Electrocortical and ocular indices of attention to fearful and neutral faces presented under high and low working memory load

Working memory capacity modulates Serial dependence in facial Identity: Evidence from behavioral and EEG data

Serial dependence (SD) is said to occur when the judgment of a current stimulus is drawn toward a no longer relevant stimulus from the recent past. Working memory (WM) contributes to the ability to discriminate between irrelevant and relevant sensory impressions. How WM contributes to SD in facial identity remains to be fully understood. In the present study, we used a WM task with varying load interleaved with a facial matching task to investigate the relations between SD in facial identity and WM. EEG was recorded to capture perceptual face processing and WM maintenance. Overall, statistically significant SD effects were obtained only at high WM load. In addition, individual differences in WM capacity predicted SD. Participants with low WM capacity showed significant SD effects regardless of changes in WM load, while participants with high WM capacity showed significant SD only at high WM load. EEG results showed significant differences in perceptual and WM processing for participants with high WM capacity, while no significant differences were obtained for participants with low WM capacity. Neural correlates of WM maintenance, and perceptual processing of a previous face were directly related to SD. The results suggest that WM capacity contributes to SD in facial identity, in terms of selective suppression of task-irrelevant and selective maintenance of task-relevant information.

Engagement and Disengagement: From the Basic Science of Emotion Regulation to an Anxiety Spectrum

Emotion regulation strategies vary in depth of processing. For instance, reappraisal requires greater engagement than distraction. This affects short-term and long-term response to stimuli. In this review, I describe how the "engagement-disengagement dimension" improves understanding of emotion regulation in normative contexts and in internalizing psychopathology. Part 1 reviews work from my laboratory and others, suggesting that relatively disengaged emotion regulation strategies (e.g., distraction), may have short-term benefits (e.g., faster implementation), but may come with long-term costs (e.g., increased processing of stimuli at subsequent encounter). Therefore, depending on the desired outcome, the adaptive selection of an emotion regulation strategy will be determined by extent of emotional engagement-disengagement. In Part 2, I describe how individuals with more comorbid internalizing psychopathology (e.g., multiple anxiety and depressive diagnoses) are characterized by disengagement from negative stimuli as measured by the late positive potential (LPP). In addition, I introduce a brain profile I have termed, HARM-A (heightened "alarm" and reduced motivated attention), which is characterized by a combination of heightened "alarm" (i.e., increased amygdala) and emotional disengagement (i.e., blunted LPPs) in response to negative stimuli. HARM-A prospectively predicts worse outcomes over 2 years in a mixed internalizing sample. As such, chronic disengagement from negative stimuli appears to contribute to more comorbid and more severe internalizing psychopathology. Overall, emotional disengagement can be beneficial in the short term but may be poorly suited to emotional coping in the longer term.

The mutual influences between working memory and empathy for pain: the role of social distance

Understanding the mechanisms behind the interaction of empathy for pain (EfP) and working memory (WM), particularly how they are influenced by social factors like perceived social distance (SD), is vital for comprehending how humans dynamically adapt to the complexities of social life. However, there is very little known about these mechanisms. Accordingly, we recruited 116 healthy participants to investigate the bidirectional influence and electrophysiological responses between WM and EfP, including the role of SD. Our research results revealed that the interaction between WM load and SD significantly influenced the processing of EfP. Specifically, high WM load and distant SD facilitated early processing of EfP. Conversely, low WM load and close SD promoted late processing of EfP. Furthermore, the interaction between EfP and SD significantly influenced the performance of ongoing WM tasks. Specifically, the kin's pain, compared to kin's nonpain, improved the participant's performance on low-load WM tasks; however, it diminished the participant's performance on tasks with high WM load. Overall, these results provide evidence at both behavioral and neural levels for the mutual influence of WM and EfP during the same temporal process, and SD emerged as a crucial moderating factor during these mutual influences.

