Consequences of emotional stimuli: age differences on pure and mixed blocks of the emotional Stroop

BackgroundStudies of aging and emotion suggest that older adults show diminished responsiveness to negative information, possibly resulting from increased emotion regulation, but the mechanisms accounting for this effect are uncertain.MethodsTo examine whether aging affects the allocation of attention to negative stimuli, we compared 20 younger and 20 older adults on 2 versions of the emotional Stroop task: "pure blocks," in which all words in each block were either emotional or neutral, and "mixed blocks," a pseudorandomized design in which either a negative emotional or a neutral category word was always followed by six neutral words. The emotional Stroop task typically elicits slower reaction times for naming the font color of negative emotional words compared to neutral, but no studies have examined the effects of aging on the immediate and sustained components of the emotional Stroop effect.ResultsBoth groups showed an emotional Stroop effect on pure blocks manifest as slower RTs on the emotional, relative to the neutral, block. However, only younger adults showed persistent slowing that carried over from emotional words onto subsequent neutral words in mixed blocks.ConclusionThese results suggest that the consequences of emotional stimuli may differ with age. Younger and older adults showed equivalent interference from the emotional words themselves, but older adults did not show a sustained effect of negative information.

Related papers:

title: Is Well-Being U-Shaped Over the Life Cycle?
abstract: We present evidence that psychological well-being is U-shaped through life. A difficulty with research on this issue is that there are likely to be omitted cohort effects (earlier generations may have been born in, say, particularly good or bad times). First, using data on 500,000 randomly sampled Americans and West Europeans, the paper designs a test that can control for cohort effects. Holding other factors constant, we show that a typical individual's happiness reaches its minimum - on both sides of the Atlantic and for both males and females - in middle age. Second, evidence is provided for the existence of a similar U-shape through the life-course in East European, Latin American and Asian nations. Third, a U-shape in age is found in separate well-being regression equations in 72 developed and developing nations. Fourth, using measures that are closer to psychiatric scores, we document a comparable well-being curve across the life cycle in 2 other data sets (1) in GHQ-N6 mental health levels among a sample of 16,000 Europeans, and (2) in reported depression-and-anxiety levels among 1 million UK citizens. Fifth, we discuss some apparent exceptions, particularly in developing nations, to the U-shape. Sixth, we note that American male birth-cohorts seem to have become progressively less content with their lives. Our results are based on regression equations in which other influences, such as demographic variables and income, are held constant.

title: May I have your attention, please: Electrocortical responses to positive and negative stimuli
abstract: Previous research has shown that negative stimuli elicit more attention than do positive stimuli. However, this research has relied on response-based measures to assess attention. The current research uses the P1 component of the event-related brain potential (ERP) as a proximal index of attention allocation to valenced stimuli. In two studies, P1 amplitude was measured while participants evaluated positive and negative pictures. In both studies, principal components analysis showed that P1 amplitudes to frequent stimuli and to rare negative stimuli were larger than P1 amplitudes to rare positive stimuli. This is (a) evidence for the extremely rapid (<120 ms) differentiation of positive and negative stimuli and (b) process-based evidence for a negativity bias in attention allocation.

title: Bad is Stronger than Good
abstract: The greater power of bad events over good ones is found in everyday events, major life events (e.g., trauma), close relationship outcomes, social network patterns, interpersonal interactions, and learning processes. Bad emotions, bad parents, and bad feedback have more impact than good ones, and bad information is processed more thoroughly than good. The self is more motivated to avoid bad self-definitions than to pursue good ones. Bad impressions and bad stereotypes are quicker to form and more resistant to disconfirmation than good ones. Various explanations such as diagnosticity and salience help explain some findings, but the greater power of bad events is still found when such variables are controlled. Hardly any exceptions (indicating greater power of good) can be found. Taken together, these findings suggest that bad is stronger than good, as a general principle across a broad range of psychological phenomena.

title: Negative information weighs more heavily on the brain: the negativity bias in evaluative categorizations.
abstract: Negative information tends to influence evaluations more strongly than comparably extreme positive information. To test whether this negativity bias operates at the evaluative categorization stage, the authors recorded event-related brain potentials (ERPs), which are more sensitive to the evaluative categorization than the response output stage, as participants viewed positive, negative, and neutral pictures. Results revealed larger amplitude late positive brain potentials during the evaluative categorization of (a) positive and negative stimuli as compared with neutral stimuli and (b) negative as compared with positive stimuli, even though both were equally probable, evaluatively extreme, and arousing. These results provide support for the hypothesis that the negativity bias in affective processing occurs as early as the initial categorization into valence classes.

title: Negativity Bias, Negativity Dominance, and Contagion
abstract: We hypothesize that there is a general bias, based on both innatepredispositions and experience, in animals and humans, to give greater weight to negative entities (e.g., events, objects, personal traits). This is manifested in 4 ways: (a) negative potency (negative entities are stronger than the equivalent positive entities), (b) steeper negative gradients (the negativity of negative events grows more rapidly with approach to them in space or time than does the positivity of positive events, (c) negativity dominance (combinations of negative and positive entities yield evaluations that are more negative than the algebraic sum of individual subjective valences would predict), and (d) negative differentiation (negative entities are more varied, yield more complex conceptual representations, and engage a wider response repertoire). We review evidence for this taxonomy, with emphasis on negativity dominance, including literary, historical, religious, and cultural sources, as well as the psychological literatures on learning, attention, impression formation, contagion, moral judgment, development, and memory. We then consider a variety of theoretical accounts for negativity bias. We suggest that 1 feature of negative events that make them dominant is that negative entities are more contagious than positive entities.

