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.     

The effect of orthographic and emotional neighbourhood in a colour categorization task

This study investigated whether and how the strength of reading interference in a colour categorization task can be influenced by lexical competition and the emotional characteristics of words not directly presented. Previous findings showed inhibitory effects of high-frequency orthographic and emotional neighbourhood in the lexical decision task. Here, we examined the effect of orthographic neighbour frequency according to the emotional valence of the higher-frequency neighbour in an emotional orthographic Stroop paradigm. Stimuli were coloured neutral words that had either (1) no orthographic neighbour (e.g. PISTIL [pistil]), (2) one neutral higher-frequency neighbour (e.g. tirade [tirade]/TIRAGE [draw]) or (3) one negative higher-frequency neighbour (e.g. idiome [idiom]/IDIOTE [idiotic]). The results showed that colour categorization times were longer for words with no orthographic neighbour than for words with one neutral neighbour of higher frequency and even longer when the higher-frequency neighbour was neutral rather than negative. Thus, it appears not only that the orthographic neighbourhood of the coloured stimulus words intervenes in a colour categorization task, but also that the emotional content of the neighbour contributes to response times. These findings are discussed in terms of lexical competition between the stimulus word and non-presented orthographic neighbours, which in turn would modify the strength of reading interference on colour categorization times.     

Emotional Stroop task: effect of word arousal and subject anxiety on emotional interference

Inconsistent findings regarding the emotional Stroop effect in healthy subjects may be explained by confounding effects of stimulus valence and arousal, as well as individual differences in anxiety. We examined reaction time data in a healthy sample using the emotional Stroop task while carefully matching arousal level of positive and negative words. Independent of valence, emotional relative to neutral words elicited emotional interference, indicating that arousal determines emotional interference. Independent of valence, emotional words were better re-called and recognized than neutral words. Individual differences in state anxiety were associated with emotional interference, that is, emotional interference was enhanced in subjects with high state anxiety. There was no influence of trait anxiety. These findings indicate that word arousal produces emotional interference independent of valence. State anxiety exacerbates interference of emotional words by further biasing attention towards emotionally salient stimuli. Thomas Dresler and Katja Mériau have contributed equally.     

Lexical characteristics of words used in emotional Stroop experiments

Validity of the emotional Stroop task hinges on equivalence between the emotion and the control words in terms of lexical features related to word recognition. The authors evaluated the lexical features of 1,033 words used in 32 published emotional Stroop studies. Emotion words were significantly lower in frequency of use, longer in length, and had smaller orthographic neighborhoods than words used as controls. These lexical features contribute to slower word recognition and hence are likely to contribute to delayed latencies in color naming. The often-replicated slowdown in color naming of emotion words may be due, in part, to lexical differences between the emotion and control words used in the majority of such studies to date.     

Relations between emotion,memory, and attention: Evidence from taboo Stroop,lexical decision,and immediate memory tasks

This article reports five experiments demonstrating theoretically coherent effects of emotion on memory and attention. Experiments 1-3 demonstrated three taboo Stroop effects that occur when people name the color of taboo words. One effect is longer color-naming times for taboo than for neutral words, an effect that diminishes with word repetition. The second effect is superior recall of taboo words in surprise memory tests following color naming. The third effect is better recognition memory for colors consistently associated with taboo words rather than with neutral words. None of these effects was due to retrieval factors, attentional disengagement processes, response inhibition, or strategic attention shifts. Experiments 4 and 5 demonstrated that taboo words impair immediate recall of the preceding and succeeding words in rapidly presented lists but do not impair lexical decision times. We argue that taboo words trigger specific emotional reactions that facilitate the binding of taboo word meaning to salient contextual aspects, such as occurrence in a task and font color in taboo Stroop tasks.     

