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

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.

Neural reactivity to infant emotion cues during pregnancy: Associations with peripartum anxiety and depressive symptoms

BACKGROUND

Pregnancy is marked by physiological and psychosocial changes for women, and event-related potentials (ERP) are comfortable and safe for examining brain function across pregnancy. The late positive potential (LPP) ERP, a measure of allocated attention to emotional stimuli, may provide insight into associations between internalizing symptoms and neural processing of infant emotion cues, which may be particularly salient in this life stage.

METHODS

We developed a task to examine neural and behavioral responses to infant faces in pregnant women (N = 120, Mage=31.09, SD=4.81), the impact of auditory infant cries on the LPP to faces, and associations between the LPP and anxiety and depressive symptoms. Participants matched distressed, happy, and neutral infant faces and shapes as a comparison condition with interspersed auditory conditions (infant cry sounds vs. white noise) while electroencephalogram data were collected. Participants also completed self-report measures of anxiety and depressive symptoms.

RESULTS

Reaction time (RT) was faster for the infant cry vs. white noise condition and when matching shapes vs. infant faces. Depressive symptoms were associated with slower RTs to neutral infant faces. The LPP was enhanced overall to faces vs. shapes, but there was no main effect of auditory condition. Anxiety symptoms were associated with an enhanced LPP to infant distressed faces in the infant cry condition.

CONCLUSIONS

Results support these methods for measuring neural and behavioral responses to infant emotional cues in pregnancy and provide evidence that combinations of auditory and visual stimuli may be particularly useful for capturing emotional processes relevant to anxiety.

Differentiated processing of emotional cues in adolescents and young adults with ICD-11 PTSD and complex PTSD after child abuse

BACKGROUND

The recent update of the International Classification of Diseases 11th revision (ICD-11) introduced the diagnosis of complex posttraumatic stress disorder (CPTSD) as a distinct entity from posttraumatic stress disorder (PTSD). Because psychophysiological alterations are a core diagnostic feature of PTSD and CPTSD, the aim of the current study was to examine potential distinctive patterns in cortical and cardiac responses to emotional words in adolescent and young adult patients with PTSD and CPTSD.

METHOD

Event-related potentials and heart rate responses were studied in 81 adolescent and young adult participants, of which 17 individuals were diagnosed with ICD-11 PTSD and 32 individuals with CPTSD, each after childhood sexual and/or physical abuse. Thirty-two individuals served as healthy controls. The paradigm consisted of a passive reading task with neutral, positive, physically threatening, and socially threatening words.

RESULTS

Differentiated early processing of emotional words was indicated by differences on P1 and left EPN components. Additionally, PTSD and CPTSD patients presented with specific patterns of heart rate responses to emotional words. In CPTSD patients, heart rate reactions to emotional words were more variable than in PTSD patients.

CONCLUSIONS

These findings provide early evidence of differentiated cortical and cardiac response patterns in adolescent and young adult patients with CPTSD and PTSD, supporting a nosological distinction between PTSD and complex PTSD. However, due to small and unequal sample sizes, findings presented in the current study are preliminary and require future research.

Hypervigilance or shutdown? Electrophysiological processing of trauma-unrelated aversive stimuli after traumatic life events

Post-Traumatic Stress Disorder (PTSD) research indicates that hyper-reactivity to trauma-related stimuli reflects reduced prefrontal cortex (PFC) modulation of amygdala reactivity. However, other studies indicate a dissociative "shutdown" reaction to overwhelming aversive stimuli, possibly reflecting PFC over-modulation. To explore this, we used an Event-Related Potential (ERP) oddball paradigm to study P3 responses in the presence of the following: 1. Trauma-unrelated morbid distractors (e.g., "injured bear") related to the Rorschach inkblot test, and 2. Negative distractors (e.g., "significant failure"), among participants with high post-traumatic stress symptoms (PTS; n = 20), low PTS (n = 17), and controls (n = 15). Distractors were presented at 20% frequency amongst the more frequent (60%) neutral standard stimuli (e.g., "desk lamp") and the equally frequent (20%) neutral trauma-unrelated target stimulus ("golden fish"). P3 amplitudes were high in the presence of morbid distractors and low in the presence of negative distractors only amongst the control group. Possible mechanisms underlying the lack of P3 amplitude modulation after trauma are discussed.

Neural reactivity to affective stimuli and internalizing symptom dimensions in a transdiagnostic patient sample

BACKGROUND

Internalizing psychopathologies (IPs) are highly comorbid and exhibit substantial overlap, such as aberrant affective reactivity. Neural reactivity to emotional images, measured via the late positive potential (LPP) event-related potential (ERP) component, has been utilized to index affective reactivity in IPs. The LPP is often examined in isolation with a specific disorder, ignoring overlap between IPs. The current study examined how transdiagnostic IP symptom dimensions relate to neural affective reactivity in a highly comorbid patient sample.

METHODS

Participants (N = 99) completed a battery of IP symptom assessments as well as a target categorization task while viewing pleasant, unpleasant, and neutral images during electroencephalography recording. ERPs to each image valence were averaged from 400 to 1000 ms following picture onset at pooled centroparietal and occipital electrodes to calculate the LPP. A principal components analysis performed on the IP symptom measures resulted in two factors: affective distress/misery and fear-based anxiety.

RESULTS

Fear-based anxiety was associated with enhanced LPP reactivity to unpleasant, but not pleasant, images. Distress/misery was related to attenuated average LPP reactivity across images.

CONCLUSIONS

Results revealed a dissociable effect of IP symptom factors in a transdiagnostic sample such that enhanced reactivity to negative images was specific to enhanced fear-based anxiety symptoms while distress/misery symptoms predicted blunted affective reactivity. Neural affective reactivity may serve as an objective biological marker to elucidate the nature of psychological concerns in individuals with comorbid IPs.

Examining the long-term cognitive effects of exposure to the Canterbury earthquakes in a resilient cohort

BACKGROUND

Although most people do not develop mental health disorders after exposure to traumatic events, they may experience subtle changes in cognitive functioning. We previously reported that 2-3 years after the Canterbury earthquake sequence, a group of trauma-exposed people, who identified as resilient, performed less well on tests of spatial memory, had increased accuracy identifying facial emotions and misclassified neutral facial expressions to threat-related emotions, compared with non-exposed controls.

AIMS

The current study aimed to examine the long-term cognitive effects of exposure to the earthquakes in this resilient group, compared with a matched non-exposed control group.

METHOD

At 8-9 years after the Canterbury earthquake sequence, 57 earthquake-exposed resilient (69% female, mean age 56.8 years) and 60 non-exposed individuals (63% female, mean age 55.7 years) completed a cognitive testing battery that assessed verbal and visuospatial learning and memory, executive functioning, psychomotor speed, sustained attention and social cognition.

RESULTS

With the exception of a measure of working memory (Digit Span Forward), no significant differences were found in performance between the earthquake-exposed resilient and non-exposed groups on the cognitive tasks. Examination of changes in cognitive functioning over time in a subset (55%) of the original earthquake-exposed resilient group found improvement in visuospatial performance and slowing of reaction times to negative emotions.

CONCLUSIONS

These findings offer preliminary evidence to suggest that changes in cognitive functioning and emotion processing in earthquake-exposed resilient people may be state-dependent and related to exposure to continued threat in the environment, which improves when the threat resolves.

Social threat and safety learning in individuals with adverse childhood experiences: electrocortical evidence on face processing, recognition, and working memory

BACKGROUND

Adverse childhood experiences (ACEs) are often associated with stress and anxiety-related disorders in adulthood, and learning and memory deficits have been suggested as a potential link between ACEs and psychopathology.

