Expectancy and attention bias to spiders: Dissecting anticipation and allocation processes using ERPs.

The current registered report focused on the temporal dynamics of the relationship between expectancy and attention toward threat, to better understand the mechanisms underlying the prioritization of threat detection over expectancy. In the current event-related potentials experiment, a-priori expectancy was manipulated, and attention bias was measured, using a well-validated paradigm. A visual search array was presented, with one of two targets: spiders (threatening) or birds (neutral). A verbal cue stating the likelihood of encountering a target preceded the array, creating congruent and incongruent trials. Following cue presentation, preparatory processes were examined using the contingent negative variation (CNV) component. Following target presentation, two components were measured: early posterior negativity (EPN) and late positive potential (LPP), reflecting early and late stages of natural selective attention toward emotional stimuli, respectively. Behaviorally, spiders were found faster than birds, and congruency effects emerged for both targets. For the CNV, a non-significant trend of more negative amplitudes following spider cues emerged. As expected, EPN and LPP amplitudes were larger for spider targets compared to bird targets. Data-driven, exploratory, topographical analyses revealed different patterns of activation for bird cues compared to spider cues. Furthermore, 400-500 ms post-target, a congruency effect was revealed only for bird targets. Together, these results demonstrate that while expectancy for spider appearance is evident in differential neural preparation, the actual appearance of spider target overrides this expectancy effect and only in later stages of processing does the cueing effect come again into play.

Using clustering algorithms to examine the association between working memory training trajectories and therapeutic outcomes among psychiatric and healthy populations.

Working memory (WM) training has gained interest due to its potential to enhance cognitive functioning and reduce symptoms of mental disorders. Nevertheless, inconsistent results suggest that individual differences may have an impact on training efficacy. This study examined whether individual differences in training performance can predict therapeutic outcomes of WM training, measured as changes in anxiety and depression symptoms in sub-clinical and healthy populations. The study also investigated the association between cognitive abilities at baseline and different training improvement trajectories. Ninety-six participants (50 females, mean age = 27.67, SD = 8.84) were trained using the same WM training task (duration ranged between 7 to 15 sessions). An algorithm was then used to cluster them based on their learning trajectories. We found three main WM training trajectories, which in turn were related to changes in anxiety symptoms following the training. Additionally, executive function abilities at baseline predicted training trajectories. These findings highlight the potential for using clustering algorithms to reveal the benefits of cognitive training to alleviate maladaptive psychological symptoms.

A single dose of escitalopram blunts the neural response in the thalamus and caudate during monetary loss.

Background: Selective serotonin reuptake inhibitors (SSRIs) show acute effects on the neural processes associated with negative affective bias in healthy people and people with depression. However, whether and how SSRIs also affect reward and punishment processing on a similarly rapid time scale remains unclear. Methods: We investigated the effects of an acute and clinically relevant dose (20 mg) of the SSRI escitalopram on brain response during reward and punishment processing in 19 healthy participants. In a doubleblind, placebo-controlled study using functional MRI, participants performed a well-established monetary reward task at 3 time points: at baseline; after receiving placebo or escitalopram; and after receiving placebo or escitalopram following an 8-week washout period. Results: Acute escitalopram administration reduced blood-oxygen-level-dependent (BOLD) response during punishment feedback in the right thalamus (family-wise error corrected [FWE] p = 0.013 at peak level) and the right caudate head (pFWE = 0.011 at peak level) compared to placebo. We did not detect any significant BOLD changes during reward feedback. Limitations: We included only healthy participants, so interpretation of findings are limited to the healthy human brain and require future testing in patient populations. The paradigm we used was based on monetary stimuli, and results may not be generalizable to other forms of reward. Conclusion: Our findings extend theories of rapid SSRI action on the neural processing of rewarding and aversive stimuli and suggest a specific and acute effect of escitalopram in the punishment neurocircuitry.

Biased distance estimation in social anxiety disorder: A new avenue for understanding avoidance behavior.

