Stroop interference and development: Influence of expectation on color-naming response times

Introduction/objective

In a sample of 171 participants aged 6 to 18, the present investigation assessed the changes in the size of the Stroop effect with age, and its relationship with the development of expectancies.

Modeling the Stroop phenomenon: processes, processing flow, and development

A model of the Stroop phenomenon is proposed which postulates that the classic effect is an additive function of three parameters, that is, dimension selection (decision making about which dimension to respond to), dimension identification (encoding and identification of the relevant dimension), and interference control (filtering out of interference from non-relevant dimensions). The study used stimuli addressed to three symbol systems (verbal, numerical, and figural), two types of stimulus composition (compatible vs. incompatible), and two types of dimension selection (decision needed about the to-be-identified dimension vs. no decision needed). Participants were 9, 11, 13, and 15 years old and they were tested twice. The model was found to hold under all stimulus and presentation conditions. Moreover, it was found that the three parameters are differentially related to age. The implications of the model for general theories of cognition and cognitive development are discussed.     

What Stroop tasks can tell us about selective attention from childhood to adulthood

A rich body of research concerns causes of Stroop effects plus applications of Stroop. However, several questions remain. We included assessment of errors with children and adults (N = 316), who sat either a task wherein each block employed only trials of one type (unmixed task) or where every block comprised of a mix of the congruent, neutral, and incongruent trials. Children responded slower than adults and made more errors on each task. Contrary to some previous studies, interference (the difference between neutral and incongruent condition) showed no reaction time (RT) differences by group or task, although there were differences in errors. By contrast, facilitation (the difference between neutral and congruent condition) was greater in children than adults, and greater on the unmixed task than the mixed task. After considering a number of theoretical accounts, we settle on the inadvertent word‐reading hypothesis, whereby facilitation stems from children and the unmixed task promoting inadvertent reading particularly in the congruent condition. Stability of interference RT is explained by fixed semantic differences between neutral and incongruent conditions, for children versus adults and for unmixed versus mixed task. We conclude that utilizing two tasks together may reveal more about how attention is affected in other groups.     

A slow component of classic Stroop interference

The interference in colour naming may extend beyond critical Stroop trials. This “slow” effect was first discovered in emotional Stroop tasks, but is extended here to classical Stroop. In two experiments, meaningless coloured letter strings followed a colour word or neutral word. Student participants (Experiment 1), and 18 stroke patients and 18 matched controls (Experiment 2) showed substantial interference by incongruent colour words, both in the word trial (fast component) and in the subsequent string trial (slow component). Different patient subgroups emerged from the comparison of Stroop performance with the controls. An association of fast and slow components was only found in one subgroup. Exploratory analyses revealed no clear differences in damage location between subgroups. Fast interference caused by colour-meaning conflict may be specific for classical Stroop, but the broader occurrence of slow effects suggests a more generalised process of disengagement from attention-demanding stimuli.     

Words may not be enough! No increased emotional Stroop effect in obsessive-compulsive disorder

Conflicting evidence has been obtained whether or not patients diagnosed with obsessive-compulsive disorder (OCD) share an attentional bias towards disorder-related stimuli. Some of these inconsistencies can be accounted for by suboptimal stimuli selection. In consideration of the heterogeneity of OCD, we investigated Stroop interference effects for two classes of OCD items (i.e., washing and checking) in 23 OCD patients and 23 healthy controls. In order to cover prevalent OCD concerns, item compilation was based on experts' appraisals. Patients neither displayed greater immediate as well as delayed Stroop interference nor any bias for OCD and subtype-congruent stimuli. On the contrary, for washing-related items, OCD patients, and here especially washers, displayed facilitation relative to healthy controls. Although the present study at first sight refutes the notion of an attentional bias in OCD in contrast to other anxiety disorders, several potential moderators need to be considered before this account is ultimately dismissed. In particular, an attentional bias may only be elicited using visual material that is more attention-grabbing than verbal stimuli. Finally, blockwise instead of random item administration and greater consideration of individual relevance may be crucial prerequisites for the effect to emerge.     