OBJECTIVE

In this preregistered study, the impact of social threat learning on the processing, encoding, and recognition of unknown faces as well as their contextual settings was measured by recognition performance and event-related brain potentials.

METHOD

Sixty-four individuals with ACEs encoded neutral faces within threatening or safe context conditions. During recognition, participants had to decide whether a face was new or had been previously presented in what context (item-source memory), looking at old and new faces. For visual working memory, participants had to detect changes in low and high load conditions during contextual threat or safety.

RESULTS

Results showed a successful induction of threat expectation in persons with ACEs. In terms of face and source recognition, overall recognition of safe and new faces was better compared to threatening face-compounds, with more socially anxious individuals having an advantage in remembering threatening faces. For working memory, an effect of task load was found on performance, irrespective of threat or safety context. Regarding electrocortical activity, an old/new recognition effect and threat-selective processing of face-context information was observed during both encoding and recognition. Moreover, neural activity associated with change detection was found for faces in a threatening context, but only at high task load, suggesting reduced capacity for faces in potentially harmful situations when cognitive resources are limited.

CONCLUSION

While individuals with ACE showed intact social threat and safety learning overall, threat-selective face processing was observed for item/source memory, and a threatening context required more processing resources for visual working memory. Further research is needed to investigate the psychophysiological processes involved in functional and dysfunctional memory systems and their importance as vulnerability factors for stress-related disorders.

Impact of Trauma Type on Startle Reactivity to Predictable and Unpredictable Threats

ABSTRACT

Trauma exposure has been repeatedly linked to psychophysiological threat reactivity, although the directionality of this association has been inconsistent. Several factors likely contribute to inconsistent findings including type of trauma and threat paradigm. The present study therefore examined the impact of trauma type on psychophysiological reactivity to predictable (P-) and unpredictable (U-) threat in young adults (N = 112). Participants were classified into three groups: history of interpersonal or noninterpersonal trauma, or no history of trauma. Startle eyeblink potentiation was recorded during a well-validated threat-of-shock paradigm. Results indicated individuals with interpersonal trauma exposure displayed exaggerated startle reactivity to U-threat (only) compared with both other groups. In contrast, individuals with noninterpersonal trauma exhibited blunted startle reactivity to U-threat (only) compared with both other groups. Findings reveal that trauma and threat type influence threat reactivity and that those with a history of interpersonal trauma may uniquely display exaggerated sensitivity to stressors that are uncertain.

Neurophysiological patterns associated with blunted emotional face processing and withdrawal tendencies in young children exposed to intimate partner violence

Studies linking child maltreatment to abnormal neurophysiological responses to emotional stimuli and mental health impairment have not specifically explored these patterns in young children exposed to intimate partner violence (IPV). The present study examined two neurophysiological indicators, resting-state electroencephalography and an emotion event-related potential (ERP) in 21 IPV exposed and 30 nonexposed children ages 4-6 years recruited from the community and domestic violence shelters. Frontal alpha asymmetry (FAA) was assessed while at rest. FAA is often associated with avoidant/withdrawn behavior and increased risk of IPV-related mental health conditions (e.g., depression). Additionally, the late positive potential (LPP) ERP component, reflecting motivated attention, was acquired in the context of an age-appropriate affective oddball paradigm with low probability animal pictures as targets and human facial expressions (angry, happy, neutral) as distracters. Results demonstrated that IPV-exposed children, compared with nonexposed children, exhibited lower left FAA during resting state and reduced LPPs to oddball targets and affective faces relative to neutral faces in the oddball task. Together, these results suggest neural patterns associated with a blunted response to emotional stimuli and withdrawal tendencies, respectively, in young children exposed to IPV. Implications for emotional socialization in this vulnerable population are discussed.

A unifying translational framework to advance treatment research for comorbid PTSD and substance use disorders

We provide a unifying translational framework that can be used to synthesize extant lines of human laboratory research in four neurofunctional domains that underlie the co-occurrence of posttraumatic stress and substance use disorders (PTSD+SUD). We draw upon the Alcohol and Addiction Research Domain Criteria (AARDOC) to include executive functioning, negative emotionality, reward, and added social cognition from the National Institute of Mental Health (NIMH) Research Domain Criteria into our framework. We review research findings across each of the four domains, emphasizing human experimental studies in PTSD, SUD, and PTSD+SUD for each domain. We also discuss the implications of research findings for treatment development by considering new ways of conceptualizing risk factors and outcomes at the level of the individual patient, which will enhance treatment matching and advance innovations in intervention.

Event related potentials indexing the influence of emotion on cognitive processing in veterans with comorbid post-traumatic stress disorder and traumatic brain injury

OBJECTIVE

Emotion regulation and cognitive executive control are significantly impaired in both post-traumatic stress disorder (PTSD) and traumatic brain injury (TBI). These illnesses are increasingly common in veterans and their co-occurrence may exacerbate symptoms and recovery. The current study sought to investigate neural correlates of these impairments via event-related potentials (ERPs) and examined the association of PTSD symptom severity and impulsivity with these correlates.

METHODS

Electroencephalographic data from seventy-nine veterans with PTSD and TBI and 17 control participants were recorded during a visual emotional oddball task and analyzed for the N2 and P3b ERPs.

RESULTS

Results revealed that veterans showed a reduced P3b ERP in response to both target images and standard images. However, for standard images that followed a negative emotional distractor, the veterans showed a heightened N2 amplitude while the controls did not. In addition, impulsivity predicted modulation of the P3b across stimulus conditions, with a greater P3b amplitude associated with an increase in impulsivity.

CONCLUSIONS

These findings suggest that veterans showed hyper-responsivity to background information and reduced ERPs to task-relevant information.

SIGNIFICANCE

These findings may reflect heightened internal states that create neural noise and a reduced ability to modulate relevant responses.

Comorbid anxiety and depression: Opposing effects on the electrocortical processing of negative imagery in a focal fear sample

BACKGROUND

Anxiety and depression are highly comorbid and share clinical characteristics, such as high levels of negative emotion. Attention toward negative stimuli in anxiety and depression has been studied primarily using negative pictures. Yet, negative mental imagery-that is, mental representations of imagined negative events or stimuli-might more closely mirror patient experience.

METHODS

The current study presents the first examination of neural response to negative imagery in 57 adults (39 female) who all shared a common "focal fear" diagnosis (i.e., specific phobia or performance-only social anxiety disorder), but varied in levels of comorbid anxiety and depression. After listening to standardized descriptions of negative and neutral scenes, participants imagined these scenes as vividly as possible. Associations between categorical and continuous measures of depression, generalized anxiety disorder (GAD), and social anxiety disorder with electrocortical and subjective responses to negative imagery were assessed.

RESULTS

Individuals who were more depressed showed reduced electrocortical processing of negative imagery, whereas those with GAD showed increased electrocortical processing of negative imagery-but only when controlling for depression. Furthermore, participants with higher levels of depression rated negative imagery as less negative and those with greater social anxiety symptoms rated negative imagery more negatively.

CONCLUSIONS

Depression and GAD are characterized by opposing electrocortical response to negative imagery; moreover, depression may suppress GAD-related increases in the electrocortical processing of negative imagery. Results highlight distinctions between different dimensions of distress-based psychopathology, and reveal the unique and complex contribution of comorbid depression to affective response in anxiety.

