Introduction: Recent research and policy (e.g., the Sergeant First Class (SFC) Heath Robinson Honoring our Promise to Address Comprehensive Toxics (PACT) Act) have highlighted the potential health consequences of toxic environmental exposures.
View Article and Find Full Text PDFIntroduction: Evidence suggests that executive function (EF) may play a key role in development of PTSD, possibly influenced by factors such as trauma type and timing. Since EF can be improved through intervention, it may be an important target for promoting resilience to trauma exposure. However, more research is needed to understand the relation between trauma exposure, EF, and PTSD.
View Article and Find Full Text PDFSensorimotor gating is a measure of pre-attentional information processing and can be measured by prepulse inhibition (PPI) of the startle reflex. Sleep deprivation has been shown to disrupt PPI in animals and humans, and has been proposed as an early phase 2 model to probe antipsychotic efficacy in heathy humans. To further investigate the reliability and efficacy of sleep deprivation to produce PPI deficits we tested the effects of total sleep deprivation (TSD) on PPI in healthy controls in a highly controlled sleep laboratory environment.
View Article and Find Full Text PDFInsomnia is a common and impairing consequence of military deployment, but little is known about pre-deployment risk factors for post-deployment insomnia. Abnormal threat learning tendencies are commonly observed in individuals with insomnia and maladaptive responses to stress have been implicated in the development of insomnia, suggesting that threat learning could be an important risk factor for post-deployment insomnia. Here, we examined pre-deployment threat learning as a predictor of post-deployment insomnia and the potential mechanisms underlying this effect.
View Article and Find Full Text PDFLittle is understood about cognitive mechanisms that confer risk and resiliency for posttraumatic stress disorder (PTSD). Prepulse Inhibition (PPI) is a measure of pre-attentional response inhibition that is a stable cognitive trait disrupted in many neuropsychiatric disorders characterized by poor behavioral or cognitive inhibition, including PTSD. Differentiating between PTSD-related phenotypes that are pre-existing factors vs.
View Article and Find Full Text PDFBackground: Anhedonia, the reduction of pleasure and reward-seeking behaviour, is a transdiagnostic symptom with well-described neural circuit mediators. Although typically observed during disease state, extant hypotheses suggest that anhedonia may also be an early risk factor for development of psychopathology. Understanding the contribution of anhedonia to the trauma-response trajectory may bolster inferences about biological mechanisms contributing to pre-trauma risk versus trauma-related symptom expression, knowledge of which could aid in targeted interventions.
View Article and Find Full Text PDFTrauma disorders are often associated with alterations in aversive anticipation and disruptions in emotion/fear circuits. Heightened or blunted anticipatory responding to negative cues in adulthood may be due to differential trauma exposure during development, and previous trauma exposure in childhood may also modify effects of subsequent trauma in adulthood. The aim of the current investigation was to examine the contributions of childhood trauma on affective modulation of startle before and after trauma exposure in adulthood (a combat deployment).
View Article and Find Full Text PDF: Insomnia is common in service members and associated with many mental and physical health problems. Recently, longitudinal data have been used to assess the impact of disturbed sleep on mental health outcomes. These studies have consistently shown relationships between sleep disturbance and development of mental illness.
View Article and Find Full Text PDFContextual threat learning is often associated with two processes: elemental and configural learning. Few studies have examined configural learning where subjects form a representation of the threat-related context as a gestalt whole from the individual features in the environment. The goal of the current study was to compare and contrast neural circuitry recruited by variation in demands placed on configural threat encoding.
View Article and Find Full Text PDFPrevious research on the effect of perturbed auditory feedback in speech production has focused on two types of responses. In the short term, speakers generate compensatory motor commands in response to unexpected perturbations. In the longer term, speakers adapt feedforward motor programmes in response to feedback perturbations, to avoid future errors.
View Article and Find Full Text PDFCurr Psychiatry Rep
January 2019
Purpose Of Review: The emotional memory and learning model of PTSD posits maladaptive fear conditioning, extinction learning, extinction recall, and safety learning as central mechanisms to PTSD. There is increasingly convincing support that sleep disturbance plays a mechanistic role in these processes. The current review consolidates the evidence on the relationships between emotional memory and learning, disturbed sleep, and PTSD acquisition, maintenance, and treatment.
View Article and Find Full Text PDFBackground: Posttraumatic Stress Disorder (PTSD) is associated with a number of negative physical and mental health consequences. Fear conditioning plays an important mechanistic role in PTSD, and PTSD patients also show deficits in safety signal learning. Sleep, particularly REM sleep, is linked to improved safety learning and extinction processes in animal models and healthy humans.
