scholarly journals Exploring the Neurocircuitry Underpinning Predictability of Threat in Soldiers with PTSD Compared to Deployment Exposed Controls

2016 ◽  
Vol 10 (1) ◽  
pp. 111-124 ◽  
Author(s):  
Michael N. Dretsch ◽  
Kimberly H. Wood ◽  
Thomas A. Daniel ◽  
Jeffrey S. Katz ◽  
Gopikrishna Deshpande ◽  
...  
Keyword(s):  
Fear Conditioning ◽  
Skin Conductance Response ◽  
Stress Disorder ◽  
Brain Regions ◽  
Emotional Dysregulation ◽  
Fear Learning ◽  
Group Differences ◽  
Significant Group ◽  
Middle Temporal ◽  
Ptsd Group

Background:Prior work examining emotional dysregulation observed in posttraumatic stress disorder (PTSD) has primarily been limited to fear-learning processes specific to anticipation, habituation, and extinction of threat. In contrast, the response to threat itself has not been systematically evaluated.Objective:To explore potential disruption in fear conditioning neurocircuitry in service members with PTSD, specifically in response to predictableversusunpredictable threats.Method:In the current study, active-duty U.S. Army soldiers with (PTSD group;n= 38) and without PTSD (deployment-exposed controls; DEC;n= 40), participated in a fear-conditioning study in which threat predictability was manipulated by presenting an aversive unconditioned stimulus (UCS) that was either preceded by a conditioned stimulus (i.e., predictable) or UCS alone (i.e., unpredictable). Threat expectation, skin conductance response (SCR), and functional magnetic resonance imaging (fMRI) signal to predictable and unpredictable threats (i.e., UCS) were assessed.Results:Both groups showed greater threat expectancy and diminished threat-elicited SCRs to predictable compared to unpredictable threat. Significant group differences were observed within the amygdala, hippocampus, insula, and superior and middle temporal gyri. Contrary to our predictions, the PTSD group showed a diminished threat-related response within each of these brain regions during predictable compared to unpredictable threat, whereas the DEC group showed increased activation.Conclusion:Although, the PTSD group showed greater threat-related diminution, hypersensitivity to unpredictable threat cannot be ruled out. Furthermore, pre-trauma, trait-like factors may have contributed to group differences in activation of the neurocircuitry underpinning fear conditioning.

scholarly journals Influence of intranasal oxytocin on fear consolidation in healthy humans

2019 ◽  
Vol 32 (6) ◽  
pp. e100131 ◽  
Author(s):  
Elizabeth Hoge ◽  
Eric Bui ◽  
Peter Rosencrans ◽  
Scott Orr ◽  
Rachel Ross ◽  
...  
Keyword(s):  
Fear Conditioning ◽  
Repeated Measures ◽  
Skin Conductance Response ◽  
De Novo ◽  
Fear Learning ◽  
Drug Trials ◽  
Conditioning Procedure ◽  
Double Blind ◽  
Healthy Humans ◽  
Main Effects

BackgroundAlthough recent data in healthy humans suggestthat treatment with intranasal oxytocin (OT) may facilitate extinction recall,to date, little is known about the effects of OT on memory consolidationprocesses.AimTo examine the effect of intranasal administration of OT compared with placebo on memory consolidation blockade of a de novo fear memory in a classical 2-day fear conditioning procedure.ResultsThere were no significant differences between the OT and the placebo groups on the first two extinction trials (mean (SD)=0.01 (0.39) vs 0.15 (0.31), t=−1.092, p=0.28). Similarly, during early extinction, analysis of variance for repeated measures failed to show significant main effects of extinction trials: trials (F(4, 112)=1.58, p=0.18), drug (F(1, 112)=0.13, p=0.72) or drug × trials interaction (F(4, 112)=0.76, p=0.56).ConclusionOur results suggest that OT administered in a double-blind fashion immediately after fear conditioning does not significantly reduce consolidation of fear learning as measured by a differential skin conductance response tested at the beginning of extinction.

scholarly journals Validating the Use of a Smartphone App for Remote Administration of a Fear Conditioning Paradigm

2019 ◽  
Author(s):  
Kirstin Lee Purves ◽  
Elena Constantinou ◽  
Thomas McGregor ◽  
Kathryn J. Lester ◽  
Tom Joseph Barry ◽  
...  
Keyword(s):  
Individual Differences ◽  
Fear Conditioning ◽  
Reliability And Validity ◽  
Fear Learning ◽  
Group Differences ◽  
Smartphone App ◽  
Total N ◽  
Conditioning Paradigm ◽  
Large Samples ◽  
Conditioning Experiment

