Attention allocation in posttraumatic stress disorder: an eye-tracking study

BACKGROUND

Eye-tracking-based attentional research implicates sustained attention to threat in posttraumatic stress disorder (PTSD). However, most of this research employed small stimuli set-sizes, small samples that did not include both trauma-exposed healthy participants and non-trauma-exposed participants, and generally failed to report the reliability of used tasks and attention indices. Here, using an established eye-tracking paradigm, we explore attention processes to different negatively-valenced cues in PTSD while addressing these limitations.

METHODS

PTSD patients (n = 37), trauma-exposed healthy controls (TEHC; n = 34), and healthy controls (HC; n = 30) freely viewed three blocks of 30 different matrices of faces, each presented for 6 s. Each block consisted of matrices depicting eight negatively-valenced faces (anger, fear, or sadness) and eight neutral faces. Gaze patterns on negative and neural areas of interest were compared. Internal consistency and test-retest reliability were evaluated for the entire sample and within groups.

RESULTS

The two trauma-exposed groups dwelled longer on negatively-valenced faces over neutral faces, while HC participants showed the opposite pattern. This attentional bias was more prominent in the PTSD than the TEHC group. Similar results emerged for first-fixation dwell time, but with no differences between the two trauma-exposed groups. No group differences emerged for first-fixation latency or location. Internal consistency and 1-week test-retest reliability were adequate, across and within groups.

CONCLUSIONS

Sustained attention on negatively-valenced stimuli emerges as a potential target for therapeutic intervention in PTSD designed to divert attention away from negatively-valenced stimuli and toward neutral ones.

Comparing neural correlates of conditioned inhibition between children with and without anxiety disorders - A preliminary study

Cognitive-behavioral therapy (CBT), a first-line treatment for pediatric anxiety disorders, is based on principles of threat learning and extinction. However, CBT does not work sufficiently for up to 40% of clinically anxious youth. The neural and behavioral correlates of conditioned inhibition might provide promising targets for attempts to improve CBT response. During conditioned inhibition, threat and safety cues appear together, forming a safety compound. Here, we test whether this safety compound elicits a reduced fear response compared to pairing the threat cue with a novel cue (novel compound). The current pilot study compares behavioral, physiological, and neural correlates of conditioned inhibition between children with (n = 17, Mage = 13.09, SDage = 3.05) and without (n = 18, Mage = 14.49, SDage = 2.38) anxiety disorders. Behavioral and physiological measures did not differ between children with and without anxiety disorders during fear acquisition. During testing, children with anxiety disorders showed overall higher skin conductance response and expected to hear the aversive sound following the novel compound more often than children without anxiety disorders. Children with anxiety disorders showed more activity in the right ventromedial prefrontal cortex (vmPFC) to the safety versus novel compound. Children without anxiety disorders showed the opposite pattern - more right vmPFC activity to the novel versus safety compound (F(1,31) = 5.40, p = 0.03). No group differences manifested within the amygdala, dorsal anterior cingulate cortex, or hippocampus. These pilot findings suggest a feasible approach for examining conditioned inhibition in pediatric anxiety disorders. If replicated in larger samples, findings may implicate perturbed conditioned inhibition in pediatric anxiety disorders and provide targets for CBT.

The influence of social motivation on neural correlates of cognitive control in girls

Motivation influences cognitive control, particularly in childhood and adolescence. Previous work finds that the error-related negativity (ERN), an event-related potential (ERP) linked to cognitive control following errors, is influenced by social motivation. However, it is unclear whether the influences of social motivation on the ERN extend to stimulus-locked neural correlates of cognitive control. This study reexamines how social motivation influences cognitive control in adolescence by exploring motivational influences on two stimulus-locked ERPs; the N2 and P3. Adolescent girls (8-17 years of age) completed a flanker task under two different conditions. In the social condition, girls were led to believe that they were evaluated by a peer during a flanker task. In the nonsocial condition, girls completed a flanker task while evaluated by a computer. Results revealed that all girls exhibited a larger P3 in social as compared to nonsocial contexts, whereas the N2 was not different between contexts. In addition, the largest P3 enhancements were observed among younger girls. These findings suggest that social motivation influences some ERP components related to cognitive control, and such influences change across development. Additionally, findings suggest the importance of including multiple ERPs when interpreting the functional significance of motivation on cognitive control.