The neuronal signature of surprised facial expression processing under different attentional focuses: A time-domain and time-frequency study

Previous studies have shown that high-arousal positive and negative facial expressions influence event-related potential (ERP) and time-frequency responses depending on attentional focuses. However, little is known about how relevant neural responses are influenced by surprised facial expressions, which are also high in arousal but ambiguous in valence. To address the issue, 38 participants were presented with surprised, happy, angry and neutral facial expressions. Attention was manipulated to focus on facial emotional attributes, facial non-emotional attributes, non-facial attributes, or was free to the participants. ERP results showed larger N170 responses to surprised compared to neutral facial expressions when attention focused on facial attributes and to surprised compared to angry and neutral facial expressions when attention focused on facial non-emotional attributes. Time-frequency analyses revealed reduced power of early occipital theta to surprised compared to happy and angry expressions when attention focused on facial emotions and to surprised compared to angry expressions when attention focused on non-facial stimuli. Parietal delta power was smaller for surprised facial expressions than for angry facial expressions when attention focused on facial emotions and for surprised facial expressions than for angry and neutral facial expressions when attention was directed to non-facial stimuli. These findings might suggest that neural responses to surprised facial expressions are modulated by attentional focus.

Positive emotion up-regulation is resistant to working memory load: An electrocortical investigation of reappraisal and savoring

Studies of emotion regulation to-date have mostly focused on negative emotion down-regulation, leaving positive emotion up-regulation poorly understood, particularly regarding factors that may modulate its success. While reappraisal and savoring have been shown to be effective at increasing electrocortical and subjective response to pictures in controlled laboratory settings, it remains unclear whether individuals can effectively enact these techniques to willfully increase positive emotions in everyday life when faced with other concurrent distractions/demands. Here, we used the late positive potential (LPP), an electrocortical measure that is larger for emotional compared to neutral stimuli, to assess the effect of working memory (WM) load on individuals' ability to reappraise or savor positive pictures. Seventy-six participants were randomly assigned to use either reappraisal or savoring to up-regulate positive emotion to pictures. Following training, participants engaged in a positive emotion up-regulation task interspersed with high and low WM load trials, while EEG was recorded. Frequentist and Bayesian statistics showed that although high WM load seemed to consume resources and reduced picture processing overall, it did not interfere with the enhancement of the LPP via positive emotion up-regulation. Nonetheless, WM performance (especially on high-load trials) was worse when participants were engaged in positive emotion up-regulation. Therefore, while both techniques appear to be effective under concurrent WM load, positive emotion up-regulation may interfere with other ongoing tasks.

The effects of visual working memory load on detection and neural processing of task-unrelated auditory stimuli

While perceptual load has been proposed to reduce the processing of task-unrelated stimuli, theoretical arguments and empirical findings for other forms of task load are inconclusive. Here, we systematically investigated the detection and neural processing of auditory stimuli varying in stimulus intensity during a stimuli-unrelated visual working memory task alternating between low and high load. We found, depending on stimulus strength, decreased stimulus detection and reduced P3, but unaffected N1 amplitudes of the event-related potential to auditory stimuli under high as compared to low load. In contrast, load independent awareness effects were observed during both early (N1) and late (P3) time windows. Findings suggest a late neural effect of visual working memory load on auditory stimuli leading to lower probability of reported awareness of these stimuli.

The effect of sad mood on early sensory event-related potentials to task-irrelevant faces

It has been shown that the perceiver's mood affects the perception of emotional faces, but it is not known how mood affects preattentive brain responses to emotional facial expressions. To examine the question, we experimentally induced sad and neutral mood in healthy adults before presenting them with task-irrelevant pictures of faces while an electroencephalography was recorded. Sad, happy, and neutral faces were presented to the participants in an ignore oddball condition. Differential responses (emotional - neutral) for the P1, N170, and P2 amplitudes were extracted and compared between neutral and sad mood conditions. Emotional facial expressions modulated all the components, and an interaction effect of expression by mood was found for P1: an emotional modulation to happy faces, which was found in neutral mood condition, disappeared in sad mood condition. For N170 and P2, we found larger response amplitudes for both emotional faces, regardless of the mood. The results add to the previous behavioral findings showing that mood already affects low-level cortical feature encoding of task-irrelevant faces.

