Controlling Stroop interference: Evidence from a bilingual task.

Skilled performance is often associated with automaticity. Automatic processes are generally thought of as uncontrollable so that automaticity implies the lack of control. The Stroop Color and Word Test is one of the most cited examples of automaticity and uncontrollability of word reading. This task is also employed extensively to investigate the structure of the bilingual lexicon. The present work employed a Hebrew-Arabic bilingual Stroop task in 2 separate experiments. To induce controlled processing, the authors varied the Ss' expectations regarding the written (irrelevant) color words. The Stroop interference effect was always present, but Ss were able to control (reduce) it in their native language but not in their second language. In addition, the presumed structure of the bilingual lexicon seems to change in accordance with proficiency in the second language. It is suggested that automaticity and control are both characteristics of skilled performance with each of them reflecting a different aspect and each subserving a different function of our cognitive system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stroop process dissociations: The relationship between facilitation and interference.

L. L. Jacoby's (see record 1992-07943-001) "process dissociation procedure" was used to quantitatively estimate the contributions of color-naming and word-reading processes to responding on the Stroop task. Results show that color naming and word reading can operate independently to determine responses. Degrading stimulus colors eliminated the typical asymmetry between Stroop facilitation and interference, as predicted by the equations (Exps 1 and 2). Degrading stimulus colors reduced the estimated contribution of color naming to responding but had no effect on the estimated contribution of word reading (Exp 2). In contrast, increasing the proportion of incongruent items reduced the estimated contribution of word reading but had no effect on the estimated contribution of color naming (Exps 3 and 4). Results indicate that the facilitating and interfering effects of automatic processes cannot be accurately measured in terms of differences from baseline. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Increased attention to the irrelevant dimension increases interference in a spatial Stroop task.

In a spatial Stroop task, it is argued that interference (ITF) results because selective attention is only partially successful. If so, increasing attention to the word should increase ITF. Three experiments, with 88 undergraduates, used the position words above, below, left, and right in incompatible positions to the left, right, or below a fixation point. Exp 1 showed increased ITF with position naming when Ss must be prepared to attend to either the word or its position. Exp 2 required Ss to first name the position of the word and then recall which word had been presented. This resulted in increased ITF with position naming when the word was followed at a short stimulus onset asynchrony by a pattern mask. Exp 3 employed both word reading and position naming and showed that a large reverse Stroop effect occurred with both vocal and manual responses when Ss were prepared to attend to either dimension of the stimulus. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attention and facilitation: Converging information versus inadvertent reading in Stroop task performance.

Disagreement exists about whether color–word Stroop facilitation is caused by converging information (e.g., Cohen et al., 1990; Roelofs, 2003) or inadvertent reading (MacLeod & MacDonald, 2000). Four experiments tested between these hypotheses by examining Stroop effects on response time (RT) both within and between languages. Words cannot be read aloud to produce facilitation between languages. Dutch–English bilingual participants named color patches while trying to ignore Dutch or English color words presented at a wide range of preexposure and postexposure stimulus onset asynchronies. The color patches were named in Dutch (Experiments 1 and 2) or English (Experiments 3 and 4). In all experiments, Stroop facilitation and interference effects were obtained in mean RTs with similar time courses within and between languages. Facilitation was generally present throughout the entire RT distributions. These results suggest that Stroop interference and facilitation have a common locus within and between languages, supporting the converging information hypothesis of Stroop facilitation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interpreting Stroop interference: An analysis of differences between task versions.

The present study investigated methodological differences between the clinical version of the Stroop Color and Word Test and the computerized single-trial version. Three experiments show that different presentations of the Stroop task can produce different levels of interference. The 1st experiment examined the effect of blocking; the 2nd experiment examined different control conditions. Greater interference in the blocked clinical version appears to result from lower response times (RTs) in the neutral condition, not from greater RTs in the incongruent condition. Experiment 3 examined the impact of shifting attention across locations while responding to Stroop stimuli. The present set of findings sheds light on the inconsistency in the clinical literature and demonstrates that the method and selection of neutral stimuli (that provide the baseline by which interference is measured) are critical because they clearly can change performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Selective and divided attention in a Stroop task.

