Emotion and cognition interactions in PTSD: a review of neurocognitive and neuroimaging studies

Restless 'rest': intrinsic sensory hyperactivity and disinhibition in post-traumatic stress disorder

Post-traumatic stress disorder is characterized by exaggerated threat response, and theoretical accounts to date have focused on impaired threat processing and dysregulated prefrontal-cortex-amygdala circuitry. Nevertheless, evidence is accruing for broad, threat-neutral sensory hyperactivity in post-traumatic stress disorder. As low-level, sensory processing impacts higher-order operations, such sensory anomalies can contribute to widespread dysfunctions, presenting an additional aetiological mechanism for post-traumatic stress disorder. To elucidate a sensory pathology of post-traumatic stress disorder, we examined intrinsic visual cortical activity (based on posterior alpha oscillations) and bottom-up sensory-driven causal connectivity (Granger causality in the alpha band) during a resting state (eyes open) and a passive, serial picture viewing state. Compared to patients with generalized anxiety disorder (n = 24) and healthy control subjects (n = 20), patients with post-traumatic stress disorder (n = 25) demonstrated intrinsic sensory hyperactivity (suppressed posterior alpha power, source-localized to the visual cortex-cuneus and precuneus) and bottom-up inhibition deficits (reduced posterior→frontal Granger causality). As sensory input increased from resting to passive picture viewing, patients with post-traumatic stress disorder failed to demonstrate alpha adaptation, highlighting a rigid, set mode of sensory hyperactivity. Interestingly, patients with post-traumatic stress disorder also showed heightened frontal processing (augmented frontal gamma power, source-localized to the superior frontal gyrus and dorsal cingulate cortex), accompanied by attenuated top-down inhibition (reduced frontal→posterior causality). Importantly, not only did suppressed alpha power and bottom-up causality correlate with heightened frontal gamma power, they also correlated with increased severity of sensory and executive dysfunctions (i.e. hypervigilance and impulse control deficits, respectively). Therefore, sensory aberrations help construct a vicious cycle in post-traumatic stress disorder that is in action even at rest, implicating dysregulated triangular sensory-prefrontal-cortex-amygdala circuitry: intrinsic sensory hyperactivity and disinhibition give rise to frontal overload and disrupt executive control, fuelling and perpetuating post-traumatic stress disorder symptoms. Absent in generalized anxiety disorder, these aberrations highlight a unique sensory pathology of post-traumatic stress disorder (ruling out effects merely reflecting anxious hyperarousal), motivating new interventions targeting sensory processing and the sensory brain in these patients.

Whole-genome DNA methylation status associated with clinical PTSD measures of OIF/OEF veterans

Emerging knowledge suggests that post-traumatic stress disorder (PTSD) pathophysiology is linked to the patients' epigenetic changes, but comprehensive studies examining genome-wide methylation have not been performed. In this study, we examined genome-wide DNA methylation in peripheral whole blood in combat veterans with and without PTSD to ascertain differentially methylated probes. Discovery was initially made in a training sample comprising 48 male Operation Enduring Freedom (OEF)/Operation Iraqi Freedom (OIF) veterans with PTSD and 51 age/ethnicity/gender-matched combat-exposed PTSD-negative controls. Agilent whole-genome array detected ~5600 differentially methylated CpG islands (CpGI) annotated to ~2800 differently methylated genes (DMGs). The majority (84.5%) of these CpGIs were hypermethylated in the PTSD cases. Functional analysis was performed using the DMGs encoding the promoter-bound CpGIs to identify networks related to PTSD. The identified networks were further validated by an independent test set comprising 31 PTSD+/29 PTSD- veterans. Targeted bisulfite sequencing was also used to confirm the methylation status of 20 DMGs shown to be highly perturbed in the training set. To improve the statistical power and mitigate the assay bias and batch effects, a union set combining both training and test set was assayed using a different platform from Illumina. The pathways curated from this analysis confirmed 65% of the pool of pathways mined from training and test sets. The results highlight the importance of assay methodology and use of independent samples for discovery and validation of differentially methylated genes mined from whole blood. Nonetheless, the current study demonstrates that several important epigenetically altered networks may distinguish combat-exposed veterans with and without PTSD.

Associations Between Trauma Type, Timing, and Accumulation on Current Coping Behaviors in Adolescents: Results from a Large, Population-based Sample

The development of adolescents' coping in response to stress is critical for adaptive functioning; these coping strategies may be shaped by numerous environmental factors during childhood, including experiences such as exposure to trauma. Childhood trauma has been shown to undermine contemporaneous coping, but how does a history of exposure to trauma and the characteristics of that trauma (type, timing, and accumulation) relate to current coping among adolescents? We addressed this question using a nationally-representative sample of 9427 adolescents (ages 13-18; 48.9% female; 66% White). Adolescents reported on their lifetime exposure to 18 different traumas, including witnessing or experiencing interpersonal violence, accidents, disasters, and violent or accidental loss of loved ones, as well as their current use of coping behaviors when under stress (problem-focused, positive emotion-focused, and negative emotion-focused coping strategies). The study's results highlight that exposure to nearly all forms of trauma was unrelated to problem-focused and positive emotion-focused coping behaviors, but strongly associated with increased negative emotion-focused coping. Use of each coping style did not vary with age at first exposure to trauma, but increased with the number of lifetime traumatic events experienced. The findings suggest that the extent of prior exposure to trauma, including variations across type and timing, may be related to a particular form of coping that has been linked to increased risk for mental health problems. Study results highlight coping strategies as a potential target for prevention and treatment efforts, and indicate a need to better understand the malleability and trajectory of coping responses to stress for promoting healthy youth development.

PTSD and cognitive symptoms relate to inhibition-related prefrontal activation and functional connectivity

BACKGROUND

Posttraumatic stress disorder (PTSD) is associated with reduced executive functioning and verbal memory performance, as well as abnormal task-specific activity in prefrontal cortex (PFC) and anterior cingulate cortices (ACC). The current study examined how PTSD symptoms and neuropsychological performance in combat veterans relates to (1) medial PFC and ACC activity during cognitive inhibition, and (2) task-independent PFC functional connectivity.

METHODS

Thirty-nine male combat veterans with varying levels of PTSD symptoms completed the multisource interference task during functional magnetic resonance imaging. Robust regression analyses were used to assess relationships between percent signal change (PSC: incongruent-congruent) and both PTSD severity and neuropsychological performance. Analyses were conducted voxel-wise and for PSC extracted from medial PFC and ACC regions of interest. Resting-state scans were available for veterans with PTSD. Regions identified via task-based analyses were used as seeds for resting-state connectivity analyses.

RESULTS

Worse PTSD severity and neuropsychological performance related to less medial PFC and rostral ACC activity during interference processing, driven partly by increased activation to congruent trials. Worse PTSD severity related to reduced functional connectivity between these regions and bilateral, lateral PFC (Brodmann area 10). Worse neuropsychological performance related to reduced functional connectivity between these regions and the inferior frontal gyrus.

CONCLUSIONS

PTSD and associated neuropsychological deficits may result from difficulties regulating medial PFC regions associated with "default mode," or self-referential processing. Further clarification of functional coupling deficits between default mode and executive control networks in PTSD may enhance understanding of neuropsychological and emotional symptoms and provide novel treatment targets.

