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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Autonomic Patterns of Emotion across Multiple Contexts

Mcginley, Jared J. 17 June 2015 (has links)
Research on the autonomic specificity of emotion has spanned several decades. Even though considerable evidence exists for supporting autonomic specificity for discrete emotion states (Kreibig, 2010), there is still an active debate, and conflicting explanations, for these findings (Quigley and Barrett, 2014). There have been several studies employing multivariate pattern classification analytic techniques and calls for those types of studies are still prevalent (Kragel and LaBar, 2014). Although many studies have explored the autonomic specificity of emotions, few have explored what effects the induction methods, themselves, have had in inducing the autonomic change. Autonomic specificity of induction methods might be a meaningful, and confounding, phenomenon in this literature. Based on this unknown variable, the current experiment was designed to see if methods for emotion elicitation could be meaningfully captured by these same pattern classification techniques. This was accomplished using three separate emotion-elicitation methods to elicit five separate emotions. A sample of 64 college-aged students watched film clips, read imagery scripts, and recalled personal memories for five discrete emotions. Using discriminant analysis, the evidence from the current study lent less support for autonomic specificity of emotion than past experiments, and lends some support for providing future exploration into autonomic change that is related to methods for induction. Potential confounds and task fatigue effects are discussed. / Ph. D.
72

Multidimensional Cardioception and Trait Anxiety: Potential Clues from Baroreflex Sensitivity

Grant, Shara Soyini 10 August 2018 (has links)
Interoception, the perception of the body's physiological state, is often studied in relation to emotion processing. Particularly, cardioception has been largely implicated in anxiety. Three related but distinct dimensions of interoception have recently emerged in the literature: sensibility (IS), accuracy (IAC), and awareness (IAW). Divergent findings regarding interoception and anxiety may result from lacking appreciation for interoceptive dimensions. Additionally, the role of cardiovascular afferent feedback in anxiety and interoception is largely unknown. Baroreflex sensitivity (BRS) has been implicated in interoceptive processes yet no known research directly measures this in relation to multidimensional cardioception. The present study aimed to assess the degree to which IS, IAC, IAW, and BRS predict trait anxiety at rest and during anticipatory anxiety. Results partially suggest increased IAC and BRS, but more variable IS and IAW in relation to trait anxiety. Overall, results show complex associations among factors, suggesting increased specificity among the constructs. Results highlight the importance of attention to construct validity and method variance in the study of interoceptive subdomains. Finally, the present study helps to pave the way for continued investigations concerning cardioception in enduring anxiety and the related role of the baroreflex in cardiac afferent processes. / PHD / Interoception, the perception of the body’s physiological state, is often studied in relation to emotion processing. Particularly, cardioception (the sense of cardiac activity, such as the perception of a racing heart) has been largely implicated in anxiety. Three related but distinct dimensions of interoception have recently emerged in the literature: sensibility (IS), accuracy (IAC), and awareness (IAW). Divergent findings regarding interoception and anxiety may result from lacking appreciation for interoceptive dimensions. Additionally, the role of cardiovascular feedback to the brain in anxiety and interoception is largely unknown. The baroreflex system rapidly modulates activity of the heart in accordance with short-term blood pressure changes. The sensitivity of this homeostatic baroreflex system (BRS) also plays a role in interoceptive processes, yet no known research directly measures this in relation to multidimensional cardioception. The present study aimed to assess the degree to which IS, IAC, IAW, and BRS predict dispositional anxiety at rest and during anticipatory anxiety. Results partially suggest increased IAC and BRS, but more variable IS and IAW in relation to dispositional anxiety. Overall, results show complex associations among factors, suggesting increased specificity among the variables. Results highlight the importance of attention to measurement precision and various ways to assess the dimensions of interoception. Finally, the present study helps to pave the way for continued research concerning perception of the heart’s activity in enduring anxiety and the related role of cardiovascular activity at various levels of conscious awareness. Ultimately, research on this topic is highly important for the eventual improvement of existing therapeutics for individuals regularly experiencing severe anxiety.
73

Investigation of somatomotor-sympathetic brain circuit abnormalities in two rat models featuring inborn differences in emotional behavior