Taboo,emotionally valenced,and emotionally neutral word norms

Although taboo words are used to study emotional memory and attention, no easily accessible normative data are available that compare taboo, emotionally valenced, and emotionally neutral words on the same scales. Frequency, inappropriateness, valence, arousal, and imageability ratings for taboo, emotionally valenced, and emotionally neutral words were made by 78 native-English-speaking college students from a large metropolitan university. The valenced set comprised both positive and negative words, and the emotionally neutral set comprised category-related and category-unrelated words. To account for influences of demand characteristics and personality factors on the ratings, frequency and inappropriateness measures were decomposed into raters’ personal reactions to the words versus raters’ perceptions of societal reactions to the words (personal use vs. familiarity and offensiveness vs. tabooness, respectively). Although all word sets were rated higher in familiarity and tabooness than in personal use and offensiveness, these differences were most pronounced for the taboo set. In terms of valence, the taboo set was most similar to the negative set, although it yielded higher arousal ratings than did either valenced set. Imageability for the taboo set was comparable to that of both valenced sets. The ratings of each word are presented for all participants as well as for single-sex groups. The inadequacies of the application of normative data to research that uses emotional words and the conceptualization of taboo words as a coherent category are discussed. Materials associated with this article may be accessed at the Psychonomic Society’s Archive of Norms, Stimuli, and Data, www.psychonomic.org/archive.     

Paying attention to emotion: an fMRI investigation of cognitive and emotional stroop tasks

In this research, we investigated the degree to which brain systems involved in ignoring emotionally salient information differ from those involved in ignoring nonemotional information. The design allowed examination of regional brain activity, using fMRI during color-word and emotional Stroop tasks. Twelve participants indicated the color of words while ignoring word meaning in conditions in which neutral words were contrasted to emotionally negative, emotionally positive, and incongruent color words. Dorsolateral frontal lobe activity was increased by both negative and incongruent color words, indicating a common system for maintaining an attentional set in the presence of salient distractors. In posterior regions of the brain, activity depended on the nature of the information to be ignored. Ignoring color-incongruent words increased left parietal activity and decreased parahippocampal gyrus activity, whereas ignoring negative emotional words increased bilateral occipito-temporal activity and decreased amygdala activity. The results indicate that emotion and attention are intimately related via a network of regions that monitor for salient information, maintain attention on the task, suppress irrelevant information, and select appropriate responses.     

Object-based attentional selection can modulate the Stroop effect

The Stroop (1935) effect is the inability to ignore a color word when the task is to report the ink color of that word (i.e., to say "green" to the word RED in green ink). The present study investigated whether object-based processing contributes to the Stroop effect. According to this view, observers are unable to ignore irrelevant features of an attended object (Kahneman & Henik, 1981). In three experiments, participants had to name the color of one of two superimposed rectangles and to ignore words that appeared in the relevant object, in the irrelevant object, or in the background. The words were congruent, neutral, or incongruent with respect to the correct color response. Words in the irrelevant object and in the background produced significant Stroop effects, consistent with earlier findings. Importantly, however, words in the relevant object produced larger Stroop effects than did the other conditions, suggesting amplified processing of all the features of an attended object. Thus, object-based processing can modulate the Stroop effect.     

Emotion effects during reading: Influence of an emotion target word on eye movements and processing

Recently, Scott, O'Donnell and Sereno reported that words of high valence and arousal are processed with greater ease than neutral words during sentence reading. However, this study unsystematically intermixed emotion (label a state of mind, e.g., terrified or happy) and emotion-laden words (refer to a concept that is associated with an emotional state, e.g., debt or marriage). We compared the eye-movement record while participants read sentences that contained a neutral target word (e.g., chair) or an emotion word (no emotion-laden words were included). Readers were able to process both positive (e.g., happy) and negative emotion words (e.g., distressed) faster than neutral words. This was true across a wide range of early (e.g., first fixation durations) and late (e.g., total times on the post-target region) measures. Additional analyses revealed that State Trait Anxiety Inventory scores interacted with the emotion effect and that the emotion effect was not due to arousal alone.     