Three experiments employed a modified version of the Stroop Color-Word Test to document some conditions under which attention may be differentially deployed. Ss were 66 undergraduates. Within limits, Ss chose either to selectively attend to a single stimulus or to distribute processing resources over several stimuli. Thus, attentional strategies may be actively chosen to suit prevailing conditions. Once established, these different modes of attending were themselves differentially open to strategic modulation. (French abstract) (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social presence effects in the Stroop task: Further evidence for an attentional view of social facilitation.

In contrast with R. B. Zajonc's (1965) classic view about social facilitation–inhibition (SFI) effects, it was found that the presence of relatively unpredictable audiences and forced social comparison with a slightly superior coactor both facilitated performance in the Stroop task while inhibiting automatic verbal processing. Not only do these findings reveal that social presence can help inhibit the emission of dominant responses, providing further support for an attentional view of SFI effects, but they also demonstrate the power of social situations over what has been thought to be invariant automatic processing. As such, they are inconsistent with the view reiterated in more than 500 articles on Stroop interference over the past 60 years and suggest that more attention should be paid to the situations in which cognition takes place. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Long-lasting attentional influence of negative and taboo words in an auditory variant of the emotional Stroop task.

Using an auditory adaptation of the emotional and taboo Stroop tasks, the authors compared the effects of negative and taboo spoken words in mixed and blocked designs. Both types of words elicited carryover effects with mixed presentations and interference with blocked presentations, suggesting similar long-lasting attentional effects. Both were also relatively resilient to the long-lasting influence of the preceding emotional word. Hence, contrary to what has been assumed (Schmidt & Saari, 2007), negative and taboo words do not seem to differ in terms of the temporal dynamics of the interdimensional shifting, at least in the auditory modality. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A time course analysis of Stroop interference and facilitation: Comparing normal individuals and individuals with schizophrenia.

Using randomized stimulus onset asynchrony (SOAs), the authors traced the time course of Stroop interference and facilitation in normal participants and participants with schizophrenia. Unlike earlier findings using blocked SOAs, singular peaks in interference, facilitation, or both occurred at particular SOAs. The peaks of normal participants and participants with schizophrenia differed. Findings are congruent with a model of Stroop performance that posits individual differences in processing speeds of target and nontarget stimulus dimensions, coupled with critical points in response selection. Participants with schizophrenia also showed more overall interference than normal control participants. A second experiment that added a temporal gap between the distractor word and target color obliterated Stroop effects only for individuals with schizophrenia. These findings provide a new empirical basis for models of Stroop effects. They are also consistent with hypotheses about the importance of the prefrontal cortex for working memory and prefrontal dysfunction in schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Volitional facilitation of difficult intentions: Joint activation of intention memory and positive affect removes Stroop interference.

Removal of Stroop interference was obtained after exposure to words eliciting positive affect. This effect was predicted by personality systems interactions (PSI) theory, which assumes that (a) an abstract (high-level) representation of a difficult intention is generated in intention memory under certain conditions (e.g., when an action plan contains more than 1 step); (b) positive affect releases the inhibition of the pathway between intention memory and its output system. Interference removal is interpreted in terms of volitional facilitation. This effect posits a challenge to current cognitive models of the Stroop effect. Compared with alternative explanations, PSI theory can explain the data in a broader context: Implications of volitional facilitation and volitional inhibition for the study of prospective memory, alienation, procrastination, and rumination in depression are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The emotional Stroop task and psychopathology.

Attentional bias is a central feature of many cognitive theories of psychopathology. One of the most frequent methods of investigating such bias has been an emotional analog of the Stroop task. In this task, participants name the colors in which words are printed, and the words vary in their relevance to each theme of psychopathology. The authors review research showing that patients are often slower to name the color of a word associated with concerns relevant to their clinical condition. They address the causes and mechanisms underlying the phenomenon, focusing on J. D. Cohen, K. Dunbar, and J. L. McClelland's (see record 1990-27437-001) parallel distributed processing model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evidence for task conflict in the Stroop effect.