OBJECTIVES: People regulate their interpersonal space appropriately to obtain a comfortable distance for interacting with others. Socially anxious individuals are especially prone to discomfort from and fear of physical closeness, leading them to prefer a greater interpersonal distance from others. Previous studies also indicate that fear can enhance the threat-related elements of a threatening stimulus. For example, spider phobia is associated with estimating spiders as bigger and faster than they actually are. Nonetheless, it is still unclear whether the preference of those with social anxiety disorder (SAD) to maintain greater distance from others is associated with biased estimations of interpersonal distance. MATERIALS AND METHODS: A total of 87 participants (44 clinically diagnosed with SAD and 43 control) performed validated computerized and ecological tasks in a real-life setting while social space estimations and preferences were measured. RESULTS: Participants with SAD felt comfortable when maintaining a greater distance from unfamiliar others compared to the control group and estimated unfamiliar others to be closer to them than they actually were. Moreover, the estimation bias predicted their preferred distance from strangers, indicating a strong association between estimation bias severity and actual approach-avoidance behavior. CONCLUSION: Our findings indicate that distance estimation bias underlies avoidance behavior in SAD, suggesting the involvement of a new cognitive mechanism in personal space regulation.

The impact of empathy and reappraisal on emotional intensity recognition.

Empathy represents a fundamental ability that allows for the creation and cultivation of social bonds. As part of the empathic process, individuals use their own emotional state to interpret the content and intensity of other people's emotions. Therefore, the current study was designed to test two hypotheses: (1) empathy for the pain of another will result in biased emotional intensity judgment; and (2) changing one's emotion via emotion regulation will modulate these biased judgments. To test these hypotheses, in experiment one we used a modified version of a well-known task that triggers an empathic reaction We found that empathy resulted in biased emotional intensity judgment. To the best of our knowledge, this is the first demonstration of a bias in the recognition of emotional facial expressions as a function of empathy for pain. In experiment two, we replicated these findings in an independent sample, and further found that this biased emotional intensity judgment can be moderated via reappraisal. Taken together, our findings suggest that the novel task used here can be employed to further explore the relation between emotion regulation and empathy.

Losing Neutrality: The Neural Basis of Impaired Emotional Control without Sleep.

Sleep deprivation has been shown recently to alter emotional processing possibly associated with reduced frontal regulation. Such impairments can ultimately fail adaptive attempts to regulate emotional processing (also known as cognitive control of emotion), although this hypothesis has not been examined directly. Therefore, we explored the influence of sleep deprivation on the human brain using two different cognitive-emotional tasks, recorded using fMRI and EEG. Both tasks involved irrelevant emotional and neutral distractors presented during a competing cognitive challenge, thus creating a continuous demand for regulating emotional processing. Results reveal that, although participants showed enhanced limbic and electrophysiological reactions to emotional distractors regardless of their sleep state, they were specifically unable to ignore neutral distracting information after sleep deprivation. As a consequence, sleep deprivation resulted in similar processing of neutral and negative distractors, thus disabling accurate emotional discrimination. As expected, these findings were further associated with a decrease in prefrontal connectivity patterns in both EEG and fMRI signals, reflecting a profound decline in cognitive control of emotion. Notably, such a decline was associated with lower REM sleep amounts, supporting a role for REM sleep in overnight emotional processing. Altogether, our findings suggest that losing sleep alters emotional reactivity by lowering the threshold for emotional activation, leading to a maladaptive loss of emotional neutrality. Significance statement: Sleep loss is known as a robust modulator of emotional reactivity, leading to increased anxiety and stress elicited by seemingly minor triggers. In this work, we aimed to portray the neural basis of these emotional impairments and their possible association with frontal regulation of emotional processing, also known as cognitive control of emotion. Using specifically suited EEG and fMRI tasks, we were able to show that sleep deprivation alters emotional reactivity by triggering enhanced processing of stimuli regarded previously as neutral. These changes were further accompanied by diminished frontal connectivity, reduced REM sleep, and poorer performance. Therefore, we suggest that sleep loss alters emotional reactivity by lowering the threshold for emotional activation, leading to a maladaptive loss of emotional neutrality.

The neural networks of subjectively evaluated emotional conflicts.

Previous work on the neural underpinnings of emotional conflict processing has largely focused on designs that instruct participants to ignore a distracter which conflicts with a target. In contrast, this study investigated the noninstructed experience and evaluation of an emotional conflict, where positive or negative cues can be subjectively prioritized. To this end, healthy participants freely watched short film scenes that evoked emotional conflicts while their BOLD responses were measured. Participants' individual ratings of conflict and valence perception during the film scenes were collected immediately afterwards, and the individual ratings were regressed against the BOLD data. Our analyses revealed that (a) amygdala and medial prefrontal cortex were significantly involved in prioritizing positive or negative cues, but not in subjective evaluations of conflict per se, and (b) superior temporal sulcus (STS) and inferior parietal lobule (IPL), which have been implicated in social cognition and emotion control, were involved in both prioritizing positive or negative cues and subjectively evaluating conflict, and may thus constitute "hubs" or "switches" in emotional conflict processing. Psychophysiological interaction (PPI) analyses further revealed stronger functional connectivity between IPL and ventral prefrontal-medial parietal areas in prioritizing negative cues, and stronger connectivity between STS and dorsal-rostral prefrontal-medial parietal areas in prioritizing positive cues. In sum, our results suggest that IPL and STS are important in the subjective evaluation of complex conflicts and influence valence prioritization via prefrontal and parietal control centers. Hum Brain Mapp 37:2234-2246, 2016. © 2016 Wiley Periodicals, Inc.

