Task duration and task order do not matter: no effect on self-control performance.

The strength model of self-control proposes that all acts of self-control are energized by one global limited resource that becomes temporarily depleted by a primary self-control task, leading to impaired self-control performance in secondary self-control tasks. However, failed replications have cast doubt on the existence of this so-called ego depletion effect. Here, we investigated between-task (i.e., variation in self-control tasks) and within-task variation (i.e., task duration) as possible explanations for the conflicting literature on ego depletion effects. In a high-powered experiment (N = 709 participants), we used two established self-control tasks (Stroop task, transcription task) to test how variations in the duration of primary and secondary self-control tasks (2, 4, 8, or 16 min per task) affect the occurrence of an ego depletion effect (i.e., impaired performance in the secondary task). In line with the ego depletion hypothesis, subjects perceived longer lasting secondary tasks as more self-control demanding. Contrary to the ego depletion hypothesis, however, performance did neither suffer from prior self-control exertion, nor as a function of task duration. If anything, performance tended to improve when the primary self-control task lasted longer. These effects did not differ between the two self-control tasks, suggesting that the observed null findings were independent of task type.

Do shorter inter-stimulus intervals in the go/no-go task enable better assessment of response inhibition?

Young, Sutherland, and McCoy indicated that a Go/No-Go Task (GNG) becomes more difficult as the inter-stimulus intervals (ISIs) becomes shorter. However, is the number of commission errors under extremely short ISIs a useful metric for assessing response inhibition? This study challenges the assumption that a shorter ISI in the GNG enables better assessment of response inhibition. University students (N = 213) completed the GNG, the Conners Continuous Performance Test 3rd Edition (CCPT), and the Modified Stroop Task. The GNG comprised four blocks of 400, 600, 800, and 1000 ms ISIs, whereas the stimulus presentation was fixed at 250 ms. Consistent with Young et al., shorter ISIs in the GNG resulted in more commission errors. In the block with the shortest ISI, participants also failed more frequently in responses in go trials than in the other blocks, which appears to increase in error variance of commission errors. Consistent with this interpretation, the association between the number of commission errors in the block with 400 ms ISI and CCPT performance was weaker than those between the number of commission errors in other blocks and CCPT performance. It is concluded that using the number of commission errors in the condition with extremely short ISIs in the GNG might be inappropriate for assessing response inhibition.

Reappraising cognitive control: normal reactive adjustments following conflict processing are abolished by proactive emotion regulation.

The congruency sequence effect (CSE) reflected by the influence of the congruency of the previous trial on the current one translates improved cognitive control (CC). Yet, it remains debated whether reactive or proactive control processes mostly contribute to this effect. To address this question, we administered a Stroop task controlling for effects of feature repetition and contingency learning to a large group of participants, where we manipulated the frequency of incongruent trials in a block-wise fashion to induce either proactive (high-conflict frequency) or reactive (low-conflict frequency) control. Moreover, as the presentation of trial-by-trial evaluative feedback could influence control processes operating at a local level, we compared effect of evaluative vs. neutral feedback on the CSE, for each control mode separately. We tested the prediction that CSE should be influenced by conflict frequency and feedback type concurrently. Results showed that when evaluative feedback was used, the CSE was increased if conflict frequency was low, confirming that the CSE stemmed from reactive control mainly. If conflict frequency was high, a different sequence effect was observed. The use of neutral feedback abolished the modulation of the CSE by conflict frequency. Moreover, correlation results showed that reappraisal, corresponding to a proactive emotion regulation strategy, was negatively related to the CSE in this condition, suggesting that proactive control can alleviate the reactive dominance of the CSE. Altogether, these results suggest that CC is flexible, and its expression depends on the subtle balance between proactive and reactive control processes.

Stroop Test Validation to Screen for Minimal Hepatic Encephalopathy in Pediatric Extrahepatic Portal Venous Obstruction.