Improving cognitive control in adolescents with post-traumatic stress disorder (PTSD)

The adverse impact of posttraumatic stress disorder (PTSD) on the developing mind in adolescence can extend well into adulthood. The developmental malleability of cognitive control capacity in this age group, however, may hold particular promise for cognitive training interventions. The present study investigated the effects of affective working memory (aWMT) compared to placebo-training on cognitive and affective functioning in adolescents with PTSD. 30 treatment-seeking adolescents trained for 20 days on either an affective dual n-back task (aWMT; n = 15) or a feature match task (placebo; n = 15). The aWMT group showed greater pre-to post-training increases in cognitive control as measured by the GoNogo task as well as improvements in symptoms of PTSD and increased use of adaptive emotion regulation strategies. These preliminary findings are promising given the potential for free and easy dissemination of the aWMT in schools and online.

Neuropsychological measurement of inhibitory control in posttraumatic stress disorder: An exploratory antisaccade paradigm

OBJECTIVE

The aim of the study was to uncover inhibitory control dynamics and assess antisaccade eye-tracking tasks for relevance in a veteran posttraumatic stress disorder (PTSD) population.

METHOD

Participants were 36 veterans enrolled at the Washington DC Veterans Affairs Medical Center. The groups (PTSD diagnosed vs. controls) did not vary between age and sex. Participants completed a testing battery of clinical neuropsychological measures and two different eye-tracking conditions, one that utilized face stimuli and one with standard shape stimuli, which test pro- (PS) and antisaccade (AS) eye movements.

RESULTS

Veterans with PTSD, t(33) = 2.2, p = .04, took longer to respond than controls in the standard condition AS. In the face condition, a group by task interaction was seen with increased latency for PTSD veterans in the AS versus PS task, F(3, 33) = 3.99, p = .05, with a large overall effect (Hedges' g = 1.18, p < .001) compared to controls. After controlling for depression, analyses suggested that only the face condition AS task significantly predicted dimensions of PTSD symptomology measured by the Clinician Administered PTSD Scale (CAPS) for veterans with PTSD.

CONCLUSIONS

This is the first study to extend AS findings to PTSD and suggests a specific capability to measure inhibitory control using eye-tracking technology. We discuss the notion that reduced capacity to regulate facial-related processing affects cognitive and attentional control networks of PTSD patients, potentially representing a core cognitive deficit.

Tai Chi for Posttraumatic Stress Disorder and Chronic Musculoskeletal Pain: A Pilot Study

PURPOSE

Explore the feasibility of a Tai Chi intervention to improve musculoskeletal pain, emotion, cognition, and physical function in individuals with posttraumatic stress disorder.

DESIGN

Two-phase, one-arm quasi-experimental design.

METHOD

Phase 1: 11 participants completed one Tai Chi session, feasibility questionnaire, and were offered participation in Phase 2, a 12-week Tai Chi intervention. Ten participants participated in Phase 2. Pain intensity, interference, physical function scales, an emotional battery, and cognition tests were used for pre- and postintervention outcome measures. Paired t tests and thematic analysis were used for analysis.

FINDINGS

In Phase 1, most felt Tai Chi would benefit health (90.9%) and expressed interest in continuing Tai Chi (6.73 out of 7). Phase 2 results showed improvement in fear-affect (raw t = -2.64, p = .03; age adjusted t = -2.90, p = .02), fear-somatic arousal (raw t = -2.53, p = .035), List Sorting Working Memory (raw t = 2.62, p = .031; age adjusted t = 2.96, p = .018), 6-Minute Walk Test ( t = 3.541, p = .008), and current level of Pain Intensity ( t = -4.00, p = .004).

CONCLUSIONS

Tai Chi is an acceptable, holistic treatment to individuals with musculoskeletal pain and posttraumatic stress disorder. It may reduce pain, improve emotion, memory, and physical function.

Compromised hippocampus-striatum pathway as a potential imaging biomarker of mild-traumatic brain injury and posttraumatic stress disorder

OBJECTIVES

Military service members risk acquiring posttraumatic stress disorder (PTSD) and mild-traumatic brain injury (mTBI), with high comorbidity. Owing to overlapping symptomatology in chronic mTBI or postconcussion syndrome (PCS) and PTSD, it is difficult to assess the etiology of a patient's condition without objective measures. Using resting-state functional MRI in a novel framework, we tested the hypothesis that their neural signatures are characterized by functionally hyperconnected brain regions which are less variable over time. Additionally, we predicted that such connectivities possessed the highest ability in predicting the diagnostic membership of a novel subject (top-predictors) in addition to being statistically significant.

METHODS

U.S. Army Soldiers (N = 87) with PTSD and comorbid PCS + PTSD were recruited along with combat controls. Static and dynamic functional connectivities were evaluated. Group differences were obtained in accordance with our hypothesis. Machine learning classification (MLC) was employed to determine top predictors.

RESULTS

From whole-brain connectivity, we identified the hippocampus-striatum connectivity to be significantly altered in accordance with our hypothesis. Diffusion tractography revealed compromised white-matter integrity between aforementioned regions only in the PCS + PTSD group, suggesting a structural etiology for the PCS + PTSD group rather than being an extreme subset of PTSD. Employing MLC, connectivities provided worst-case accuracy of 84% (9% more than psychological measures). Additionally, the hippocampus-striatum connectivities were found to be top predictors and thus a potential biomarker of PTSD/mTBI.

CONCLUSIONS

PTSD/mTBI are associated with hippocampal-striatal hyperconnectivity from which it is difficult to disengage, leading to a habit-like response toward episodic traumatic memories, which fits well with behavioral manifestations of combat-related PTSD/mTBI. Hum Brain Mapp 38:2843-2864, 2017. © 2017 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

Death scene investigation: parents’ experiences

This article presents the results of a study undertaken to evaluate how parents experience voluntary Death Scene Investigation (DSI) in their homes. In total, 35 parents were interviewed using semi-structured qualitative interview guidelines developed for this project. These focused on the parents’: 1) appraisal of information provided prior to the DSI and motivation for participating in the study, 2) experience of, and reactions to the DSI, and 3) thoughts and reactions following the DSI. The evaluation shows that performing a DSI is an important part of providing good care for bereaved parents following Sudden Infant Death Syndrome. If such an investigation is undertaken by professionals with extensive professional knowledge and experience in meeting bereaved parents in an empathic and caring manner, it can be a positive experience for parents, and help support them in coping with the painful death of their infant.

Performance in a blocked versus randomized emotional Stroop task in an aged, early traumatized group with and without posttraumatic stress symptoms

BACKGROUND AND OBJECTIVES

Attentional biases (AB) for trauma-related stimuli have been examined in many studies assessing different trauma samples. In emotional Stroop tasks (EST), blocked and single-trial formats are used almost interchangeably in clinical research. There is reason to believe that different designs yield different results and assess different processes, which, however, has been hardly examined in studies. Furthermore, there is a dearth of information about AB in older trauma survivors with posttraumatic stress symptoms.

METHODS

Older adults with (n = 20) and without PTSD symptoms (n = 26) as well as non-traumatized controls (n = 21) completed an EST, in which words were presented both blocked and randomized.

RESULTS

Analyses revealed that individuals with PTSD symptoms showed AB for trauma- and depression-related words; however, mode of administration did not significantly influence reaction times.