The hidden price and possible benefit of repeated traumatic exposure.

There is a growing evidence showing that first-responders who are frequently exposed to traumatic events as part of their occupational routine may pay a hidden price. Although they display low to moderate levels of post-traumatic stress disorder (PTSD) symptoms, similar to individuals with full-blown PTSD, they show impaired ability to process and react according to contextual demands. We aimed to test whether this impairment affects performance on simple unrelated tasks and its association with cumulative traumatic exposure and level of PTSD symptoms. Thirty-nine trauma-exposed criminal scene investigator police and 35 unexposed civilians matched for age, gender, and education performed a simple discrimination task in the presence of aversive pictures with low or high intensity. We predicted and found that trauma-exposed individuals failed to modify their behavior in accordance with levels of negative intensity. Hence they were equally distracted in both low and high negative intensity conditions, compared to unexposed controls who showed improved performance in low intensity conditions. Importantly, performance of trauma-exposed individuals on conditions of low intensity negatively correlated with their levels of PTSD symptoms. These results highlight the maladaptive tendency of individuals with repeated traumatic exposure to maintain the same behavior in low-intensity contextual conditions when it is no longer adequate. Interestingly however, in high-intensity conditions trauma-exposed individuals outperformed unexposed controls. Specifically, when completing simple tasks in high intensity conditions. The results suggest that repeated traumatic exposure has both positive and negative consequences on the way individuals interpret and react to their environment.

Neural control of vascular reactions: impact of emotion and attention.

This study investigated the neural regions involved in blood pressure reactions to negative stimuli and their possible modulation by attention. Twenty-four healthy human subjects (11 females; age = 24.75 ± 2.49 years) participated in an affective perceptual load task that manipulated attention to negative/neutral distractor pictures. fMRI data were collected simultaneously with continuous recording of peripheral arterial blood pressure. A parametric modulation analysis examined the impact of attention and emotion on the relation between neural activation and blood pressure reactivity during the task. When attention was available for processing the distractor pictures, negative pictures resulted in behavioral interference, neural activation in brain regions previously related to emotion, a transient decrease of blood pressure, and a positive correlation between blood pressure response and activation in a network including prefrontal and parietal regions, the amygdala, caudate, and mid-brain. These effects were modulated by attention; behavioral and neural responses to highly negative distractor pictures (compared with neutral pictures) were smaller or diminished, as was the negative blood pressure response when the central task involved high perceptual load. Furthermore, comparing high and low load revealed enhanced activation in frontoparietal regions implicated in attention control. Our results fit theories emphasizing the role of attention in the control of behavioral and neural reactions to irrelevant emotional distracting information. Our findings furthermore extend the function of attention to the control of autonomous reactions associated with negative emotions by showing altered blood pressure reactions to emotional stimuli, the latter being of potential clinical relevance.

Disorder-specific versus transdiagnostic cognitive mechanisms in anxiety and depression: Machine-learning-based prediction of symptom severity.

INTRODUCTION: Psychiatric evaluation of anxiety and depression is currently based on self-reported symptoms and their classification into discrete disorders. Yet the substantial overlap between these disorders as well as their within-disorder heterogeneity may contribute to the mediocre success rates of treatments. The proposed research examines a new framework for diagnosis that is based on alterations in underlying cognitive mechanisms. In line with the Research Domain Criteria (RDoC) approach, the current study directly compares disorder-specific and transdiagnostic cognitive patterns in predicting the severity of anxiety and depression symptoms. METHODS: The sample included 237 individuals exhibiting differing levels of anxiety and depression symptoms, as measured by the STAI-T and BDI-II. Random Forest regressors were used to analyze their performance on a battery of six computerized cognitive-behavioral tests targeting selective and spatial attention, expectancy, interpretation, memory, and cognitive control biases. RESULTS: Unique anxiety-specific biases were found, as well as shared anxious-depressed bias patterns. These cognitive biases exhibited relatively high fitting rates when predicting symptom severity (questionnaire scores common range 0-60, MAE = 6.03, RMSE = 7.53). Interpretation and expectancy biases exhibited the highest association with symptoms, above all other individual biases. LIMITATIONS: Although internal validation methods were applied, models may suffer from potential overfitting due to sample size limitations. CONCLUSION: In the context of the ongoing dispute regarding symptom-centered versus transdiagnostic approaches, the current study provides a unique comparison of these two views, yielding a novel intermediate approach. The results support the use of mechanism-based dimensional diagnosis for adding precision and objectivity to future psychiatric evaluations.