OBJECTIVES: Minimal hepatic encephalopathy (MHE) has been reported in children with extrahepatic portal vein obstruction (EHPVO). MHE assessment is restricted to research situations as neuropsychiatric tests are time-intensive. Computerized Stroop Test (CST) has been used in cirrhotic adults for MHE screening. The study aims to assess MHE frequency in young Indian children with EHPVO and validate CST for MHE screening in pediatric EHPVO. METHODS: Thirty-seven children with EHPVO between 7 and 12 years of age and 37 age- and sex-matched controls were enrolled. Fasting plasma ammonia was measured. MHE was diagnosed by Revised Amsterdamse Kinder Intelligentie Test. The performance of a Tamil language version of CST in MHE screening was assessed. RESULTS: MHE was diagnosed in 18.9% (7/37) of EHPVO (EHPVO-MHE). Plasma ammonia levels were higher in EHPVO-MHE compared to EHPVO without MHE (EHPVO-No-MHE) but abnormal plasma ammonia levels are unsuitable for MHE screening. CST was administered in 35 EHPVO and 37 controls. EHPVO-MHE, compared to EHPVO-No-MHE, had longer "on time," "off time," "(on+off) time," and "(on-off) time." For MHE diagnosis, specificity and sensitivity of "(on+off) time" were 100% and 89.6% for a cutoff of >180.4 seconds (area under receiver operating characteristic = 0.97). CONCLUSIONS: In the absence of other risk factors for neurological insult or patent surgical shunts, MHE frequency in young Indian children with EHPVO, determined by Revised Amsterdamse Kinder Intelligentie Test, was lesser than in earlier studies. CST is suitable for MHE screening in clinical practice to select patients for neuropsychiatric evaluation.

Do young adults show conceptual knowledge of previous distractors?

Using implicit tests, older adults have been found to retain conceptual knowledge of previously seen task-irrelevant information. While younger adults typically do not show the same effect, evidence from one study [Gopie, N., Craik, F. I. M., & Hasher, L. (2011). A double dissociation of implicit and explicit memory in younger and older adults. Psychological Science, 22, 634-640. doi: 10.1177/0956797611403321 ] suggests otherwise. In that study, young adults showed greater explicit than implicit memory for previous distractors on a word fragment completion task. This was interpreted as evidence for maintaining access to previous conceptual knowledge of the distractors. Here, we report two failures to replicate that original finding, followed by a third study designed to test directly whether young adults use conceptual-level information that was previously irrelevant. Our findings agree with others that young adults show weak to no evidence of conceptual knowledge of previously irrelevant information.

The automatic activation of emotion words measured using the emotional face-word Stroop task in late Chinese-English bilinguals.

In the current study, late Chinese-English bilinguals performed a facial expression identification task with emotion words in the task-irrelevant dimension, in either their first language (L1) or second language (L2). The investigation examined the automatic access of the emotional content in words appearing in more than one language. Significant congruency effects were present for both L1 and L2 emotion word processing. Furthermore, the magnitude of emotional face-word Stroop effect in the L1 task was greater as compared to the L2 task, indicating that in L1 participants could access the emotional information in words in a more reliable manner. In summary, these findings provide more support for the automatic access of emotional information in words in the bilinguals' two languages as well as attenuated emotionality of L2 processing.

Proactive and reactive control depends on emotional valence: a Stroop study with emotional expressions and words.

We examined proactive and reactive control effects in the context of task-relevant happy, sad, and angry facial expressions on a face-word Stroop task. Participants identified the emotion expressed by a face that contained a congruent or incongruent emotional word (happy/sad/angry). Proactive control effects were measured in terms of the reduction in Stroop interference (difference between incongruent and congruent trials) as a function of previous trial emotion and previous trial congruence. Reactive control effects were measured in terms of the reduction in Stroop interference as a function of current trial emotion and previous trial congruence. Previous trial negative emotions exert greater influence on proactive control than the positive emotion. Sad faces in the previous trial resulted in greater reduction in the Stroop interference for happy faces in the current trial. However, current trial angry faces showed stronger adaptation effects compared to happy faces. Thus, both proactive and reactive control mechanisms are dependent on emotional valence of task-relevant stimuli.

Intentional and automatic processing of numerical information in mathematical anxiety: testing the influence of emotional priming.

Current theoretical approaches suggest that mathematical anxiety (MA) manifests itself as a weakness in quantity manipulations. This study is the first to examine automatic versus intentional processing of numerical information using the numerical Stroop paradigm in participants with high MA. To manipulate anxiety levels, we combined the numerical Stroop task with an affective priming paradigm. We took a group of college students with high MA and compared their performance to a group of participants with low MA. Under low anxiety conditions (neutral priming), participants with high MA showed relatively intact number processing abilities. However, under high anxiety conditions (mathematical priming), participants with high MA showed (1) higher processing of the non-numerical irrelevant information, which aligns with the theoretical view regarding deficits in selective attention in anxiety and (2) an abnormal numerical distance effect. These results demonstrate that abnormal, basic numerical processing in MA is context related.