LIMITATIONS

The emotional Stroop task cannot disentangle the underlying cognitive mechanism (i.e., facilitation, interference, avoidance).

CONCLUSIONS

PTSD symptoms in older trauma survivors are associated with AB. Overall, participants with PTSD symptoms did not show greater impairment of cognitive control in comparison to both control groups. Results also illustrate that methodological differences between task versions need to be considered more thoroughly.

Functional brain alterations during self-reference processing in adolescents with sexual abuse-related post-traumatic stress disorder: A preliminary report

We proposed to explore the functional brain changes during a self-reference processing (SRP) task in adolescents with sexual abuse-related post-traumatic stress disorder (N = 10), compared with healthy adolescents (N = 10). While patients showed no behavioral disturbances in (SRP), they exhibited changes in activity and connectivity in regions involved in emotional regulation (amygdala and dorsal prefrontal cortex) and semantic memory (temporal and ventrolateral prefrontal regions). These preliminary results suggest that these alterations may have an effect on self-esteem which may contribute to a possible retention and impairment of symptoms in adulthood.

Dissociation between working memory performance and proactive interference control in post-traumatic stress disorder

Deficits in working memory (WM) and cognitive control processes have been reported in post-traumatic stress disorder (PTSD), in addition to clinical symptoms such as hypervigilance, re-experiencing, and avoidance of trauma reminders. Given the uncontrollable nature of intrusive memories, an important question is whether PTSD is associated with altered control of interference in WM. Some studies also suggest that episodic memory shows a material-specific dissociation in PTSD, with greater impairments in verbal memory and relative sparing of nonverbal memory. It is unclear whether this dissociation applies to WM, as no studies have used identical task parameters across material. Here we tested 29 combat Veterans with PTSD and 29 age-matched control Veterans on a recent probes WM task with words and visual patterns in separate blocks. Participants studied four-item sets, followed by a probe stimulus that had been presented in the previous set (recent probe) or not (nonrecent probe). Participants with PTSD made more errors than controls, and this decrement was similar for verbal and visual stimuli. Proactive interference from items recently presented, but no longer relevant, was not significantly different in the PTSD group and showed no relationship to re-experiencing symptom severity. These results demonstrate that PTSD is not reliably associated with increased intrusions of irrelevant representations into WM when non-emotional stimuli are used. Future studies that use trauma-related material may provide insight into the flashbacks and intrusive thoughts that plague those with PTSD.

A meta-analysis of the relationship between symptom severity of Posttraumatic Stress Disorder and executive function

INTRODUCTION

Some studies of Posttraumatic Stress Disorder (PTSD) find executive dysfunction, whereas others do not. We meta-analytically examined the association between executive function and PTSD and used meta-regression to examine the potential moderating effect of PTSD severity on executive function.

METHODS

We conducted a meta-analysis according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We identified published peer-reviewed articles containing measures of executive function and PTSD symptom severity in subjects with PTSD compared to trauma-unexposed controls or trauma-exposed controls without PTSD, or both. We calculated an effect size for each study containing at least one measure of executive function and PTSD symptom severity.

RESULTS

PTSD subjects for whom the Clinician-Administered PTSD Scale (CAPS) score was available had worse executive function compared to both trauma-unexposed controls (g = 0.464, p < .001) and to trauma-exposed controls without PTSD (g = 0.414, p = .001), as did PTSD subjects for whom the Mississippi Scale for Combat-Related PTSD (M-PTSD) score was available (g = 0.390, p < .001). Neither CAPS nor M-PTSD scores significantly moderated the effect size of executive function.

CONCLUSIONS

PTSD is associated with executive dysfunction, but this association was not moderated by PTSD symptom severity, suggesting that once PTSD occurs, executive dysfunction may occur regardless of PTSD severity.

Defining biotypes for depression and anxiety based on large-scale circuit dysfunction: a theoretical review of the evidence and future directions for clinical translation

Complex emotional, cognitive and self-reflective functions rely on the activation and connectivity of large-scale neural circuits. These circuits offer a relevant scale of focus for conceptualizing a taxonomy for depression and anxiety based on specific profiles (or biotypes) of neural circuit dysfunction. Here, the theoretical review first outlines the current consensus as to what constitutes the organization of large-scale circuits in the human brain identified using parcellation and meta-analysis. The focus is on neural circuits implicated in resting reflection (default mode), detection of "salience," affective processing ("threat" and "reward"), "attention," and "cognitive control." Next, the current evidence regarding which type of dysfunctions in these circuits characterize depression and anxiety disorders is reviewed, with an emphasis on published meta-analyses and reviews of circuit dysfunctions that have been identified in at least two well-powered case:control studies. Grounded in the review of these topics, a conceptual framework is proposed for considering neural circuit-defined "biotypes." In this framework, biotypes are defined by profiles of extent of dysfunction on each large-scale circuit. The clinical implications of a biotype approach for guiding classification and treatment of depression and anxiety is considered. Future research directions will develop the validity and clinical utility of a neural circuit biotype model that spans diagnostic categories and helps to translate neuroscience into clinical practice in the real world.

Does trauma event type matter in the assessment of traumatic load?

Background: The likelihood of developing Posttraumatic Stress Disorder (PTSD) depends on the interaction of individual risk factors and cumulative traumatic experiences. Hence, the identification of individual susceptibility factors warrants precise quantification of trauma exposure. Previous research indicated that some traumatic events may have more severe influences on mental health than others; thus, the assessment of traumatic load may be improved by weighting event list items rather than calculating the simple sum score. Objective: We compared two statistical methods, Random Forests using Conditional Interference (RF-CI) and Least Absolute Shrinkage and Selection Operator (LASSO), based on their ability to rank traumatic experiences according to their importance for predicting lifetime PTSD. Methods: Statistical models were initially fitted in a sample of N₁ = 441 survivors of the Northern Ugandan rebel war. The ability to correctly predict lifetime PTSD was then tested in an independent sample of N₂ = 211, and subsequently compared with predictions by the simple sum score of different traumatic event types experienced. Results: Results indicate that RF-CI and LASSO allow for a ranking of traumatic events according to their predictive importance for lifetime PTSD. Moreover, RF-CI showed slightly better prediction accuracy than the simple sum score, followed by LASSO when comparing prediction results in the validation sample. Conclusion: Given the expense in time and calculation effort by RF-CI and LASSO, and the relatively low increase in prediction accuracy by RF-CI, we recommend using the simple sum score to measure the environmental factor traumatic load, e.g., in analyses of gene × environment interactions.

Binding neutral information to emotional contexts: Brain dynamics of long-term recognition memory

There is abundant evidence in memory research that emotional stimuli are better remembered than neutral stimuli. However, effects of an emotionally charged context on memory for associated neutral elements is also important, particularly in trauma and stress-related disorders, where strong memories are often activated by neutral cues due to their emotional associations. In the present study, we used event-related potentials (ERPs) to investigate long-term recognition memory (1-week delay) for neutral objects that had been paired with emotionally arousing or neutral scenes during encoding. Context effects were clearly evident in the ERPs: An early frontal ERP old/new difference (300-500 ms) was enhanced for objects encoded in unpleasant compared to pleasant and neutral contexts; and a late central-parietal old/new difference (400-700 ms) was observed for objects paired with both pleasant and unpleasant contexts but not for items paired with neutral backgrounds. Interestingly, objects encoded in emotional contexts (and novel objects) also prompted an enhanced frontal early (180-220 ms) positivity compared to objects paired with neutral scenes indicating early perceptual significance. The present data suggest that emotional--particularly unpleasant--backgrounds strengthen memory for items encountered within these contexts and engage automatic and explicit recognition processes. These results could help in understanding binding mechanisms involved in the activation of trauma-related memories by neutral cues.