Shupe, Elizabeth Anne 27 July 2023 (has links)
Major depressive disorder (MDD) features symptoms spanning cognitive, affective, behavioral, and physiological domains. While many of the neural circuit disruptions mediating emotional and cognitive disturbances in depression have been described, far fewer studies have explored neurobiological mechanisms underlying its associated motor or physiological impairments. Emotionally motivated behaviors, including responses to stress, are characterized by concomitant somatomotor actions and autonomic changes that require intricate coordination of the motor and autonomic systems. Prior investigations by our group used a pseudorabies virus (PRV)-mediated retrograde tract-tracing approach to identify brain regions with parallel descending premotor and presympathetic efferents that play a role in integrating somatomotor and sympathetic functions. Several nodes of this circuitry, including the hypothalamic paraventricular nucleus (PVN), locus coeruleus (LC), and periaqueductal gray (PAG), are implicated in responses to stressful and emotionally salient stimuli. Based on this observation, it was hypothesized that these parallel descending circuits shape responses to diverse stressors and are altered in clinical depression and comorbid anxiety disorders. To explore this possibility, the experiments in this dissertation used two recombinant PRV strains to trace polysynaptic premotor and presympathetic pathways innervating sympathectomized skeletal muscle and adrenal gland, respectively, in two rat models with heritable differences in emotionality and stress reactivity: the Wistar-Kyoto (WKY) rat and the selectively bred Low Novelty Responder (bLR) rat. During our initial neuroanatomical investigations in the PVN, we observed that both WKY and bLR rats displayed significant decreases in the quantity of PVN neurons with premotor projections to skeletal muscle compared to their respective control strains. Labeling of neurons with presympathetic projections to adrenal gland or dual-labeled polysynaptic projections to both motor and sympathetic targets was not altered in either model. Our subsequent neuroanatomical studies focused on comparing premotor efferent projections from LC and PAG. In LC, fewer premotor efferent projections to skeletal muscle were observed in both models. There were also reductions in the number of premotor efferents in the four subdivisions of the PAG. WKY rats had significantly fewer premotor projections in the dorsomedial (DMPAG), lateral (LPAG), and ventrolateral (VLPAG) subdivisions, while bLR rats had significantly fewer premotor efferents in dorsolateral (DL)PAG. The final experiments in this dissertation sought to determine whether one potential therapeutic intervention, environmental enrichment during late childhood and adolescence, can improve emotional behavior disturbances and reverse premotor circuit alterations in bLR rats. Rearing young bLR rats in conditions with increased environmental complexity partially but incompletely improved aspects of depression- and anxiety-relevant behaviors and their corresponding PVN premotor circuit abnormalities. Cumulatively, these findings highlight somatomotor circuits in several brain structures involved in responses to stress and emotional stimuli that could be implicated in mediating motor-related impairments in clinical depression. / Doctor of Philosophy / Depression is a common and complex illness that features many types of impairing symptoms. Some of these symptoms involve functions regulated by the somatic motor system, which controls movement, and the autonomic nervous system, which regulates many basic bodily functions (for example, heart rate and blood pressure) that occur outside of our conscious control. The ability to coordinate the actions of these two systems is important for many behaviors, including how we respond to emotional or stressful situations. Past experiments in our laboratory used a type of virus (pseudorabies virus, PRV) that travels backwards through neural circuits containing multiple neurons and allows us to label parts of the brain that project to peripheral areas regulated by the somatic motor system (i.e., hindlimb skeletal muscle), the autonomic nervous system (i.e., adrenal gland), or both. These labeling experiments identified neurons in these motor and autonomic circuits in several parts of the brain, including the paraventricular nucleus of the hypothalamus (PVN), locus coeruleus (LC), and periaqueductal gray (PAG). Of note, all of these structures are involved in regulating responses to stressful or emotional situations. This observation led us to hypothesize that motor and autonomic projections from these areas of the brain are important for regulating how we respond to stress and might be altered in individuals suffering from depression. To test this idea, we labeled motor- and autonomic-projections with PRV in two separate rat models with a genetic disposition for emotional behaviors that resemble symptoms of clinical depression or anxiety. When we analyzed the PVN, LC, and PAG of rats with depression-relevant behaviors, we discovered that each of these brain areas contained fewer labeled neurons with motor projections to skeletal muscle. Based on these findings, we were interested in exploring whether enriching or stimulating experiences during early life had the potential to reverse deficits in the PVN motor projections and improve emotional behavior in one of our rat models for depression. Although enrichment partially improved behavioral and circuit-level outcomes, it was not fully effective. Taken together, our experimental findings highlight disruptions of motor projecting circuits in several brain structures implicated in mediating responses to stressful or emotional stimuli in two rat models relevant to depression and anxiety disorders. These motor circuit disruptions could be implicated in mediating motor-related symptoms observed in clinically depressed patients.
74