Perception of interpersonal distance and social distancing before and during COVID-19 pandemic.

Since COVID-19 is easily transmitted among people in close physical proximity, the focus of epidemiological policy during the COVID-19 crisis included major restrictions on interpersonal distance. However, the way in which distance restrictions affected spatial perception is unclear. In the current study, we examined interpersonal distance preferences and perceptions at three time points: pre-pandemic, early post-pandemic, and late post-pandemic. The results indicate that following the pandemic outbreak, people perceived others as farther away than they actually were, suggesting that the distance restrictions were associated with an enlargement of perceived interpersonal distance. Interestingly, however, people maintained the same distance from one another as before the outbreak, indicating no change in actual distance behavior due to the risk of infection. These findings suggest that COVID-19 was associated with a change in the way distance is perceived, while in practice, people maintain the same distance as before. In contrast, COVID-related anxiety predicted both a preference for maintaining a greater distance and a bias toward underestimating perceived distance from others. Thus, individuals who were highly fearful of COVID-19 perceived other people to be closer than they actually were and preferred to maintain a larger distance from them. The results suggest that subjective risk can lead to an increased perception of danger and a subsequent change in behavior. Taken together, even when behaviors should logically change, the decision-making process can be based on distorted perceptions. This insight may be used to predict public compliance.

The dark side of the alpha rhythm: fMRI evidence for induced alpha modulation during complete darkness.

The unique role of the EEG alpha rhythm in different states of cortical activity is still debated. The main theories regarding alpha function posit either sensory processing or attention allocation as the main processes governing its modulation. Closing and opening eyes, a well-known manipulation of the alpha rhythm, could be regarded as attention allocation from inward to outward focus though during light is also accompanied by visual change. To disentangle the effects of attention allocation and sensory visual input on alpha modulation, 14 healthy subjects were asked to open and close their eyes during conditions of light and of complete darkness while simultaneous recordings of EEG and fMRI were acquired. Thus, during complete darkness the eyes-open condition is not related to visual input but only to attention allocation, allowing direct examination of its role in alpha modulation. A data-driven ridge regression classifier was applied to the EEG data in order to ascertain the contribution of the alpha rhythm to eyes-open/eyes-closed inference in both lighting conditions. Classifier results revealed significant alpha contribution during both light and dark conditions, suggesting that alpha rhythm modulation is closely linked to the change in the direction of attention regardless of the presence of visual sensory input. Furthermore, fMRI activation maps derived from an alpha modulation time-course during the complete darkness condition exhibited a right frontal cortical network associated with attention allocation. These findings support the importance of top-down processes such as attention allocation to alpha rhythm modulation, possibly as a prerequisite to its known bottom-up processing of sensory input.

Spider vs. guns: expectancy and attention biases to phylogenetic threat do not extend to ontogenetic threat.

Introduction: Attention bias plays an important role in specific fears and phobias. Previous studies revealed that a-priori expectancies affect attention toward neutral stimuli but not threatening stimuli. The aim of the current study was to test whether this selective influence of expectancies on attention is specific to phylogenetic threat (i.e., spiders) or whether it can be generalized to ontogenetic threat (i.e., guns). Correspondingly, we directly compared expectancy effects on attentional allocation to phylogenetically vs. ontogenetically threatening stimuli. Method: Expectancies were manipulated by presenting a cue indicating the likelihood of the appearance of a deviant picture in a visual search array. The array included eight distractors and one neutral (phone/bird) or threatening (gun/spider) deviant picture. In a comprehensive design, we examined the effects of stimulus type (phylogenetic/ontogenetic) and visual background (white and sterile/complex and ecological). Individual differences such as intolerance of uncertainty and spider fear were also measured. Results: Results showed that attention bias toward spiders does not extend to threatening ontogenetic stimuli (i.e., guns). Our previous findings on attention bias toward spiders were replicated and a small to medium positive correlation was found between reaction time to bird targets and pre-existing fear of spider levels. Cues were used to detect threatening as well as neutral targets on both background types, except for spider targets on a complex background, replicating previous results. A small to medium positive correlation was also found between fear of spiders and intolerance of uncertainty. Discussion: Together, these results suggest that expectancy and attentional processes may differ between ontogenetic and phylogenetic threat. Importantly, the effects of expectancy on attentional allocation depend on an interaction between the type of threat (ontogenetic/phylogenetic), visual factors, and individual differences.