Examination of emotional Stroop interference in obsessive-compulsive disorder

Previous research has produced conflicting findings on whether or not patients with subclinical or manifest obsessive-compulsive disorder (OCD) share an attentional bias for anxiety-related material. In the present study, 35 OCD patients were compared with 20 healthy controls on their performance in an emotional Stroop paradigm. Nine different stimulus conditions were compiled, including sets for depression-related and anxiety-related words as well as stimuli from two constructs with a potential relevance for the pathogenesis and maintenance of OCD symptomatology: responsibility and conscientiousness. Patients did not show enhanced interference for any of the conditions. Syndrome subtype and severity, avoidance and speed of information processing did not moderate results. The present study concurs with most prior research that OCD patients display no interference effect for general threat words. It deserves further consideration, that emotional interference effects in OCD as seen in other anxiety disorders occur when using idiosyncratic word material with a direct relation to the individual's primary concerns.     

The role of modality: Auditory and visual distractors in Stroop interference

As a commonly used measure of selective attention, it is important to understand the factors contributing to interference in the Stroop task. The current research examined distracting stimuli in the auditory and visual modalities to determine whether the use of auditory distractors would create additional interference, beyond what is typically observed in the print-based Stroop task. Research by Cowan and Barron supported the additive effects of auditory and visual distractors; however, there is only one empirical demonstration of this finding to date. Using different versions of the Stroop colour-naming task, behavioural analyses of reaction times (RT) were conducted, along with distributional RT analyses. The results indicated that a combination of visual and auditory distraction did not lead to a larger interference effect than visually based distraction alone. These findings suggest that methodological issues may have influenced the prior finding of additive effects of the two modalities, and are discussed in relation to the word production architecture account of Stroop effects.     

Conflict: Run! Reduced Stroop interference with avoidance responses

Conflict has been hypothesized to be aversive, triggering avoidance behaviour (Botvinick, 2007). To test this hypothesis, a standard Stroop task was modified such that avoiding was part of the response set. More precisely, participants were asked to move a manikin towards or away from Stroop stimuli, depending on the colour of the words. Results showed that the type of response (approach versus avoidance) modulated the Stroop congruency effect. Specifically, the reaction time analysis revealed that the stimulus congruency effect disappeared with avoidance responses, contrary to approach responses where a stimulus congruency effect was present. Moreover, the error data showed a reduction of the general congruency effect when avoiding. These results suggest that in the face of conflict, avoidance is the predominant response.     

Stroop interference is a composite phenomenon: Evidence from distinct developmental trajectories of its components

Only one previous developmental study of Stroop task performance (Schiller, 1966) has controlled for differences in processing speed that exist both within and between age groups. Therefore, the question of whether the early developmental change in the magnitude of Stroop interference actually persists after controlling for processing speed needs further investigation; work that is further motivated by the possibility that any remaining differences would be caused by process(es) other than processing speed. Analysis of data from two experiments revealed that, even after controlling for processing speed using z‐transformed reaction times, early developmental change persists such that the magnitude of overall Stroop interference is larger in 3rd‐ and 5th graders as compared to 1st graders. This pattern indicates that the magnitude of overall Stroop interference peaks after 2 or 3 years of reading practice (Schadler & Thissen, 1981). Furthermore, this peak is shown to be due to distinct components of Stroop interference (resulting from specific conflicts) progressively falling into place. Experiment 2 revealed that the change in the magnitude of Stroop interference specifically results from joint contributions of task, semantic and response conflicts in 3rd‐ and 5th graders as compared to a sole contribution of task conflict in 1st graders. The specific developmental trajectories of different conflicts presented in the present work provide unique evidence for multiple loci of Stroop interference in the processing stream (respectively task, semantic and response conflict) as opposed to a single (i.e. response) locus predicted by historically – favored response competition accounts.     

An emotional Stroop task with faces and words. A comparison of young and older adults

AntecedentsGiven the contradictions of previous studies on the changes in attentional responses produced in aging a Stroop emotional task was proposed to compare young and older adults to words or faces with an emotional valence.MethodThe words happy or sad were superimposed on faces that express the emotion of happiness or sadness. The emotion expressed by the word and the face could agree or not (cued and uncued trials, respectively). 85 young and 66 healthy older adults had to identify both faces and words separately, and the interference between the two types of stimuli was examined.ResultsAn interference effect was observed for both types of stimuli in both groups. There was more interference on positive faces and words than on negative stimuli.ConclusionsOlder adults had more difficulty than younger in focusing on positive uncued trials, whereas there was no difference across samples on negative uncued trials.     