title: Looking at the Sunny Side of Life
abstract: Studies of the negativity bias have demonstrated that negative information has a stronger influence than positive information in a wide range of cognitive domains. At odds with this literature is extensive work now documenting emotional and motivational shifts that result in a positivity effect in older adults. It remains unclear, however, whether this age-related positivity effect results from increases in processing of positive information or from decreases in processing of negative information. Also unknown is the specific time course of development from a negative bias to an apparently positive one. The present study was designed to investigate the negativity bias across the life span using an event-related potential measure of responding to emotionally valenced images. The results suggest that neural reactivity to negative images declines linearly with age, but responding to positive images is surprisingly age invariant across most of the adult life span.

title: Anticipation of monetary gain but not loss in healthy older adults
abstract: Although global declines in structure have been documented in the aging human brain, little is known about the functional integrity of the striatum and prefrontal cortex in older adults during incentive processing. We used event-related functional magnetic resonance imaging to determine whether younger and older adults differed in both self-reported and neural responsiveness to anticipated monetary gains and losses. The present study provides evidence for intact striatal and insular activation during gain anticipation with age, but shows a relative reduction in activation during loss anticipation. These findings suggest that there is an asymmetry in the processing of gains and losses in older adults that may have implications for decision-making.

title: Older adults as adaptive decision makers: evidence from the Iowa Gambling Task.
abstract: Older adults process emotional information differently than younger adults and may demonstrate less of a negativity bias on cognitive tasks. The Iowa Gambling Task designed by A. Bechara, H. Damasio, D. Tranel, and A. R. Damasio (1997) has been used to examine the integration of emotion and cognition in a risky-choice decision task and may give insight into differences in the decision-making strategies in younger and older adults. Eighty-eight younger adults (18-34 years) and 67 older adults (65-88 years) completed the Iowa Gambling Task. Using a theoretical decomposition of the task designed by J. R. Busemeyer and J. C. Stout (2002), the authors found that both groups were successful at solving the task but used very different strategies that reflected each group's strength. For younger adults, that strength was learning and memory. For older adults, that strength was an accurate representation of wins and losses (valence).

title: The negativity bias is eliminated in older adults: age-related reduction in event-related brain potentials associated with evaluative categorization.
abstract: Studies of younger adults have found that negative information has a stronger influence than positive information across a wide range of domains. T. A. Ito, J. T. Larsen, N. K. Smith, and J. T. Cacioppo (1998) reported that during evaluative categorization, extreme negative images produced greater brain activity than did equally extreme positive images in younger adults. Older adults have been reported to optimize affect and attend less to negative information. In this article, the negativity bias was examined in 20 older versus 20 younger adults during evaluative categorization, with a focus on brain activity occurring roughly 500 ms after presentation of visual stimuli. Results demonstrated a significant decrease in brain activity to both positive and negative stimuli (p < .05) and an elimination of the negativity bias in older adults.

title: Age differences in everyday problem-solving effectiveness: older adults select more effective strategies for interpersonal problems.
abstract: Using the Everyday Problem Solving Inventory of Cornelius and Caspi, we examined differences in problem-solving strategy endorsement and effectiveness in two domains of everyday functioning (instrumental or interpersonal, and a mixture of the two domains) and for four strategies (avoidance-denial, passive dependence, planful problem solving, and cognitive analysis). Consistent with past research, our research showed that older adults were more problem focused than young adults in their approach to solving instrumental problems, whereas older adults selected more avoidant-denial strategies than young adults when solving interpersonal problems. Overall, older adults were also more effective than young adults when solving everyday problems, in particular for interpersonal problems.

title: Aging and visual search: automatic and controlled attentional bias to threat faces.
abstract: Using a visual search paradigm, we investigated how age affected attentional bias to emotional facial expressions. In Experiments 1 and 2, participants searched for a discrepant facial expression in a matrix of otherwise homogeneous faces. Both younger and older adults showed a more effective search when the discrepant face was angry rather than happy or neutral. However, when the angry faces served as non-target distractors, younger adults' search was less effective than happy or neutral distractor conditions. In contrast, older adults showed a more efficient search with angry distractors than happy or neutral distractors, indicating that older adults were better able to inhibit angry facial expressions. In Experiment 3, we found that even a top-down search goal could not override the angry face superiority effect in guiding attention. In addition, RT distribution analyses supported that both younger and older adults performed the top-down angry face search qualitatively differently from the top-down happy face search. The current research indicates that threat face processing involves automatic attentional shift and a controlled attentional process. The current results suggest that age only influenced the controlled attentional process.

title: Selective preference in visual fixation away from negative images in old age? An eye-tracking study.
abstract: Recent studies have suggested that older individuals selectively forget negative information. However, findings on a positivity effect in the attention of older adults have been more mixed. In the current study, eye tracking was used to record visual fixation in nearly real-time to investigate whether older individuals show a positivity effect in their visual attention to emotional information. Young and old individuals (N = 64) viewed pairs of synthetic faces that included the same face in a nonemotional expression and in 1 of 4 emotional expressions (happiness, sadness, anger, or fear). Gaze patterns were recorded as individuals viewed the face pairs. Older adults showed an attentional preference toward happy faces and away from angry ones; the only preference shown by young adults was toward afraid faces. The age groups were not different in overall cognitive functioning, suggesting that these attentional differences are specific and motivated rather than due to general cognitive change with age.