Differences in frontal and limbic brain activation in a small sample of monozygotic twin pairs discordant for severe stressful life events

Monozygotic twin pairs provide a valuable opportunity to control for genetic and shared environmental influences while studying the effects of nonshared environmental influences. The question we address with this design is whether monozygotic twins selected for discordance in exposure to severe stressful life events during development (before age 18) demonstrate differences in brain activation during performance of an emotional word-face Stroop task. In this study, functional magnetic resonance imaging was used to assess brain activation in eighteen young adult twins who were discordant in exposure to severe stress such that one twin had two or more severe events compared to their control co-twin who had no severe events. Twins who experienced higher levels of stress during development, compared to their control co-twins with lower stress, exhibited significant clusters of greater activation in the ventrolateral and medial prefrontal cortex, basal ganglia, and limbic regions. The control co-twins showed only the more typical recruitment of frontoparietal regions thought to be important for executive control of attention and maintenance of task goals. Behavioral performance was not significantly different between twins within pairs, suggesting the twins with stress recruited additional neural resources associated with affective processing and updating working memory when performing at the same level. This study provides a powerful glimpse at the potential effects of stress during development while accounting for shared genetic and environmental influences.

Affect and neural activity in women with PTSD during a task of emotional interference

BACKGROUND

The current study sought to determine the relationship between self-reported dimensions of affect and activation in brain regions associated with emotion regulation in PTSD during a task of non-conscious emotional processing in interpersonal trauma survivors with PTSD and healthy controls.

METHODS

Participants included 52 women diagnosed with PTSD and 18 female healthy controls. All participants completed a clinical assessment including the SCID, CAPS, and PANAS followed by a functional MRI assessment including a task of implicit emotional conflict.

RESULTS

When PTSD participants were oriented to fearful faces, negative affect (NA) was inversely related to activation in the left amygdala and positive affect (PA) was inversely related to activation in the right amygdala. When ignoring fearful faces, NA was positively associated with activation in the right parahippocampal gyrus and PA was inversely related to activation in the left hippocampus. Similar results were observed in healthy controls regarding PA. However, NA was not significantly related to any region of interest in healthy controls.

LIMITATIONS

Limitations include the homogeneity of the healthy controls with regard to racial diversity, results may only be specific to female interpersonal trauma survivors with PTSD, and neutral faces within the conflict task may be perceived as negative by clinical samples.

CONCLUSIONS

Persistent, increased NA may represent a proxy for disruptions in emotional processing in interpersonal trauma survivors with PTSD. As such, clinicians may prioritize increasing emotional awareness through emotion regulation and/or distress tolerance strategies in this population.

How Veterans With Post-Traumatic Stress Disorder and Comorbid Health Conditions Utilize eHealth to Manage Their Health Care Needs: A Mixed-Methods Analysis

Background

Mental health conditions are prevalent among US veterans and pose a number of self-management and health care navigation challenges. Post-Traumatic Stress Disorder (PTSD) with comorbid chronic medical conditions (CMCs) is especially common, in both returning Iraq or Afghanistan and earlier war-era veterans. Patient-facing electronic health (eHealth) technology may offer innovative strategies to support these individuals’ needs.

Objective

This study was designed to identify the types of eHealth tools that veterans with PTSD and comorbid CMCs use, understand how they currently use eHealth technology to self-manage their unique health care needs, and identify new eHealth resources that veterans feel would empower them to better manage their health care.

Methods

A total of 119 veterans with PTSD and at least one CMC who have used the electronic personal health record system of the US Department of Veterans Affairs (VA) responded to a mailed survey about their chronic conditions and preferences related to the use of technology. After the survey, 2 focus groups, stratified by sex, were conducted with a subgroup of patients to explore how veterans with PTSD and comorbid CMCs use eHealth technology to support their complex health care needs. Focus groups were transcribed verbatim and analyzed using standard content analysis methods for coding textual data, guided by the “Fit between Individual, Task, and Technology” framework.

Results

Survey respondents had a mean age of 64.0 (SD 12.0) years, 85.1% (97/114) were male, 72.4% (84/116) were white, and 63.1% (70/111) had an annual household income of < US $50,000. Mean score on a measure of eHealth literacy was 27.7 (SD 9.8). Of the respondents, 44.6% (50/112) used health-related technology 1 to 3 times per month and 21.4% (24/112) used technology less than once per month. Veterans reported using technology most often to search for health information (78.9%, 90/114), communicate with providers (71.1%, 81/114), and track medications (64.9%, 74/114). Five major themes emerged that describe how eHealth technology influences veterans with PTSD and comorbid CMCs: (1) interactions with social support, (2) condition management, (3) access to and communication with providers, (4) information access, and (5) coordination of care.

Conclusions

The “Fit between Individual, Task, and Technology” model provided a useful framework to examine the clinical tasks that arose for veterans and their resourceful adoption of eHealth tools. This study suggests that veterans who use the Web are eager to incorporate eHealth technology into their care and self-management activities. Findings illustrate a number of ways in which the VA and eHealth technology developers can refine existing applications, develop new resources, and better promote tools that address challenges experienced by veterans with PTSD and comorbid CMCs.

Convergence of prefrontal and parietal anatomical projections in a connectional hub in the striatum

Visual attentional bias forms for rewarding and punishing stimuli in the environment. While this attentional bias is adaptive in healthy situations, it is maladaptive in disorders such as drug addiction or PTSD. In both these disorders, the ability to exert control over this attentional bias is associated with drug abstinence rates or reduced PTSD symptoms, indicating the interaction of visual attention, cognitive control, and stimulus association. The inferior parietal lobule (IPL) is central to attention, while the prefrontal cortex (PFC) is critical for reward, cognitive control, and attention. Importantly, regions of the IPL and PFC commonly project to the rostral dorsal caudate (rdCaud) of the striatum. We propose an anatomical network architecture in which IPL projections converge with PFC projections in a connectional hub in the rdCaud, providing an anatomical substrate for the interaction of these projections and their competitive influence on striatal processing. To investigate this, we mapped the dense projections from the caudal IPL and prefrontal (dlPFC, vlPFC, OFC, dACC, and dmPFC) regions that project to the medial rdCaud with anatomical tract-tracing tracer injections in monkeys. These inputs converge in a precise site in the medial rdCaud, rostral to the anterior commissure. Small retrograde tracer injections confirmed these inputs to the medial rdCaud and showed that a proximal ventral striatal location has a very different pattern of cortical inputs. We next used human resting-state functional connectivity MRI (fcMRI) to examine whether a striatal hub exists in the human medial rdCaud. Seed regions in the human medial rdCaud revealed cortical correlation maps similar to the monkey retrograde injection results. A subsequent analysis of these correlated cortical regions showed that their peak correlation within the striatum is in the medial rdCaud, indicating that this is a connectional hub. In contrast, this peak striatal correlation was not found in the ventral striatal location, suggesting that this site is not a connectional hub of cortical regions. Taken together, this work uses the precision of monkey anatomy to identify a connectional hub of IPL and PFC projections in the medial rdCaud. It also translates this anatomical precision to humans, demonstrating that, guided by anatomy, connectional hubs can be identified in humans with fcMRI. These connectional hubs provide more specific treatment targets for drug addiction, PTSD, and other neurological and psychiatric disorders involving the striatum.