Eye-movement Patterns of Chinese Children with Developmental Dyslexia during the Stroop Test.

OBJECTIVE: To compare the eye-movement patterns of Chinese children with developmental dyslexia (DD children) with those of non-dyslexic children as they perform the Stroop Color and Word Test (SCWT), and to explore the relationship between their eye-movement patterns and interference effect. METHODS: An EyeLink II was used to record the eye-movement parameters of 32 DD children and 37 non-dyslexic children as they performed the SCWT. The independent samples t-test and repeated measures were used to analyze behavioral and eye-movement parameters. RESULTS: Compared to the control group, Chinese DD children presented lower accuracy (F = 8.488), slower response time (F = 25.306), and larger interference effect (t = 2.29); Chinese DD children also exhibited lower frequency of fixations (F = 6.069), greater numbers of saccades (F = 7.914) and fixations (F = 5.272), and shorter mean saccade distance (F = 4.03). All behavioral and eye-movement parameters differed significantly among the three tasks in the SCWT. There was significant interaction between groups and tasks in accuracy (F = 5.844), and marginally significant interaction in response time (F = 3.040). Chinese DD children tended to have lower accuracy and longer response time than the control group in the 'color-word naming' task. CONCLUSION: Compared to non-dyslexic children, Chinese DD children are subject to a stronger interference effect. When performing the SCWT, Chinese DD children exhibit abnormal eye-movement patterns, namely shorter mean saccade distance, lower frequency of fixations, and more fixations and saccades. These abnormal eye movements may be relatively stable oculomotor patterns of DD children performing visual processing, and not influenced by impaired interference effect.

An updated Italian normative dataset for the Stroop color word test (SCWT).

The Stroop color and word test (SCWT) is widely used to evaluate attention, information processing speed, selective attention, and cognitive flexibility. Normative values for the Italian population are available only for selected age groups, or for the short version of the test. The aim of this study was to provide updated normal values for the full version, balancing groups across gender, age decades, and education. Two kinds of indexes were derived from the performance of 192 normal subjects, divided by decade (from 20 to 90) and level of education (4 levels: 3-5; 6-8; 9-13; >13 years). They were (i) the correct answers achieved for each table in the first 30 s (word items, WI; color items, CI; color word items, CWI) and (ii) the total time required for reading the three tables (word time, WT; color time, CT; color word time, CWT). For each index, the regression model was evaluated using age, education, and gender as independent variables. The normative data were then computed following the equivalent scores method. In the regression model, age and education significantly influenced the performance in each of the 6 indexes, whereas gender had no significant effect. This study confirms the effect of age and education on the main indexes of the Stroop test and provides updated normative data for an Italian healthy population, well balanced across age, education, and gender. It will be useful to Italian researchers studying attentional functions in health and disease.

The next trial will be conflicting! Effects of explicit congruency pre-cues on cognitive control.

The dual mechanisms of control account proposed a role for proactive and reactive mechanisms in minimizing or resolving interference in conflict tasks. Proactive mechanisms are activated in advance of stimulus onset and lead to preparatory biasing of attention in a goal-directed fashion. Reactive mechanisms are triggered post-stimulus onset. Using an explicit, trial-by-trial pre-cueing procedure in a 4-choice color-word Stroop task, we investigated effects of congruency pre-cues on cognitive control. Under conditions of stimulus uncertainty (i.e., each word was associated with multiple, equally probable responses), pre-cue benefits were observed on incongruent trials when cues were 100% valid but not when they were 75% valid. These benefits were selectively found at the longest cue-to-stimulus interval (2,000 ms), consistent with a preparation-dependent proactive control mechanism. By contrast, when a reactive strategy of switching attention to the irrelevant dimension to predict the single correlated response was viable, pre-cue benefits were observed on incongruent trials for all cue-to-stimulus intervals including the shortest that afforded only 500 ms to prepare. The findings (a) suggest a restricted role for the preparation-dependent biasing of attention via proactive control in response to explicit, trial-by-trial pre-cues while (b) highlighting strategies that lead to pre-cue benefits but which appear to reflect primarily reactive use of the information afforded by the pre-cues. We conclude that pre-cues, though available in advance of stimulus onset, may stimulate proactive or reactive minimization of interference.

