptation. An alternative view proposes that PC effects result from simple learning biases unrelated to conflict. The temporal learning account proposes that LLPC effects stem from a different task rhythm in the mostly congruent and mostly incongruent conditions. Two prime-probe experiments provide a critical test of this notion. In both, half of the participants were forced to withhold responding for a short period of time on inducer trials. This equates the task rhythm in the mostly congruent and mostly incongruent lists, while still maintaining differing levels of conflict. Consistent with the temporal learning account, but inconsistent with the conflict monitoring account, the LLPC effect was eliminated when rhythms were equated. (PsycINFO Database Record

The effects of awareness and secondary task demands on Stroop performance in the pre-cued lists paradigm

Prior research has demonstrated that explicit pre-cues informing participants of the proportion congruence of an upcoming list of Stroop trials affect performance in mostly congruent lists but not mostly incongruent lists. This pattern suggests a limited role for expectations in influencing Stroop performance. An alternative explanation, however, is that the effects of pre-cues may be masked by a bleed-over of awareness (of the proportion congruence manipulation) from cued to uncued lists given use of a within-subjects manipulation of cueing in prior research. One aim of the current study was to test this explanation by examining patterns of cueing effects when cueing is manipulated between subjects. A second aim was to examine the effects of a secondary, stimulus detection task on expectation and experience-driven effects in the pre-cued lists paradigm. Countering the bleed-over of awareness account, the prior finding of a selective effect of expectations in mostly congruent lists was again observed in the current experiments, and post-experimental assessments of awareness in the uncued condition were unrelated to Stroop performance. Additionally, it was demonstrated that the secondary task did not disrupt experience-driven control but did disrupt the expectation-driven use of pre-cues especially when participants did not know that secondary task stimuli would appear in advance of a list. These findings advance our understanding of the role of awareness in patterns of Stroop performance, and raise interesting questions about the types of advance knowledge that can be integrated in an expectation-driven fashion to optimize Stroop performance.

異なる競合が併存する事態における視覚情報選択の調整

The proportion congruency (PC) effect is a congruency effect that decreases as the ratio of congruent to incongruent trials within a given block increases. Researchers have been interested in the transference from a set of congruent to incongruent trials, with different ratios to a set of congruent and incongruent trials with equal ratios (diagnostic task). This present study investigated whether the PC effect is transferred across tasks with a coexisting Stimulus-Response conflict (Simon task) and Stimulus-Stimulus conflict (spatial-Stroop task) in a Stimulus-Response compatibility task. Right-handed students (N = 16) were required to identify the direction of an up/down arrow presented in four possible locations (right/up, right/down, left/up and left/down). We observed the transference from two perspectives, i.e., the Simon and spatial-Stroop views. The results indicated that the PC effect was not transferred across different types of conflicts. Therefore, these results suggest that attentional control in the Simon and spatial-Stroop tasks is independent and has a simultaneous effect.

冲突控制中比例效应的理论争议与进展

冲突控制在过去几十年里主要关注于研究冲突适应现象的行为表现和神经机制，却忽略了另一个影响冲突解决的重要方面——任务背景。比例效应是指冲突效应的大小会随着不一致试次比例的升高而减小的现象，其反映了执行控制根据不同的任务背景进行自上而下调整的能力。本文梳理了比例效应相关研究，总结了有关比例效应的主流理论解释。关于比例效应争议主要存在于两方面：比例效应是否由认知控制主导；以及来源于LWPC还是ISPC。借助于行为和神经影响的研究证据，作者认为比例效应反映了不同任务背景下的冲突控制加工，并在此基础上提出从认知策略灵活性角度来解释比例效应的可能性。 The studies of interference control have prosperously development in the past decades and most of the surveys focused on the behavior performance and neural mechanism of confliction adaptation which means participants enhance the efficiency of interference resolution after they experienced confliction. Whereas, task context, which may be has important influence on interference control, has neglected by these studies. Proportion congruent (PC) effect, which means the size of Stroop effect could be linearly decreased with the proportion of incongruent trials increased, reflects how the interference control exerts the top-down adjustment according to different task contexts. In this article, we first summarized the studies related to PC effect and elucidated the theoretical accounts about PC effect. There is a fierce debate among these theories: 1) Whether the PC effect is modulated by cognitive control or not? 2) Is the PC effect originated from LWPC or ISPC? Based on behavior and fMRI studies, we think cognitive flexibility may be a good way to make a full understand of PC effect. PC effect reflects the process of interference control which modulated by different task context. The flexibility of cognitive control strategies, which exerts through distinct ways of top-down control and adjusts by task contexts, may be the neural mechanism underlying PC effect.