Testing stimulus exposure time as the critical factor of increased EPN and LPP amplitudes for fearful faces during perceptual distraction tasks

Fearful facial expressions are prioritized across different information processing stages, as evident in early, intermediate, and late components of event-related brain potentials (ERPs). Recent studies showed that, in contrast to early N170 modulations, mid-latency (Early Posterior Negativity, EPN) and late (Late Positive Potential, LPP) emotional modulations depend on the attended perceptual feature. Nevertheless, several studies reported significant differences between emotional and neutral faces for the EPN or LPP components during distraction tasks. One cause for these conflicting findings might be that when faces are presented sufficiently long, participants attend to task-irrelevant features of the faces. In this registered report, we tested whether the presentation duration of faces is the critical factor for differences between reported emotional modulations during perceptual distraction tasks. To this end, 48 participants were required to discriminate the orientation of lines overlaid onto fearful or neutral faces, while face presentation varied (100 msec, 300 msec, 1,000 msec, 2,000 msec). While participants did not need to pay attention to the faces, we observed main effects of emotion for the EPN and LPP, but no interaction between emotion and presentation duration. Of note, unregistered exploratory tests per presentation duration showed no significant EPN and LPP emotion differences during short durations (100 and 300 msec) but significant differences with longer durations. While the presentation duration seems not to be a critical factor for EPN and LPP emotion effects, future studies are needed to investigate the role of threshold effects and the applied analytic designs to explain conflicting findings in the literature.

Room for Feelings: A “Working Memory” Account of Affective Processing

In the past decades, affective science has overwhelmingly demonstrated the unique properties of affective information to bias our attention, memory, and decisions. At the same time, accumulating evidence suggests that neutral and affective representations rely on the same working memory substrates for the selection and computation of information and that they are therefore restricted by the same capacity limitations that these substrates impose. Here, we integrate these insights into a working memory model of affective processing (WMAP). Drawing on competitive access models of working memory, we discuss its role in the various stages of affective processing, from attentional selection to maintenance and memory storage, and resulting feelings and actions. We end our overview with some open questions and future directions.

Surprising Threats Accelerate Conscious Perception

The folk psychological notion that "we see what we expect to see" is supported by evidence that we become consciously aware of visual stimuli that match our prior expectations more quickly than stimuli that violate our expectations. Similarly, "we see what we want to see," such that more biologically-relevant stimuli are also prioritised for conscious perception. How, then, is perception shaped by biologically-relevant stimuli that we did not expect? Here, we conducted two experiments using breaking continuous flash suppression (bCFS) to investigate how prior expectations modulated response times to neutral and fearful faces. In both experiments, we found that prior expectations for neutral faces hastened responses, whereas the opposite was true for fearful faces. This interaction between emotional expression and prior expectations was driven predominantly by participants with higher trait anxiety. Electroencephalography (EEG) data collected in Experiment 2 revealed an interaction evident in the earliest stages of sensory encoding, suggesting prediction errors expedite sensory encoding of fearful faces. These findings support a survival hypothesis, where biologically-relevant fearful stimuli are prioritised for conscious access even more so when unexpected, especially for people with high trait anxiety.

Influence of scene-based expectation on facial expression perception: the moderating effect of cognitive load

Prior expectations play an important role in the process of perception. In real life, facial expressions always appear within a scene, which enables individuals to generate predictions that affect facial expression judgments. In the present study, using event-related potentials, we investigated the influence of scene-based expectation on facial expression processing. In addition, we used a cognitive task to manipulate cognitive load to interfere with scene-based expectation. Results showed that under the condition of sufficient cognitive resources, faces elicited more negative N170 amplitudes and more positive N400 amplitudes when the emotional valence of the scenes and faces was congruent. However, in the condition of cognitive load, no such difference was observed. The findings suggested that the effect of expectation on facial expression recognition emerges during both the early and late stages of facial expression processing, and the effect is weakened when cognitive resources are occupied by unrelated tasks.