Disentangling fast and slow attentional influences of negative and taboo spoken words in the emotional Stroop paradigm.

Although the influence of the emotional content of stimuli on attention has been considered as occurring within trial, recent studies revealed that the presentation of such stimuli would also involve a slow component. The aim of the present study was to investigate fast and slow effects of negative (Exp. 1) and taboo (Exp. 2) spoken words. For this purpose, we used an auditory variant of the emotional Stroop paradigm in which each emotional word was followed by a sequence of neutral words. Replicating results from our previous study, we observed slow but no fast effects of negative and taboo words, which we interpreted as reflecting difficulties to disengage attention from their emotional dimension. Interestingly, while the presentation of a negative word only delayed the processing of the immediately subsequent neutral word, slow effects of taboo words were long-lasting. Nevertheless, such attentional effects were only observed when the emotional words were presented in the first block of trials, suggesting that once participants develop strategies to perform the task, attention-grabbing effects of emotional words disappear. Hence, far from being automatic, the occurrence of these effects would depend on participants' attentional set.

Unconscious context-specific proportion congruency effect in a stroop-like task.

Cognitive control is a central topic of interest in psychology and cognitive neuroscience and has traditionally been associated with consciousness. However, recent research suggests that cognitive control may be unconscious in character. The main purpose of our study was to further explore this area of research focusing on the possibly unconscious nature of the conflict adaptation effect, specifically the context-specific proportion congruency effect (CSPCE), by using a masked Stroop-like task where the proportion of congruency was associated to various masks. We used electrophysiological measures to analyze the neural correlates of the CSPCE. Results showed evidence of an unconscious CSPCE in reaction times (RTs) and the N2 and P3 components. In addition, the P2 component evoked by both target and masks indicated that the proportion of congruency was processed earlier than the congruency between the color word and the ink color of the target. Taken together, our results provided evidence pointing to an unconscious CSPCE.

COMPARISON OF ATHLETES WITH AND WITHOUT BURNOUT USING THE STROOP COLOR AND WORD TEST.

The present study compared brain activity of adolescents with or without burnout during their responses to a computerized version of the Stroop Color and Word Test. The Sport Adaptation of the Maslach Burnout Inventory was administered to 460 Korean high school student athletes. Electroencephalographic data were recorded from frontal, central, parietal, and occipital brain regions while these participants were performing the Stroop Color and Word Test. A 2 (group) × 2 (condition) × 15 (electrodes) three-way analysis of variance was used to analyze the data. Results indicated that the athletes without burnout exhibited significantly higher accuracy than their counterparts with burnout on the Stroop Color and Word Test. The athletes without burnout also showed higher amplitudes for theta, alpha, and beta power in the frontal areas than the athletes with burnout.

Conceptual processing of distractors by older but not younger adults.

Evidence from perceptually based implicit memory tasks demonstrates greater priming from distracting information among older compared with younger adults. We examined whether older adults also show greater conceptually based implicit priming from distracting information. We measured priming using a general-knowledge test that was preceded by an incidental-encoding task (a color-naming Stroop task in one experiment and a 1-back task involving pictures with irrelevant words superimposed in a second experiment). Younger adults showed no priming from the distracting information in either experiment, whereas older adults showed reliable priming in both experiments. Thus, unlike young adults, older adults process irrelevant information conceptually and then can use that information to boost their performance on a subsequent task.

The working memory stroop effect: when internal representations clash with external stimuli.

Working memory (WM) has recently been described as internally directed attention, which implies that WM content should affect behavior exactly like an externally perceived and attended stimulus. We tested whether holding a color word in WM, rather than attending to it in the external environment, can produce interference in a color-discrimination task, which would mimic the classic Stroop effect. Over three experiments, the WM Stroop effect recapitulated core properties of the classic attentional Stroop effect, displaying equivalent congruency effects, additive contributions from stimulus- and response-level congruency, and susceptibility to modulation by the percentage of congruent and incongruent trials. Moreover, WM maintenance was inversely related to attentional demands during the WM delay between stimulus presentation and recall, with poorer memory performance following incongruent than congruent trials. Together, these results suggest that WM and attention rely on the same resources and operate over the same representations.