Fear conditioning models key processes related to the development, maintenance and treatment of anxiety disorders and is associated with group differences in anxiety. However, laboratory administration of tasks is time and cost intensive, precluding assessment in large samples, necessary for analysis of individual differences. This study introduces a newly developed smartphone app that delivers a fear conditioning paradigm remotely. Three groups of participants (total n=152) took part in three studies involving a differential fear conditioning experiment to assess the reliability and validity of a smartphone administered fear conditioning paradigm. This comprised of fear acquisition, generalisation, extinction, and renewal phases. We show that smartphone app delivery of a fear conditioning paradigm results in a pattern of fear learning comparable to traditional laboratory delivery, and is able to detect individual differences in performance that show comparable associations with anxiety to the prior group differences literature.

Machine learning multivariate pattern analysis predicts classification of posttraumatic stress disorder and its dissociative subtype: a multimodal neuroimaging approach

2018 ◽  
Vol 49 (12) ◽  
pp. 2049-2059 ◽  
Author(s):  
Andrew A. Nicholson ◽  
Maria Densmore ◽  
Margaret C. McKinnon ◽  
Richard W.J. Neufeld ◽  
Paul A. Frewen ◽  
...  
Keyword(s):  
Machine Learning ◽  
Posttraumatic Stress Disorder ◽  
Posttraumatic Stress ◽  
Stress Disorder ◽  
Mean Amplitude ◽  
Machine Learning Algorithms ◽  
Group Differences ◽  
Significant Group ◽  
Dissociative Subtype

AbstractBackgroundThe field of psychiatry would benefit significantly from developing objective biomarkers that could facilitate the early identification of heterogeneous subtypes of illness. Critically, although machine learning pattern recognition methods have been applied recently to predict many psychiatric disorders, these techniques have not been utilized to predict subtypes of posttraumatic stress disorder (PTSD), including the dissociative subtype of PTSD (PTSD + DS).MethodsUsing Multiclass Gaussian Process Classification within PRoNTo, we examined the classification accuracy of: (i) the mean amplitude of low-frequency fluctuations (mALFF; reflecting spontaneous neural activity during rest); and (ii) seed-based amygdala complex functional connectivity within 181 participants [PTSD (n = 81); PTSD + DS (n = 49); and age-matched healthy trauma-unexposed controls (n = 51)]. We also computed mass-univariate analyses in order to observe regional group differences [false-discovery-rate (FDR)-cluster corrected p < 0.05, k = 20].ResultsWe found that extracted features could predict accurately the classification of PTSD, PTSD + DS, and healthy controls, using both resting-state mALFF (91.63% balanced accuracy, p < 0.001) and amygdala complex connectivity maps (85.00% balanced accuracy, p < 0.001). These results were replicated using independent machine learning algorithms/cross-validation procedures. Moreover, areas weighted as being most important for group classification also displayed significant group differences at the univariate level. Here, whereas the PTSD + DS group displayed increased activation within emotion regulation regions, the PTSD group showed increased activation within the amygdala, globus pallidus, and motor/somatosensory regions.ConclusionThe current study has significant implications for advancing machine learning applications within the field of psychiatry, as well as for developing objective biomarkers indicative of diagnostic heterogeneity.

scholarly journals S159. SUBCORTICAL GRAY MATTER VOLUME IS ASSOCIATED WITH SCHIZOPHRENIA AND WITH BOTH ITS FAMILIAL AND CLINICAL RISK

2020 ◽  
Vol 46 (Supplement_1) ◽  
pp. S96-S97
Author(s):  
Roberta Passiatore ◽  
Linda A Antonucci ◽  
Leonardo Fazio ◽  
Barbara Gelao ◽  
Andrea Falsetti ◽  
...  
Keyword(s):  
Gray Matter ◽  
Gray Matter Volume ◽  
Familial Risk ◽  
Structural Features ◽  
Brain Regions ◽  
Anterior Cingulate ◽  
Group Differences ◽  
Intracranial Volume ◽  
Significant Group ◽  
Clinical Risk