The controllability of aversive and neutral pictures: an event-related potential study

Control over physically aversive stimuli may reduce stress, arousal and physiological responses to these stimuli. Nonetheless, avoidance of emotionally aversive stimuli/excessive attempts to control negative emotion might alternatively increase the salience of these stimuli. Here, we used a novel paradigm to examine the effect of controllability on the processing of aversive and neutral pictures (using the late positive potential, LPP) and response uncertainty (using the post-imperative negative variation, PINV). Participants (n = 48) were told that they could press a button to terminate the presentation of an aversive or neutral picture, but this was only true during some blocks of the experiment and not others. Results showed that the LPP was larger for control compared to no control blocks and that this was driven by larger LPPs to aversive pictures during the first control block, but only for participants who had started the task in a no control block. Therefore, knowing that aversive stimuli might not always be controllable (i.e., a prior experience of uncontrollability) appears to increase the motivational salience of these stimuli once control becomes possible. In addition, uncontrollability increased both the early and late PINV, and the late PINV was larger for the second compared to the first control block. As such, the current study provides the first evidence that the PINV can be elicited using aversive and neutral pictures and suggests functional differentiation between the early and late portions of the PINV. Results support the utility of this novel paradigm for examining control over emotional stimuli.

Violence Exposure Is Associated With Atypical Appraisal of Threat Among Women: An EEG Study

Introduction

The present study investigates the association of lifetime interpersonal violence (IPV) exposure, related posttraumatic stress disorder (IPV-PTSD), and appraisal of the degree of threat posed by facial avatars.

Methods

We recorded self-rated responses and high-density electroencephalography (HD-EEG) among women, 16 of whom with lifetime IPV-PTSD and 14 with no PTSD, during a face-evaluation task that displayed male face avatars varying in their degree of threat as rated along dimensions of dominance and trustworthiness.

Results

The study found a significant association between lifetime IPV exposure, under-estimation of dominance, and over-estimation of trustworthiness. Characterization of EEG microstates supported that lifetime IPV-PTSD modulates emotional appraisal, specifically in encoding and decoding processing associated with N170 and LPP evoked potentials. EEG source localization demonstrated an overactivation of the limbic system, in particular the parahippocampal gyrus, in response to non-threatening avatars. Additionally, dysfunctional involvement of attention-related processing anterior prefrontal cortex (aPFC) was found in response to relatively trustworthy avatars in IPV-PTSD individuals compared with non-PTSD controls.

Discussion

This study showed that IPV exposure and related PTSD modulate individuals' evaluation of facial characteristics suggesting threat. Atypical processing of these avatar characteristics was marked by group differences in brain regions linked to facial processing, emotion regulation, and memory.

Psychometric properties of the late positive potential in combat-exposed veterans

Trauma exposure is prevalent, associated with multiple forms of psychopathology, and thought to alter the neurobiological substrates of threat processing. The late positive potential (LPP) is an event-related potential (ERP) that may be a clinically useful probe of the neurobiology of threat processing. Despite evidence that combat-exposed veterans exhibit aberrant threat modulation of the LPP, no studies to date have tested the psychometric properties of the LPP in combat trauma-exposed, symptomatic veterans. The primary aim of the current study was to evaluate the reliability (internal consistency, retest reliability) and convergent validity of LPP modulation by threatening faces and scenes in two common tasks among combat-exposed veterans. Participants included 82 combat-exposed veterans who completed face-matching and emotion regulation tasks during EEG recording at baseline and twelve weeks. Internal consistencies of the early LPP time windows (<1000 ms) were acceptable in both tasks, whereas they were poor in late time windows (>1000 ms). Twelve-week retest reliabilities were fair for the early window LPPs to threatening scenes and fear faces, as well as in the late time window for fear faces. Reliabilities were better for individual condition compared to difference scores. Finally, LPPs modulated by threatening scenes and faces were unrelated. Together, these results suggest that the LPPs to threatening scenes and faces reflect distinct forms of threat processing in combat-exposed veterans, and their reliabilities for the early window indicate potential clinical utility in this population.

The impact of posttraumatic stress disorder on event-related potentials in affective and non-affective paradigms: A systematic review with meta-analysis

Post-traumatic stress disorder (PTSD) is associated with neural processing deficits affecting early automatic and later conscious processing. Event-related Potentials (ERPs) are high resolution indices of automatic and conscious processing, but there are no meta-analyses that have examined automatic and conscious ERPs in PTSD across multiple paradigms. This systematic review examined 69 studies across affective and non-affective auditory and visual paradigms. Individuals with PTSD were compared to trauma-exposed and non-trauma controls on ERPs reflecting automatic (N1, P1, N2, P2) and conscious (P3, LPP) processing. Trauma exposure was associated with increased automatic ERP amplitudes to irrelevant auditory information. PTSD further showed increased automatic and conscious allocation of resources to affective information, reduced automatic attending and classification as well as reduced attention processing and working memory updating of non-affective information. Therefore, trauma exposure is associated with enhanced early processing of incoming stimuli, and PTSD with enhanced processing of affective stimuli and impaired processing of non-affective stimuli. This review highlights the need for longitudinal ERP studies in PTSD, adopting standardized procedures and methodological designs.

Processing of Positive Visual Stimuli Before and After Symptoms Provocation in Posttraumatic Stress Disorder - A Functional Magnetic Resonance Imaging Study of Trauma-Affected Male Refugees

Background

Symptoms of anhedonia are often central to posttraumatic stress disorder (PTSD), but it is unclear how anhedonia is affected by processes induced by reliving past traumatic memories.

Methods

Sixty-nine male refugees (PTSD = 38) were interviewed and scanned with functional magnetic resonance imaging while viewing positive, neutral and Scrambled Pictures after being read personalized scripts evoking an emotionally neutral memory and a traumatic memory. We further measured postprovocation state symptoms, physiological measures and PTSD symptoms. We tested whether neural activity associated with positive picture viewing in participants with PTSD was differentially affected by symptom provocation compared to controls.

Results

For the pictures > scrambled contrast (Positive contrast), PTSD participants had significantly less activity than controls in fusiform gyrus, right inferior temporal gyrus and left middle occipital gyrus. The Positive contrast activity in fusiform gyrus scaled negatively with anhedonia symptoms in PTSD participants after controlling for total PTSD severity. Relative to the emotionally Neutral Script, the Trauma Script decreased positive picture viewing activity in posterior cingulate cortex, precuneus and left calcarine gyrus, but there was no difference between PTSD participants and controls.

Conclusions

We found reduced responsiveness of higher visual processing of emotionally positive pictures in PTSD. The significant correlation found between positive picture viewing activity and anhedonia suggests the reduced responsiveness to be due to the severity of anhedonia.

The Relation Between Posttraumatic Stress Symptom Severity and Startle Potentiation to Predictable and Unpredictable Threat

Aberrant threat reactivity has been implicated in the pathophysiology of posttraumatic stress disorder (PTSD); however, the literature on this association is mixed. One factor that may contribute to this inconsistent association is differences in severity of posttraumatic stress symptoms (PTSSs) across studies, but no studies have tested this hypothesis. The relation between PTSD and threat reactivity may also differ between unpredictable threats (U-threats) and predictable threats (P-threats), given burgeoning evidence to support a particular role for aberrant responding to U-threat in PTSD. The present study examined how PTSS severity relates to startle potentiation to U-threat and P-threat in a trauma-exposed community sample (N = 258). There was a negative linear, but not quadratic, relation between PTSS severity and startle potentiation to U-threat, but not P-threat. Blunted defensive responding to U-threat may therefore contribute to higher levels of PTSSs and may represent a novel treatment target for higher levels of PTSSs.