The Effect of Cognitive Load on the Retrieval of Long-Term Memory: An fMRI Study

One of the less well-understood aspects of memory function is the mechanism by which the brain responds to an increasing load of memory, either during encoding or retrieval. Identifying the brain structures which manage this increasing cognitive demand would enhance our knowledge of human memory. Despite numerous studies about the effect of cognitive loads on working memory processes, whether these can be applied to long-term memory processes is unclear. We asked 32 healthy young volunteers to memorize all possible details of 24 images over a 12-day period ending 2 days before the fMRI scan. The images were of 12 categories relevant to daily events, with each category including a high and a low load image. Behavioral assessments on a separate group of participants (#22) provided the average loads of the images. The participants had to retrieve these previously memorized images during the fMRI scan in 15 s, with their eyes closed. We observed seven brain structures showing the highest activation with increasing load of the retrieved images, viz. parahippocampus, cerebellum, superior lateral occipital, fusiform and lingual gyri, precuneus, and posterior cingulate gyrus. Some structures showed reduced activation when retrieving higher load images, such as the anterior cingulate, insula, and supramarginal and postcentral gyri. The findings of this study revealed that the mechanism by which a difficult-to-retrieve memory is handled is mainly by elevating the activation of the responsible brain areas and not by getting other brain regions involved, which is a help to better understand the LTM retrieval process in the human brain.

Working memory load reduces the processing of outcome evaluation involving others but not oneself: Event-related potential evidence

Previous event-related potential (ERP) studies have suggested that self-related and non-self-related outcomes are processed simultaneously. However, the studies investigated situations in which individuals had sufficient attentional/cognitive resources to process both of the outcomes. It is unknown whether self-related and non-self-unrelated outcomes could still be processed simultaneously when resources are limited. To address this issue, 32 female participants in the present study were asked to perform a working memory task. To manipulate the amount of available attentional/cognitive resources, participants were asked to memorize a letter in the low load condition and five letters in the high load condition. During letter consolidation, participants were informed that they and another player each performed a gambling task and were subsequently presented with both of the outcomes. ERP results showed that others' monetary loss elicited larger P200 and late positive potential amplitudes than others' monetary gain under a low working memory load, whereas a high load reduced these effects. However, working memory load did not influence the effect of self-outcome on ERP responses. Therefore, the findings suggest that the amount of available attentional/cognitive resources alters the evaluation of non-self-related but not self-related outcomes.

The discrepant effect of acute stress on cognitive inhibition and response inhibition

This study aimed to investigate how acute stress impinges on individual's cognitive inhibition and response inhibition abilities. Electroencephalography was adopted when 35 healthy adult females performing the No Go Flanker task before and after the Trier Social Stress Test. Both inhibition processes evoked N2 and P3 components, but only the response inhibition evoked the late positive potential (LPP), indicating the response inhibition needed continuous cognitive effort to inhibit the prepotent response. The N2 and the P3 amplitudes were decreased, while the LPP amplitudes were increased under acute stress. These results suggested that acute stress caused the detrimental effect by occupying cognitive resources. Contrastingly, individuals actively regulated and made more efforts to counteract the detrimental effect of acute stress on response inhibition. Thus, acute stress impaired cognitive inhibition but did not affect response inhibition.

Working memory load reduces the electrocortical processing of positive pictures

To date, the emotion regulation literature has focused primarily on the down-regulation of negative emotion, with far fewer studies interrogating the mechanisms at work in positive emotion regulation. This body of work has suggested that nonaffective mechanisms, such as cognitive load have a role to play in reducing emotional response. For example, the late positive potential (LPP), which tracks attention to salient stimuli, is reduced when task-irrelevant negative and neutral stimuli are presented under high compared with low working memory load. Using positive stimuli, working memory load has been shown to reduce the LPP elicited by positive words and faces but has not previously been shown to modulate the LPP elicited by positive scenes. Emotional scenes are the predominant type of stimuli used in the broader emotion regulation literature, are more arousing than faces, and have been shown to more strongly modulate the LPP. Here, 41 participants performed a working memory task interspersed with the presentation of positive and neutral scenes, while electroencephalography was recorded. Results showed that the LPP was increased for positive compared with neutral pictures and reduced on high-load compared to low-load trials. Working memory performance was worse on high-load compared with low-load trials, although it was not significantly correlated with the LPP, and picture type did not affect working memory performance. Results bridge to the willful emotion regulation literature to increase understanding of the mechanisms underlying positive emotion regulation, which has been relatively unexamined.