A randomized controlled trial of gaze-contingent music reward therapy for major depressive disorder

BACKGROUND

Heightened attention allocation toward negative-valanced information and reduced attention allocation toward positive-valanced information represent viable targets for attention bias modification in major depressive disorder. Accordingly, we conducted a randomized controlled trial testing the efficacy of a novel gaze-contingent attention bias modification procedure for major depressive disorder.

METHOD

Sixty patients with major depressive disorder were randomly assigned to either eight training sessions of feedback-based gaze-contingent music reward therapy designed to divert patients' gaze toward positive over sad stimuli, or to a control condition which entailed eight sessions of gaze-noncontingent music. Clinician-rated and self-reported measures of depression, and proportion of dwell-time on sad faces, were assessed pretreatment, posttreatment, and at a 3-month follow-up.

RESULTS

Gaze-contingent music reward therapy produced a greater reduction in dwell-time on sad faces compared with the control condition, but it failed to generalize to novel faces. Both groups manifested similarly significant reductions in depression symptoms from pre- to posttreatment that were maintained at follow-up. Exploratory analyses suggest that first-episode patients may benefit more from this therapy than patients with a history of multiple episodes.

CONCLUSIONS

Gaze-contingent music reward therapy can modify attention biases in depression, but clear differential clinical effects did not emerge. Theoretical and practical implications are discussed.

Converging Multi-modal Evidence for Implicit Threat-Related Bias in Pediatric Anxiety Disorders

This report examines the relationship between pediatric anxiety disorders and implicit bias evoked by threats. To do so, the report uses two tasks that assess implicit bias to negative-valence faces, the first by eye-gaze and the second by measuring body-movement parameters. The report contrasts task performance in 51 treatment-seeking, medication-free pediatric patients with anxiety disorders and 36 healthy peers. Among these youth, 53 completed an eye-gaze task, 74 completed a body-movement task, and 40 completed both tasks. On the eye-gaze task, patients displayed longer gaze duration on negative relative to non-negative valence faces than healthy peers, F(1, 174) = 8.27, p = .005. In contrast, on the body-movement task, patients displayed a greater tendency to behaviorally avoid negative-valence faces than healthy peers, F(1, 72) = 4.68, p = .033. Finally, implicit bias measures on the two tasks were correlated, r(38) = .31, p = .049. In sum, we found an association between pediatric anxiety disorders and implicit threat bias on two tasks, one measuring eye-gaze and the other measuring whole-body movements. Converging evidence for implicit threat bias encourages future research using multiple tasks in anxiety.

Attention control therapy for acute stress disorder: A randomized controlled trial

BACKGROUND

A subset of people exposed to traumatic events develop acute stress disorder (ASD), and approximately half of people with ASD develop posttraumatic stress disorder (PTSD). This randomized controlled trial examined the efficacy of internet-delivered attention control therapy (ACT), previously shown to reduce PTSD symptoms, as an adjuvant to treatment as usual in the community for patients with ASD.

METHODS

About 119 participants with ASD were randomly assigned to ACT or treatment as usual in the community within the first month following their traumatic event. PTSD symptoms and attention patterns were measured.

RESULTS

A significant reduction in stress-related symptoms was noted across participants with no difference between the two groups. Approximately half of the participants developed PTSD 2 months after the trauma. High attention bias variability was associated with elevated PTSD symptoms. However, attention bias variability did not change due to the therapy sessions.

CONCLUSIONS

Internet-delivered ACT was no more effective in reducing risk for PTSD in participants with ASD than treatment as usual in the community. Although elevated attention bias variability was detected in the patients with ASD, ACT failed to engage this cognitive target. Finally, ACT-based prevention research should proceed with caution given the possibility that this intervention might be associated with symptom worsening as indexed by the Clinical Global Impression scale.