Nonlinear relations between post-traumatic stress symptoms and electrocortical reactivity during emotional face processing in combat-exposed veterans

Combat-related post-traumatic stress symptoms (PTSS) are prevalent among recently deployed veterans, making identification of biomarkers of PTSS in this population a public health priority. Given the link between threat processing neurobiology and PTSS, the threat-related late positive potential (LPP), an ERP reflective of attentional processing sensitive to emotion and its regulation, may have utility as a cost-effective biomarker. Existing PTSS/threat-related LPP findings are mixed, possibly due to variability in PTSS across samples, but this has never been explicitly tested. To address this gap, LPP amplitudes to angry, fearful, and happy emotional face stimuli were recorded among 81 combat-exposed veterans at a VA hospital. A quadratic relationship between self-reported PTSS and LPP amplitude modulation by angry faces emerged such that greater PTSS was related to a decreased LPP response to angry faces among veterans with subthreshold PTSD and an enhanced LPP response to angry faces among veterans with probable PTSD. These results suggest that prior mixed findings may be due to variability in PTSS severity. In addition, exploratory moderation analysis revealed that PTSS was positively associated with late LPP modulation for veterans reporting low cognitive reappraisal use and negatively associated with late LPP modulation for veterans reporting high cognitive reappraisal use. All results were specific to the 1,000-3,000 ms LPP time window. Thus, the functional nature of LPP modulation by direct threat cues may depend upon PTSS severity and/or related variables (e.g., cognitive reappraisal utilization).

Social cognition in post-traumatic stress disorder: A systematic review

OBJECTIVES

Post-traumatic stress disorder (PTSD) is a common psychiatric condition. Patients with PTSD have marked symptoms that significantly impair their social and emotional abilities, and numerous studies have explored this issue. We hypothesized that impairment of social cognition takes part in functional disability of individuals with PTSD.

METHODS

We conducted a systematic review by querying PubMed database for the titles of articles published up to February 2018 with the terms [PTSD] [Post traumatic disorder] AND [Emotion recognition] OR [Facial expression of emotion] OR [Facial expression perception] OR [Empathy] OR [Affective empathy] OR [Mentalizing] OR [Social cognition] OR [Theory of Mind] OR [Mental state attribution] OR [Cognitive empathy] OR [Emotional empathy] OR [Social behaviour deficits].

RESULTS

Our results suggest that affective and cognitive aspect of theory of mind is comprehensively disturbed in patients with PTSD, showing a significant impairment in their ability to predict what others feel, think, or believe. They could also be massively altered in their perception of basic emotional expressions whether it is an expression of threat or happiness. Their affective empathy appears to be systematically disturbed and correlated to verbal and/or physical aggressive behaviour.

CONCLUSIONS

Social cognition is disturbed in PTSD and should be regarded as an important symptom. Damages in social cognition seem to take part in the functional disability of people with PTSD. We highlight the interest of a systematic assessment of social cognition in the care of patients with PTSD and suggest which tests could be the most relevant for this evaluation.

PRACTITIONER POINTS

•PTSD is no longer regarded as a subtype of anxiety disorder, but as part of a new category in the DSM-5. In clinical practice, symptoms tied to alterations in arousal and reactivity - such as irritability and vigilance - and to the disturbance of cognition and mood, are particularly closely correlated with poorer quality of life. Impaired social cognition clearly impacts the functional disability of people with PTSD. There are potential benefits of individualized cognitive remediation based on empathy and the emotional component of ToM (cognitive remediation, cognitive-behavioural therapy, therapeutic education, etc.) in PTSD people.

Posttraumatic stress disorder and the social brain: Affect-related disruption of the default and mirror networks

BACKGROUND

Social cognitive impairments, specifically in mentalizing and emotion recognition, are common and debilitating symptoms of posttraumatic stress disorder (PTSD). Despite this, little is known about the neurobiology of these impairments, as there are currently no published neuroimaging investigations of social inference in PTSD.

METHODS

Trauma-exposed veterans with and without PTSD (n = 20 each) performed the Why/How social inference task during functional magnetic resonance imaging (fMRI). Patients with PTSD had two fMRI sessions, between which they underwent affect labeling training. We probed the primary networks of the "social brain"-the default mode network (DMN) and mirror neuron system (MNS)-by examining neural activity evoked by mentalizing and action identification prompts, which were paired with emotional and nonemotional targets.

RESULTS

Hyperactivation to emotional stimuli differentiated PTSD patients from controls, correlated with symptom severity, and predicted training outcomes. Critically, these effects were nonsignificant or marginal for nonemotional stimuli. Results were generally consistent throughout DMN and MNS. Unexpectedly, effects were nonsignificant in core affect regions, but robust in regions that overlap with the dorsal attention, ventral attention, and frontoparietal control networks.

CONCLUSIONS

The array of social cognitive processes subserved by DMN and MNS appear to be inordinately selective for emotional stimuli in PTSD. However, core affective processes do not appear to be the primary instigators of such selectivity. Instead, we propose that affective attentional biases may instigate widespread affect-selectivity throughout the social brain. Affect labeling training may inhibit such biases. These accounts align with numerous reports of affect-biased attentional processes in PTSD.

Processing of affective words in adolescent PTSD-Attentional bias toward social threat

Post-traumatic stress disorder (PTSD) is associated with a hypersensitivity to potential threat. This hypersensitivity manifests through differential patterns of emotional information processing and has been demonstrated in behavioral and neurophysiological experimental paradigms. However, the majority of research has been focused on adult patients with PTSD. To examine possible differences in underlying neurophysiological patterns for adolescent patients with PTSD after childhood sexual and/or physical abuse (CSA/CPA), ERP correlates of emotional word processing in 38 healthy participants and 40 adolescent participants with PTSD after experiencing CSA/CPA were studied. The experimental paradigm consisted of a passive reading task with neutral, positive (e.g., paradise), physically threatening (e.g., torment), and socially threatening (i.e., swearing, e.g., son of a bitch) words. A modulation of P3 amplitudes by emotional valence was found, with positive words inducing less elevated amplitudes over both groups. Interestingly, in later processing, the PTSD group showed augmented early late positive potential (LPP) amplitudes for socially threatening stimuli, while there were no modulations within the healthy control group. Also, region-specific emotional modulations for anterior and posterior electrode clusters were found. For the anterior LPP, highest activations have been found for positive words, while socially and physically threatening words led to strongest modulations in the posterior LPP cluster. There were no modulations by group or emotional valence at the P1 and EPN stage. The findings suggest an enhanced conscious processing of socially threatening words in adolescent patients with PTSD after CSA/CPA, pointing to the importance of a disjoined examination of threat words in emotional processing research.

Angry and Fearful Face Conflict Effects in Post-traumatic Stress Disorder

In the presence of threatening stimuli, post-traumatic stress disorder (PTSD) can manifest as hypervigilance for threat and disrupted attentional control. PTSD patients have shown exaggerated interference effects on tasks using trauma-related or threat stimuli. In studies of PTSD, faces with negative expressions are often used as threat stimuli, yet angry and fearful facial expressions may elicit different responses. The modified Eriksen flanker task, or the emotional face flanker, has been used to examine response interference. We compared 23 PTSD patients and 23 military controls on an emotional face flanker task using angry, fearful and neutral expressions. Participants identified the emotion of a central target face flanked by faces with either congruent or incongruent emotions. As expected, both groups showed slower reaction times (RTs) and decreased accuracy on emotional target faces, relative to neutral. Unexpectedly, both groups showed nearly identical interference effects on fearful and neutral target trials. However, post hoc testing suggested that PTSD patients showed faster RTs than controls on congruent angry faces (target and flanker faces both angry) relative to incongruent, although this finding should be interpreted with caution. This possible RT facilitation effect with angry, but not fearful faces, also correlated positively with self-report measures of PTSD symptoms. These results suggest that PTSD patients may be more vigilant for, or primed to respond to, the appearance of angry faces, relative to fearful, but further study is needed.