Reactive and regulative temperament in patients with compulsive buying and non-clinical controls measured by self-report and performance-based tasks.

OBJECTIVE: To examine reactive and regulative temperament in patients with compulsive buying (CB) by means of self-report measures and performance-based tasks and to explore the relationship between both measurement approaches. METHOD: The study included 31 treatment-seeking patients with CB (25 women, 6 men) and an age and gender matched non-clinical control group without CB (CG). All participants answered the Compulsive Buying Scale (CBS). Reactive temperament was assessed using the Behavioral Inhibition System/Behavioral Activation System Scales (BIS/BAS) and the Iowa Gambling Task (IGT). Regulative temperament was measured using the Effortful Control subscale of the Adult Temperament Questionnaire (ATQ-EC) and a computerized version of the Stroop Task. To control the results for depression, the Patient Health Questionnaire-Depression Scale (PHQ-9) was administered. RESULTS: Crude group comparisons revealed higher BIS and BAS scores, poorer IGT performance and lower ATQ-EC scores in the CB-group compared to the CG. The groups did not differ in their performance on the Stroop task. After controlling for depressive symptoms that were significantly higher in the CB-group, only the group differences in BAS reactivity remained significant. No significant associations were found between questionnaires and performance-based tasks. CONCLUSION: Overall, the findings indicate that CB in the present clinical sample of treatment-seeking patients was mainly associated with higher approach tendencies and more depressive symptoms. The lacking correlation between self-reports and performance-based tasks is in line with prior research and suggests that both methodologies tap into different aspects of temperament.

An electrophysiological investigation of the effects of social rejection on self control.

Previous studies have shown that social rejection leads to impaired performance on a variety of tasks that require self control, including the Stroop color-word interference task; however, mechanisms underlying the effect remain to be elucidated. We attempted to clarify the effects of social rejection on self control resources by measuring event-related potentials (ERPs) during a computerized Stroop test. Stroop performance and ERPs from 54 participants in rejected, control, and accepted groups were analyzed. A significant difference in the pattern of results for the N450 ERP was found, with rejected participants showing less negativity on incongruent trials and more on congruent trials compared to accepted participants and controls. The results suggest social rejection reduces the engagement of cognitive control mechanisms, and are more consistent with a limited strength resource model than with limited capacity resource models that focus on limitations in attention.

Lax decision criteria lead to negativity bias: evidence from the emotional stroop task.

Negativity bias means that negative information is usually given more emphasis than comparable positive information. Under signal detection theory, recent research found that people more frequently and incorrectly identify negative task-related words as having been presented originally than positive words, even when they were not presented. That is, people have lax decision criteria for negative words. However, the response biases for task-unrelated negative words and for emotionally important words are still unclear. This study investigated response bias for these two kinds of words. Study 1 examined the response bias for task-unrelated negative words using an emotional Stroop task. Proportions of correct recognition to negative and positive words were assessed by non-parametric signal detection analysis. Participants have lower (i.e., more lax) decision criteria for task-unrelated negative words than for positive words. Study 2 supported and expanded this result by investigating participants' response bias for highly emotional words. Participants have lower decision criteria for highly emotional words than for less emotional words. Finally, possible evolutionary sources of the response bias were discussed.

Cognitive dysfunction in fibromyalgia: slow access to the mental lexicon.

Lexical access speed, the time needed for the brain to access the catalogue of words in long-term memory, is assumed to provide a foundation for a broad array of cognitive operations. It was hypothesized that deficits in lexical speed are likely to play a central role in deficiencies in cognitive performance of patients with fibromyalgia, who as a group show deficits in lexical speed. This was tested in a sample of 209 patients with fibromyalgia and in 72 control patients with memory deficits. Participants completed the Stroop word-naming measure of lexical access speed and 12 neurocognitive measures. Deficit in lexical access speed occurred at approximately twice the frequency (48.3% vs 25.0%) in fibromyalgia. The average delay in speed of lexical access was 171 msec. in fibromyalgia and 163 msec. in controls. Those with deficits in lexical access speed displayed deficiencies on 10 of 12 cognitive measures in the fibromyalgia group, and on 8 of 12 cognitive measures in the control group. The premise that lexical access speed is disproportionately present in fibromyalgia and serves as a foundation for a wide array of cognitive operations is supported.