Turning to the negative: attention allocation to emotional faces in adolescents with dysregulation profile-an event-related potential study

Patients with irritability, temper outbursts, hyperactivity and mood swings often meet the dysregulation profile (DP) of the Child Behavior Checklist (CBCL) or the Strengths and Difficulties Questionnaire (SDQ), which have been investigated over the past few decades. While the DP has emerged as a transdiagnostic marker with a negative impact on therapeutic outcome and psychosocial functioning, little is known about its underlying mechanisms such as attention and emotion regulation processes. In this study, we tested whether adolescent psychiatric patients (n = 27) with the SDQ-DP show impaired emotional face processing for task-irrelevant stimuli compared to psychiatric patients without the SDQ-DP (n = 30) and non-clinical adolescents (n = 21). Facial processing was tested with event-related potential (ERP) measures known to be modulated by attention (i.e., P1, N1, N170, P2, and Nc) during a modified Attention Network Task, to which task-irrelevant emotional stimuli (sad, fearful, and neutral faces) were added prior to the actual trial. The results reveal group differences in the orienting and in the conflicting network. Patients with DP showed a less efficient orienting network and the clinical control group showed a less efficient conflicting network. Moreover, patients with the dysregulation profile had a shorter N1/N170 latency than did the two control groups, suggesting that dysregulation in adolescents is associated with a faster but less arousing encoding of (task-irrelevant) emotional information and less top-down control.

Significance?& Significance! Empirical, methodological, and theoretical connections between the late positive potential and P300 as neural responses to stimulus significance: An integrative review

Event-related potential studies of emotional processing have focused on the late positive potential (LPP), a sustained positive deflection in the ERP that is increased for emotionally arousing stimuli. A prominent theory suggests that modulation of the LPP is a response to stimulus significance, defined in terms of the activation of appetitive and aversive motivational systems. The current review incorporates experimental studies showing that manipulations that alter the significance of stimuli alter LPP amplitude. Complementing these within-person studies, also included is individual differences research on depression wherein the LPP has been used to study reduced neural sensitivity to emotional stimuli. Finally, the current review builds an existing framework that the LPP observed in studies in emotional processing and the P300 observed in classic oddball studies may reflect a common response to stimulus significance. This integrative account has implications for the functional interpretation of these ERPs, their neurobiological mechanisms, and clinical applications.

Working Memory Load and Negative Picture Processing: Neural and Behavioral Associations With Panic, Social Anxiety, and Positive Affect

BACKGROUND

Internalizing disorders such as anxiety may be characterized by an imbalance between bottom-up (stimulus-driven) and top-down (goal-directed) attention. The late positive potential (LPP) can be used to assess these processes when task-irrelevant negative and neutral pictures are presented within a working memory paradigm. Prior work using this paradigm has found that working memory load reduces the picture-elicited LPP across participants; however, anxious individuals showed a reduced effect of working memory load on the LPP, suggesting increased distractibility.

METHODS

The current study assessed transdiagnostic associations between specific symptom dimensions of anxiety, the LPP, and behavior in a clinically representative, heterogeneous group of 76 treatment-seeking patients with internalizing disorders, who performed a working memory task interspersed with negative and neutral pictures.

RESULTS

As expected, negative pictures enhanced the LPP, and working memory load reduced the LPP. Participants with higher social anxiety showed increased LPPs to negative stimuli during early and late portions of picture presentation. Panic symptoms were associated with reduced LPPs to negative pictures compared with neutral pictures as well as a reduced effect of working memory load on the LPP during the late time window. Reduced positive affect was associated with greater behavioral interference from negative pictures.