Cognitive Avoidance Is Associated with Decreased Brain Responsiveness to Threat Distractors under High Perceptual Load.

Cognitive coping strategies to deal with anxiety-provoking events have an impact on mental and physical health. Dispositional vigilance is characterized by an increased analysis of the threatening environment, whereas cognitive avoidance comprises strategies to inhibit threat processing. To date, functional neuroimaging studies on the neural underpinnings of these coping styles are scarce and have revealed discrepant findings. In the present study, we examined automatic brain responsiveness as a function of coping styles using functional magnetic resonance imaging. We administered a perceptual load paradigm with contemptuous and fearful faces as distractor stimuli in a sample of N = 43 healthy participants. The Mainz Coping Inventory was used to assess cognitive avoidance and vigilance. An association of cognitive avoidance with reduced contempt and fear processing under high perceptual load was observed in a widespread network including the amygdala, thalamus, cingulate gyrus, insula, and frontal, parietal, temporal, and occipital areas. Our findings indicate that the dispositional tendency to divert one's attention away from distressing stimuli is a valuable predictor of diminished automatic neural responses to threat in several cortical and subcortical areas. A reduced processing in brain regions involved in emotion perception and attention might indicate a potential threat resilience associated with cognitive avoidance.

The role of fear in hierarchical processing of fear-related stimuli.

According to a widely accepted definition, visual objects are composed of hierarchical structures classified as either global or local, depending on their location in the hierarchy. Previous research has demonstrated that fear and anxiety are associated with faster identification of local level stimuli, supporting the popular view that fear narrows attention. Nevertheless, the modulating role of fear in hierarchical processing has never been examined for stimuli that are personally relevant. To fill this research gap, we used emotional modification of a global-local paradigm to examine hierarchical processing of spider and snake stimuli among participants with high specific fear of spiders or snakes, respectively. The results indicate that personal fear facilitates identification of an animal's global configuration and interferes with identification of its local features (i.e., body pattern). This effect was found in comparison with participants with low fear and in comparison with other threatening but fear-irrelevant stimulus. Furthermore, a general global bias was found, highlighting the ecological validity of Navon's theory. The current findings are inconsistent with the view that anxiety narrows attention to local features. We suggest that the results can be reconciled with existing literature if we consider the narrowing of attention to the global level. The current study offers initial evidence for the role of fear in hierarchical processing of fear-relevant information, which may, in turn, play an important role in the etiology and maintenance of fear and serve as a new target for interventions. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

How Social Experiences Affect Interpretation Bias Among Individuals With Non-clinical Depression: The Role of Ostracism.

BACKGROUND: Extensive knowledge and research indicate that interpretation bias is very common among individuals with sub-clinical and clinical levels of depression. Nevertheless, little is known about the role of social experiences in enhancing interpretation bias. Given the major relevance of social experiences in the context of depression, the present study investigated the role of potential interactions between social experiences and levels of depression symptoms in the interpretation of ambiguous information. METHOD: Seventy participants underwent a laboratory controlled manipulation either of social ostracism or of overinclusion. Participants completed a computerized task that measured both direct and indirect interpretation bias and reported their level of depression symptoms. RESULTS: The findings show that ostracism enhanced interpretation bias when symptom levels were higher, while overinclusion did not. This interaction effect between social ostracism and symptom level was found both for direct and for indirect interpretation bias. CONCLUSION: Whereas previous research showed the existence of interpretation bias among people with symptoms of depression, the present study expands previous knowledge by shedding light on the conditions under which interpretation bias emerges, suggesting that ostracism enhances negative interpretation of ambiguous information when levels of depression symptoms are higher.

The attention-emotion interaction in healthy female participants on oral contraceptives during 1-week escitalopram intake.