title: Aging and Attentional Biases for Emotional Faces
abstract: We examined age differences in attention to and memory for faces expressing sadness, anger, and happiness. Participants saw a pair of faces, one emotional and one neutral, and then a dot probe that appeared in the location of one of the faces. In two experiments, older adults responded faster to the dot if it was presented on the same side as a neutral face than if it was presented on the same side as a negative face. Younger adults did not exhibit this attentional bias. Interactions of age and valence were also found for memory for the faces, with older adults remembering positive better than negative faces. These findings reveal that in their initial attention, older adults avoid negative information. This attentional bias is consistent with older adults' generally better emotional well-being and their tendency to remember negative less well than positive information.

title: Aging and goal-directed emotional attention: distraction reverses emotional biases.
abstract: Previous findings reveal that older adults favor positive over negative stimuli in both memory and attention (for a review, see Mather & Carstensen, 2005). This study used eye tracking to investigate the role of cognitive control in older adults' selective visual attention. Younger and older adults viewed emotional-neutral and emotional-emotional pairs of faces and pictures while their gaze patterns were recorded under full or divided attention conditions. Replicating previous eye-tracking findings, older adults allocated less of their visual attention to negative stimuli in negative-neutral stimulus pairings in the full attention condition than younger adults did. However, as predicted by a cognitive-control-based account of the positivity effect in older adults' information processing tendencies (Mather & Knight, 2005), older adults' tendency to avoid negative stimuli was reversed in the divided attention condition. Compared with younger adults, older adults' limited attentional resources were more likely to be drawn to negative stimuli when they were distracted. These findings indicate that emotional goals can have unintended consequences when cognitive control mechanisms are not fully available.

title: Emotional enhancement of perceptual priming is preserved in aging and early-stage Alzheimer's disease
abstract: Perceptual priming for emotionally-negative and neutral scenes was tested in early-stage Alzheimer's disease (AD) patients and healthy younger, middle-aged and older adults. In the study phase, participants rated the scenes for their arousal properties. In the test phase, studied and novel scenes were initially presented subliminally, and the exposure duration was gradually increased until a valence categorization was made. The difference in exposure duration required to categorize novel versus studied items was the dependent measure of priming. Aversive content increased the magnitude of priming, an effect that was preserved in healthy aging and AD. Results from an immediate recognition memory test showed that the priming effects could not be attributable to enhanced explicit memory for the aversive scenes. These findings implicate a dissociation between the modulatory effect of emotion across implicit and explicit forms of memory in aging and early-stage AD.

title: Taking time seriously. A theory of socioemotional selectivity.
abstract: Socioemotional selectivity theory claims that the perception of time plays a fundamental role in the selection and pursuit of social goals. According to the theory, social motives fall into 1 of 2 general categories--those related to the acquisition of knowledge and those related to the regulation of emotion. When time is perceived as open-ended, knowledge-related goals are prioritized. In contrast, when time is perceived as limited, emotional goals assume primacy. The inextricable association between time left in life and chronological age ensures age-related differences in social goals. Nonetheless, the authors show that the perception of time is malleable, and social goals change in both younger and older people when time constraints are imposed. The authors argue that time perception is integral to human motivation and suggest potential implications for multiple subdisciplines and research interests in social, developmental, cultural, cognitive, and clinical psychology.

title: Aging and motivated cognition: the positivity effect in attention and memory
abstract: As people get older, they experience fewer negative emotions. Strategic processes in older adults' emotional attention and memory might play a role in this variation with age. Older adults show more emotionally gratifying memory distortion for past choices and autobiographical information than younger adults do. In addition, when shown stimuli that vary in affective valence, positive items account for a larger proportion of older adults' subsequent memories than those of younger adults. This positivity effect in older adults' memories seems to be due to their greater focus on emotion regulation and to be implemented by cognitive control mechanisms that enhance positive and diminish negative information. These findings suggest that both cognitive abilities and motivation contribute to older adults' improved emotion regulation.

title: Effects of arousing emotional scenes on the distribution of visuospatial attention: changes with aging and early subcortical vascular dementia
abstract: The modulation of attention by emotionally arousing stimuli is highly important for each individual's social function. Disturbances of emotional processing are a supportive feature for the diagnosis of subcortical vascular dementia (SVD). We address here whether these disturbances might be useful as an early disease marker.



In order to examine the modulation of visual attention by emotionally arousing stimuli of different valence, 12 elderly patients with early SVD, 12 age-comparable healthy adults and 12 young healthy subjects were studied while looking at pairs of pictures from the International Affective Picture Battery that were either neutral-neutral, neutral-positive or neutral-negative in terms of emotional content. Eye movements were recorded with an infrared eye-tracking system. The direction of the first saccade and the dwell time during the 10 s of presentation were measured and compared among groups with parametric tests.



All subjects showed a modulation of initial attentional orienting as well as a higher percentage of dwell time towards the pictures containing emotional material. Patients with SVD and old controls did not differ in either experimental measure. Young patients showed a stronger bias towards emotionally negative material than both groups of older individuals.



