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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.
161

Caregiving Burden and Heart Rate Variability: Differences by Race and Gender

Williams, Elizabeth A. 02 June 2020 (has links)
No description available.
162

The Associations of Extraversion and Heart Rate Variability

Channell, Rachel Marie 21 May 2021 (has links)
Heart rate variability as a measure of cardiovascular health and autonomic activity correlates with psychological resiliency but is not consistently related to trait extraversion, a strong predictor of emotional well-being. This study intends to clarify research findings about trait extraversion and heart rate variability by identifying the context and nature of the relationship between extraversion and physiological responses. As a secondary analysis of data from a study comparing biofeedback and compassionate breathing, extraversion scores were compared with heart rate variability data at three different points including prior to a stressor, during exposure to a stressor, and recovery to a stressor to determine the influence of extraversion on stress reactivity and stress recovery. In our sample population of 80 participants who were mostly young and in good health determined by self-report, the average extraversion score 79.14. Linear regression was used to compare differences at each time point and data was analyzed for significance at p=.05; a post-hoc power analysis revealed β = .81, 1 – β. There were no significant findings between extraversion and heart rate variability at any time point. The results of this study support no relationship between extraversion, health, and stress-resiliency.
163

Physiological Arousal, Emotion, and Word Retrieval in Aphasia: Effects and Relationships

Johnson, Angela Lynne 16 June 2021 (has links)
People with aphasia are known to have poor word retrieval abilities in communicative tasks. It has also been reported that they have lower, non-optimal levels of physiological arousal, which may cause lower attention levels therefore contributing to poor performance on linguistic tasks. The purpose of this study was to investigate the relationship between physiological arousal and word retrieval in adults with aphasia and neurotypical adults when presented with emotional stimuli within a confrontational naming task. Participants included 6 people with aphasia and 15 neurotypical controls. All participants completed a confrontational naming task within 3 emotional conditions (neutral, positive, negative) and physiological measures (Heart Rate Variability, Skin Conductance) were taken simultaneously. No statistically significant results were found; however, numerical trends were identified in the data that may provide direction when designing future studies.
164

Technological Architecture with Low Cost Sensors to Improve Physical Therapy Monitoring

Zambrano, Ericsson Ocas, Munoz, Kemeli Reyes, Armas-Aguirre, Jimmy, Gonzalez, Paola A. 01 June 2020 (has links)
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / In this article, we propose a wireless monitoring solution for gait parameters using low-cost sensors in the physical rehabilitation of patients with gait disorders. This solution consists of infrared speed sensors (IRSS), force-sensing Resistor (FSR) and microcontrollers placed in a walker. These sensors collect the pressure distribution on the walker's handle and the speed of the steps during therapy session. The proposal allows to improve the traditional physiotherapy session times through a mobile application to perform the monitoring controlled by a health specialist in real time. The proposed solution consists of 4 stages: 1. Obtaining gear parameters, 2. Data transmission, 3. Information Storage and 4. Data collection and processing. Solution was tested with 10 patients from a physical rehabilitation center in Lima, Peru. Preliminary results revealed a significant reduction in the rehabilitation session from 25 to 5.2 minutes. / Revisión por pares
165

Prioritized memory consolidation over sleep: Do psychological and physiological markers at encoding set the stage?

Bottary, Ryan January 2022 (has links)
Thesis advisor: Elizabeth A. Kensinger / Emotion enhances memory longevity and vividness. Perceiving an experience as emotional, as well as the autonomic and functional brain responses involved in initially encoding an emotional experience, have been theorized to “tag” these memories. Tagged memories may then be prioritized for consolidation during sleep. However, direct evidence supporting this theory is sparse. The aim of the present study was to determine which encoding-related indicators of memory tagging interact with post-encoding sleep oscillations to promote emotional memory retention and vividness. To test this, participants incidentally encoded positive, neutral and negative multisensory stimuli during 3T fMRI scanning with concurrent heart rate monitoring. Participants provided emotional intensity ratings after each stimulus presentation. Following a 120-min post-encoding nap opportunity recorded with polysomnography, participants completed a surprise memory test. Memory for emotional and neutral stimuli was equivalent, though emotional stimuli tended to be remembered more vividly. Perceived emotional intensity, but not heart rate deceleration (HRD) magnitude or functional brain activity, was diagnostic of later successful retrieval of emotional, but not neutral stimuli. Higher REM sleep theta power during the nap was associated with a greater emotional intensity (EI) subsequent memory effect (i.e., higher EI for later remembered compared to forgotten stimuli) for positive stimuli, which were also remembered more vividly. Higher NREM spindle density was associated with a greater EI subsequent memory effect for neutral stimuli and lesser EI subsequent memory effect for negative stimuli. Lastly, higher numbers of NREM spindle-slow oscillation coupling events predicted a negative relationship between perceived emotional intensity at encoding and memory vividness for negative stimuli. Taken together, the present findings suggest that subjective, rather than objective, encoding-related arousal responses acted as emotion “tags”. How subjective arousal impacted later memory varied as a function of the memory’s emotion category and REM and NREM-specific oscillations. Future work is needed to clarify the underlying mechanisms for these observed effects. / Thesis (PhD) — Boston College, 2022. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Psychology.
166

Characterization of Responses to Neurokinin a in the Isolated Perfused Guinea Pig Heart