Previous findings in healthy humans suggest that selective serotonin reuptake inhibitors (SSRIs) modulate emotional processing via earlier changes in attention. However, many previous studies have provided inconsistent findings. One possible reason for such inconsistencies is that these studies did not control for the influence of either sex or sex hormone fluctuations. To address this inconsistency, we administered 20 mg escitalopram or placebo for seven consecutive days in a randomized, double-blind, placebo-controlled design to sixty healthy female participants with a minimum of 3 months oral contraceptive (OC) intake. Participants performed a modified version of an emotional flanker task before drug administration, after a single dose, after 1 week of SSRI intake, and after a 1-month wash-out period. Supported by Bayesian analyses, our results do not suggest a modulatory effect of escitalopram on behavioral measures of early attentional-emotional interaction in female individuals with regular OC use. While the specific conditions of our task may be a contributing factor, it is also possible that a practice effect in a healthy sample may mask the effects of escitalopram on the attentional-emotional interplay. Consequently, 1 week of escitalopram administration may not modulate attention toward negative emotional distractors outside the focus of attention in healthy female participants taking OCs. While further research in naturally cycling females and patient samples is needed, our results represent a valuable contribution toward the preclinical investigation of antidepressant treatment.

Spatio-temporal indications of sub-cortical involvement in leftward bias of spatial attention.

A leftward bias is well known in humans and animals, and commonly related to the right hemisphere dominance for spatial attention. Our previous fMRI study suggested that this bias is mediated by faster conduction from the right to left parietal cortices, than the reverse (Siman-Tov et al., 2007). However, the limited temporal resolution of fMRI and evidence on the critical involvement of sub-cortical regions in orienting of spatial attention suggested further investigation of the leftward bias using multi-scale measurement. In this simultaneous EEG-fMRI study, healthy participants were presented with face pictures in either the right or left visual fields while performing a central fixation task. Temporo-occipital event related potentials, time-locked to the stimulus onset, showed an association between faster conduction from the right to the left hemisphere and higher fMRI activation in the left pulvinar nucleus following left visual field stimulation. This combined-modal finding provides original evidence of the involvement of sub-cortical central attention-related regions in the leftward bias. This assertion was further strengthened by a DCM analysis designated at cortical (i.e., inferior parietal sulcus; IPS) and sub-cortical (pulvinar nucleus) attention-related nodes that revealed: 1. Stronger inter-hemispheric connections from the right to left than vice versa, already at the pulvinar level. 2. Stronger connections within the right than the left hemisphere, from the pulvinar to the IPS. This multi-level neural superiority can guide future efforts in alleviating attention deficits by focusing on improving network connectivity.

Fear-related pictures deteriorate the performance of university students with high fear of snakes or spiders.

Despite research regarding emotional processing, it is still unclear whether fear-evoking stimuli are processed when they are irrelevant and when attention is oriented elsewhere. In this study, 63 healthy university students with high fear from snakes or spiders participated in two different experiments. In an emotional modification of the spatial cueing task, 31 subjects (5 males) were asked to detect a target letter while ignoring a neutral or fear-related distracting picture. The distribution of attention was independently manipulated by a spatial cue that preceded the appearance of the picture and the target letter. In an emotional modification of the cognitive load paradigm, 32 subjects (4 males) were asked to discriminate between two target letters, while ignoring a central neutral or fear-related picture, and additional 1, 3, or 5 distracting letters that created a varied attentional load. Fear-related pictures interfered with the performance of highly fearful participants, even when the pictures were presented outside the focus of attention and when the task taxed attentional resources. We suggest that highly fearful individuals process fear-related information automatically, either inattentively or with prioritized attention capture over competing items, leading to deteriorated cognitive performance. Different results were shown in healthy individuals while processing negative--but not phobic--pictures, suggesting that emotional processing depends on the fear value of the stimulus for a specific observer.

Using international emotional picture sets in countries suffering from violence.

It is hypothesized that ratings of emotional stimuli are affected by a constant threat of traumatic events. Ratings of valence and arousal on the International Affective Picture System from young adults in the United States were compared to those of young Israeli adults. Israelis rated the pictures as less negative and less positive than did participants from the United States. Israeli women gave higher arousal ratings compared to the American women. These differences may be due to compulsory military service in Israel, during which exposure to traumatic events is more likely to occur, and to the timing of the study which followed a year of frequent suicide bomb attacks. The authors suggest that these findings may reflect mild symptoms of stress disorders.