Temporal Dynamics of the Defense Cascade

Nackley, Brittany B. January 2020 (has links)
Understanding physiological responses to threat can inform therapeutic interventions for phobias, anxieties, and PTSD. The defense cascade is reviewed as a theoretical model that predicts behavioral and physiological responses to threats. Nineteen undergraduates (five male), average age 19.4 experienced a novel virtual reality (VR) threat scenario while their physiology was measured. The Subjective Units of Distress Scale (SUDS) was used as a self-report indicator of distress in the research setting. Averaged SUDS reports suggested that the VR stimulus was experienced as threatening for most participants, but their autonomic response patterns did not fit those predicted by the defense cascade. Participants who had scored high on adaptive response questionnaires tended to show uncoupled ANS activation during baseline, but varied across the stimulus condition. Nearly all participants showed either coactivation or reciprocal activation during the stimulus period except those reporting the most dissociative trauma experiences, who mostly showed uncoupled ANS activation. / M.S. / The more we understand about how people’s bodies and their energies act when they feel threatened, the better we can find help for folks who struggle with anxiety, trauma or other challenging conditions. This research uses a theoretical model called the defense cascade to explore how people respond mentally and physically to threatening situations. Nineteen undergraduates went through a virtual reality (VR) experience that was designed to feel threatening while their body and its energy systems were measured. A scale was introduced called the Subjective Units of Distress Scale (SUDS) and was used to help the researchers understand how distressed people felt while they were in the VR experience. Averaged SUDS reports suggested that the VR stimulus was experienced as threatening for most participants, but their body response patterns did not fit those predicted by the defense cascade. Participants whose questionnaire responses suggested they were not anxiety-prone or traumatized, tended to show bodily activation that uncoupled their two autonomic bodily systems during a baseline period before the threatening stimulus. However, their autonomic responses during the stimulus period varied. Nearly all participants showed either both autonomic systems acting together or only one system acting in a mutually exclusive way to the other system during the stimulus period. This was the case for most participants except those reporting the most trauma involving dissociative experiences. This latter group mostly showed uncoupled autonomic bodily patterns.
75

Design of an autonomic system for IP-network environments

Ljungdahl, Emil, Andersson, Erik January 2009 (has links)
<p>A2B Electronics AB is a company that develops and manufactures products and technology for digital cable television. A2B's new EXM-product family translates digital television channels from multiple source networks into a single destination network. Multiple EXM-units are connected in a system to provide a custom set of TV channels. To minimize the administrative effort, the units in a system should be able to interact and collaborate without manual intervention. The purpose of this thesis is to propose an underlying system that supports seamless interaction and collaboration between units.</p><p>The autonomic system concept has served as a foundation for the proposed solution. The requirements for the EXM-system proved to be similar to many properties of an autonomic system. The proposed solution was elaborated by answering five reseach questions. The answers describe how an autonomic system can be implemented with the prerequisites of the EXM-system. Solutions for service availability, configuration preservation, system state changes and automatic addressing and communication are provided.</p><p>The project has resulted in a proposal of a general autonomic system. The solution has also been implemented as prototype that runs both in a simulator and on the EXM-hardware. The simulator was also developed in the scope of this project as a side-effect of the limited access to EXM-hardware.</p><p>The proposed solution together with the prototype can hopefully serve as a base for projects with prerequisites similar to the project described in this thesis.</p>
76

