A wealth of research demonstrates attentional biases toward threat in the anxiety disorders. Several models have been advanced to explain these biases in anxiety, yet the mechanisms comprising and ...mediating the biases remain unclear. In the present article, we review evidence regarding the mechanisms of attentional biases through careful examination of the components of attentional bias, the mechanisms underlying these components, and the stage of information processing during which the biases occur. Facilitated attention, difficulty in disengagement, and attentional avoidance comprise the components of attentional bias. A threat detection mechanism likely underlies facilitated attention, a process that may be neurally centered around the amygdala. Attentional control ability likely underlies difficulty in disengagement, emotion regulation goals likely underlie attentional avoidance, and both of these processes may be neurally centered around prefrontal cortex functioning. The threat detection mechanism may be a mostly automatic process, attentional avoidance may be a mostly strategic process, and difficulty in disengagement may be a mixture of automatic and strategic processing. Recommendations for future research are discussed.
Many cognitive and clinical neuroscience research studies seek to determine how contextual factors modulate cognitive processes. In fMRI, hypotheses about how context modulates distributed patterns ...of information processing are often tested by comparing functional connectivity between neural regions A and B as a function of task conditions X and Y, which is termed context-modulated functional connectivity (FC). There exist two exploratory statistical approaches to testing context-modulated FC: the beta-series method and psychophysiological interaction (PPI) analysis methods. While these approaches are commonly used, their relative power for detecting context-modulated FC is unknown, especially with respect to real-world experimental parameters (e.g., number of stimulus repetitions, inter-trial-interval, stimulus duration). Here, we use simulations to compare power for detecting context-modulated FC between the standard PPI formulation (sPPI), generalized PPI formulation (gPPI), and beta series methods. Simulation results demonstrate that gPPI and beta series methods are generally more powerful than sPPI. Whether gPPI or beta series methods performed more powerfully depended on experiment parameters: block designs favor the gPPI, whereas the beta series method was more powerful for designs with more trial repetitions and it also retained more power under conditions of hemodynamic response function variability. On a real dataset of adolescent girls, the PPI methods appeared to have greater sensitivity in detecting task-modulated FC when using a block design and the beta series method appeared to have greater sensitivity when using an event-related design with many trial repetitions. Implications of these performance results are discussed.
•We compared statistical methods for detecting task-modulated functional connectivity•psychophyiological interaction analyses were most sensitive on block designs•beta series method was more robust to changes in the hemodynamic response function
Numerous clinical trials have supported the efficacy of cognitive behavioral therapy (CBT) for the treatment of anxiety disorders. Accordingly, CBT has been formally recognized as an empirically ...supported treatment for anxiety-related conditions. This article reviews the evidence supporting the efficacy of CBT for anxiety disorders. Specifically, contemporary meta-analytic studies on the treatment of anxiety disorders are reviewed and the efficacy of CBT is examined. Although the specific components of CBT differ depending on the study design and the anxiety disorder treated, meta-analyses suggest that CBT procedures (particularly exposure-based approaches) are highly efficacious. CBT generally outperforms wait-list and placebo controls. Thus, CBT provides incremental efficacy above and beyond nonspecific factors. For some anxiety disorders, CBT also tends to outperform other psychosocial treatment modalities. The implications of available meta-analytic findings in further delineating the efficacy and dissemination of CBT for anxiety disorders are discussed.
Altered functional connectivity (FC) between the medial prefrontal cortex (mPFC) and amygdala is widely implicated as a neural mechanism explaining risk for psychopathology among those exposed to ...early life trauma. Nonetheless, contemporary neuroimaging research has shifted toward large-scale network models of brain function, and it is not clear how this common bi-nodal finding fits into larger-scale network models. Here, using dynamic functional connectivity (DFC) approaches combined with large-scale network analyses, the larger role of bi-nodal FC between mPFC and amygdala among a sample of adolescent girls is investigated. The sample was comprised of 30 healthy control girls and 26 girls exposed to either physical or sexual assault who underwent a resting-state scan during 3T MRI. DFC using a sliding window approach was used to create weighted, undirected, graphs from the resting-state data following parcellation with a 215 regions-of-interest (ROI) atlas. Using
ROI, the predicted finding of lessor FC between mPFC and amygdala as a function of early life trauma was replicated in this sample. By contrast, early life trauma was associated with greater large-scale network modularity. Using a dynamic FC approach, it is also demonstrated that within-subject variability in this bi-nodal FC closely tracks within-subject fluctuations in large-scale network patterns, including connectivity between a limbic and default mode network (in which the amygdala and mPFC nodes belong, respectively) as well as overall modular organization. These results suggest that bi-nodal FC, such as amygdala-mPFC FC, may generally reflect larger-scale network patterns. Future research is necessary to understand whether these associations between nodal FC and large-scale network organization better reflect top-down processes (larger-scale network organization drives bi-nodal FC) or bottom-up processes (bi-nodal FC drives larger-scale network organization) and the related impact of early life trauma.
There has been significant interest in the impact of anxiety disorders on quality of life. In this meta-analytic review, we empirically evaluate differences in quality of life between patients with ...anxiety disorders and nonclinical controls. Thirty-two patient samples from 23 separate studies (
N
=
2892) were included in the analysis. The results yielded a large effect size indicating poorer quality of life among anxiety disorder patients vs. controls and this effect was observed across all anxiety disorders. Compared to control samples, no anxiety disorder diagnosis was associated with significantly poorer overall quality of life than was any other anxiety disorder diagnosis. Examination of specific domains of QOL suggests that impairments may be particularly prominent among patients with post-traumatic stress disorder. QOL domains of mental health and social functioning were associated with the highest levels of impairment among anxiety disorder patients. These findings are discussed in the context of future research on the assessment of quality of life in the anxiety disorders.