The impact of cultural differences in self-representation on the neural substrates of posttraumatic stress disorder

A significant body of literature documents the neural mechanisms involved in the development and maintenance of posttraumatic stress disorder (PTSD). However, there is very little empirical work considering the influence of culture on these underlying mechanisms. Accumulating cultural neuroscience research clearly indicates that cultural differences in self-representation modulate many of the same neural processes proposed to be aberrant in PTSD. The objective of this review paper is to consider how culture may impact on the neural mechanisms underlying PTSD. We first outline five key affective and cognitive functions and their underlying neural correlates that have been identified as being disrupted in PTSD: (1) fear dysregulation; (2) attentional biases to threat; (3) emotion and autobiographical memory; (4) self-referential processing; and (5) attachment and interpersonal processing. Second, we consider prominent cultural theories and review the empirical research that has demonstrated the influence of cultural variations in self-representation on the neural substrates of these same five affective and cognitive functions. Finally, we propose a conceptual model that suggests that these five processes have major relevance to considering how culture may influence the neural processes underpinning PTSD.

Altered resting-state functional activity in posttraumatic stress disorder: A quantitative meta-analysis

Many functional neuroimaging studies have reported differential patterns of spontaneous brain activity in posttraumatic stress disorder (PTSD), but the findings are inconsistent and have not so far been quantitatively reviewed. The present study set out to determine consistent, specific regional brain activity alterations in PTSD, using the Effect Size Signed Differential Mapping technique to conduct a quantitative meta-analysis of resting-state functional neuroimaging studies of PTSD that used either a non-trauma (NTC) or a trauma-exposed (TEC) comparison control group. Fifteen functional neuroimaging studies were included, comparing 286 PTSDs, 203 TECs and 155 NTCs. Compared with NTC, PTSD patients showed hyperactivity in the right anterior insula and bilateral cerebellum, and hypoactivity in the dorsal medial prefrontal cortex (mPFC); compared with TEC, PTSD showed hyperactivity in the ventral mPFC. The pooled meta-analysis showed hypoactivity in the posterior insula, superior temporal, and Heschl’s gyrus in PTSD. Additionally, subgroup meta-analysis (non-medicated subjects vs. NTC) identified abnormal activation in the prefrontal-limbic system. In meta-regression analyses, mean illness duration was positively associated with activity in the right cerebellum (PTSD vs. NTC), and illness severity was negatively associated with activity in the right lingual gyrus (PTSD vs. TEC).

Severe, multimodal stress exposure induces PTSD-like characteristics in a mouse model of single prolonged stress

Appropriate animal models of posttraumatic stress disorder (PTSD) are needed because human studies remain limited in their ability to probe the underlying neurobiology of PTSD. Although the single prolonged stress (SPS) model is an established rat model of PTSD, the development of a similarly-validated mouse model emphasizes the benefits and cross-species utility of rodent PTSD models and offers unique methodological advantages to that of the rat. Therefore, the aims of this study were to develop and describe a SPS model for mice and to provide data that support current mechanisms relevant to PTSD. The mouse single prolonged stress (mSPS) paradigm, involves exposing C57Bl/6 mice to a series of severe, multimodal stressors, including 2h restraint, 10 min group forced swim, exposure to soiled rat bedding scent, and exposure to ether until unconsciousness. Following a 7-day undisturbed period, mice were tested for cue-induced fear behavior, effects of paroxetine on cue-induced fear behavior, extinction retention of a previously extinguished fear memory, dexamethasone suppression of corticosterone (CORT) response, dorsal hippocampal glucocorticoid receptor protein and mRNA expression, and prefrontal cortex glutamate levels. Exposure to mSPS enhanced cue-induced fear, which was attenuated by oral paroxetine treatment. mSPS also disrupted extinction retention, enhanced suppression of stress-induced CORT response, increased mRNA expression of dorsal hippocampal glucocorticoid receptors and decreased prefrontal cortex glutamate levels. These data suggest that the mSPS model is a translationally-relevant model for future PTSD research with strong face, construct, and predictive validity. In summary, mSPS models characteristics relevant to PTSD and this severe, multimodal stress modifies fear learning in mice that coincides with changes in the hypothalamo-pituitary-adrenal (HPA) axis, brain glucocorticoid systems, and glutamatergic signaling in the prefrontal cortex.

Genetic Moderation of Stress Effects on Corticolimbic Circuitry

Stress exposure is associated with individual differences in corticolimbic structure and function that often mirror patterns observed in psychopathology. Gene x environment interaction research suggests that genetic variation moderates the impact of stress on risk for psychopathology. On the basis of these findings, imaging genetics, which attempts to link variability in DNA sequence and structure to neural phenotypes, has begun to incorporate measures of the environment. This research paradigm, known as imaging gene x environment interaction (iGxE), is beginning to contribute to our understanding of the neural mechanisms through which genetic variation and stress increase psychopathology risk. Although awaiting replication, evidence suggests that genetic variation within the canonical neuroendocrine stress hormone system, the hypothalamic-pituitary-adrenal axis, contributes to variability in stress-related corticolimbic structure and function, which, in turn, confers risk for psychopathology. For iGxE research to reach its full potential it will have to address many challenges, of which we discuss: (i) small effects, (ii) measuring the environment and neural phenotypes, (iii) the absence of detailed mechanisms, and (iv) incorporating development. By actively addressing these challenges, iGxE research is poised to help identify the neural mechanisms underlying genetic and environmental associations with psychopathology.

Soldiers With Posttraumatic Stress Disorder See a World Full of Threat: Magnetoencephalography Reveals Enhanced Tuning to Combat-Related Cues

BACKGROUND

Posttraumatic stress disorder (PTSD) is linked to elevated arousal and alterations in cognitive processes. Yet, whether a traumatic experience is linked to neural and behavioral differences in selective attentional tuning to traumatic stimuli is not known. The present study examined selective awareness of threat stimuli and underlying temporal-spatial patterns of brain activation associated with PTSD.

METHODS

Participants were 44 soldiers from the Canadian Armed Forces, 22 with PTSD and 22 without. All completed neuropsychological tests and clinical assessments. Magnetoencephalography data were collected while participants identified two targets in a rapidly presented stream of words. The first target was a number and the second target was either a combat-related or neutral word. The difference in accuracy for combat-related versus neutral words was used as a measure of attentional bias.

RESULTS

All soldiers showed a bias for combat-related words. This bias was enhanced in the PTSD group, and behavioral differences were associated with distinct patterns of brain activity. At early latencies, non-PTSD soldiers showed activation of midline frontal regions associated with fear regulation (90-340 ms after the second target presentation), whereas those with PTSD showed greater visual cortex activation linked to enhanced visual processing of trauma stimuli (200-300 ms).