Autonomic cardiac control in patients with epilepsy : spectral analysis of heart rate variability /

Persson, Håkan, January 2006 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 5 uppsatser.
77

Cardiovascular autonomic modulation following maximal exercise Its relationship to race, VO2max, and resting heart rate variability /

Esco, Michael R. Blessing, Daniel L., January 2009 (has links)
Thesis (Ph. D.)--Auburn University. / Abstract. Includes bibliographical references.
78

Design of an autonomic system for IP-network environments

Ljungdahl, Emil, Andersson, Erik January 2009 (has links)
A2B Electronics AB is a company that develops and manufactures products and technology for digital cable television. A2B's new EXM-product family translates digital television channels from multiple source networks into a single destination network. Multiple EXM-units are connected in a system to provide a custom set of TV channels. To minimize the administrative effort, the units in a system should be able to interact and collaborate without manual intervention. The purpose of this thesis is to propose an underlying system that supports seamless interaction and collaboration between units. The autonomic system concept has served as a foundation for the proposed solution. The requirements for the EXM-system proved to be similar to many properties of an autonomic system. The proposed solution was elaborated by answering five reseach questions. The answers describe how an autonomic system can be implemented with the prerequisites of the EXM-system. Solutions for service availability, configuration preservation, system state changes and automatic addressing and communication are provided. The project has resulted in a proposal of a general autonomic system. The solution has also been implemented as prototype that runs both in a simulator and on the EXM-hardware. The simulator was also developed in the scope of this project as a side-effect of the limited access to EXM-hardware. The proposed solution together with the prototype can hopefully serve as a base for projects with prerequisites similar to the project described in this thesis.
79

Correlates of autonomic nervous system function in a general population with special reference to HbA₁c: The Nagahama study / 一般住民における自律神経機能と特にHbA₁cとの関連:ながはまスタディ

Takahashi, Naomi 25 January 2021 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(社会健康医学) / 甲第22888号 / 社医博第112号 / 新制||社医||11(附属図書館) / 京都大学大学院医学研究科社会健康医学系専攻 / (主査)教授 川上 浩司, 教授 今中 雄一, 教授 稲垣 暢也 / 学位規則第4条第1項該当 / Doctor of Public Health / Kyoto University / DFAM
80

Autonomic Dysfunction : a conceptual model, the effects of a physical therapeutic manipulation targeting the T3-T4 segment on the autonomic nervous system

Sillevis, Rob 01 January 2008 (has links)
Purpose: This study will identify that patients with chronic neck pain have an altered autonomic functioning compared to a control group, and that manipulation might directly influence the autonomic nervous system as measured by using a fully automated pupillometry system. Subjects: 100 chronic pain patients and 50 control subjects participated in this study to achieve a power of 0.80, effect size of 0.5, and a type I error rate of 0.05 for two-tailed hypothesis testing. Method: A quasi-experimental design was be used. The ANOVA and Chi square test were used to establish homogeneity of baseline characteristics. The Mann-Whitney U test was performed to compare the pre-intervention pupil diameter amongst the groups. The Friedman's test was used to determine the pupil diameter change during the three measurements. The Wilcoxen Signed-ranks test was used to analyze the difference in pupil size between the pre- and post-intervention measures and to determine if there was a difference in pupil diameter between the two groups undergoing the thoracic manipulation. The Kruskal-Wallis test was used to compare the pupil diameter change to the presence of joint sounds. And the Fisher's Exact test was used to determine the relationship between the number of pops and the VAS change score > 13mm. Results: This study demonstrated that the chronic pain group had a statistically significant smaller pupil diameter than the healthy control group (P=0.022). Manipulation resulted in a relative increase in pupil diameter following the manipulation, however this was not statistical significant. There was a statistical significant decrease in pupil diameter in the placebo group (pConclusions: It appears that a T3-T4 manipulation results in a relative non-specific increase in sympathetic activity. Recommendations: Manipulation may be used by physical therapists to affect the autonomic nervous system. Visual pupil assessment may become part of the evaluation process to identify patients that might present with autonomic dysfunction and to determine the effect of treatment modalities.

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