Modulation of visuospatial attention is preserved in early SVD. This might have implications for therapeutic interventional approaches. A weakened sustained attention towards negative but not positive emotional pictures in the elderly is in accordance with the socioemotional selectivity theory, describing a relative selection of positive stimuli with aging.

title: A content analysis of involuntary autobiographical memories: Examining the positivity effect in old age
abstract: Although research on autobiographical memory is growing steadily, very little is known about involuntary autobiographical memories that are spontaneously recalled in everyday life. In addition, very few studies have examined the actual content of autobiographical memories and how the content might change as a function of age. The present study carried out a content analysis of involuntary autobiographical memories recorded by young (N = 11) and old (N = 10) volunteers over a period of 1 week. A total of 224 memories were classified into 17 categories according to the type of content recalled (e.g., births, holidays, school). The results support the socioemotional theory of ageing (Carstensen, Isaacowitz & Charles, 1999) by showing that although young and old adults recalled a similar number of memories with a typically positive content (e.g., holidays, special occasions), older adults recalled very few memories with a typically negative content (e.g., accidents, stressful events). Moreover, even when such negative memories were recalled, they were rated by older adults as neutral or even positive. This so-called positivity effect in old age could not be entirely explained by participants' ratings of mood at the time of recall. Theoretical and practical implications of these findings for ageing and autobiographical memory research are discussed.

title: No aging bias favoring memory for positive material: evidence from a heterogeneity-homogeneity list paradigm using emotionally toned words.
abstract: Some authors argue for a memory advantage of older adults for positively toned material. To investigate the contribution of selective processing to a positivity effect, the authors investigated young (n = 72, aged 18 to 31) and older (n = 72, aged 64 to 75) adults' memory for emotionally toned words using a multitrial paradigm that compares performance for heterogeneous (mixed valence) and homogeneous (single valence) lists. Regarding the age comparison, there was no evidence for an aging bias favoring positive material. Moreover, older adults' memory was less affected by emotion-based processing prioritization. Although there was no support for age-specific processing biases in memory for emotionally toned words, the findings are consistent with proposals that negative information receives processing priority in some contexts. Possible limits to the generalizability of the present findings (e.g., to nonverbal material) are discussed.

title: The automaticity of emotional Stroop: a meta-analysis.
abstract: An automatic bias to threat is often invoked to account for colour-naming interference in emotional Stroop. Recent findings by McKenna and Sharma [(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], however, cast doubt on the fast and non-conscious nature of emotional Stroop. Interference by threat words only occurred with colour naming in the trial subsequent to the threat trial (i.e., a "slow" effect), but not immediately (i.e., a "fast" effect, as would be predicted by the bias hypothesis). In a meta-analysis of 70 published emotional Stroop studies the largest effects occurred when presentation of threat words was blocked, suggesting a strong contribution by slow interference. We did not find evidence; moreover, for interference in suboptimal (less conscious) presentation conditions and the only significant effects were observed in optimal (fully conscious) conditions with high-anxious non-clinical participants and patients. The emotional Stroop effect seems to rely more on a slow disengagement process than on a fast, automatic, bias.

title: Reversing the emotional Stroop effect reveals that it is not what it seems: the role of fast and slow components.
abstract: The relative contributions of slow and fast (online) components in a modified emotional Stroop task were evaluated. The slow component, neglected in previous research, was shown to lead to the prediction of a reversed emotional intrusion effect using pseudorandomly mixed negative and neutral stimuli. This prediction was supported in Experiments 1 and 2. In Experiments 3 and 4, a new paradigm was developed that allowed a more direct observation of the nature of disruptive effects from negative stimuli. The results provided a clear demonstration of the presence of the slow component. The fast component, which has generally been assumed to be the source of the interference, was shown, in fact, to have little or no role in the disruption.

title: A rational look at the emotional stroop phenomenon: a generic slowdown, not a stroop effect.
abstract: The role of Stroop processes in the emotional Stroop effect was subjected to a conceptual scrutiny augmented by a series of experiments entailing reading or lexical decision as well as color naming. The analysis showed that the Stroop effect is not defined in the emotional Stroop task. The experiments showed that reading, lexical decision, and color naming all are slower with emotional words and that this delay is immune to task-irrelevant variation and to changes in the relative salience of the words and the colors. The delay was absent when emotional and neutral words appeared in a single block. A threat-driven generic slowdown is implicated, not a selective attention mechanism associated with the classic Stroop effect.

title: Paying attention to emotion:
abstract: 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.

title: The emotional Stroop task and psychopathology.
abstract: 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 (1990) parallel distributed processing model.

title: Performance in auditory and visual emotional stroop tasks: a comparison of older and younger adults.
abstract: Research has shown age-related declines in the cognitive ability to inhibit irrelevant information. Thirty-six younger adults (mean age = 22 years) and 36 older adults (mean age = 74 years) performed 2 versions of an emotional Stroop task. In one, they made lexical decisions to emotion words spoken in 1 of several tones of voice. Latencies were longer for test words spoken in an incongruent tone of voice, but only for older adults. In another, words were displayed on a computer screen in a colored font, and participants quickly named the font color. Latencies were longer for test words high on arousal, but only for older adults. Results are discussed in terms of inhibitory cognitive processes, attention, and theories of emotional development.

title: The Effects of Blocked Versus Random Presentation and Semantic Relatedness of Stimulus Words on Response to a Modified Stroop Task Among Social Phobics
abstract: Previous studies of the modified Stroop Color-Naming Task with social phobics have demonstrated increased latencies for the color-naming of social threat words in comparison to neutral or physical threat words. However, these effects could be partially due to differences in the semantic relatedness of the words in these various categories and/or the blocked format (i.e., all words of one type presented sequentially) in which words have been presented. To examine these issues, color-naming latencies of individuals with social phobia to social threat, semantically related neutral, and unrelated neutral words were examined in both blocked and randomly intermixed formats. Significant differences in color-naming were found for word stimuli presented in the blocked format only. In the blocked format, social phobics were significantly slower to color-name social threat words than related neutral words and significantly slower to color-name related neutral words than unrelated neutral words. Color-naming latencies also increased across trials regardless of word type. There were no effects of word type in the random format. Thus, both presentation format and semantic priming, as well as threat value, may have contributed to color-naming interference for the social threat words. Possible interpretations of our findings along with implications for future Stroop research in persons with social phobia are discussed.