CONCLUSIONS

These findings suggest that attentional biases in PTSD are linked to deficits in very rapid regulatory activation observed in healthy control subjects. Thus, sufferers with PTSD may literally see a world more populated by traumatic cues, contributing to a positive feedback loop that perpetuates the effects of trauma.

Characterising intra- and inter-intrinsic network synchrony in combat-related post-traumatic stress disorder

Soldiers with post-traumatic stress disorder (PTSD) exhibit elevated gamma-band synchrony in left fronto-temporal cortex, and connectivity measures in these regions correlate with comorbidities and PTSD severity, which suggests increased gamma synchrony is related to symptomology. However, little is known about the role of intrinsic, phase-synchronised networks in the disorder. Using magnetoencephalography (MEG), we characterised spectral connectivity in the default-mode, salience, visual, and attention networks during resting-state in a PTSD population and a trauma-exposed control group. Intrinsic network connectivity was examined in canonical frequency bands. We observed increased inter-network synchronisation in the PTSD group compared with controls in the gamma (30-80 Hz) and high-gamma range (80-150 Hz). Analyses of connectivity and symptomology revealed that PTSD severity was positively associated with beta synchrony in the ventral-attention-to-salience networks, and gamma synchrony within the salience network, but also negatively correlated with beta synchrony within the visual network. These novel results show that frequency-specific, network-level atypicalities may reflect trauma-related alterations of ongoing functional connectivity, and correlations of beta synchrony in attentional-to-salience and visual networks with PTSD severity suggest complicated network interactions mediate symptoms. These results contribute to accumulating evidence that PTSD is a complicated network-based disorder expressed as altered neural interactions.

Acute posttraumatic stress symptoms but not generalized anxiety symptoms are associated with severity of exposure to war trauma: A study of civilians under fire

Posttraumatic stress (PTSS) and generalized anxiety symptoms (GAS) may ensue following trauma. While they are now thought to represent different psychopathological entities, it is not clear whether both GAS and PTSS show a dose-response to trauma exposure. The current study aimed to address this gap in knowledge and to investigate the moderating role of subjects' demographics in the exposure-outcome associations. The sample included 249 civilian adults, assessed during the 2014 Israel-Gaza military conflict. The survey probed demographic information, trauma exposure, and symptoms. PTSS but not GAS was associated with exposure severity. Women were at higher risk for both PTSS and GAS than men. In addition, several demographic variables were only associated with PTSS levels. PTSS dose-response effect was moderated by education. These findings are in line with emerging neurobiological and cognitive research, suggesting that although PTSS and GAS have shared risk factors they represent two different psychopathological entities. Clinical and theoretical implications are discussed.

Decreased somatosensory activity to non-threatening touch in combat veterans with posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is a severe psychiatric disorder prevalent in combat veterans. Previous neuroimaging studies have demonstrated that patients with PTSD exhibit abnormal responses to non-threatening visual and auditory stimuli, but have not examined somatosensory processing. Thirty male combat veterans, 16 with PTSD and 14 without, completed a tactile stimulation task during a 306-sensor magnetoencephalography (MEG) recording. Significant oscillatory neural responses were imaged using a beamforming approach. Participants also completed clinical assessments of PTSD, combat exposure, and depression. We found that veterans with PTSD exhibited significantly reduced activity during early (0-125 ms) tactile processing compared with combat controls. Specifically, veterans with PTSD had weaker activity in the left postcentral gyrus, left superior parietal area, and right prefrontal cortex in response to nonthreatening tactile stimulation relative to veterans without PTSD. The magnitude of activity in these brain regions was inversely correlated with symptom severity, indicating that those with the most severe PTSD had the most abnormal neural responses. Our findings are consistent with a resource allocation view of perceptual processing in PTSD, which directs attention away from nonthreatening sensory information.

Fear and the Defense Cascade: Clinical Implications and Management

Evolution has endowed all humans with a continuum of innate, hard-wired, automatically activated defense behaviors, termed the defense cascade. Arousal is the first step in activating the defense cascade; flight or fight is an active defense response for dealing with threat; freezing is a flight-or-fight response put on hold; tonic immobility and collapsed immobility are responses of last resort to inescapable threat, when active defense responses have failed; and quiescent immobility is a state of quiescence that promotes rest and healing. Each of these defense reactions has a distinctive neural pattern mediated by a common neural pathway: activation and inhibition of particular functional components in the amygdala, hypothalamus, periaqueductal gray, and sympathetic and vagal nuclei. Unlike animals, which generally are able to restore their standard mode of functioning once the danger is past, humans often are not, and they may find themselves locked into the same, recurring pattern of response tied in with the original danger or trauma. Understanding the signature patterns of these innate responses--the particular components that combine to yield the given pattern of defense-is important for developing treatment interventions. Effective interventions aim to activate or deactivate one or more components of the signature neural pattern, thereby producing a shift in the neural pattern and, with it, in mind-body state. The process of shifting the neural pattern is the necessary first step in unlocking the patient's trauma response, in breaking the cycle of suffering, and in helping the patient to adapt to, and overcome, past trauma.

Reward functioning in PTSD: a systematic review exploring the mechanisms underlying anhedonia

Post-traumatic stress disorder (PTSD) is a debilitating psychiatric disorder. An important diagnostic feature of PTSD is anhedonia, which may result from deficits in reward functioning. This has however never been studied systematically in PTSD. To determine if PTSD is associated with reward impairments, we conducted a systematic review of studies in which reward functioning was compared between PTSD patients and healthy control participants, or investigated in relation to PTSD symptom severity. A total of 29 studies were included, covering reward anticipation and approach ('wanting'), and hedonic responses to reward ('liking'). Overall, results were mixed, although decreased reward anticipation and approach and reduced hedonic responses were repeatedly observed in PTSD patients compared to healthy controls. Decreased reward functioning was seen more often in female than in male PTSD samples and most often in response to social positive stimuli. Though more research is needed, these findings are a first step in understanding the possible mechanisms underlying anhedonia in PTSD.

Neural circuits in anxiety and stress disorders: a focused review

Anxiety and stress disorders are among the most prevalent neuropsychiatric disorders. In recent years, multiple studies have examined brain regions and networks involved in anxiety symptomatology in an effort to better understand the mechanisms involved and to develop more effective treatments. However, much remains unknown regarding the specific abnormalities and interactions between networks of regions underlying anxiety disorder presentations. We examined recent neuroimaging literature that aims to identify neural mechanisms underlying anxiety, searching for patterns of neural dysfunction that might be specific to different anxiety disorder categories. Across different anxiety and stress disorders, patterns of hyperactivation in emotion-generating regions and hypoactivation in prefrontal/regulatory regions are common in the literature. Interestingly, evidence of differential patterns is also emerging, such that within a spectrum of disorders ranging from more fear-based to more anxiety-based, greater involvement of emotion-generating regions is reported in panic disorder and specific phobia, and greater involvement of prefrontal regions is reported in generalized anxiety disorder and posttraumatic stress disorder. We summarize the pertinent literature and suggest areas for continued investigation.