创伤性分离个体注意加工的Stroop效应

研究采用Stroop色词命名任务。实验主要考察创伤性分离个体注意的加工模式。实验中,高分离个体在标准Stroop任务条件,明显受到Stroop效应的干扰,对创伤性词汇反应时间减慢。实验结果表明,创伤性分离个体的集中注意能力遭到破坏,实验符合创伤的回避加工理论,创伤性分离个体运用分离无意识忽略注意伤害性的刺激,如果无法忽略,则会有意识的回避加工。     

Differences between Chinese morphosyllabic and German alphabetic readers in the Stroop interference effect

The goal of our study was to localize the source of the stronger Stroop interference effect found in morphosyllabic readers as compared with alphabetic readers. Twenty-three Chinese and 24 German undergraduate students were tested in a Stroop paradigm with the following stimuli: color patches, colorneutral words (e.g.,friend printed in yellow), incongruent color-associated words (e.g.,blood printed in blue), and incongruent color words (e.g.,yellow printed in blue). Results revealed no differences in German and Chinese students’ response times to color patches. Chinese participants, however, showed longer color naming latencies for neutral words as well as for color words and color-related words. No differences between German and Chinese participants were found when print color latencies for neutral words were subtracted from print color latencies for color words and color-related words. This result does not support theories which suggest that for morphosyllabic readers there is a direct route from orthography to the semantics of a word. We rather argue, with reference to dual route models of reading, that access from print to phonology is faster for morphosyllabic than for alphabetic readers, and therefore interference caused by conflicting phonologies of color name and written word will be stronger in Chinese readers than in German readers.     

Automatic vigilance for negative words in lexical decision and naming: comment on Larsen, Mercer, and Balota (2006)

An automatic vigilance hypothesis states that humans preferentially attend to negative stimuli, and this attention to negative valence disrupts the processing of other stimulus properties. Thus, negative words typically elicit slower color naming, word naming, and lexical decisions than neutral or positive words. Larsen, Mercer, and Balota analyzed the stimuli from 32 published studies, and they found that word valence was confounded with several lexical factors known to affect word recognition. Indeed, with these lexical factors covaried out, Larsen et al. found no evidence of automatic vigilance. The authors report a more sensitive analysis of 1011 words. Results revealed a small but reliable valence effect, such that negative words (e.g., "shark") elicit slower lexical decisions and naming than positive words (e.g., "beach"). Moreover, the relation between valence and recognition was categorical rather than linear; the extremity of a word's valence did not affect its recognition. This valence effect was not attributable to word length, frequency, orthographic neighborhood size, contextual diversity, first phoneme, or arousal. Thus, the present analysis provides the most powerful demonstration of automatic vigilance to date.     

Seeking the source of emotional Stroop interference effects in PTSD: A study of P3s to traumatic words

We investigated the source of emotional Stroop interference effects in posttraumatic stress disorder (PTSD) by measuring reaction times and P3 latencies and amplitudes to personal traumatic, personal positive, and neutral words in a modified Stroop paradigm. Individuals with PTSD were slower to indicate word color, especially for traumatic words, thereby replicating emotional Stroop interference in PTSD. Individuals with PTSD also had significantly reduced and delayed P3 components across word types. Across diagnostic groups, frontal P3 amplitudes were larger to personal positive and traumatic words compared to standard neutral words. However, the absence of Diagnosis x Word Type interactions for P3 measures suggests that individuals with PTSD do not differ from individuals without PTSD in the encoding and recognition of the color of traumatic relative to nontraumatic words, and that Stroop interference does not occur during these early stages of processing.     

Orthographic and phonological activation in auditory and visual word recognition

A discrete-trials color naming (Stroop)’paradigm was used to examine activation along orthographic and phonological dimensions in visual and auditory word recognition. Subjects were presented a prime word, either auditorily or visually, followed 200 msec later by a target word printed in a color. The orthographic and phonological similarity of prime-target pairs varied. Color naming latencies were longer when the primes and targets were orthographically and/or phonologically similar than when they were unrelated. This result obtained for both prime presentation modes. The results suggest that word recognition entails activation of multiple codes and priming of orthographically and phonologically similar words.     