title: Effects of mood manipulation and anxiety on performance of an emotional Stroop task.
abstract: In Study 1 subjects high and low in trait anxiety were asked to identify the colour of anxiety-related, anxiety-matched neutral, happiness-related and happiness-matched neutral words. There were two types of stimulus presentation: blocked trials, where stimuli were blocked with respect to their valence, and mixed trials, where stimuli were mixed with respect to their valence. Subjects high in trait anxiety took longer to identify the colour of anxiety-related compared to matched neutral words for blocked-trial presentation only. In Study 2 subjects were exposed to either a positive or a negative mood-manipulation followed by a mixed-trial Stroop task. The mood manipulation procedure was successful in producing predicted changes in self-reported state anxiety. Analyses showed that high-trait-anxiety subjects exhibited interference effects consistent with the induced mood. No such effects were observed for the low-trait-anxiety subjects.

title: Effects of unattended emotional stimuli on color-naming performance
abstract: The effect of irrelevant emotional and neutral stimuli on the performance of a color-naming task is examined with two groups of subjects: pilots and bus drivers. It is found that (1) the emotional stimuli disrupt performance in both groups, (2) the decrement in performance is relatively larger in the pilot group, and (3) the effect of the emotional stimuli appears to persist over time.

title: Generalizability of carry-over effects in the emotional Stroop task.
abstract: The emotional Stroop task has been the most widely used task to examine attentional bias to emotionally salient stimuli. In one format of this task, words are presented to participants in a mixed randomized or quasi-randomized sequence. Using a mixed smoking Stroop task, we have previously demonstrated that smokers are slower to respond to words which follow smoking-related words than words which follow neutral words. Here we show that this carry-over effect is present in heroin addicts-but not control subjects-in a heroin Stroop task, and in normal subjects in a stress Stroop task. Thus, the effect generalizes to other populations. In addition, an examination of the studies that have collected data from both mixed and blocked formats provides converging evidence for the presence of carry-over effects. We discuss the implications of the carry-over effect for research using the emotional Stroop task.

title: Emotion and aging: experience, expression, and control.
abstract: Age differences in emotional experience, expression, and control were investigated in 4 studies. A community sample of 127 African Americans and European Americans (ages 19-96 years) was used in Study 1; a community sample of 82 Chinese Americans and European Americans (ages 20-85 years) was used in Study 2; a community sample of 49 Norwegians drawn from 2 age groups (ages 20-35 years and 70+ years) was used in Study 3; and a sample of 1,080 American nuns (ages 24-101 years) was used in Study 4. Across studies, a consistent pattern of age differences emerged. Compared with younger participants, older participants reported fewer negative emotional experiences and greater emotional control. Findings regarding emotional expressivity were less consistent, but when there were age differences, older participants reported lesser expressivity. Results are interpreted in terms of increasingly competent emotion regulation across the life span.

title: Behavioral inhibition and amplification during emotional arousal: a comparison of two age groups.
abstract: This study investigated age differences in the ability to suppress and amplify expressive behavior during emotional arousal. Young and old participants viewed 3 film clips about medical procedures while their behavioral, autonomic, and subjective responses were recorded. Half of the participants viewed all 3 films without additional instructions; the other half was asked to suppress and amplify their behavioral expression during the 2nd and 3rd films. Except for heart rate, suppression and amplification produced similar patterns of autonomic activation. Neither suppression nor amplification had effects on self-reported emotion. There were no age differences in the ability to suppress or amplify emotional expression or in their physiological or subjective consequences. Considering that older people's unregulated reactivity was lower than that of young adults, suppression may have been easier and amplification more difficult for older adults. Voluntary emotion regulation might be one domain of human performance that is spared from age-related losses.

title: Lexical characteristics of words used in emotional Stroop experiments.
abstract: 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.

title: Affective Norms for English Words (ANEW): Instruction Manual and Affective Ratings
abstract: depressed individuals recalled fewer positive words than did their taken from the Affective Norms for English. Words list (ANEW, Bradley Affective norms for English words (ANEW): Instruction manual and affective ratings (pp. 1–45). Publication » Affective Norms for English Words (ANEW): Instruction Manual and Affective Ratings. Affective norms. English words (ANEW): Stimuli, instruction manual and affective ratings. Technical report. The Center for Research in Psychophysiology.

title: Stroop interference and disorders of selective attention
abstract: Fourteen patients with right-hemisphere CVA and 8 patients with a left-hemisphere CVA were examined for selective attention deficits using a variant of the Stroop color-word task: the picture-word interference task. Experiments 1 and 2 first compared the performance of the two patient groups and a control group in three tasks of increasing difficulty: picture-word detection, word reading, and picture naming. The results showed that (a) the two patient groups were significantly slower than the control group, but did not differ from each other, and (b) the difference in mean RT between the two patient groups and the control group did not increase with task difficulty. In Experiment 3, the subjects were required to name pictures while ignoring accompanying distractors: nonletter symbols, unrelated words or semantically related words. In this task, the right hemisphere patients showed a much larger semantic interference effect than both the left hemisphere patients and the control group. It is argued that this finding most probably reflects problems in visual selective attention with the right hemisphere patients.