View Article and Find Full Text PDFSpeaking is a complex motor skill which requires near instantaneous integration of sensory and motor-related information. Current theory hypothesizes a complex interplay between motor and auditory processes during speech production, involving the online comparison of the speech output with an internally generated forward model. To examine the neural correlates of this intricate interplay between sensory and motor processes, the current study uses altered auditory feedback (AAF) in combination with magnetoencephalography (MEG).
View Article and Find Full Text PDFWhen talking, speakers continuously monitor and use the auditory feedback of their own voice to control and inform speech production processes. When speakers are provided with auditory feedback that is perturbed in real time, most of them compensate for this by opposing the feedback perturbation. But some responses follow the perturbation.
View Article and Find Full Text PDFPTSD has been associated consistently with abnormalities in fear acquisition and extinction learning and retention. Fear acquisition refers to learning to discriminate between threat and safety cues. Extinction learning reflects the formation of a new inhibitory-memory that competes with a previously learned threat-related memory.
View Article and Find Full Text PDFAn important part of understanding speech motor control consists of capturing the interaction between speech production and speech perception. This study tests a prediction of theoretical frameworks that have tried to account for these interactions: If speech production targets are specified in auditory terms, individuals with better auditory acuity should have more precise speech targets, evidenced by decreased within-phoneme variability and increased between-phoneme distance. A study was carried out consisting of perception and production tasks in counterbalanced order.
View Article and Find Full Text PDFThere has been a great deal of recent interest in human models of contextual fear learning, particularly due to the use of such paradigms for investigating neural mechanisms related to the etiology of posttraumatic stress disorder. However, the construct of "context" in fear conditioning research is broad, and the operational definitions and methods used to investigate contextual fear learning in humans are wide ranging and lack specificity, making it difficult to interpret findings about neural activity. Here we will review neuroimaging studies of contextual fear acquisition in humans.
View Article and Find Full Text PDFBackground: Risk for posttraumatic stress disorder (PTSD) is thought to be mediated by gene × environment (G × E) interactions that affect core cognitive processes such as fear learning. The catechol-O-methyltransferase (COMT) val158met polymorphism has been associated with risk for PTSD and impaired fear inhibition. We used a large, relatively homogenous population to (1) replicate previous findings of poor fear inhibition in COMT Met/Met carriers with PTSD; (2) determine if COMT association with fear inhibition is moderated by childhood trauma (CT), an environmental risk factor for PTSD; and (3) determine if COMT is associated with altered fear processes after recent exposure to combat trauma.
View Article and Find Full Text PDFBiol Psychiatry Cogn Neurosci Neuroimaging
March 2017
Background: Learned fear is crucial in the development and maintenance of posttraumatic stress disorder (PTSD) and other anxiety disorders, and extinction of learned fear is necessary for response to exposure-based treatments. In humans, research suggests disrupted sleep impairs consolidation of extinction, though no studies have examined this experimentally using total sleep deprivation.
Methods: Seventy-one healthy controls underwent a paradigm to acquire conditioned fear to a visual cue.
Front Psychol
September 2016
This study investigates cross-language lexical competition in the bilingual mental lexicon. It provides evidence for the occurrence of inhibition as well as the commonly reported facilitation during the production of cognates (words with similar phonological form and meaning in two languages) in a mixed picture naming task by highly proficient Welsh-English bilinguals. Previous studies have typically found cognate facilitation.
View Article and Find Full Text PDFBackground: Heightened startle response is a symptom of PTSD, but evidence for exaggerated startle in PTSD is inconsistent. This prospective study aimed to clarify whether altered startle reactivity represents a trait risk-factor for developing PTSD or a marker of current PTSD symptoms.
Methods: Marines and Navy Corpsmen were assessed before (n = 2,571) and after (n = 1,632) deployments to Iraq or Afghanistan with the Clinician-Administered PTSD Scale (CAPS).
Studies of animal behavior consistently demonstrate that the social environment impacts cooperation, yet the effect of social dynamics has been largely excluded from studies of human cooperation. Here, we introduce a novel approach inspired by nonhuman primate research to address how social hierarchies impact human cooperation. Participants competed to earn hierarchy positions and then could cooperate with another individual in the hierarchy by investing in a common effort.
View Article and Find Full Text PDFAn important issue in current psycholinguistics is how the time course of utterance planning affects the generation of grammatical structures. The current study investigated the influence of parallel activation of the components of complex noun phrases on the generation of subject-verb agreement. Specifically, the lexical interference account (Gillespie & Pearlmutter, 2011b; Solomon & Pearlmutter, 2004) predicts more agreement errors (i.
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