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。     

Stroop dilution depends on the nature of the color carrier but not on its location

Stroop dilution is the reduction of the Stroop effect in the presence of a neutral word. It has been attributed to competition for attention between the color word and neutral word, to competition between all stimuli in the visual field, and to perceptual interference. Five experiments tested these accounts. The critical manipulation was whether the color to be named was carried by the color word or the neutral word. Neutral words diluted the Stroop effect when they were the color carrier, but not when the color word was the color carrier. We argue that Stroop dilution is due to attentional competition between the color word and neutral word, with priority given to the color carrier.     

The lateralized emotional stroop task: left visual field interference in women

In a visual hemifield emotional Stroop task, 54 women were asked to name the color of laterally flashed emotional and neutral words while ignoring their semantic content. Vocal reaction times for color naming were recorded. The participants exhibited significant emotional interference effects in the left visual field, which tended to be larger for negative words than for positive words. Participants with higher trait anxiety scores exhibited larger interference for positive words in the left relative to the right visual field. The outcome indicates that, in women, emotional Stroop interference arises in the right rather than in the left hemisphere, with a larger impact of negative than of positive words, and with trait anxiety modulating the lateralized interference for positive words.     

Emotion words affect eye fixations during reading

Emotion words are generally characterized as possessing high arousal and extreme valence and have typically been investigated in paradigms in which they are presented and measured as single words. This study examined whether a word's emotional qualities influenced the time spent viewing that word in the context of normal reading. Eye movements were monitored as participants read sentences containing an emotionally positive (e.g., lucky), negative (e.g., angry), or neutral (e.g., plain) word. Target word frequency (high or low) was additionally varied to help determine the temporal locus of emotion effects, with interactive results suggesting an early lexical locus of emotion processing. In general, measures of target fixation time demonstrated significant effects of emotion and frequency as well as an interaction. The interaction arose from differential effects with negative words that were dependent on word frequency. Fixation times on emotion words (positive or negative) were consistently faster than those on neutral words with one exception-high-frequency negative words were read no faster than their neutral counterparts. These effects emerged in the earliest eye movement measures, namely, first and single fixation duration, suggesting that emotionality, as defined by arousal and valence, modulates lexical processing. Possible mechanisms involved in processing emotion words are discussed, including automatic vigilance and desensitization, both of which imply a key role for word frequency. Finally, it is important that early lexical effects of emotion processing can be established within the ecologically valid context of fluent reading.     

Is the emotional Stroop task a special case of mood induction? Evidence from sustained effects of attention under emotion

Sustained effects of emotion are well known in everyday experience. Surprisingly, such effects are seldom recorded in laboratory studies of the emotional Stroop task, in which participants name the color of emotion and neutral words. Color performance is more sluggish with emotion words than with neutral words, the emotional Stroop effect (ESE). The ESE is not sensitive to the order in which the two groups of words are presented, so the effect of exposure to emotion words does not extend to disrupting performance in a subsequent block with neutral words. We attribute this absence of a sustained effect to habituation engendered by excessive repetition of the experimental stimuli. In a series of four experiments, we showed that sustained effects do occur when habituation is removed, and we also showed that the massive exposure to negative stimuli within the ESE paradigm induces a commensurately negative mood. A novel perspective is offered, in which the ESE is considered a special case of mood induction.     

Processing of threat-related information in rape victims

We investigated selective processing of threat information in persons with posttraumatic stress disorder (PTSD) by using a modified Stroop procedure. Subjects were 15 rape victims with PTSD, 13 rape victims without the disorder, and 16 nontraumatized control subjects. They were asked to name the color of four types of words: specific threat (rape-related) words, general threat (related to physical harm and death) words, neutral words, and nonwords. Rape victims with PTSD evidenced a longer response latency for color naming of rape-related words than for other target-word types. Response latencies of non-PTSD victims and nonvictim control subjects did not differ across word types. Possible mechanisms underlying the selective processing of threat material are considered, and clinical implications are discussed.