Decomposing the emotional Stroop effect

The emotional Stroop effect refers to the phenomenon that participants are faster in responding to the ink colour of neutral than of negative word stimuli, possibly reflecting fast and automatic allocation of attention towards negative stimuli. However, this interpretation was challenged by McKenna and Sharma (2004) McKenna, F. P. and Sharma, D. 2004. Reversing the emotional Stroop effect reveals that it is not what it seems: The role of fast and slow components. Journal of Experimental Psychology: Learning, Memory, and Cognition, 30: 382–392. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar] who found that the emotional Stroop effect reflected a generic slowdown after negative stimuli. In fact, they even found reversed effects in a design in which neutral stimuli more often followed negative stimuli and vice versa. Yet, besides reversing the emotional Stroop effect this contingency might in fact have counteracted the fast effect, which was usually interpreted as the emotional Stroop effect. To decompose the emotional Stroop effect we used a design in which the foregoing and the current valence were uncorrelated and in which the fast and slow effects could be computed independently from each other. We found evidence for both fast and slow effects and discuss the practical implications for researchers using the emotional Stroop task as a measurement and the theoretical implications for researchers interested in the underlying cognitive mechanisms that contribute to the emotional Stroop effect.     

青少年Stroop效应和反转Stroop效应的脑事件相关电位研究

研究了初中生、高中生和大学生在完成Stroop任务时的脑事件相关电位特征。以中文Stroop色字为材料,对颜色和字义任务中一致刺激和不一致刺激的脑电叠加平均,并相减(不一致刺激减一致刺激)得到差异波,比较各组被试的波形。结果发现:在顶区,初中生的P3比高中生和大学生更为正走向;大学生、高中生和初中生的头皮分布呈现出不同的特征;Nd4与Stroop效应和反转的Stroop效应有关,可能反映了对无关信息的抑制,而Pd6则反映了对语义信息的再加工。     

Interference suppression vs. response inhibition: An explanation for the absence of a bilingual advantage in preschoolers’ Stroop task performance

The well-documented advantage that bilingual speakers demonstrate across the lifespan on measures of controlled attention is not observed in preschoolers’ performance on Stroop task variations. We examined the role of task demands in explaining this discrepancy. Whereas the Color/Word Stroop used with adult participants requires interference suppression, the Stroop task typically used with preschoolers requires only response inhibition. We developed an age-appropriate conflict task that measures interference suppression. Fifty-one preschool children (26 bilinguals) completed this new Bivalent Shape Task and the Day/Night task used in previous research. Bilingual in comparison to monolingual children performed better on incongruent trials of the Bivalent Shape Task, but did not differ on other measures. The results indicate that the discrepancy between preschoolers and older individuals in performance on Stroop task adaptations results from characteristics of the task rather than developmental differences. Further, the findings provide additional support for the importance of interference suppression as a mechanism underlying the bilingual advantage.     

Independent race of colour and word can predict the Stroop effect

Mainstream theories of the Stroop effect suggest that faster colour classification on congruent trials (say, the word RED printed in red colour) relative to incongruent trials (GREEN in red) is due to channel interaction. Namely, information from the irrelevant word channel perturbs processing of the print colour, causing in turn slower processing of incongruent displays. In this note, I advance a new model in which colour and word are processed in parallel and completely independent channels. The Stroop effect is then the outcome of signal redundancy in congruent displays, where both colour and word contribute to the same response. Numerical computations show that the model can produce the Stroop effect (along with high accuracy rates) for a subset of parameter values. Thus, it provides a proof of existence for a separate channel theory, and a challenge to many existing theories.     