ターゲットに対する反応回数は遂行成績並びに視覚的注意に影響するのか

Visual attention refers to cognitive functions for selecting task-relevant information and filtering out task-irrelevant information. Psychological research on visual attention has utilized congruency effects observed in Stimulus-Response compatibility paradigms, such as the Stroop task, the Flanker task, and the Simon task as the benchmark for investigating cognitive control. A number of studies (e.g., Egner, 2007) have demonstrated that the congruency effect is larger when congruent trials appear frequently within a given block than when they appear infrequently. This phenomenon is termed the proportion congruency (PC) effect, which is considered to reflect fluctuations in visual selectivity. Recently, however, a number of researchers have challenged the view that the PC effect reflects the modulation of visual selectivity. Schmidt (2013) for example argued that the PC effect is driven by performance improvements based on learning predictive relationships between stimuli and responses, rather than by the modulation of visual selectivity. It is notably unclear whether performance improvements are caused by increased contingency of a specific stimulus-response, or high response frequency resulting from the increased contingency in a block. This study was designed to examine the effect of response frequency on Simon task performance by manipulating the number of responses (pushing response buttons) to a target in the Simon task. More specifically, right-handed undergraduate and graduate students (N = 16) were requested to press a key once for a specific target (e.g., red circle) and press the key twice for the other target (e.g., green circle). Our results demonstrated that reaction times and error rates were not dependent on the number of reactions. This finding suggests that performance improvement is caused by contingency learning of stimulus-response pairs and not by the high response frequency.

Context-Specific Proportion Congruency Effects: An Episodic Learning Account and Computational Model.

In the Stroop task, participants identify the print color of color words. The congruency effect is the observation that response times and errors are increased when the word and color are incongruent (e.g., the word “red” in green ink) relative to when they are congruent (e.g., “red” in red). The proportion congruent (PC) effect is the finding that congruency effects are reduced when trials are mostly incongruent rather than mostly congruent. This PC effect can be context-specific. For instance, if trials are mostly incongruent when presented in one location and mostly congruent when presented in another location, the congruency effect is smaller for the former location. Typically, PC effects are interpreted in terms of strategic control of attention in response to conflict, termed conflict adaptation or conflict monitoring. In the present manuscript, however, an episodic learning account is presented for context-specific proportion congruent (CSPC) effects. In particular, it is argued that context-specific contingency learning can explain part of the effect, and context-specific rhythmic responding can explain the rest. Both contingency-based and temporal-based learning can parsimoniously be conceptualized within an episodic learning framework. An adaptation of the Parallel Episodic Processing model is presented. This model successfully simulates CSPC effects, both for contingency-biased and contingency-unbiased (transfer) items. The same fixed-parameter model can explain a range of other findings from the learning, timing, binding, practice, and attentional control domains.

Dissociable early attentional control mechanisms underlying cognitive and affective conflicts.

It has been well documented that cognitive conflict is sensitive to the relative proportion of congruent and incongruent trials. However, few studies have examined whether affective conflict processing is modulated as a function of proportion congruency (PC). To address this question we recorded event-related potentials (ERP) while subjects performed both cognitive and affective face-word Stroop tasks. By varying the proportion of congruent and incongruent trials in each block, we examined the extent to which PC impacts both cognitive and affective conflict control at different temporal stages. Results showed that in the cognitive task an anteriorly localized early N2 component occurred predominantly in the low proportion congruency context, whereas in the affective task it was found to occur in the high proportion congruency one. The N2 effects across the two tasks were localized to the dorsolateral prefrontal cortex, where responses were increased in the cognitive task but decreased in the affective one. Furthermore, high proportions of congruent items produced both larger amplitude of a posteriorly localized sustained potential component and a larger behavioral Stroop effect in cognitive and affective tasks. Our findings suggest that cognitive and affective conflicts engage early dissociable attentional control mechanisms and a later common conflict response system.

The Effect of Aging on the Dynamics of Reactive and Proactive Cognitive Control of Response Interference.

A prime-target interference task was used to investigate the effects of cognitive aging on reactive and proactive control after eliminating frequency confounds and feature repetitions from the cognitive control measures. We used distributional analyses to explore the dynamics of the two control functions by distinguishing the strength of incorrect response capture and the efficiency of suppression control. For reactive control, within-trial conflict control and between-trial conflict adaption were analyzed. The statistical analysis showed that there were no reliable between-trial conflict adaption effects for either young or older adults. For within-trial conflict control, the results revealed that older adults showed larger interference effects on mean RT and mean accuracy. Distributional analyses showed that the decline mainly stemmed from inefficient suppression rather than from stronger incorrect responses. For proactive control, older adults showed comparable proactive conflict resolution to young adults on mean RT and mean accuracy. Distributional analyses showed that older adults were as effective as younger adults in adjusting their responses based on congruency proportion information to minimize automatic response capture and actively suppress the direct response activation. The results suggest that older adults were less proficient at suppressing interference after conflict was detected but can anticipate and prevent inference in response to congruency proportion manipulation. These results challenge earlier views that older adults have selective deficits in proactive control but intact reactive control.