title: The interaction between stop signal inhibition and distractor interference in the flanker and Stroop task.
abstract: In the present study, two experiments were conducted to investigate the interaction between the behavioral inhibition, measured by the stop signal task, and distractor interference, measured by the flanker task and the Stroop task. In the first experiment, the stop signal task was combined with a flanker task. Analysis revealed that participants responded faster when the distractors were congruent to the target. Also, the data suggest that it is more difficult to suppress a reaction when the distractors were incongruent. Whether the incongruent distractor was part of the response set (i.e. the distractor could also be a target) or not, had no influence on stopping reactions. In the second experiment, the stop signal task was combined with a manual version of the Stroop task and the degree of compatibility was varied. Even though in the second experiment of the present study interference control is differently operationalized, similar results as in the first experiment were found, indicating that inhibition of motor responses is influenced by the presentation of distracting information that is not part of the response set.

title: Effects of aging on slowing of motor-response generation.
abstract: The aim of the present study was to analyze different stages of central processing mechanisms during a choice reaction task and to evaluate their contribution to aging-related response slowing. Event-related potentials (ERPs) were recorded from two groups of subjects, young (mean 22 years) and older adults (mean 58 years), who performed a four-alternative choice-reaction task. The results showed the expected reaction time slowing in the older subjects. This behavioural slowing was not due to delays in stimulus processing (as reflected by latencies of early ERP components), or in response selection (as reflected by the onset of the lateralized readiness potential). Instead, this slowing was due to an alteration of movement-related components, particularly an amplitude enhancement and prolongation of the motor-related potential at the cortex contralateral to the responding hand. This alteration was reliable and of general nature since it was also found in a second study using a different choice-reaction task with a more direct stimulus-response relation. The results suggest that the overt response requires a higher activation level in older vs. young subjects; this extra-activation needs time and hence prolongs reaction time with aging.

title: Neuroanatomical correlates of selected executive functions in middle-aged and older adults: a prospective MRI study
abstract: Neuroanatomical substrates of age-related differences in working memory and perseverative behavior were examined in a sample of healthy adults (50-81 years old). The participants, who were screened for history of neurological, psychiatric, and medical conditions known to be linked to poor cognitive performance, underwent magnetic resonance imaging (MRI) and were administered tests of working memory and perseveration. Regional brain volumes and the volume of white matter hyperintensities (WMH) were measured on magnetic resonance images. The analyses indicate that the volume of the prefrontal cortex (PFC) and the volume of white matter hyperintensities in the prefrontal region are independently associated with age-related increases in perseverative errors on the Wisconsin Card Sorting Test (WCST). When participants taking antihypertensive medication were excluded from the analysis, both the volume of the prefrontal cortex and the frontal white matter hyperintensities (FWMH) still predicted increases in perseveration. Neither reduced volume of the prefrontal cortex nor the FWMH volume was linked to age-associated declines in working memory. The volumes of the fusiform gyrus (FG) and the temporal white matter hyperintensities (TWMH) were unrelated to cognitive performance.

title: Functional changes in the activity of brain regions underlying emotion processing in the elderly
abstract: Aging is associated with a decline in both cognitive and motor abilities that reflects deterioration of underlying brain circuitry. While age-related alterations have also been described in brain regions underlying emotional behavior (e.g., the amygdala), the functional consequence of such changes is less clear. To this end, we used blood oxygenation-level dependent (BOLD) functional magnetic resonance imaging (fMRI) to explore age-related changes in brain regions underlying emotion processing. Twelve young (age <30 years) and 14 elderly subjects (age >60 years) were studied with BOLD fMRI during a paradigm that involved perceptual processing of fearful and threatening stimuli. Consistent with previous reports, direct group comparisons revealed relatively increased BOLD fMRI responses in prefrontal cortical regions, including Broca's area, and relatively decreased responses in the amygdala and posterior fusiform gyri in elderly subjects. Importantly, additional analyses using an elderly-specific brain template for spatial normalization of the elderly BOLD fMRI data confirmed these divergent regional response patterns. While there was no difference between groups in accuracy on the task, elderly subjects were significantly slower (delayed reaction times) in performing the task. Our current data suggest that elderly subjects engage a more distributed neocortical network during the perceptual processing of emotional facial expressions. In light of recent converging data from two other studies, our observed effects may reflect age-related compensatory responses and/or alternative strategies in processing emotions, as the elderly appear to engage cognitive/linguistic systems in the context of reduced sensory and/or limbic responses.

title: Evidence for frontally mediated controlled processing differences in older adults.
abstract: Advanced aging is associated with slower and less flexible performance on demanding cognitive tasks. Here we used rapid event-related functional magnetic resonance imaging to explore differences between young (n = 65) and older adults (n = 75) during memory retrieval. Methods were optimized to afford exploration of both amplitude and timing differences in neural activity. Although many correlates of retrieval were similar between the groups, including medial and lateral parietal responses to successful recognition, older adults showed increased recruitment of frontal regions relative to young adults when retrieval demanded heavy use of control processes. This effect was not significant during less effortful retrieval. Moreover, the timing of increased recruitment in older adults occurred at relatively late stages of the retrieval event, suggesting a strategy shift. One possibility is that older adults fail to engage appropriate top-down attentional sets at early stages of the retrieval event; as a consequence, frontally mediated processing is extended at late stages to compensate. This strategy shift, which we conceptualize in a framework called the "load-shift" model, may underlie the often observed retention of high-level cognitive function during advanced aging but at the cost of less flexible and slower performance on demanding cognitive tasks.