情绪Stroop效应:来自汉字的证据

通过颜色命名和词汇阅读两种作业任务,采用情绪词、中性词两类刺激材料,探索情绪Stroop效应中Stroop加工的特点和机制。结果发现：（1）两种作业任务都发现明显的情绪Stroop效应;（2）两种作业任务中情绪Stroop效应不受情绪词的抽象性影响。它说明情绪stroop效应与经典的Stroop效应是两种独立的现象,前者的加工过程是由于情绪词所产生的情绪威胁而导致反应延迟,而不是经典Stroop效应的选择性注意机制。     

Think the thought, walk the walk - social priming reduces the Stroop effect

In the Stroop task, participants name the color of the ink that a color word is written in and ignore the meaning of the word. Naming the color of an incongruent color word (e.g., RED printed in blue) is slower than naming the color of a congruent color word (e.g., RED printed in red). This robust effect is known as the Stroop effect and it suggests that the intentional instruction – “do not read the word” – has limited influence on one’s behavior, as word reading is being executed via an automatic path. Herein is examined the influence of a non-intentional instruction – “do not read the word” – on the Stroop effect. Social concept priming tends to trigger automatic behavior that is in line with the primed concept. Here participants were primed with the social concept “dyslexia” before performing the Stroop task. Because dyslectic people are perceived as having reading difficulties, the Stroop effect was reduced and even failed to reach significance after the dyslectic person priming. A similar effect was replicated in a further experiment, and overall it suggests that the human cognitive system has more success in decreasing the influence of another automatic process via an automatic path rather than via an intentional path.     

Wheel chairs and arm chairs: A novel experimental design for the emotional Stroop effect

The emotional Stroop effect demonstrates that people are slower to name the ink colour of emotionally charged words than that of neutral words. Attributing this slowdown to emotionality or threat requires that the emotion and neutral words presented are equal on all extraneous variables. However, it is impossible in principle to match the two types of words on all conceivable variables. To address the problem, we presented the same set of words, polarised to be negative in one condition and neutral in another by using appropriate prime words that produced the desired valence through idiomatic two-word expressions. Across two studies, participants took longer to name the colour of the same words when they were rendered negative than when they were rendered neutral. This difference reflects a true emotional Stroop effect given the control provided for all potentially confounding variables tied to the target stimuli. The new procedure also enables researchers to calculate item-specific emotional Stroop effects for the first time.     

Cognitive control and word recognition speed influence the Stroop effect in bilinguals

Bilinguals have been shown to be less susceptible to Stroop interference in their first language than monolinguals, though the cause is currently being debated. In two experiments, we explored how cognitive control and word recognition contribute to the Stroop effect by contrasting cognitive control (via a Simon arrow task), word recognition speed (via a Chinese/English word recognition task) and Stroop susceptibility (via a verbal Stroop task) between proficient and non‐proficient Chinese–English bilinguals. Compared to non‐proficient bilinguals, proficient bilinguals showed better cognitive control at inhibiting irrelevant information, and they were slower at recognising Chinese words but quicker at recognising English words. Critically, we also showed that proficient bilinguals showed a smaller Stroop effect than non‐proficient bilinguals in Chinese but a comparable Stroop effect as non‐proficient bilinguals in English. The results cannot be accounted for by cognitive control or word recognition speed alone; instead, they are best accommodated by assuming that cognitive control and word recognition speed jointly determine the Stroop effect. Thus, we conclude that enhanced cognitive control and delayed word recognition combine to reduce Stroop effect in bilinguals as compared to monolinguals.     

阈上与阈下知觉启动之间的差异:来自Stroop效应的证据

本研究采用Oddball与Stroop相结合的范式,对导致Merikle与Daza等研究结果之间的矛盾进行了考察。研究发现,在启动刺激与目标刺激之问的SOA为300毫秒的即时掩蔽条件下,启动刺激“红”和“绿”对随后的目标刺激的判断产生了不同的影响。前者表现出典型的Stroop效应,后者表现出反转的Stroop效应;主观觉知阈限测验显示,启动刺激“红”是在阈下状态被知觉的,而启动刺激“绿”是在阈上状态被知觉的。结果表明．阈下知觉启动具有一定的时问延续性。并不局限在某一特定时问点上,启动刺激的知觉状态受多种因素影响。