CONCLUSIONS

Hypervigilance for negative stimuli was uniquely explained by social anxiety symptoms, whereas panic symptoms were associated with the opposing effect-blunted processing/avoidance of these stimuli. Panic symptoms were uniquely associated with reduced top-down control. Results reveal distinct associations between neural reactivity and anxiety symptom dimensions that transcend traditional diagnostic boundaries.

Convergence of fMRI and ERP measures of emotional face processing in combat-exposed U. S. military veterans

The late positive potential (LPP) and fMRI blood-oxygen-level dependent (BOLD) activity can provide complementary measures of the processing of affective and social stimuli. Separate lines of research using these measures have often employed the same stimuli, paradigms, and samples; however, there remains relatively little understanding of the way in which individual differences in one of these measures relates to the other, and all prior research has been conducted in psychiatrically healthy samples and using emotional scenes (not faces). Here, 32 combat-exposed U. S. military veterans with varying levels of posttraumatic stress symptomatology viewed affective social stimuli (angry, fearful, and happy faces) and geometric shapes during separate EEG and fMRI BOLD recordings. Temporospatial principal component analysis was used to quantify the face-elicited LPP in a data-driven manner, prior to conducting whole-brain correlations between resulting positivities and fMRI BOLD elicited by faces. Participants with larger positivities to fearful faces (> shapes) showed increased activation in the amygdala; larger positivities to angry and happy faces (> shapes) were associated with increased BOLD activation in the posterior fusiform gyrus and inferior temporal gyrus, respectively. Across all face types, larger positivities were associated with increased activation in the fusiform "face" area. Correlations using mean area amplitude LPPs showed an association with increased activation in the anterior insula for angry faces (> shapes). LPP-BOLD associations were not moderated by PTSD. Findings provide the first evidence of correspondence between face-elicited LPP and BOLD activation across a range of (normal to disordered) psychiatric health.

The influence of self-relevant materials on working memory in dysphoric undergraduates

Difficulties in updating working memory (WM) may underlie problems with regulating emotions that contribute to depression. To examine the ability of updating affective materials in WM, 33 dysphoric and 34 non-dysphoric participants were asked to evaluate the self-descriptiveness of emotional adjectives and provide answers to self-relevant questions. Within 3-7 days, they completed a two-back task with a series of self-irrelevant or self-relevant emotional words (they had generated previously) and four conditions (match-set, break-set, perseveration-set, and no-set). After the WM task, an unexpected recall task was administered; controls recalled more positive self-relevant words and intrusions while dysphoric participants recalled more negative self-relevant words and intrusions. In break-set trials of the two-back task, dysphoric individuals showed slower response to self-relevant words regardless of valence. In the match-set and perseveration-set trials, dysphoric participants showed delayed response to self-related negative words. Moreover, longer reaction times for self-relevant negative words were correlated with higher rumination and worse depression. The results suggest that dysphoric undergraduates are interfered more by and have a better memory of self-relevant negative stimuli in WM, which is closely correlated with rumination. This study is among the first to confirm the potential mechanism that could underwrite the involvement of self-schema in effectively regulating negative affect.

Cognitive tasks during expectation affect the congruency ERP effects to facial expressions

Expectancy congruency has been shown to modulate event-related potentials (ERPs) to emotional stimuli, such as facial expressions. However, it is unknown whether the congruency ERP effects to facial expressions can be modulated by cognitive manipulations during stimulus expectation. To this end, electroencephalography (EEG) was recorded while participants viewed (neutral and fearful) facial expressions. Each trial started with a cue, predicting a facial expression, followed by an expectancy interval without any cues and subsequently the face. In half of the trials, participants had to solve a cognitive task in which different letters were presented for target letter detection during the expectancy interval. Furthermore, facial expressions were congruent with the cues in 75% of all trials. ERP results revealed that for fearful faces, the cognitive task during expectation altered the congruency effect in N170 amplitude; congruent compared to incongruent fearful faces evoked larger N170 in the non-task condition but the congruency effect was not evident in the task condition. Regardless of facial expression, the congruency effect was generally altered by the cognitive task during expectation in P3 amplitude; the amplitudes were larger for incongruent compared to congruent faces in the non-task condition but the congruency effect was not shown in the task condition. The findings indicate that cognitive tasks during expectation reduce the processing of expectation and subsequently, alter congruency ERP effects to facial expressions.