C. M. MacLeod and P. A. MacDonald (2000) suggested that congruent and incongruent Stroop stimuli cause more task conflict than neutral stimuli because the anterior cingulate cortex is more activated with these stimuli. This study investigated behavioral expression for this pattern. Experiment 1 reduced task conflict control by increasing the proportion of nonword neutrals. Additionally, half the trials had conflict or neutral cues. The control reduction revealed the task conflict. For noncued trials, response time was longer for congruent stimuli than for neutral stimuli (reverse facilitation effect). In addition, response time for congruent stimuli was longer when stimuli were uncued vs. cued. Experiment 2 increased task conflict control by changing the neutral stimuli to noncolor words. Consequently, the task conflict expression disappeared. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of Stroop interference in Chinese-English bilinguals.

120 Chinese-English bilingual students in Grades 2, 4, 8, and 10 in college used both Chinese and English to name the colors of patches and Chinese and English words that consisted of incongruent color names. Examples of stimulus items for the Stroop test are included. Ss of all levels showed greater within- than between-language interference when responding in their primary language, Chinese. When English was the response language, however, a developmental shift from greater between-language interference to greater within-language interference was observed. These results argue against E. Magiste's (see record 1985-06307-001) language proficiency hypothesis and suggest that the pattern of the between- and within-language interference in bilinguals is determined by both language similarity and language proficiency. Further implications of the obtained results for language processing of bilinguals and for the traditional horse race model of the Stroop effect are also discussed. (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Processing in the Stroop task: Mental set as a determinant of performance.

Examined whether the Stroop effect is inevitable under conditions where the stimuli and overt responses are held constant across 2 instructional conditions, but the mental set given to the Ss is different. 112 Ss responded to the print color of an irrelevant word that spelled a congruent or incongruent color word. In the CLASSIFY condition, Ss were instructed to map 1 color to 1 response button and the other color to another response button. In the DETECT condition, Ss were instructed to signal the presence of a target color with 1 response button, and its absence with another response button. The CLASSIFY instructions produced the standard result: The incongruent condition was slower than the congruent condition. In contrast, there was no Stroop effect given DETECT instructions. Results are discussed in terms of mental set as an important determinant of processing, and contrasted with the received view that reading the irrelevant word is largely "automatic" and virtually always results in a Stroop effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prospective memory and task interference in a continuous monitoring dynamic display task.

Theories and methods from the prospective memory literature were used to anticipate how individuals would maintain and retrieve intentions in a continuous monitoring dynamic display task. Participants accepted aircraft into sectors and detected aircraft conflicts during an air traffic control simulation. They were sometimes required to substitute new actions for routine actions when accepting aircraft traveling at certain speeds or altitudes, or with certain call signs. In Experiment 1, prospective memory error increased with intent to deviate from strong compared to weak routine, and this effect was larger for altitude intentions compared to speed intentions. In addition, errors increased when intentions were general compared to specific. Participants also missed more conflicts when deviating from strong compared to weak routine. In Experiment 2, errors increased for intentions nonfocal to ongoing tasks compared to focal, and this effect was larger for altitude intentions compared to call sign intentions. Participants were slower to accept aircraft when holding nonfocal compared to focal intentions, and slower to accept aircraft and detect conflicts when holding focal intentions compared to no intentions. These findings are consistent with theories that assume that individuals allocate limited-capacity attentional resources to prospective memory tasks. Increased error for altitude intentions, together with the effect of routine strength, suggest a vulnerability to error with increased strength of association between prospective memory cues and competing ongoing tasks. Ongoing tasks that focus attention on cues may sometimes impair, rather than benefit, intention retrieval. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related equivalence of identity suppression in the Stroop color-word task.