The Electrical Aftermath: Brain Signals of Posttraumatic Stress Disorder Filtered Through a Clinical Lens

This review aims to identify patterns of electrical signals identified using electroencephalography (EEG) linked to posttraumatic stress disorder (PTSD) diagnosis and symptom dimensions. We filter EEG findings through a clinical lens, evaluating nuances in findings according to study criteria and participant characteristics. Within the EEG frequency domain, greater right than left parietal asymmetry in alpha band power is the most promising marker of PTSD symptoms and is linked to exaggerated physiological arousal that may impair filtering of environmental distractors. The most consistent findings within the EEG time domain focused on event related potentials (ERPs) include: 1) exaggerated frontocentral responses (contingent negative variation, mismatch negativity, and P3a amplitudes) to task-irrelevant distractors, and 2) attenuated parietal responses (P3b amplitudes) to task-relevant target stimuli. These findings suggest that some individuals with PTSD suffer from attention dysregulation, which could contribute to problems concentrating on daily tasks and goals in lieu of threatening distractors. Future research investigating the utility of alpha asymmetry and frontoparietal ERPs as diagnostic and predictive biomarkers or intervention targets are recommended.

Cumulative childhood interpersonal trauma is associated with reduced cortical differentiation between threat and non-threat faces in posttraumatic stress disorder adults

OBJECTIVE

Posttraumatic stress disorder and childhood trauma frequently co-occur. Both are associated with abnormal neural responses to salient emotion stimuli. As childhood trauma is a risk factor for posttraumatic stress disorder, differentiating between their neurophysiological effects is necessary to elucidate the neural pathways by which childhood trauma exposure contributes to increased posttraumatic stress disorder risks.

METHODS

Face-specific N170 evoked response potentials for backward-masked (non-conscious) and conscious threat (fear, angry) and non-threat (happy) faces were measured in 77 adults (18-64 years old, 64% women, 78% right-handed) symptomatic for posttraumatic stress disorder. Differences in N170 peak amplitudes for fear-versus-happy and angry-versus-happy faces at bilateral temporo-occipital (T5, T6) sites were computed. The effect of cumulative exposure to childhood interpersonal trauma, other childhood trauma, adult trauma, depression and posttraumatic stress disorder symptom severity on the N170 response was assessed using hierarchical multiple regression analyses.

RESULTS

T5 N170 peak amplitudes for non-conscious fear-versus-happy faces were inversely related to cumulative childhood interpersonal trauma after accounting for socio-demographic, clinical symptom and other trauma factors. Posttraumatic stress disorder Avoidance was positively associated with N170 peak amplitudes for non-conscious fear-versus-happy faces, primarily due to reduced N170 responsivity to happy faces.

CONCLUSION

Childhood interpersonal trauma exposure is associated with reduced discrimination between fear and happy faces, while avoidance symptom severity is associated with dampened responsivity to automatically processed happy faces in posttraumatic stress disorder adults. Results are discussed in terms of the likely contributions of impaired threat discrimination and deficient reward processing during neural processing of salient emotion stimuli, to increased risks of posttraumatic stress disorder onset and chronicity in childhood interpersonal trauma-exposed adults.

The social cognitive appraisal of trustworthiness in individuals with dimensional levels of post-traumatic stress symptoms: a translational study

Background: Misappraisals in evaluating the trustworthiness of others may be one mechanism contributing to the interpersonal difficulties individuals with posttraumatic stress disorder (PTSD) face. Objective: This study used a translational experimental design to examine the behavioural and neural correlates underlying the appraisal of facial stimuli morphed on dimensions of trustworthiness across three groups: individuals with high posttraumatic stress symptoms (HPTS), low posttraumatic stress symptoms (LPTS), and healthy controls (HC). Methods: Participants (N = 70) rated how trustworthy to untrustworthy they perceived three facial morphs (trustworthy, neutral, and untrustworthy) while undergoing electroencephalography (EEG). Results: Behavioural results showed that the HPTS group rated the untrustworthy morph as more untrustworthy than the HC group (β = 0.20, SE = .07, 95% CI [0.06, 0.33], z = 2.88, p = .004). The HPTS group also showed no variation in response time across morphs ( X 2 (2) = 0.92, p = 0.63), while the LPTS and HC groups did ( X 2 (2) = 9.60, p = .008; X 2 (2) = 23.62, p < .001). EEG data revealed significant group by morph interactions at the N170 latency and the Vertex Positive Potential (VPP): the HPTS and LPTS identified the untrustworthy morph faster than the HCs, but diverged to the degree to which they encoded each facial morph. Conclusions: Taken together our results suggest that HPTS individuals demonstrate an early attentional avoidance of faces morphed on dimensions of trustworthiness. This early, preconscious, avoidance may be one mechanism contributing to the miscalculations individuals with PTSD make in interpersonal situations.

Neurophysiological Response to Olfactory Stimuli in Combat Veterans With Posttraumatic Stress Disorder

There is a need for a better understanding of underlying pathology in posttraumatic stress disorder (PTSD) to develop more effective treatments. The late positive potential (LPP) amplitude from electroencephalogram has been used to assess individual differences in emotional reactivity. There is evidence that olfaction is particularly important in emotional processing in PTSD. The current study examined LPP amplitudes in response to olfactory stimuli in 24 combat veterans with PTSD and 24 nonmilitary/non-PTSD controls. An olfactometer delivered three negatively valenced odorants, with 12 trials of each delivered in a random order. The groups did not differ in LPP amplitude across odorants. However, within the PTSD group, higher Clinician-Administered PTSD Scale scores related to an increased LPP amplitude after diesel fuel and rotten egg, but not n_butanol, odorants. Results provide specific targets and theory for further research into clinical applications such as selection of idiographic odorants for use in virtual-reality exposure therapy.

Neural indices of emotional reactivity and regulation predict course of PTSD symptoms in combat-exposed veterans

After diagnosis, veterans with posttraumatic stress disorder (PTSD) display significant variability in the natural course of illness (Bonanno et al., 2012)). Cross-sectional work reveals that abnormal neural response during emotion reactivity-measured using the late positive potential (LPP)-correlates with PTSD symptom severity; however, whether the LPP during emotional reactivity and regulation predicts symptoms over time is unknown. The current study examined the LPP during emotion reactivity and regulation as predictors of PTSD symptoms over one year in OEF/OIF/OND combat-exposed veterans. At baseline, participants completed an Emotion Regulation Task (ERT) during electroencephalogram recording. The Clinician Administered PTSD Scale (CAPS) was completed at baseline (N=86), 6-months (N=54) and 1-year (N=49) later. During ERT, participants viewed negative pictures; partway through they were instructed to "reappraise" (i.e., reduce negative affect/regulate) or "look" (i.e., passively react). Change in LPP during emotional reactivity (ΔLPP-E) and reappraisal (ΔLPP-R) were calculated and used in multilevel mixed modeling to predict CAPS over time. Findings demonstrated that deficiency in reappraisal (ΔLPP-R) predicted more overall symptoms over time, while greater neural responses to emotion (ΔLPP-E) and greater change in neural response as a function of reappraisal (ΔLPP-R) predicted a decline in avoidance symptoms over time. Together, results support the utility of neural markers of emotional reactivity and regulation as predictors of PTSD symptoms-and change in symptoms-across one year.