Preclinical perspectives on posttraumatic stress disorder criteria in DSM-5

Posttraumatic stress disorder (PTSD) now sits within the newly created "Trauma- and Stressor-Related Disorders" section of the Diagnostic and Statistical Manual of Mental Disorders (fifth edition; DSM-5). Through the refinement and expansion of diagnostic criteria, the DSM-5 version better clarifies the broad and pervasive effects of trauma on functioning, as well as the impact of development on trauma reactions. Aggressive and dissociative symptoms are more thoroughly characterized, reflecting increasing evidence that reactions to trauma often reach beyond the domains of fear and anxiety (these latter domains were emphasized in DSM-IV). These revised criteria are supported by decades of preclinical and clinical research quantifying traumatic stress-induced changes in neurobiological and behavioral function. Several features of the DSM-5 PTSD criteria are similarly and consistently represented in preclinical animal models and humans following exposure to extreme stress. In rodent models, for example, increases in anxiety-like, helplessness, or aggressive behavior, along with disruptions in circadian/neurovegetative function, are typically induced by severe, inescapable, and uncontrollable stress. These abnormalities are prominent features of PTSD and can help us in understanding the pathophysiology of this and other stress-associated psychiatric disorders. In this article we examine some of the changes to the diagnostic criteria of PTSD in the context of trauma-related neurobiological dysfunction, and discuss implications for how preclinical data can be useful in current and future clinical conceptualizations of trauma and trauma-related psychiatric disorders.

[Trauma and stressor-related disorders: diagnostic conceptualization in DSM-5]

The Diagnostic and Statistical Manual of Mental Disorders 5 (DSM-5) includes a distinct diagnostic group of trauma and stressor-related disorders that has been set apart from anxiety disorders. From a perspective of adult psychiatry this new disorder category includes posttraumatic stress disorder (PTSD), acute stress disorder (ASD), and adjustment disorders. The PTSD is based on narrower trauma criteria that focus on acute life-threatening situations, serious injury, or sexual violence by way of direct confrontation, witnessing or indirect confrontation. Indirect confrontation, however, is reserved only for violent or accidental events that occurred to close family members or friends. The former A2 criterion of an intense emotional reaction to trauma has been removed. A deliberately broad approach to clinical PTSD phenomenology has created an empirically driven new cluster of persistent negative alterations in cognition and mood due to experiencing traumatic events. The ASD has been reconceptualized as an intense stress syndrome with a clear need of acute treatment during the early course after traumatic exposure. Adjustment disorders continue to emphasize maladaptive emotional and behavioral responses to unspecific, non-traumatic stressors in an intensity that is beyond social or cultural norms. Neither complex PTSD nor prolonged grief disorders have received an independent diagnostic status within DSM-5. With respect to stress-related disorders major divergences between DSM-5 and the future International Classification of Diseases 11 (ICD-11) are to be expected.

PTSD symptom severity is associated with increased recruitment of top-down attentional control in a trauma-exposed sample

Background

Recent neuroimaging work suggests that increased amygdala responses to emotional stimuli and dysfunction within regions mediating top down attentional control (dorsomedial frontal, lateral frontal and parietal cortices) may be associated with the emergence of anxiety disorders, including posttraumatic stress disorder (PTSD). This report examines amygdala responsiveness to emotional stimuli and the recruitment of top down attention systems as a function of task demands in a population of U.S. military service members who had recently returned from combat deployment in Afghanistan/Iraq. Given current interest in dimensional aspects of pathophysiology, it is worthwhile examining patients who, while not meeting full PTSD criteria, show clinically significant functional impairment.

Methods

Fifty-seven participants with sub-threshold levels of PTSD symptoms completed the affective Stroop task while undergoing fMRI. Participants with PTSD or depression at baseline were excluded.

Results

Greater PTSD symptom severity scores were associated with increased amygdala activation to emotional, particularly positive, stimuli relative to neutral stimuli. Furthermore, greater PTSD symptom severity was associated with increased superior/middle frontal cortex response during task conditions relative to passive viewing conditions. In addition, greater PTSD symptom severity scores were associated with: (i) increased activation in the dorsolateral prefrontal, lateral frontal, inferior parietal cortices and dorsomedial frontal cortex/dorsal anterior cingulate cortex (dmFC/dACC) in response to emotional relative to neutral stimuli; and (ii) increased functional connectivity during emotional trials, particularly positive trials, relative to neutral trials between the right amygdala and dmFC/dACC, left caudate/anterior insula cortex, right lentiform nucleus/caudate, bilateral inferior parietal cortex and left middle temporal cortex.

Conclusions

We suggest that these data may reflect two phenomena associated with increased PTSD symptomatology in combat-exposed, but PTSD negative, armed services members. First, these data indicate increased emotional responsiveness by: (i) the positive relationship between PTSD symptom severity and amygdala responsiveness to emotional relative to neutral stimuli; (ii) greater BOLD response as a function of PTSD symptom severity in regions implicated in emotion (striatum) and representation (occipital and temporal cortices) during emotional relative to neutral conditions; and (iii) increased connectivity between the amygdala and regions implicated in emotion (insula/caudate) and representation (middle temporal cortex) as a function of PTSD symptom severity during emotional relative to neutral trials. Second, these data indicate a greater need for the recruitment of regions implicated in top down attention as indicated by (i) greater BOLD response in superior/middle frontal gyrus as a function of PTSD symptom severity in task relative to view conditions; (ii) greater BOLD response in dmFC/dACC, lateral frontal and inferior parietal cortices as a function of PTSD symptom severity in emotional relative to neutral conditions and (iii) greater functional connectivity between the amygdala and inferior parietal cortex as a function of PTSD symptom severity during emotional relative to neutral conditions.

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Greater PTSD symptoms associated with increased amygdala activation to emotional stimuli

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PTSD symptoms associated with greater top down attention response in task and emotion conditions

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PTSD symptoms were associated with slower reaction times.

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Increased top down attention recruitment may compensate for heightened emotional responses.

Interactive Effects of Anxiety Sensitivity and Difficulties in Emotion Regulation: An Examination among Individuals in Residential Substance Use Treatment with Comorbid Posttraumatic Stress Disorder

Individuals with posttraumatic stress disorder (PTSD) exhibit deficits in cognitive and emotional processes. PTSD severity is positively associated with anxiety sensitivity (AS) and difficulties in emotion regulation, and difficulties in emotion regulation mediate the relation between AS and PTSD. However, previous research has not examined the interactive nature of these variables. Associations between PTSD, AS, and difficulties in emotion regulation were examined in patients with PTSD in a residential substance treatment program (N = 120). Conditional process analyses indicated an interactive effect of difficulties in emotion regulation and AS for predicting PTSD symptom severity. For individuals high in emotion regulation difficulties, PTSD symptom severity was high regardless of level of AS; conversely, for individuals high in AS, increased PTSD severity was observed regardless of level of emotion regulation difficulties. Results suggest directions for future research, including targeting patient specific cognitive-affective processes to enhance PTSD treatment response among substance dependent individuals.

Effect of posttraumatic stress on study time in a task measuring four component processes underlying text-level reading

PURPOSE

To investigate the effect of combat-related posttraumatic stress disorder (PTSD) on 4 components underlying text-level reading comprehension.

METHOD

A group of 17 veterans with PTSD and 17 matched control participants took part. An experimental task required participants to read and study 3-sentence paragraphs describing semantic features associated with real and unreal objects. Each paragraph was followed by true-false statements that assessed knowledge access, text memory, inference, and integration.