Symptom structure of PTSD and co-morbid depressive symptoms - a network analysis of combat veteran patients

BACKGROUND

Despite extensive research, symptom structure of posttraumatic stress disorder (PTSD) is highly debated. The network approach to psychopathology offers a novel method for understanding and conceptualizing PTSD. However, extant studies have mainly used small samples and self-report measures among sub-clinical populations, while also overlooking co-morbid depressive symptoms.

METHODS

PTSD symptom network topology was estimated in a sample of 1489 treatment-seeking veteran patients based on a clinician-rated PTSD measure. Next, clinician-rated depressive symptoms were incorporated into the network to assess their influence on PTSD network structure. The PTSD-symptom network was then contrasted with the network of 306 trauma-exposed (TE) treatment-seeking patients not meeting full criteria for PTSD to assess corresponding network differences. Finally, a directed acyclic graph (DAG) was computed to estimate potential directionality among symptoms, including depressive symptoms and daily functioning.

RESULTS

The PTSD symptom network evidenced robust reliability. Flashbacks and getting emotionally upset by trauma reminders emerged as the most central nodes in the PTSD network, regardless of the inclusion of depressive symptoms. Distinct clustering emerged for PTSD and depressive symptoms within the comorbidity network. DAG analysis suggested a key triggering role for re-experiencing symptoms. Network topology in the PTSD sample was significantly distinct from that of the TE sample.

CONCLUSIONS

Flashbacks and psychological reactions to trauma reminders, along with their strong connections to other re-experiencing symptoms, have a pivotal role in the clinical presentation of combat-related PTSD among veterans. Depressive and posttraumatic symptoms constitute two separate diagnostic entities, but with meaningful between-disorder connections, suggesting two mutually-influential systems.

Associations between brain activity and endogenous and exogenous cortisol - A systematic review

To arrive at a coherent understanding of the relation between glucocorticoids and the human brain, we systematically reviewed the literature for studies examining the associations between endogenous or exogenous cortisol and human brain function. Higher levels of endogenous cortisol during psychological stress were related to increased activity in the middle temporal gyrus and perigenual anterior cingulate cortex (ACC), decreased activity in the ventromedial prefrontal cortex, and altered function (i.e., mixed findings, increased or decreased) in the amygdala, hippocampus and inferior frontal gyrus. Moreover, endogenous cortisol response to psychological stress was related to increased activity in the inferior temporal gyrus and altered function in the amygdala during emotional tasks that followed psychological stress. Exogenous cortisol administration was related to increased activity in the postcentral gyrus, superior frontal gyrus and ACC, and altered function in the amygdala and hippocampus during conditioning, emotional and reward-processing tasks after cortisol administration. These findings were in line with those from animal studies on amygdala activity during and after stress.

Emotional distractors and attentional control in anxious youth: eye tracking and fMRI data

Attentional control theory suggests that high cognitive demands impair the flexible deployment of attention control in anxious adults, particularly when paired with external threats. Extending this work to pediatric anxiety, we report two studies utilising eye tracking (Study 1) and functional magnetic resonance imaging (Study 2). Both studies use a visual search paradigm to examine anxiety-related differences in the impact of threat on attentional control at varying levels of task difficulty. In Study 1, youth ages 8-18 years (N = 109), completed the paradigm during eye tracking. Results indicated that youth with more severe anxiety took longer to fixate on and identify the target, specifically on difficult trials, compared to youth with less anxiety. However, no anxiety-related effects of emotional distraction (faces) emerged. In Study 2, a separate cohort of 8-18-year-olds (N = 72) completed a similar paradigm during fMRI. Behaviourally, youth with more severe anxiety were slower to respond on searches following non-threatening, compared to threatening, distractors, but this effect did not vary by task difficulty. The same interaction emerged in the neuroimaging analysis in the superior parietal lobule and precentral gyrus-more severe anxiety was associated with greater brain response following non-threatening distractors. Theoretical implications of these inconsistent findings are discussed.