Transfer of location-specific control to untrained locations

Recent research highlights a seemingly flexible and automatic form of cognitive control that is triggered by potent contextual cues, as exemplified by the location-specific proportion congruence effect--reduced compatibility effects in locations associated with a high as compared to low likelihood of conflict. We investigated just how flexible location-specific control is by examining whether novel locations effectively cue control for congruency-unbiased stimuli. In two experiments, biased (mostly compatible or mostly incompatible) training stimuli appeared in distinct locations. During a final block, unbiased (50% compatible) stimuli appeared in novel untrained locations spatially linked to biased locations. The flanker compatibly effect was reduced for unbiased stimuli in novel locations linked to a mostly incompatible compared to a mostly compatible location, indicating transfer. Transfer was observed when stimuli appeared along a linear function (Experiment 1) or in rings of a bullseye (Experiment 2). The novel transfer effects imply that location-specific control is more flexible than previously reported and further counter the complex stimulus-response learning account of location-specific proportion congruence effects. We propose that the representation and retrieval of control settings in untrained locations may depend on environmental support and the presentation of stimuli in novel locations that fall within the same categories of space as trained locations.

Temporal and spectral dynamics underlying cognitive control modulated by task-irrelevant stimulus-response learning

Behavioral and recent neuroimaging findings have shown reversal of interference effects due to manipulating proportion congruency (PC), which suggests that task-irrelevant stimulus-response (S-R) associations are strengthened and applied to predict responses. However, it is unclear how the strengthened S-R associations are represented and applied in the brain. We investigated with a between-subjects PC paradigm of the Hedge and Marsh task using electroencephalography (EEG). The behavioral results showed the reversal of the conflict effects, suggesting that task-irrelevant S-R associations were strengthened and used to prepare responses. The EEG results revealed the PC-related reversal of the conflict effects in the frontocentral N2 and parietal P3b amplitudes. Time-frequency analyses showed more pronounced PC-related reversal of the conflict effects in theta band (4-8Hz) activity in frontocentral sites. These results suggest that the strengthened S-R associations due to PC manipulation modulated cognitive control. Importantly, the amplitude of lateralized readiness potential was higher in the high-PC condition than in the low-PC condition, suggesting that the strengthened short-term-memory spatial S-R associations that modulated cognitive control were applied similarly to long-term-memory spatial S-R associations.

Proportion congruency and practice: A contingency learning account of asymmetric list shifting effects.

Performance is impaired when a distracting stimulus is incongruent with the target stimulus (e.g., "green" printed in red). This congruency effect is decreased when the proportion of incongruent trials is increased, termed the proportion congruent effect. This effect is typically interpreted in terms of the adaptation of attention in response to conflict. In contrast, the contingency account argues that the effect is driven by the learning of predictive relationships between words and responses. In a recent report, Abrahamse, Duthoo, Notebaert, and Risko (2013) demonstrated larger changes in the magnitude of the proportion congruent effect when switching from a mostly congruent list to a mostly incongruent list, relative to the reverse order. They argued that this asymmetric list shifting effect fits only with the conflict adaptation perspective. However, the current paper presents reanalyses of this data and an adaptation of the Parallel Episodic Processing model that together demonstrate how the contingency account can explain these findings equally well when considering the generally accepted notion that performance improves with practice. The contingency account may still be the most parsimonious view. (PsycINFO Database Record

ERP Evidence for Implicit Priming of Top-Down Control of Attention.

Proportion congruency effects are the observation that the magnitude of the Stroop effect increases as the proportion of congruent trials in a block increases. Contemporary work shows that proportion effects can be specific to a particular context. For example, in a Simon task in which items appearing above fixation are mostly congruent and items appearing below fixation are mostly incongruent, the Simon effect is larger for the items appearing at the top. There is disagreement as to whether these context-specific effects result from simple associative learning or, instead, a type of conflict-mediated associative learning. Here, we address this question in an ERP study using a Simon task in which the proportion congruency effect was context-specific, manipulating the proportion of congruent trials based on location (upper vs. lower visual field). We found significant behavioral proportion congruency effects that varied with the specific contexts. In addition, we observed that the N2 response of the ERPs to the stimuli was larger in amplitude for the high congruent (high conflict) versus low congruent (low conflict) conditions/contexts. Because the N2 is known to be greater in amplitude also for trials where conflict is high and is believed to be an electrical signal related to conflict detection in the medial frontal cortex, this supports the idea that conflict-mediated associative learning is involved in the proportion congruency effect.