Abstract Background Patients with schizophrenia (SCZ) show lower volumetric estimates of gray matter (GM) than healthy controls (HC). Similar results have been reported in healthy siblings of patients (SIB). However, it is unclear whether this phenotype is also present in individuals at clinical high-risk (CHR), characterized by sub-threshold symptoms and loss of functioning. We hypothesized that GM volumetric differences are associated with both familial and clinical risk for schizophrenia Methods We processed the T1-weighted MRI scans acquired at 3 Tesla of 544 HC, 63 SIB, 20 CHR and 120 SCZ using CAT12. We used ANCOVA to assess group differences (HC vs. CHR vs. SIB vs. SCZ), with linear and quadratic age, gender and total intracranial volume as nuisance covariates. We assessed the reproducibility of our case/control findings in an independent sample of 127 HC and 36 SCZ. Group differences were tested post hoc through Fisher’s test. Results We found significant group effects in the bilateral thalamus, bilateral hippocampus and anterior cingulate (FWE&lt;0.05). Specifically, SCZ presented the lowest GM volume in these regions compared to the other three groups, with SIB and CHR’s GM estimates intermediate between HC and SCZ (p&lt;0.05). The associations with schizophrenia were replicated in the independent validation sample. Discussion Individuals with familial or clinical risk for schizophrenia have lower GM estimates in the same brain regions. These findings, suggest that these structural features are not only associated with familial risk for schizophrenia but that they are also associated with its sub-threshold symptoms.

scholarly journals Network supporting contextual fear learning after dorsal hippocampal damage has increased dependence on retrosplenial cortex

2017 ◽  
Author(s):  
Cesar A.O. Coelho ◽  
Tatiana L. Ferreira ◽  
Juliana C.K. Soares ◽  
João R. Sato ◽  
Maria Gabriela M. Oliveira
Keyword(s):  
Fear Conditioning ◽  
Correlation Coefficients ◽  
Brain Regions ◽  
Memory System ◽  
Retrosplenial Cortex ◽  
Contextual Fear Conditioning ◽  
Fear Learning ◽  
Hippocampal Damage ◽  
Contextual Fear ◽  
Dorsal Hippocampal

ABSTRACTHippocampal damage results in profound retrograde, but no anterograde amnesia in contextual fear conditioning (CFC). Although the content learned in the latter have been discussed, the compensating regions were seldom proposed and never empirically addressed. Here, we employed network analysis of pCREB expression quantified from brain slices of rats with dorsal hippocampal lesion (dHPC) after undergoing CFC session. Using inter-regional correlations of pCREB-positive nuclei between brain regions, we modelled functional networks using different thresholds. The dHPC network showed small-world topology, equivalent to SHAM (control) network. However, diverging hubs were identified in each network. In a direct comparison, hubs in both networks showed consistently higher centrality values compared to the other network. Further, the distribution of correlation coefficients was different between the groups, with most significantly stronger correlation coefficients belonging to the SHAM network. These results suggest that dHPC network engaged in CFC learning is partially different, and engage alternative hubs. We next tested if pre-training lesions of dHPC and one of the new dHPC network hubs (perirhinal, Per; or disgranular retrosplenial, RSC, cortices) would impair CFC. Only dHPC-RSC, but not dHPC-Per, impaired CFC. Interestingly, only RSC showed a consistently higher centrality in the dHPC network, suggesting that the increased centrality reflects an increased functional dependence on RSC. Our results provide evidence that, without hippocampus, the RSC, an anatomically central region in the medial temporal lobe memory system might support CFC learning and memory.AUTHOR SUMMARYWhen determined cognitive performances are not affected by brain lesions of regions generally involved in that performance, the interpretation is that the remaining regions can compensate the damaged one. In contextual fear conditioning, a memory model largely used in laboratory rodents, hippocampal lesions produce amnesia for events occurred before, but not after the lesion, although the hippocampus is known to be important for new learning. Addressing compensation in animal models has always been challenging as it requires large-scale brain mapping. Here, we quantified 30 brain regions and used mathematical tools to model how a brain network can compensate hippocampal loss and learn contextual fear. We described that the damaged network preserved general interactivity characteristics, although different brain regions were identified as highly important for the network (e.g. highly connected). Further, we empirically validated our network model by performing double lesions of the hippocampus and the alternative hubs observed in the network models. We verified that double lesion of the hippocampus and retrosplenial cortex, one of the hubs, impaired contextual fear learning. We provide evidence that without hippocampus, the remaining network relies on alternative important regions from the memory system to coordinate contextual fear learning.