Association of anxiety phenotypes with risk of depression and suicidal ideation in community youth

BACKGROUND

Anxiety symptoms are common in adolescence and are often considered developmentally benign. Yet for some, anxiety presents with serious comorbid nonanxiety psychopathology. Early identification of such "malignant" anxiety presentations is a major challenge. We aimed to characterize anxiety symptoms suggestive of risk for depression and suicidal ideation (SI) in community youths.

METHODS

Cross-sectional associations were evaluated in community youths (n = 7,054, mean age: 15.8) who were assessed for anxiety, depression, and SI. We employed factor and latent class analyses to identify anxiety clusters and subtypes. Longitudinal risk of anxiety was evaluated in a subset of 330 youths with longitudinal data on depression and SI (with baseline mean age of 12.3 years and follow-up mean age of 16.98 years).

OUTCOMES

Almost all (92%) adolescents reported anxiety symptoms. Data-driven approaches revealed anxiety factors and subtypes that were differentially associated with depression and SI. Cross-sectional analyses revealed that panic and generalized anxiety symptoms show the most robust associations with depression and SI. Longitudinal, multivariate analyses revealed that panic symptoms during early adolescence, not generalized anxiety symptoms, predict depression and SI for later adolescent years, particularly in males.

INTERPRETATION

Anxiety is common in youths, with certain symptom clusters/subtypes predicting risk for depression and SI. Panic symptoms in early adolescence, even below disorder threshold, predict high risk for late adolescent depression and SI.

Neural mechanisms underlying heterogeneous expression of threat-related attention in social anxiety

Theoretical frameworks propose that threat-related attention, which is typically assessed using the dot-probe paradigm, plays a key role in social anxiety. Within the dot-probe paradigm, novel computational approaches demonstrate that anxious individuals exhibit multiple patterns of threat-related attention on separate trials. However, no research has leveraged such novel computational methods to delineate the neural substrates of threat-related attention patterns in social anxiety. To address this issue, fifty-three socially anxious adults (22.38 ± 3.12, 33 females) completed an fMRI-based dot-probe paradigm. A novel, response-based computation approach revealed conjoint patterns of vigilant orientation, avoidant orientation, slow disengagement, and fast disengagement, which were masked by standard computation measures. Compared to vigilant orientation and fast disengagement, avoidant orientation and slow disengagement were greater in magnitude, respectively. Mirroring behavioral findings, avoidant orientation and slow disengagement elicited greater deactivation of several regions within the Default Mode Network and stronger connectivity between the right amygdala and superior temporal sulcus. Taken together, these results suggest that distinct neural processes facilitate the heterogeneous expression of threat-related attention in social anxiety.

Age Moderates Link Between Training Effects and Treatment Response to Attention Bias Modification Treatment for Social Anxiety Disorder

Attention bias modification treatment (ABMT) aims to reduce anxiety symptoms via practice on computerized attention training tasks. Despite evidence of efficacy, clinical effects appear heterogeneous. More research on ABMT mechanisms and moderators of treatment response is needed. Age is one potentially important moderator, as developmental differences in training effects may impact response. We examined developmental links between ABMT training effects and response in social anxiety disorder (SAD). We pooled data from two randomized controlled trials in treatment-seeking youths and adults with SAD (N = 99) that used identical ABMT methods. We first characterized learning effects associated with the eight-session ABMT training protocol. We then tested whether learning magnitude predicted the clinical (change in SAD symptoms) and cognitive (change in attention bias) responses to treatment. Finally, we tested whether age moderated the association between ABMT learning and treatment response. Results indicate that ABMT was associated with an incremental learning curve during the protocol, and that learning improved with age. Age further moderated the association between learning gains during the ABMT protocol and subsequent reduction in self-reported SAD symptoms, such that this association was stronger with age. These effects were not evident in bias scores or clinician ratings. Finally, pre-treatment SAD symptoms and bias scores predicted ABMT learning gains. This study highlights the links among age, learning processes, and clinical response to ABMT. These insights may inform attempts to increase the clinical efficacy of ABMT for anxiety.