Hoover, Donald B., Chang, Yingzi, Hancock, John C. 01 January 1998 (has links)
Goals of this study were to identify and characterize effects of neurokinin A (NKA) in isolated guinea pig hearts. Bradycardia, augmentation of ventricular contractions, and reduction of perfusion pressure were prominent responses to bolus injections of NKA (0.25-25 nmol). NKA was more potent than substance P (SP) in causing bradycardia but did not differ in potency for lowering perfusion pressure. Doses of SP of 25 nmol or less decreased ventricular force, whereas 100 nmol caused a biphasic response. The percent decrease in heart rate produced by 25 nmol NKA was reduced from 58.0 ± 4.8 to 39.6 ± 3.5% in the presence of μM atropine (n = 5). The positive inotropic response to 25 nmol of NKA in spontaneously beating hearts was replaced by a negative inotropic response during pacing (22.5 ± 3.3% increase vs. 11.7 ± 1.7% decrease, n = 5). Reserpine pretreatment did not affect the positive inotropic response to NKA. Specific binding sites for (125)I-labeled NKA were localized to intracardiac ganglia and coronary arteries but not to myocardium. It was concluded that 1) negative chronotropic responses to NKA involve cholinergic and noncholinergic mechanisms, and 2) the positive inotropic response is an indirect action.
167

Neural Control Hierarchy of the Heart Has Not Evolved to Deal With Myocardial Ischemia

Kember, G., Armour, J. A., Zamir, M. 01 August 2013 (has links)
The consequences of myo-cardial ischemia are examined from the standpoint of the neural control system of the heart, a hierarchy of three neuronal centers residing in central command, intrathoracic ganglia, and intrinsic cardiac ganglia. The basis of the investigation is the premise that while this hierarchical control system has evolved to deal with "normal" physiological circumstances, its response in the event of myocardial ischemia is unpredictable because the singular circumstances of this event are as yet not part of its evolutionary repertoire. The results indicate that the harmonious relationship between the three levels of control breaks down, because of a conflict between the priorities that they have evolved to deal with. Essentially, while the main priority in central command is blood demand, the priority at the intrathoracic and cardiac levels is heart rate. As a result of this breakdown, heart rate becomes less predictable and therefore less reliable as a diagnostic guide as to the traumatic state of the heart, which it is commonly used as such following an ischemic event. On the basis of these results it is proposed that under the singular conditions of myocardial ischemia a determination of neural control indexes in addition to cardiovascular indexes has the potential of enhancing clinical outcome.
168

Dynamic Neural Networking as a Basis for Plasticity in the Control of Heart Rate

Kember, G., Armour, J. A., Zamir, M. 01 January 2013 (has links)
A model is proposed in which the relationship between individual neurons within a neural network is dynamically changing to the effect of providing a measure of "plasticity" in the control of heart rate. The neural network on which the model is based consists of three populations of neurons residing in the central nervous system, the intrathoracic extracardiac nervous system, and the intrinsic cardiac nervous system. This hierarchy of neural centers is used to challenge the classical view that the control of heart rate, a key clinical index, resides entirely in central neuronal command (spinal cord, medulla oblongata, and higher centers). Our results indicate that dynamic networking allows for the possibility of an interplay among the three populations of neurons to the effect of altering the order of control of heart rate among them. This interplay among the three levels of control allows for different neural pathways for the control of heart rate to emerge under different blood flow demands or disease conditions and, as such, it has significant clinical implications because current understanding and treatment of heart rate anomalies are based largely on a single level of control and on neurons acting in unison as a single entity rather than individually within a (plastically) interconnected network.
169

Neural Control Hierarchy of the Heart Has Not Evolved to Deal With Myocardial Ischemia

Kember, G., Armour, J. A., Zamir, M. 01 August 2013 (has links)
The consequences of myo-cardial ischemia are examined from the standpoint of the neural control system of the heart, a hierarchy of three neuronal centers residing in central command, intrathoracic ganglia, and intrinsic cardiac ganglia. The basis of the investigation is the premise that while this hierarchical control system has evolved to deal with "normal" physiological circumstances, its response in the event of myocardial ischemia is unpredictable because the singular circumstances of this event are as yet not part of its evolutionary repertoire. The results indicate that the harmonious relationship between the three levels of control breaks down, because of a conflict between the priorities that they have evolved to deal with. Essentially, while the main priority in central command is blood demand, the priority at the intrathoracic and cardiac levels is heart rate. As a result of this breakdown, heart rate becomes less predictable and therefore less reliable as a diagnostic guide as to the traumatic state of the heart, which it is commonly used as such following an ischemic event. On the basis of these results it is proposed that under the singular conditions of myocardial ischemia a determination of neural control indexes in addition to cardiovascular indexes has the potential of enhancing clinical outcome.
170

Dynamic Neural Networking as a Basis for Plasticity in the Control of Heart Rate

Kember, G., Armour, J. A., Zamir, M. 01 January 2013 (has links)
A model is proposed in which the relationship between individual neurons within a neural network is dynamically changing to the effect of providing a measure of "plasticity" in the control of heart rate. The neural network on which the model is based consists of three populations of neurons residing in the central nervous system, the intrathoracic extracardiac nervous system, and the intrinsic cardiac nervous system. This hierarchy of neural centers is used to challenge the classical view that the control of heart rate, a key clinical index, resides entirely in central neuronal command (spinal cord, medulla oblongata, and higher centers). Our results indicate that dynamic networking allows for the possibility of an interplay among the three populations of neurons to the effect of altering the order of control of heart rate among them. This interplay among the three levels of control allows for different neural pathways for the control of heart rate to emerge under different blood flow demands or disease conditions and, as such, it has significant clinical implications because current understanding and treatment of heart rate anomalies are based largely on a single level of control and on neurons acting in unison as a single entity rather than individually within a (plastically) interconnected network.

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