Differential impact of post-deployment stress and PTSD on neural reactivity to emotional stimuli in Iraq and Afghanistan veterans

For many veterans returning from combat in Iraq and Afghanistan, the transition from military to civilian life is complicated by an array of postdeployment stressors. In addition to significant stress associated with reintegration after deployment, many returning veterans also contend with the added burden conferred by PTSD symptoms. While the relationship between PTSD symptoms and the neurobiological substrates of emotion dysregulation has begun to be studied, even less is known about the effects of postdeployment stress on neural function. In order to assess the relationship among a neural measure of attention to emotion (i.e. the late positive potential; LPP), PTSD symptoms and postdeployment stressors, EEG was recorded and examined in a linear mixed model of 81 OEF/OIF/OND veterans. Results revealed a main effect for postdeployment stressors such that increased postdeployment stress was associated with a relatively enhanced LPP across all emotion types. There was also a main effect for PTSD symptoms such that greater symptoms were related to a relatively blunted LPP across all emotion types. Findings may have important implications for understanding how both current stress and PTSD symptoms affect motivated attention as measured by the LPP. Moreover, this work highlights the need to consider the effects of current stress, in addition to PTSD symptoms, on the functioning of returning veterans.

Intranasal oxytocin increases neural responses to social reward in post-traumatic stress disorder

Therapeutic alliance and perceived social support are important predictors of treatment response for post-traumatic stress disorder (PTSD). Intranasal oxytocin administration may enhance treatment response by increasing sensitivity for social reward and thereby therapeutic alliance and perceived social support. As a first step to investigate this therapeutical potential, we investigated whether intranasal oxytocin enhances neural sensitivity to social reward in PTSD patients. Male and female police officers with (n = 35) and without PTSD (n = 37) were included in a double-blind, randomized, placebo-controlled cross-over fMRI study. After intranasal oxytocin (40 IU) and placebo administration, a social incentive delay task was conducted to investigate neural responses during social reward and punishment anticipation and feedback. Under placebo, PTSD patients showed reduced left anterior insula (AI) responses to social rewards (i.e. happy faces) compared with controls. Oxytocin administration increased left AI responses during social reward in PTSD patients, such that PTSD patients no longer differed from controls under placebo. Furthermore, in PTSD patients, oxytocin increased responses to social reward in the right putamen. By normalizing abberant insula responses and increasing putamen responses to social reward, oxytocin administration may enhance sensitivity for social support and therapeutic alliance in PTSD patients. Future studies are needed to investigate clinical effects of oxytocin.

In the mind's eye: The late positive potential to negative and neutral mental imagery and intolerance of uncertainty

There are many advantages to human beings' ability to generate and sustain mental imagery in the absence of exteroceptive stimuli; however, this ability may also underlie emotional disorders characterized by worry, rumination, or excessive concern about the future. For instance, fear-based disorders may be characterized by heightened ERPs to negative imagery. On the other hand, distress disorders may be characterized by attempts to avoid engaging with negative mental imagery, and therefore reduced electrocortical response. Prior ERP work has used negative and neutral pictorial stimuli to establish the parameters of response in healthy individuals, before taking these paradigms to clinical samples to assess aberrant emotion processing. Yet despite its clinical relevance, no study to date has elicited a late positive potential (LPP), a robust measure of emotion processing, to standardized negative imagined scenes. Here, participants listened to audio descriptions of negative and neutral scenes, and were asked to imagine these scenes as vividly as possible. Results showed that negative imagined scenes elicited an increased LPP, lasting approximately 10 s after audio description offset, as well as heightened ratings of arousal and unpleasantness. Moreover, participants with greater self-reported cognitive concerns about uncertain future events (higher prospective intolerance of uncertainty) showed reduced emotional modulation of the LPP. These data provide the first evidence of sustained electrocortical processing of standardized negative imagery elicited in the absence of salient visual cues, and suggest that cognitive risk for anxiety in an unselected sample may be represented phenotypically by blunted LPPs to negative imagery.

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.

An electrocortical investigation of emotional face processing in military-related posttraumatic stress disorder

PTSD is a disorder of emotion dysregulation. Although much work has intended to elucidate the neural underpinnings of the disorder, much remains unknown about the neurobiological substrates of emotion dysregulation in PTSD. In order to assess the relationship between a neural measure of attention to emotion (i.e. the late positive potential; LPP) and PTSD symptoms, EEG was recorded and examined as a potential predictor of military-related PTSD symptoms in a sample of 73 OEF/OIF/OND veterans. Results revealed that higher PTSD symptoms were related to an attenuated LPP response to angry facial expressions. This finding was not observed for happy or fearful faces. The current study provides initial evidence that, in a relatively young, mostly male sample of OEF/OIF/OND veterans, hyporeactivity to angry faces at the neural level may provide phenotypic data to characterize individual differences in PTSD symptom severity. This work may assist in future studies that seek to examine useful psychophysiologic targets for treatment and early interventions.

Affective and cognitive correlates of PTSD: Electrocortical processing of threat and perseverative errors on the WCST in combat-related PTSD

PTSD is characterized by both affective and cognitive dysfunction. Affectively, PTSD is associated with both heightened emotional reactivity and disengagement. Cognitively, perseverative thinking is a core feature of the disorder. In order to assess the interactive effects of affective and cognitive correlates of PTSD symptoms, 47 OEF/OIF/OND veterans completed an emotional faces matching task while EEG (i.e., late positive potential; LPP) was recorded, and separately completed the Wisconsin Card Sorting Test (WCST) to assess perseverative errors. There was no relationship between PTSD symptoms and either perseverative errors or EEG reactivity to faces. However, an interaction was found such that high perseverative errors on the WCST and a relatively enhanced LPP to angry faces was associated with greater PTSD symptoms, while low errors on the WCST and a relatively blunted LPP to angry faces also related to greater PTSD symptoms. These findings suggest that emotion-cognition interactions are important for understanding PTSD, and that distinct emotion-cognition constellations interact with symptoms.

Attenuated neural reactivity to happy faces is associated with rule breaking and social problems in anxious youth

Pediatric anxiety is associated with comorbid externalizing behaviors and social problems, and these associations may be related to altered emotion processing. The late positive potential (LPP), an event-related potential component, is a neural marker of emotion processing, and there is evidence that anxious youth exhibits enhanced LPPs to threatening signals. It is unknown, however, if differences in the LPP are related to externalizing behaviors and social problems co-occurring with anxiety and if these associations are driven by altered processing of threatening (angry or fearful faces) or rewarding (happy faces) socio-emotional signals. Thus, in the present study, we examined, in a sample of 39 anxious youth, the association between LPPs, following socio-emotional signals and externalizing behaviors and social problems. Results indicated an association between attenuated LPPs in response to happy faces and greater rule-breaking and social problems. These findings suggest that differences in positive socio-emotional signal processing are related to heterogeneity in pediatric anxiety and that LPPs are a sensitive index of such heterogeneity.

Earthquake Brain: Altered Recognition and Misclassification of Facial Expressions Are Related to Trauma Exposure but Not Posttraumatic Stress Disorder

OBJECTIVES

The study investigated facial expression recognition (FER) in posttraumatic stress disorder (PTSD) caused by exposure to earthquakes, and in particular whether people with this condition showed a bias toward interpreting facial expressions as threat-related emotions (i.e., as anger, fear, or disgust). The study included a trauma-exposed control group who had been similarly exposed to the earthquakes but had not developed PTSD. We hypothesized that individuals with PTSD would have increased sensitivity to threat-related facial emotions compared with the trauma-exposed control group. This would be shown by increased accuracy in recognition of threat-related emotions and the misinterpretation of neutral expressions to these emotions (i.e., misidentifying them as anger, fear, or disgust). The availability of a group of healthy controls from a previous study who had been tested on a similar task before the earthquakes allowed a further non-exposed comparison.

METHOD

Twenty-eight individuals with PTSD (71% female, mean age 42.8 years) and 89 earthquake-exposed controls (66% female, mean age 50.1 years) completed an FER task, which featured six basic emotions. Further comparisons were made with 50 non-exposed controls (64% female, mean age 38.5 years) who had been tested before the earthquakes.