Multi-method assessment of irritability and differential linkages to neurophysiological indicators of attention allocation to emotional faces in young children

Facilitated attention toward angry stimuli (attention bias) may contribute to anger proneness and temper outbursts exhibited by children with high irritability. However, most studies linking attention bias and irritability rely on behavioral measures with limited precision and no studies have explored these associations in young children. The present study explores irritability-related attention biases toward anger in young children (N = 128; ages 4-7 years) engaged in a dot-probe task with emotional faces, as assessed with event-related brain potential (ERP) indices of early selective attention and multi-method assessment of irritability. Irritability assessed via semi-structured clinical interview predicted larger anterior N1 amplitudes to all faces. In contrast, irritability assessed via a laboratory observation paradigm predicted reduced P1 amplitudes to angry relative to neutral faces. These findings suggest that altered early attentional processing occurs in young children with high irritability; however, the nature of these patterns may vary with methodological features of the irritability assessments. Future investigations using different assessment tools may provide greater clarity regarding the underlying neurocognitive correlates of irritability. Such studies may also contribute to the ongoing debates about how to best define and measure irritability across the developmental spectrum in a manner that is most informative for linkage to neural processes.

Genetic and environmental risk structure of internalizing psychopathology in youth

BACKGROUND

Internalizing disorders (IDs), consisting of syndromes of anxiety and depression, are common, debilitating conditions often beginning early in life. Various trait-like psychological constructs are associated with IDs. Our prior analysis identified a tripartite model of Fear/Anxiety, Dysphoria, and Positive Affect among symptoms of anxiety and depression and the following constructs in youth: anxiety sensitivity, fearfulness, behavioral activation and inhibition, irritability, neuroticism, and extraversion. The current study sought to elucidate their overarching latent genetic and environmental risk structure.

METHODS

The sample consisted of 768 juvenile twin subjects ages 9-14 assessed for the nine, abovementioned measures. We compared two multivariate twin models of this broad array of phenotypes.

RESULTS

A hypothesis-driven, common pathway twin model reflecting the tripartite structure of the measures were fit to these data. However, an alternative independent pathway model provided both a better fit and more nuanced insights into their underlying genetic and environmental risk factors.

CONCLUSIONS

Our findings suggest a complex latent genetic and environmental structure to ID phenotypes in youth. This structure, which incorporates both clinical symptoms and various psychological traits, informs future phenotypic approaches for identifying specific genetic and pathophysiological mechanisms underlying ID risk.

The Heterogeneity of Anxious Phenotypes: Neural Responses to Errors in Treatment-Seeking Anxious and Behaviorally Inhibited Youths

OBJECTIVE

Although behaviorally inhibited (BI) temperament predicts risk for anxiety, anxiety in BI may involve distinct neural responses to errors. The current study examines the relations between anxiety and neural correlates of error processing both in youths identified as BI in early childhood and in youths seeking treatment for an anxiety disorder.

METHOD

All participants underwent functional magnetic resonance imaging using a flanker task to assess responses to errors. A study in healthy subjects assessed test-retest reliability to inform analyses in two other samples. For one sample, a cohort of BI youths (Low BI, n = 28; High BI, n = 27) was followed into adolescence. For the other, participants were recruited based on the presence or absence of an anxiety disorder. Using identical methods in medication-free subjects, analyses compared relations between anxiety and error processing across the two samples.

RESULTS

Error-processing exhibited acceptable reliability. Within a ventromedial-prefrontal-cortex (vmPFC) cluster, anxiety related to error processing only in youths whose early-life BI status was known. In the high BI group, anxiety related to reduced neural response to errors. No such associations manifested in treatment-seeking youths. Other analyses mapped relations between error-processing and anxiety in each sample on its own. However, only the vmPFC cluster statistically differentiated the neural correlates of anxiety in BI.