title: Event-related potentials during an emotional Stroop task.
abstract: Emotional Stroop tasks have gained wide interest in scientific literature in the last two decades. Although no direct measure of attention is employed, these studies infer the presence of preferential processing of threatening information based on reaction time (RT) impairment in a competing task. Because event-related potential (ERP) measures are sensitive to both the extent (amplitude) and speed (latency) of cerebral processing, they are valuable tools with which to examine more directly the claim that threatening stimuli are associated with enhanced attention. Twenty-two students rated a pool of words to identify those that were personally disturbing. Two word types (threat and neutral) were then compared in two tasks (color relevant, in which the color ink of words was identified, and word relevant in which words were classified as threatening or not). No emotional Stroop effect was observed in terms of longer RTs to identify the colors of threat words. ERP results provided valuable information about threat processing which was not observed with behavioral measures. Threat content was associated with larger P2 amplitude in the right than left hemisphere, and larger P3 amplitude, across tasks. The results indicate strong evidence for enhanced processing of threat-related stimuli in healthy individuals. It is concluded that ERPs are a sensitive measure of processes underlying emotional Stroop performance, which can be used to elucidate attentional biases in healthy and clinical populations.

title: Practice Effect and Test-Retest Reliability of Attentional and Executive Tests in Middle-Aged to Elderly Subjects
abstract: There is a lack of data about the practice effect and test-retest reliability(TRR)on many attentional and executive tests in neuropsychology. In this study, 37 subjects aged 52 to 80 were tested three times with an inter-assessment interval of 14 days. The battery included the Rey Auditory Verbal Learning Test, the Stroop interference test, the Letter-Number Sequencing test, Wechsler Adult Intelligence Scale-III(WAIS-III), the Ruff 2 and 7 Selective Attention Test, the Tower of London, the Verbal Fluency test, and simple, choice, and sequential reaction time tests. The results showed that tasks were generally subject to a practice effect, except for those with alternate forms. In all tests, there were a number of scores demonstrating good TRR, but others, although largely used in clinical practice, failed to reach acceptable TRR standards. Usually, time derived scores were associated with the best TRR.

title: Enhanced Early Emotional Intrusion Effects and Proportional Habituation of Threat Response for Symptom and Illness Words in College Students with Elevated Health Anxiety
abstract: Studies evaluating attentional biases in health anxiety have produced equivocal results. Little is known about the details and potential moderators of prioritized processing of illness related information. We compared individuals with health anxiety (HAG; N = 54) to not health anxious participants (CG; N = 53) in a blocked emotional Stroop paradigm. Analyses focused on differences between categories of health threatening information (words referring to symptoms and illnesses), on the time course of the emotional intrusion effect, and on test order effects. When symptom words were presented first in the experiment (i.e., before the illness words), the HAG showed a stronger emotional intrusion effect to symptom words in the first test half (trials 1–20) compared to the CG. A similar pattern of results with a smaller effect size was apparent for the illness words, when they were presented first in the experiment. The results contribute to a more fine-grained understanding of attentional processes towards external sources of threat in health anxiety. In particular, they emphasize the importance of taking into account the time course when analyzing data from an emotional Stroop paradigm.

title: Secondary trauma: assessing inter-generational transmission of war experiences with a modified Stroop procedure.
abstract: Intergenerational transmission of war experiences was assessed using a modified Stroop task. Adult children of war veterans and those of nonveterans named the colors in which war related words were printed. They also named the colors of neutral, positive, and OCD related words in addition to color naming a series of zeros contained on a control card. All participants completed the MMPI-II PTSD Scale, the Impact of Event Scale, and a demographic questionnaire. A statistically significant difference between the children of veterans and nonveterans was found only on the Stroop card containing war related words. Results suggest that the modified Stroop task is a sensitive measure that may have value in assessing transmission of war experiences from parents to children.

title: Responding to subliminal threat cues is related to trait anxiety and emotional vulnerability: a successful replication of Macleod and Hagan (1992)
abstract: Macleod and Hagan (1992) [Behaviour Research and Therapy, 30, 151-161] reported that threat-relevant interference on a masked Stroop task, where neutral and negative words cannot be consciously perceived, is positively correlated with trait anxiety and emotional vulnerability to stressful life events. Their findings were obtained from subjects who were currently stressed. The aim of the present study was to determine whether the Macleod and Hagan findings could be replicated in a sample that was not currently stressed. Using a sample of 32 volunteers, we found a significant correlation between trait anxiety and threat-relevant interference on a masked Stroop. Furthermore, it was found that the single best predictor of vulnerability to life stress was the interference on the masked Stroop. The findings of the present study correspond quite closely to those reported by Macleod and Hagan (1992).