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

2021 ◽  
Vol 11 ◽  
Author(s):  
Virginie Chloé Perizzolo Pointet ◽  
Dominik Andrea Moser ◽  
Marylène Vital ◽  
Sandra Rusconi Serpa ◽  
Alexander Todorov ◽  
...  
Keyword(s):  
Interpersonal Violence ◽  
Stress Disorder ◽  
Brain Regions ◽  
Parahippocampal Gyrus ◽  
Group Differences ◽  
Evaluation Task ◽  
Emotional Appraisal ◽  
Eeg Source Localization ◽  
Anterior Prefrontal Cortex

IntroductionThe present study investigates the association of lifetime interpersonal violence (IPV) exposure, related posttraumatic stress disorder (IPV-PTSD), and appraisal of the degree of threat posed by facial avatars.MethodsWe recorded self-rated responses and high-density electroencephalography (HD-EEG) among women, 16 of whom with lifetime IPV-PTSD and 14 with no PTSD, during a face-evaluation task that displayed male face avatars varying in their degree of threat as rated along dimensions of dominance and trustworthiness.ResultsThe study found a significant association between lifetime IPV exposure, under-estimation of dominance, and over-estimation of trustworthiness. Characterization of EEG microstates supported that lifetime IPV-PTSD modulates emotional appraisal, specifically in encoding and decoding processing associated with N170 and LPP evoked potentials. EEG source localization demonstrated an overactivation of the limbic system, in particular the parahippocampal gyrus, in response to non-threatening avatars. Additionally, dysfunctional involvement of attention-related processing anterior prefrontal cortex (aPFC) was found in response to relatively trustworthy avatars in IPV-PTSD individuals compared with non-PTSD controls.DiscussionThis study showed that IPV exposure and related PTSD modulate individuals’ evaluation of facial characteristics suggesting threat. Atypical processing of these avatar characteristics was marked by group differences in brain regions linked to facial processing, emotion regulation, and memory.

scholarly journals Value Estimation and Latent-State Update-Related Neural Activity During Fear Conditioning Predict Posttraumatic Stress Disorder Symptom Severity

2021 ◽  
Author(s):  
Allison Letkiewicz ◽  
Amy L. Cochran ◽  
Anthony Privatsky ◽  
G. Andrew James ◽  
Josh M. Cisler
Keyword(s):  
Posttraumatic Stress Disorder ◽  
Posttraumatic Stress ◽  
Fear Conditioning ◽  
Stress Disorder ◽  
State Model ◽  
Fear Learning ◽  
Ptsd Symptoms ◽  
Model Based ◽  
Model Free ◽  
Value Estimation

Learning theories of posttraumatic stress disorder (PTSD) purport that fear learning processes, such as those that support fear acquisition and extinction, are impaired. Computational models that aim to capture specific processes involved in fear learning have primarily assessed model free, or trial-and-error, reinforcement learning (RL). Although prior research indicates that aspects of model-free RL are disrupted among individuals with PTSD, models have yet to quantify and identify whether more nuanced, contextually driven learning is also disrupted. Given empirical evidence of aberrant contextual modulation of fear in PTSD, the present study sought to identify whether model-based RL processes are altered during fear conditioning among women with interpersonal violence (IPV)-related PTSD (n=85) using computational modeling. Several traditional models and a latent-state model that captured model-based RL were applied to skin conductance responses (SCR) collected during fear acquisition and extinction, and the latent-state model was identified as the best fitting model. Model-derived parameters from the latent-state model were carried forward to neuroimaging analyses (voxel-wise and independent component analysis) and results revealed that reduced latent-state related activity within visual processing regions uniquely predicted higher PTSD symptoms. Additionally, after controlling for latent-state update-related encoding, greater value estimation encoding within the left frontoparietal network during fear acquisition and reduced value estimation encoding within the dorsomedial prefrontal cortex during fear extinction predicted greater PTSD symptoms. Results provide evidence of disrupted model-based RL processes in women with IPV-related PTSD, which may contribute to difficulties revising fear and safety information. Future work should further assess model-based RL in PTSD.

Startle Reactivity and Peritraumatic Dissociations in Acute Stress Disorder

2008 ◽  
Vol 22 (4) ◽  
pp. 185-194 ◽  
Author(s):  
Karin Elsesser ◽  
Claudia Freyth ◽  
Thomas Lohrmann ◽  
Gudrun Sartory
Keyword(s):  
Stress Disorder ◽  
Acute Stress ◽  
Acute Stress Disorder ◽  
Group Differences ◽  
Protective Mechanism ◽  
Healthy Controls ◽  
Significant Group ◽  
Startle Magnitude ◽  
Dissociative Symptoms ◽  
Skin Conductance Responses