RESULTS

There was no difference in sensitivity to threat-related facial expressions (as measured by accuracy in recognition of threat-related facial expressions and the misinterpretation of neutral expressions as threatening) in individuals with PTSD compared with similarly earthquake-exposed controls. Supplementary comparison with an historical, non-exposed control group showed that both earthquake-exposed groups had increased accuracy for the identification of all facial emotions and showed a bias in the misclassification of neutral facial expressions to the threat-related emotions of anger and disgust.

CONCLUSION

These findings suggest that it is exposure to earthquakes and repeated aftershocks, rather than the presence of PTSD that affects FER accuracy and misinterpretation. The importance of these biases in both PTSD and trauma-exposed controls needs further exploration and is an area for future research.

Try to look on the bright side: Children and adults can (sometimes) override their tendency to prioritize negative faces

We used eye tracking to examine 4- to 10-year-olds' and adults' (N = 173) visual attention to negative (anger, fear, sadness, disgust) and neutral faces when paired with happy faces in 2 experimental conditions: free-viewing ("look at the faces") and directed ("look only at the happy faces"). Regardless of instruction, all age groups more often looked first to negative versus positive faces (no age differences), suggesting that initial orienting is driven by bottom-up processes. In contrast, biases in more sustained attention-last looks and looking duration-varied by age and could be modified by top-down instruction. On the free-viewing task, all age groups exhibited a negativity bias which attenuated with age and remained stable across trials. When told to look only at happy faces (directed task), all age groups shifted to a positivity bias, with linear age-related improvements. This ability to implement the "look only at the happy faces" instruction, however, fatigued over time, with the decrement stronger for children. Controlling for age, individual differences in executive function (working memory and inhibitory control) had no relation to the free-viewing task; however, these variables explained substantial variance on the directed task, with children and adults higher in executive function showing better skill at looking last and looking longer at happy faces. Greater anxiety predicted more first looks to angry faces on the directed task. These findings advance theory and research on normative development and individual differences in the bias to prioritize negative information, including contributions of bottom-up salience and top-down control. (PsycINFO Database Record

Individual differences in cognitive reappraisal use and emotion regulatory brain function in combat-exposed veterans with and without PTSD

BACKGROUND

Veterans with posttraumatic stress disorder (PTSD) exhibit marked deficits in emotion regulation. Past research has demonstrated underengagement of the prefrontal cortex during regulation of negative affect in those with PTSD, but has been unable to find evidence of impaired downregulation of the amygdala. One possibility is that there exists variability in amygdala reactivity that cuts across diagnostic status and which can be characterized using a continuous measure of individual differences. In healthy/nontraumatized volunteers, individual variability in amygdala engagement during emotion processing and regulation has been shown to relate to habitual use of regulation strategies.

METHODS

The current study examined whether self-reported use of cognitive reappraisal and expressive suppression regulation strategies correlated with brain activation during cognitive reappraisal in combat-exposed veterans with (n = 28) and without PTSD (combat-exposed controls, CEC; n = 20).

RESULTS

Results showed that greater self-reported use of cognitive reappraisal was associated with less activation in the right amygdala during volitional attempts to attenuate negative affect using reappraisal, irrespective of PTSD diagnosis.

CONCLUSIONS

This finding is in line with prior work and extends evidence of an association between habitual use of regulation strategies and amygdala engagement during emotion regulation to a trauma-exposed sample of individuals both with and without PTSD. Furthermore, by providing evidence of individual differences in regulation-related amygdala response in a traumatized sample, this result may increase understanding of the neural mechanisms that support variability in symptom manifestation observed across individuals with PTSD.

Impact of alcohol use disorder comorbidity on defensive reactivity to errors in veterans with posttraumatic stress disorder

Converging lines of evidence suggest that individuals with comorbid posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) may be characterized by heightened defensive reactivity, which serves to maintain drinking behaviors and anxiety/hyperarousal symptoms. However, it is important to note that very few studies have directly tested whether individuals with PTSD and AUD exhibit greater defensive reactivity compared with individuals with PTSD without AUD. Therefore, the aim of the current study was to test this emerging hypothesis by examining individual differences in error-related negativity (ERN), an event-related component that is larger among anxious individuals and is thought to reflect defensive reactivity to errors. Participants were 66 military veterans who completed a well-validated flanker task known to robustly elicit the ERN. Veterans were comprised of 3 groups: controls (i.e., no PTSD or AUD), PTSD-AUD (i.e., current PTSD but no AUD), and PTSD + AUD (i.e., current comorbid PTSD and AUD). Results indicated that individuals with PTSD and controls generally did not differ in ERN amplitude. However, among individuals with PTSD, those with comorbid AUD had significantly larger ERNs than those without AUD. These findings suggest that PTSD + AUD is a neurobiologically unique subtype of PTSD, and the comorbidity of AUD may enhance defensive reactivity to errors in individuals with PTSD. (PsycINFO Database Record

Enhanced Neural Reactivity to Threatening Faces in Anxious Youth: Evidence from Event-Related Potentials

Anxiety disorders are characterized by enhanced reactivity to threat, and event-related potentials (ERPs) are useful neural measures of the dynamics of threat processing. In particular, the late positive potential (LPP) is an ERP component that reflects sustained attention towards motivationally salient information. Previous studies in adults suggest that the LPP is enhanced to threatening stimuli in anxiety but blunted in depression; however, very little work has evaluated the LPP to threat in anxious youth. We measured the LPP during an emotional face-matching task in youth (age 7-19) with current anxiety disorders (n = 53) and healthy controls with no history of psychopathology (n = 37). We evaluated group differences, as well as the effect of depressive symptoms on the LPP. Youth with anxiety disorders exhibited enhanced LPPs to angry and fearful faces 1000-2000 ms after stimulus onset. Higher depressive symptoms were associated with reduced LPPs to angry faces across both groups. Enhanced LPPs to threatening faces were most apparent for social anxiety disorder, as opposed to generalized anxiety disorder or separation anxiety disorder. Results suggest the LPP may be a useful neural measure of threat reactivity in youth with anxiety disorders and highlight the importance of accounting for symptoms of both depression and anxiety when examining emotional processing.

Neural Reactivity to Emotional Stimuli Prospectively Predicts the Impact of a Natural Disaster on Psychiatric Symptoms in Children

BACKGROUND

Natural disasters expose entire communities to stress and trauma, leading to increased risk for psychiatric symptoms. Yet, the majority of exposed individuals are resilient, highlighting the importance of identifying underlying factors that contribute to outcomes.

METHODS

The current study was part of a larger prospective study of children in Long Island, New York (n = 260). At age 9, children viewed unpleasant and pleasant images while the late positive potential (LPP), an event-related potential component that reflects sustained attention toward salient information, was measured. Following the event-related potential assessment, Hurricane Sandy, the second costliest hurricane in United States history, hit the region. Eight weeks after the hurricane, mothers reported on exposure to hurricane-related stress and children's internalizing and externalizing symptoms. Symptoms were reassessed 8 months after the hurricane.

RESULTS

The LPP predicted both internalizing and externalizing symptoms after accounting for prehurricane symptomatology and interacted with stress to predict externalizing symptoms. Among children exposed to higher levels of hurricane-related stress, enhanced neural reactivity to unpleasant images predicted greater externalizing symptoms 8 weeks after the disaster, while greater neural reactivity to pleasant images predicted lower externalizing symptoms. Moreover, interactions between the LPP and stress continued to predict externalizing symptoms 8 months after the hurricane.

CONCLUSIONS

Results indicate that heightened neural reactivity and attention toward unpleasant information, as measured by the LPP, predispose children to psychiatric symptoms when exposed to higher levels of stress related to natural disasters, while greater reactivity to and processing of pleasant information may be a protective factor.