RESULTS

The results revealed that the PTSD group took significantly longer than the control group to study the paragraphs. Although there was no group difference in test statement accuracy, the PTSD group also took significantly longer to respond to the test statements.

CONCLUSIONS

Overall, the results provide evidence for the control theory of attention but suggest that more direct measures of task-irrelevant processing during text-level reading are needed. More important, the results begin to lay a foundation for developing not only diagnostic but also intervention strategies.

Current Emotion Research in Cognitive Neuroscience: Linking Enhancing and Impairing Effects of Emotion on Cognition

Emotions can have both enhancing and impairing effects on various cognitive processes, from lower (e.g., perceptual) to higher level (e.g., mnemonic and executive) processes. The present article discusses emerging brain imaging evidence linking these opposing effects of emotion, which points to overlapping and dissociable neural systems involving both bottom-up and top-down mechanisms. The link between the enhancing and impairing effects is also discussed in a clinical context, with a focus on posttraumatic stress disorder (PTSD), where these opposing effects tend to co-occur, are exacerbated, and are detrimental. Overall, the present review highlights the need to consider together enhancing and impairing effects of emotion on cognition in studies investigating emotion–cognition interactions.

From Pavlov to PTSD: the extinction of conditioned fear in rodents, humans, and anxiety disorders

Nearly 100 years ago, Ivan Pavlov demonstrated that dogs could learn to use a neutral cue to predict a biologically relevant event: after repeated predictive pairings, Pavlov's dogs were conditioned to anticipate food at the sound of a bell, which caused them to salivate. Like sustenance, danger is biologically relevant, and neutral cues can take on great salience when they predict a threat to survival. In anxiety disorders such as posttraumatic stress disorder (PTSD), this type of conditioned fear fails to extinguish, and reminders of traumatic events can cause pathological conditioned fear responses for decades after danger has passed. In this review, we use fear conditioning and extinction studies to draw a direct line from Pavlov to PTSD and other anxiety disorders. We explain how rodent studies have informed neuroimaging studies of healthy humans and humans with PTSD. We describe several genes that have been linked to both PTSD and fear conditioning and extinction and explain how abnormalities in fear conditioning or extinction may reflect a general biomarker of anxiety disorders. Finally, we explore drug and neuromodulation treatments that may enhance therapeutic extinction in anxiety disorders.

Applying a traumatic stress approach to understanding PCS following pediatric mild TBI

Pediatric traumatic brain injury is a significant public health concern affecting hundreds of thousands of children each year. The majority of children who sustain traumatic brain injuries are classified as having a mild traumatic brain injury, and a subset of these children go on to experience persistent physical, cognitive, and emotional symptoms. These symptoms, known as postconcussive symptoms, can endure for months and even years after injury. The outcomes of mild traumatic brain injury are variable and not well understood for a small percentage of children who experience persistent symptoms. The current article explores the potential influence of children's posttraumatic stress symptoms on persistent postconcussive symptoms. Despite the high incidence of posttraumatic stress symptoms after pediatric accidental injury, they have not yet been identified as an important factor for consideration in the understanding of pediatric postconcussive outcomes. The article will review the literature on posttraumatic stress and postconcussive symptoms after pediatric injury and consider neurobiological and cognitive factors to propose a model explaining a pathway through which posttraumatic stress reactions may serve as the mechanism for the expression and maintenance of postconcussive symptoms after mild traumatic brain injury. The clinical implications for the proposed relationship between posttraumatic stress symptoms and postconcussive symptoms are considered prior to the conclusion of the article, which acknowledges limitations in the current literature and provides suggestions for future research.

Aberrant EEG functional connectivity and EEG power spectra in resting state post-traumatic stress disorder: a sLORETA study

The aim of the present study was to explore the modifications of EEG power spectra and EEG connectivity of resting state (RS) condition in patients with post-traumatic stress disorder (PTSD). Seventeen patients and seventeen healthy subjects matched for age and gender were enrolled. EEG was recorded during 5min of RS. EEG analysis was conducted by means of the standardized Low Resolution Electric Tomography software (sLORETA). In power spectra analysis PTSD patients showed a widespread increase of theta activity (4.5-7.5Hz) in parietal lobes (Brodmann Area, BA 7, 4, 5, 40) and in frontal lobes (BA 6). In the connectivity analysis PTSD patients also showed increase of alpha connectivity (8-12.5Hz) between the cortical areas explored by Pz-P4 electrode. Our results could reflect the alteration of memory systems and emotional processing consistently altered in PTSD patients.

PACAP receptor gene polymorphism impacts fear responses in the amygdala and hippocampus

We have recently found higher circulating levels of pituitary adenylate cyclase-activating polypeptide (PACAP) associated with posttraumatic stress disorder (PTSD) symptoms in a highly traumatized cohort of women but not men. Furthermore, a single nucleotide polymorphism in the PACAP receptor gene ADCYAP1R1, adenylate cyclase activating polypeptide 1 receptor type 1, was associated with individual differences in PTSD symptoms and psychophysiological markers of fear and anxiety. The current study outlines an investigation of individual differences in brain function associated with ADCYAP1R1 genotype. Forty-nine women who had experienced moderate to high levels of lifetime trauma participated in a functional MRI task involving passive viewing of threatening and neutral face stimuli. Analyses focused on the amygdala and hippocampus, regions that play central roles in the pathophysiology of PTSD and are known to have high densities of PACAP receptors. The risk genotype was associated with increased reactivity of the amygdala and hippocampus to threat stimuli and decreased functional connectivity between the amygdala and hippocampus. The findings indicate that the PACAP system modulates medial temporal lobe function in humans. Individual differences in ADCYAP1R1 genotype may contribute to dysregulated fear circuitry known to play a central role in PTSD and other anxiety disorders.

Neural correlates of opposing effects of emotional distraction on working memory and episodic memory: an event-related FMRI investigation

A fundamental question in the emotional memory literature is why emotion enhances memory in some conditions but disrupts memory in other conditions. For example, separate studies have shown that emotional stimuli tend to be better remembered in long-term episodic memory (EM), whereas emotional distracters tend to impair working memory (WM) maintenance. The first goal of this study was to directly compare the neural correlates of EM enhancement (EME) and WM impairing (WMI) effects, and the second goal was to explore individual differences in these mechanisms. During event-related functional magnetic resonance imaging (fMRI), participants maintained faces in WM while being distracted by emotional or neutral pictures presented during the delay period. EM for the distracting pictures was tested after scanning and was used to identify successful encoding activity for the picture distracters. The first goal yielded two findings: (1) emotional pictures that disrupted face WM but enhanced subsequent EM were associated with increased amygdala (AMY) and hippocampal activity (ventral system) coupled with reduced dorsolateral PFC (dlPFC) activity (dorsal system); (2) trials in which emotion enhanced EM without disrupting WM were associated with increased ventrolateral PFC activity. The ventral-dorsal switch can explain EME and WMI, while the ventrolateral PFC effect suggests a coping mechanism. The second goal yielded two additional findings: (3) participants who were more susceptible to WMI showed greater amygdala increases and PFC reductions; (4) AMY activity increased and dlPFC activity decreased with measures of attentional impulsivity. Taken together, these results clarify the mechanisms linking the enhancing and impairing effects of emotion on memory, and provide insights into the role of individual differences in the impact of emotional distraction.