Startle reactions and their relationship to dissociative symptoms were assessed in acute stress disorder (ASD) patients. Electromyographic (EMG) responses, heart-rate reactions (HRR), and skin conductance responses (SCR) to startle stimuli were compared between victims of mixed traumatic events (n = 31) and healthy controls without trauma exposure (n = 20). All ASD patients met criteria for acute stress disorder (although 12 of them did not demonstrate the required number of dissociative symptoms). Compared to controls, ASD patients showed increased HRR and slower habituation, as well as increased SCRs to the startle stimuli. There were no significant group differences in relation to EMG responses. In ASD patients, reported intensity of peritraumatic dissociations was related to lower EMG startle magnitude and more rapid EMG habituation, suggesting a protective mechanism of dissociative symptoms that may come into effect in response to arousing situations and stimuli.

scholarly journals Parent-Child Autonomic Synchrony During Vicarious Extinction Learning in Pediatric PTSD

2022 ◽  
Author(s):  
Grace C George ◽  
Sara A Heyn ◽  
Shuka Konishi ◽  
Marie-France Marin ◽  
Mohammed R Milad ◽  
...  
Keyword(s):  
Child Psychopathology ◽  
Behavioral Therapy ◽  
Fear Extinction ◽  
Fear Learning ◽  
Group Differences ◽  
Typically Developing ◽  
Significant Group ◽  
Quantification Analysis ◽  
Parental Coaching ◽  
Parent Child

Children must learn basic functional processes directly from their caregivers and child psychopathology may disrupt this transmission. This transmission may be seen through biological measures like peripheral nervous system outputs like skin conductance (SCR). Fear learning deficits have been seen in affective disorders like PTSD and are useful for studying parent-child learning transmission. Our study uses a vicarious fear extinction paradigm to study if biological synchrony (SCR and heart rate variability (HRV)) are potential mechanisms in which children learn safety cues from their parents. There were 16 dyads (PTSD n=11, TD n=5) undergoing a vicarious fear extinction paradigm. We used cross-recurrence quantification analysis (CRQA) to assess SCR and HRV synchrony between parent-child dyads. We then used a linear model looking at group differences between PTSD dyads and typically developing (TD) dyads. For SCR, we saw a significant group difference (p=.037) indicating that TD dyads had higher SCR synchrony compared to PTSD dyads. For HRV, there were no group differences between PTSD and TD dyads (p=.325). These results suggest that SCR synchrony, but not HRV, may be a potential mechanism that allows for fear and safety learning in youth. While this is preliminary, it may give the first insights on how therapies such as Trauma-Focused Cognitive Behavioral Therapy critically rely on parental coaching to model appropriate fear responses to help their child to recover from trauma.

Comparison of Auditory, Language, Memory, and Attention Abilities in Children With and Without Listening Difficulties

2020 ◽  
Vol 29 (4) ◽  
pp. 710-727
Author(s):  
Beula M. Magimairaj ◽  
Naveen K. Nagaraj ◽  
Alexander V. Sergeev ◽  
Natalie J. Benafield
Keyword(s):  
Auditory Processing ◽  
Short Term Memory ◽  
Group Differences ◽  
Long Term Memory ◽  
Short Term ◽  
Significant Group ◽  
Term Memory ◽  
Memory And Attention ◽  
Speed And Accuracy

Objectives School-age children with and without parent-reported listening difficulties (LiD) were compared on auditory processing, language, memory, and attention abilities. The objective was to extend what is known so far in the literature about children with LiD by using multiple measures and selective novel measures across the above areas. Design Twenty-six children who were reported by their parents as having LiD and 26 age-matched typically developing children completed clinical tests of auditory processing and multiple measures of language, attention, and memory. All children had normal-range pure-tone hearing thresholds bilaterally. Group differences were examined. Results In addition to significantly poorer speech-perception-in-noise scores, children with LiD had reduced speed and accuracy of word retrieval from long-term memory, poorer short-term memory, sentence recall, and inferencing ability. Statistically significant group differences were of moderate effect size; however, standard test scores of children with LiD were not clinically poor. No statistically significant group differences were observed in attention, working memory capacity, vocabulary, and nonverbal IQ. Conclusions Mild signal-to-noise ratio loss, as reflected by the group mean of children with LiD, supported the children's functional listening problems. In addition, children's relative weakness in select areas of language performance, short-term memory, and long-term memory lexical retrieval speed and accuracy added to previous research on evidence-based areas that need to be evaluated in children with LiD who almost always have heterogenous profiles. Importantly, the functional difficulties faced by children with LiD in relation to their test results indicated, to some extent, that commonly used assessments may not be adequately capturing the children's listening challenges. Supplemental Material https://doi.org/10.23641/asha.12808607

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