Visual short-term memory load modulates the early attention and perception of task-irrelevant emotional faces

The ability to focus on task-relevant information, while suppressing distraction, is critical for human cognition and behavior. Using a delayed-match-to-sample (DMS) task, we investigated the effects of emotional face distractors (positive, negative, and neutral faces) on early and late phases of visual short-term memory (VSTM) maintenance intervals, using low and high VSTM loads. Behavioral results showed decreased accuracy and delayed reaction times (RTs) for high vs. low VSTM load. Event-related potentials (ERPs) showed enhanced frontal N1 and occipital P1 amplitudes for negative faces vs. neutral or positive faces, implying rapid attentional alerting effects and early perceptual processing of negative distractors. However, high VSTM load appeared to inhibit face processing in general, showing decreased N1 amplitudes and delayed P1 latencies. An inverse correlation between the N1 activation difference (high-load minus low-load) and RT costs (high-load minus low-load) was found at left frontal areas when viewing negative distractors, suggesting that the greater the inhibition the lower the RT cost for negative faces. Emotional interference effect was not found in the late VSTM-related parietal P300, frontal positive slow wave (PSW) and occipital negative slow wave (NSW) components. In general, our findings suggest that the VSTM load modulates the early attention and perception of emotional distractors.

Cognitive load and emotional processing in generalized anxiety disorder: electrocortical evidence for increased distractibility

Generalized anxiety disorder (GAD) may be characterized by emotion regulation deficits attributable to an imbalance between top-down (i.e., goal-driven) and bottom-up (i.e., stimulus-driven) attention. In prior work, these attentional processes were examined by presenting unpleasant and neutral pictures within a working memory paradigm. The late positive potential (LPP) measured attention toward task-irrelevant pictures. Results from this prior work showed that working memory load reduced the LPP across participants; however, this effect was attenuated for individuals with greater self-reported state anxiety, suggesting reduced top-down control. In the current study, the same paradigm was used with 106 medication-free female participants-71 with GAD and 35 without GAD. Unpleasant pictures elicited larger LPPs, and working memory load reduced the picture-elicited LPP. Compared with healthy controls, participants with GAD showed large LPPs to unpleasant pictures presented under high working memory load. Self-reported symptoms of anhedonic depression were related to a reduced effect of working memory load on the LPP elicited by neutral pictures. These results indicate that individuals with GAD show less flexible modulation of attention when confronted with unpleasant stimuli. Furthermore, among those with GAD, anhedonic depression may broaden attentional deficits to neutral distracters.

Electrocortical processing of social signals of threat in combat-related post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is characterized by avoidance, emotional numbing, increased arousal and hypervigilance for threat following a trauma. Thirty-three veterans (19 with PTSD, 14 without PTSD) who had experienced combat trauma while on deployment in Iraq and/or Afghanistan completed an emotional faces matching task while electroencephalography was recorded. Vertex positive potentials (VPPs) elicited by happy, angry and fearful faces were smaller in veterans with versus without PTSD. In addition, veterans with PTSD exhibited smaller late positive potentials (LPPs) to angry faces and greater intrusive symptoms predicted smaller LPPs to fearful faces in the PTSD group. Veterans with PTSD were also less accurate at identifying angry faces, and accuracy decreased in the PTSD group as hyperarousal symptoms increased. These findings show reduced early processing of emotional faces, irrespective of valence, and blunted prolonged processing of social signals of threat in conjunction with impaired perception for angry faces in PTSD.