Previous failures to find reliable identity suppression (identity negative priming) in older adults have led to conclusions that older adults suffer from an impairment in the inhibitory component of selective attention. Here, 2 experiments using the Stroop procedure found identity suppression in older adults that was both reliable and equivalent to that in younger adults. Experiment 1 with repeated target colors produced correlations consistent with an episodic retrieval explanation of identity suppression, Experiment 2 without repeated targets produced correlations inconsistent with the episodic retrieval interpretation. These patterns were found for both younger and older adults. No evidence was found for reduced identity suppression that would be consistent with a general inhibitory impairment in older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interference and facilitation effects during selective attention: an H215O PET study of Stroop task performance

To investigate the functional anatomy of interference and facilitation during selective attention, we studied 15 normal subjects using the H215O positron emission tomography technique and a computer presented single-trial Stroop task for cognitive activation. Increases in regional cerebral blood flow (rCBF) were observed in a network of structures that have been previously associated with selective attention, including the anterior cingulate gyrus, the frontal polar cortex, the inferior parietal lobule, and the thalamus, as well as the lingual gyrus. Furthermore rCBF decreases (compared to control states) were observed in lateral extra-striate cortex. rCBF changes in prefrontal and extra-striate regions varied with differences in the need to modulate the influence of word and color information while subjects responded to either incongruent or congruent Stroop stimuli. These results indicate the utility of Stroop procedures for investigating the functional anatomy of selective attention. Given recent interest regarding the role of the anterior cingulate gyrus in the pathophysiology of neuropsychiatric disorders, our results also suggest that the Stroop task can serve as a reliable neurobehavioral probe for this region. The significance of these results for understanding processing mechanisms underlying selective attention is discussed within the framework of a parallel distributed processing model of Stroop task performance.     

Revealing list-level control in the Stroop task by uncovering its benefits and a cost.

Interference is reduced in mostly incongruent relative to mostly congruent lists. Classic accounts of this list-wide proportion congruence effect assume that list-level control processes strategically modulate word reading. Contemporary accounts posit that reliance on the word is modulated poststimulus onset by item-specific information (e.g., proportion congruency of the word). To adjudicate between these accounts, we used novel designs featuring neutral trials. In two experiments, we showed that the list-wide proportion congruence effect is accompanied by a change in neutral trial color-naming performance. Because neutral words have no item-specific bias, this pattern can be attributed to list-level control. Additionally, we showed that list-level attenuation of word reading led to a cost to performance on a secondary prospective memory task but only when that task required processing of the irrelevant, neutral word. These findings indicate that the list-wide proportion congruence effect at least partially reflects list-level control and challenge purely item-specific accounts of this effect. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The task dependence of staged versus cascaded processing: An empirical and computational study of Stroop interference in speech perception.

The authors investigated the online relationship between overt articulation and the central processes of speech production. In 2 experiments manipulating the timing of Stroop interference in color naming, the authors found that naming behavior can shift between exhibiting a staged or cascaded mode of processing, depending on task demands: An effect of Stroop interference on naming durations arose only when there was increased pressure for speeded responding. In a simple connectionist model of information processing applied to color naming, the authors accounted for the current results by manipulating a single parameter, termed "gain," modulating the rate of information accrual within the network. Results are discussed in relation to mechanisms of strategic control and the link between cognition and action. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic interference and orthographic facilitation in definition naming.

Semantic interference and orthographic facilitation are common findings in Stroop-like color and picture-naming tasks. The authors investigated whether these context effects are also obtained when, instead of colors or pictures, definitions are used as target stimuli. In Exp 1, both effects were obtained when definitions of colors such as "the color of tomatoes?" had to be named. This finding was replicated in Exp 2, in which the definitions were taken from a larger set of semantic categories. The remaining 4 experiments showed that the semantic interference effect cannot be attributed to a strategic match or nonmatch decision (Exp 3) and does not show up when the distractor word precedes the definition (Exps 4, 5, and 6). The findings are discussed in relation to accounts of context effects in naming tasks and in relation to word-retrieval problems in the tip-of-the-tongue state. (PsycINFO Database Record (c) 2010 APA, all rights reserved)