Many models of classical conditioning fail to describe important phenomena, notably the rapid return of fear after extinction. To address this shortfall, evidence converged on the idea that learning ...agents rely on latent-state inferences, i.e. an ability to index disparate associations from cues to rewards (or penalties) and infer which index (i.e. latent state) is presently active. Our goal was to develop a model of latent-state inferences that uses latent states to predict rewards from cues efficiently and that can describe behavior in a diverse set of experiments. The resulting model combines a Rescorla-Wagner rule, for which updates to associations are proportional to prediction error, with an approximate Bayesian rule, for which beliefs in latent states are proportional to prior beliefs and an approximate likelihood based on current associations. In simulation, we demonstrate the model's ability to reproduce learning effects both famously explained and not explained by the Rescorla-Wagner model, including rapid return of fear after extinction, the Hall-Pearce effect, partial reinforcement extinction effect, backwards blocking, and memory modification. Lastly, we derive our model as an online algorithm to maximum likelihood estimation, demonstrating it is an efficient approach to outcome prediction. Establishing such a framework is a key step towards quantifying normative and pathological ranges of latent-state inferences in various contexts.
Structural neuroimaging studies of posttraumatic stress disorder (PTSD) have typically reported reduced cortical thickness (CT) and gray matter volume (GMV) in subcortical structures and networks ...involved in memory retrieval, emotional processing and regulation, and fear acquisition and extinction. Although PTSD is more common in women, and interpersonal violence (IPV) exposure is a more potent risk factor for developing PTSD relative to other forms of trauma, most of the existing literature examined combat-exposed men with PTSD. Vertex-wise CT and subcortical GMV analyses were conducted to examine potential differences in a large, well-characterized sample of women with PTSD stemming from IPV-exposure (n = 99) compared to healthy trauma-free women without a diagnosis of PTSD (n = 22). Subgroup analyses were also conducted to determine whether symptom severity within specific PTSD symptom clusters (e.g., re-experiencing, active avoidance, hyperarousal) predict CT and GMV after controlling for comorbid depression and anxiety. Results indicated that a diagnosis of PTSD in women with IPV-exposure did not significantly predict differences in CT across the cortex or GMV in the amygdala or hippocampus compared to healthy controls. However, within the PTSD group, greater re-experiencing symptom severity was associated with decreased CT in the left inferior and middle temporal gyrus, and decreased CT in the right parahippocampal and medial temporal gyrus. In contrast, greater active avoidance symptom severity was associated with greater CT in the left lateral fissure, postcentral gyrus, and middle/lateral occipital cortex, and greater CT in the right paracentral, posterior cingulate, and superior occipital gyrus. In terms of GMV, greater hyperarousal symptom severity was associated with reduced left amygdala GMV, while greater active avoidance symptom severity was associated with greater right amygdala GMV. These findings suggest that structural brain alterations among women with IPV-related PTSD may be driven by symptom severity within specific symptom clusters and that PTSD symptom clusters may have a differential (increased or decreased) association with brain structures.
Posttraumatic stress disorder (PTSD) in adolescents is common and debilitating. In contrast to adult PTSD, relatively little is known about the neurobiology of adolescent PTSD, nor about how current ...treatments may alter adolescent neurodevelopment to allow recovery from PTSD. Improving our understanding of biological mechanisms of adolescent PTSD, taken in the context of neurodevelopment, is crucial for developing novel and personalized treatment approaches. In this review, we highlight prevailing constructs of PTSD and current findings on these domains in adolescent PTSD. Notably, little data exist in adolescent PTSD for prominent adult PTSD constructs, including threat learning and attentional threat bias. Most work to date has examined general threat processing, emotion regulation, and their neural substrates. These studies suggest that adolescent PTSD, while phenomenologically similar to adult PTSD, shows unique neurodevelopmental substrates that may impair recovery but could also be targeted in the context of adolescent neuroplasticity to improve outcomes. Both cross-sectional and longitudinal data suggest abnormal frontolimbic development compared with typically developing youths, a pattern that may differ from resilient youths. Whether current treatments such as trauma-focused psychotherapy engage these targets and restore healthy neurodevelopment remains an open question. We end our review by highlighting emerging areas and knowledge gaps that could be addressed to better characterize the biology underlying adolescent PTSD. Emerging studies in computational modeling of decision making, caregiver-related transmission of traumatic stress, and other areas may offer new targets that could harness adolescent neurobehavioral plasticity to improve resilience and recovery for some of our most vulnerable youths.
Anxiety disorders have traditionally been conceptualized as reflecting the emotions of fear and anxiety. A developing program of research demonstrates a relation between disgust and three specific ...anxiety disorders: blood-injection-injury (BII) phobia, spider phobia, and contamination-related obsessive–compulsive disorder (OCD). This review serves three purposes. First, the authors review the response patterns predicted to be observed if the emotional response in these disorders involved disgust versus fear. The review suggests specific response patterns that characterize disgust and fear in the domains of heart rate, facial expression, neural activity, and cognitive processes. Second, the authors review extant research employing measures of these domains in spider phobia, BII phobia, and contamination-related OCD. The evidence suggests that both fear and disgust characterize each of these disorders, but the magnitude at which the emotions characterize the disorders may depend on the response domain measured. For example, disgust may be more involved in spider phobia in appraisals and facial expression, but less involved in neural correlates or heart rate domains. Third, the authors suggest guidelines for future research, including concurrent use of specific measures as well as examining whether the different emotions in different response domains respond to similar interventions (e.g., exposure).
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