title: Increased Attention to the Irrelevant Dimension Increases Interference in a Spatial Stroop Task
abstract: In a spatial version of the Stroop task where subjects must attend to the position of a word and ignore the word itself, we argue that interference results because selective attention is only partially successful. If so, then increasing attention to the word should increase interference. Experiment 1 showed increased interference with position naming when subjects must be prepared to attend to either the word or its position. Experiment 2 required subjects to first name the position of the word and then later to recall which word had been presented. This resulted in increased interference with position naming when the word was followed at a short SOA by a pattern mask. Experiment 3 employed both word reading and position naming and showed that a large reverse Stroop effect occurred with both vocal and manual responses when subjects had to be prepared to attend to either dimension of the stimulus.In a typical Stroop task, a word is presented to a subject and the subject is required either to read the word or to report some other attribute of the word, such as its colour or position. In the latter case, response times are strongly influenced by whether the word and the attribute to be reported are congruent or incongruent. For example, when subjects are asked to report whether the stimulus words left, right, above or below are located to the left, to the right, above or below a fixation point, responding is faster if the stimulus word and its position are congruent, and is slower if the stimulus word and its position differ (Seymour, 1973). On the other hand, if the word is to be named, the congruity or incongruity of the spatial attribute of the word has little effect on response time. The word naming situation has often been referred to as the reverse Stroop condition.Interference effects in the Stroop task have frequently been attributed to a failure of selective attention in that subjects seem to be unable to avoid processing the stimulus word. Treisman (1969) has attributed this failure of attention to an inability to selectively attend to different dimensions of an object. On the other hand, there are data which indicate that Stroop interference may not simply reflect a breakdown of selective attention, because the amount of interference can be influenced by the way attention is deployed. Francolini and Egeth (1980) presented their subjects with a circular array containing a variable number of red and black items and asked them to report the number of red items. When the red items were digits which were inconsistent with the number of red items, reaction times were longer, but when the to-be-ignored black items were inconsistent digits, no interference was obtained. Kahneman and Henik (1981) presented their subjects with two words, one on either side of the fixation point. One of the words was printed in coloured ink and the other was printed in black. Subjects were instructed to ignore the black word and report the colour of the other word. When the non-black word was an incompatible colour word, the usual Stroop interference effects were obtained, but no interference was obtained when the to-be-ignored black word was an incompatible colour word. These studies indicate that when attention is directed elsewhere in the visual field, words or numbers are not automatically processed to the extent necessary to produce Stroop interference.There is also evidence that subjects may be able to focus attention on one dimension of a stimulus object and ignore other dimensions. Harvey (1984, Experiment 4) presented a cue (X or x) followed by the words HI or LO in congruent or incongruent positions. The case of the cue indicated whether the subject was to report the position of the word or name it. The interstimulus interval (ISI) between the cue and the word varied from 50 to 950 ms. For both the position and word naming tasks, responses were slower on incongruent trials, but this effect declined with ISI. …

title: Top-down suppression deficit underlies working memory impairment in normal aging
abstract: In this study, we assess the impact of normal aging on top-down modulation, a cognitive control mechanism that supports both attention and memory by the suppression and enhancement of sensory processing in accordance with task goals. Using fMRI (functional magnetic resonance imaging), we show that healthy older adults demonstrated a prominent deficit in the suppression of cortical activity associated with task-irrelevant representations, whereas enhancement of task-relevant activity was preserved. Moreover, this suppression-specific attention deficit correlated with impaired working memory performance.

title: Age Differences in Stroop Interference in Working Memory
abstract: Working memory capacity can be conceptualized as the ability to use controlled attention in short term memory (Engle, Tuholski, Laughlin, & Conway, 1999). We tested this idea in young and older adults by combining the task demands of two neuropsychological tests, word span, and Stroop color-naming. Young and older adults were asked to name the colors of a series of congruent and incongruent color-words (between 2 and 6 words/trial). After all the color-words were presented participants attempted to recall the colors in their serial order. This task required inhibition of the prepotent word reading response (i.e., color naming), with a concurrent memory load (caused by the need to maintain already named colors in short-term memory). Older adults showed greater interference effects, and these interference effects increased as a function of memory load. Regression analyses showed that measures of working memory capacity and executive function accounted for unique variance in incongruent color-word errors for older adults. Defining working memory capacity as the ability to use controlled attention in short-term memory may be a fruitful way to think about this concept in studies of executive function.

title: Intentional modulation of emotional responding to unpleasant pictures: an ERP study.
abstract: Intentionally altering responses to unpleasant stimuli affects physiological and hemodynamic activity associated with emotional and cognitive processing. In the present experiment, we measured the late-positive potential (LPP) of the visually evoked event-related brain potential to examine the effects of intentional emotion modulation on electrophysiological correlates of emotional and cognitive processing. Seventeen participants received instructions to view, suppress, and enhance emotional responses to unpleasant stimuli. Results revealed significantly decreased electrophysiological activity during suppression of emotional responses beginning around 250 ms poststimulus and lasting several hundred milliseconds. These data suggest that ERPs are sensitive to emotion modulation/regulation processes.

title: The Mellow Years?: Neural Basis of Improving Emotional Stability over Age
abstract: Contrary to the pervasive negative stereotypes of human aging, emotional functions may improve with advancing age. However, the brain mechanisms underlying changes in emotional function over age remain unknown. Here, we demonstrate that emotional stability improves linearly over seven decades (12–79 years) of the human lifespan. We used both functional magnetic resonance imaging and event-related potential recording to examine the neural basis of this improvement. With these multimodal techniques, we show that better stability is predicted by a shift toward greater medial prefrontal control over negative emotional input associated with increased activity later in the processing sequence (beyond 200 ms after stimulus) and less control over positive input, related to a decrease in early activity (within 150 ms). This shift was independent from gray matter loss, indexed by structural magnetic resonance data. We propose an integrative model in which accumulated life experience and the motivation for meaning over acquisition in older age contribute to plasticity of medial prefrontal systems, achieving a greater selective control over emotional functions.