CONCLUSION

BI temperament may define a unique pathway into anxiety involving perturbed neural responding to errors. Although BI is a risk factor for later anxiety, the neural and associated features of anxiety in BI youths may differ from those in treatment-seeking youths.

Infant behavioral reactivity predicts change in amygdala volume 12 years later

The current study examined the link between temperamental reactivity in infancy and amygdala development in middle childhood. A sample (n = 291) of four-month-old infants was assessed for infant temperament, and two groups were identified: those exhibiting negative reactivity (n = 116) and those exhibiting positive reactivity (n = 106). At 10 and 12 years of age structural imaging was completed on a subset of these participants (n = 75). Results indicate that, between 10 and 12 years of age, left amygdala volume increased more slowly in those with negative compared to positive reactive temperament. These results provide novel evidence linking early temperament to distinct patterns of brain development over middle childhood.

Anticipatory Threat Responding: Associations With Anxiety, Development, and Brain Structure

BACKGROUND

While translational theories link neurodevelopmental changes in threat learning to pathological anxiety, findings from studies in patients inconsistently support these theories. This inconsistency may reflect difficulties in studying large patient samples with wide age ranges using consistent methods. A dearth of imaging data in patients further limits translational advances. We address these gaps through a psychophysiology and structural brain imaging study in a large sample of patients across the lifespan.

METHODS

A total of 351 participants (8-50 years of age; 209 female subjects; 195 healthy participants and 156 medication-free, treatment-seeking patients with anxiety) completed a differential threat conditioning and extinction paradigm that has been validated in pediatric and adult populations. Skin conductance response indexed psychophysiological response to conditioned (CS+, CS-) and unconditioned threat stimuli. Structural magnetic resonance imaging data were available for 250 participants. Analyses tested anxiety and age associations with psychophysiological response in addition to associations between psychophysiology and brain structure.

RESULTS

Regardless of age, patients and healthy comparison subjects demonstrated comparable differential threat conditioning and extinction. The magnitude of skin conductance response to both conditioned stimulus types differentiated patients from comparison subjects and covaried with dorsal prefrontal cortical thickness; structure-response associations were moderated by anxiety and age in several regions. Unconditioned responding was unrelated to anxiety and brain structure.

CONCLUSIONS

Rather than impaired threat learning, pathological anxiety involves heightened skin conductance response to potential but not immediately present threats; this anxiety-related potentiation of anticipatory responding also relates to variation in brain structure. These findings inform theoretical considerations by highlighting anticipatory response to potential threat in anxiety.

Infant behavioral inhibition predicts personality and social outcomes three decades later

Does infant temperament predict adult personality and life-course patterns? To date, there is scant evidence examining relations between child temperament and adult outcomes, and extant research has relied on limited methods for measuring temperament such as maternal report. This prospective longitudinal study followed a cohort of infants (n = 165) for three decades to examine whether infant behavioral inhibition, a temperament characterized by cautious and fearful behaviors to unfamiliar situations, shapes long-term personality, social relationships, vocational/education, and mental health outcomes in adulthood. At age 14 mo, behavioral inhibition was assessed using an observation paradigm. In adolescence (15 y; n = 115), error monitoring event-related potentials were measured in a flanker task. In adulthood (26 y; n = 109), personality, psychopathology, and sociodemographics were self-reported using questionnaires. We found that infants with higher levels of behavioral inhibition at 14 mo grew up to become more reserved and introverted adults (β = 0.34) with lower social functioning with friends and family (β = -0.23) at age 26. Infant behavioral inhibition was also a specific risk factor for adult internalizing (i.e., anxiety and depression, β = 0.20) psychopathology, rather than a transdiagnostic risk for general and externalizing psychopathology. We identified a neurophysiologic mechanism underlying risk and resilience for later psychopathology. Heightened error monitoring in adolescence moderated higher levels of adult internalizing psychopathology among behaviorally inhibited individuals. These findings suggest meaningful continuity between infant temperament and the development of adult personality. They provide the earliest evidence suggesting that the foundation of long-term well-being is rooted in individual differences in temperament observed in infancy.