Emotional Processing and Attention Control Impairments in Children with Anxiety: An Integrative Review of Event-Related Potentials Findings

Anxiety disorders in adults have been associated with biased processing of emotional information which may be due to a deficit in attentional control. This deficit leads to an hypervigilance and a selective attention toward threatening information. Event-related potentials (ERPs) have been used to study this topic in anxious adults. Similar biases have been reported in children with anxiety but researches investigating the ERPs components underpinning these biases are more scarce. However, the understanding of the neural correlates of attentional biases in anxious children seem quite important since they could play a role in the etiology and the maintenance of this disorder. This review summarizes the results of researches having used ERPs to index emotional processing and attention control in children suffering from anxiety. We will focus on the P1, indexing basic visual perceptual processing, the N2, thought to reflect cognitive control process, the P3 typically associated with response inhibition, and the late positive potential (LPP) that indicates sustained attention toward motivationally salient stimuli. We will also examine the error-related negativity (ERN) that indexes monitoring system for detecting errors. Electro-physiological studies generally reported increased amplitudes of these components in anxious children, even when they did not differ from typically developing children at a behavioral level. These results suggest diminished cognitive control that influences children's selective attention mechanisms toward threatening information. Theoretical perspectives and implications for future researches will be discussed in the framework of current models of childhood anxiety.

An electrocortical investigation of voluntary emotion regulation in combat-related posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) - a debilitating disorder characterized by severe deficits in emotion regulation - is prevalent among U.S. military veterans. Research into the pathophysiology of PTSD has focused primarily on emotional reactivity, showing evidence of heightened neural response during negative affect provocation. By comparison, studies of brain functioning during the voluntary regulation of negative affect are limited. In the current study, combat-exposed U.S. military veterans with (n=25) and without (n=25) PTSD performed an emotion regulation task during electroencephalographic (EEG) recording. The late positive potential (LPP) was used as a measure of sustained attention toward, and processing of, negative and neutral pictures, and was scored prior to and after instructions to either maintain or down-regulate emotional response using the strategy of cognitive reappraisal. Results showed that groups did not differ in picture-elicited LPP amplitude either prior to or during cognitive reappraisal; reappraisal reduced the LPP in both groups over time. Time-dependent increases in LPP amplitude as a function of emotional reactivity maintenance were evident in the non-PTSD group only. This latter finding may signal PTSD-related deficits in sustained engagement with emotion-processing over the course of several seconds.

[Psychiatric, Cognitive and Emotional Profile in Ex-combatants of Illegal Armed Groups in Colombia]

INTRODUCTION

Exposure to armed conflict produces biological adaptations oriented to handle the highly stressful conditions in war environments. The special features of The Colombian armed create a special scenario to evaluate the human behavior.

OBJECTIVE

In this study, psychiatric, cognitive and emotional processing characteristics of a group of Colombian armed illegal forces of ex-combatants are described.

METHODS

Sixty-three ex combatants and 22 controls were assessed with WAIS (IQ), INECO frontal screening (executive functions), Interpersonal Reactivity Index (empathy), emotional features recognition and MINI (psychiatric profile).

RESULTS

When compared to the control group, ex-combatants showed higher frequency of antisocial personality disorder (P=.031) and behavioral dissocial disorder (P=.017). In cognitive profile, the ex-combatants showed a lower score in the executive function test (Me=18.50; RQ=4.00), control (Me=23.00; RQ=5.25), with a poor personal distress in emphatic profile (Me=10.00; RQ=5.00) compared to control group (Me=37.00; RQ=7.25).

CONCLUSIONS

We found differences in cognitive and psychiatric profile in ex-combatants in comparison with controls.

A Pilot Study of Mindfulness-Based Exposure Therapy in OEF/OIF Combat Veterans with PTSD: Altered Medial Frontal Cortex and Amygdala Responses in Social-Emotional Processing

Combat-related posttraumatic stress disorder (PTSD) is common among returning veterans, and is a serious and debilitating disorder. While highly effective treatments involving trauma exposure exist, difficulties with engagement and early drop may lead to sub-optimal outcomes. Mindfulness training may provide a method for increasing emotional regulation skills that may improve engagement in trauma-focused therapy. Here, we examine potential neural correlates of mindfulness training and in vivo exposure (non-trauma focused) using a novel group therapy [mindfulness-based exposure therapy (MBET)] in Afghanistan (OEF) or Iraq (OIF) combat veterans with PTSD. OEF/OIF combat veterans with PTSD (N = 23) were treated with MBET (N = 14) or a comparison group therapy [Present-centered group therapy (PCGT), N = 9]. PTSD symptoms were assessed at pre- and post-therapy with Clinician Administered PTSD scale. Functional neuroimaging (3-T fMRI) before and after therapy examined responses to emotional faces (angry, fearful, and neutral faces). Patients treated with MBET had reduced PTSD symptoms (effect size d = 0.92) but effect was not significantly different from PCGT (d = 0.43). Improvement in PTSD symptoms from pre- to post-treatment in both treatment groups was correlated with increased activity in rostral anterior cingulate cortex, dorsal medial prefrontal cortex (mPFC), and left amygdala. The MBET group showed greater increases in amygdala and fusiform gyrus responses to Angry faces, as well as increased response in left mPFC to Fearful faces. These preliminary findings provide intriguing evidence that MBET group therapy for PTSD may lead to changes in neural processing of social-emotional threat related to symptom reduction.

EEG correlates of the severity of posttraumatic stress symptoms: A systematic review of the dimensional PTSD literature

BACKGROUND

Considering the Research Domain Criteria (RDoC) framework, it is crucial to investigate posttraumatic stress disorder (PTSD) as a spectrum that ranges from normal to pathological. This dimensional approach is especially important to aid early PTSD detection and to guide better treatment options. In recent years, electroencephalography (EEG) has been used to investigate PTSD; however, reviews regarding EEG data related to PTSD are lacking, especially considering the dimensional approach. This systematic review examined the literature regarding EEG alterations in trauma-exposed people with posttraumatic stress symptoms (PTSS) to identify putative EEG biomarkers of PTSS severity.

METHOD

A systematic review of EEG studies of trauma-exposed participants with PTSS that reported dimensional analyses (e.g., correlations or regressions) between PTSS and EEG measures was performed.

RESULTS

The literature search yielded 1178 references, of which 34 studies were eligible for inclusion. Despite variability among the reviewed studies, the PTSS severity was often associated with P2, P3-family event-related potentials (ERPs) and alpha rhythms.

LIMITATIONS

The search was limited to articles published in English; no information about non-published studies or studies reported in other languages was obtained. Another limitation was the heterogeneity of studies, which made meta-analysis challenging.

CONCLUSIONS

EEG provides promising candidates to act as biomarkers, although further studies are required to confirm the findings. Thus, EEG, in addition to being cheaper and easier to implement than other central techniques, has the potential to reveal biomarkers of PTSS severity.

Age-related changes in emotional face processing across childhood and into young adulthood: Evidence from event-related potentials

Socio-emotional processing is an essential part of development, and age-related changes in its neural correlates can be observed. The late positive potential (LPP) is a measure of motivated attention that can be used to assess emotional processing; however, changes in the LPP elicited by emotional faces have not been assessed across a wide age range in childhood and young adulthood. We used an emotional face matching task to examine behavior and event-related potentials (ERPs) in 33 youth aged 7-19 years old. Younger children were slower when performing the matching task. The LPP elicited by emotional faces but not control stimuli (geometric shapes) decreased with age; by contrast, an earlier ERP (the P1) decreased with age for both faces and shapes, suggesting increased efficiency of early visual processing. Results indicate age-related attenuation in emotional processing that may stem from greater efficiency and regulatory control when performing a socio-emotional task.