Дисертації з теми "Connectivity Functions"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 дисертацій для дослідження на тему "Connectivity Functions".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
Williams, Kathleen Anne. "Resting State Connectivity in the Rat Brain." Thesis, Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/14059.
Повний текст джерелаTaixés, i. Ventosa Jordi. "Connectivity of Julia sets of transcendental meromorphic functions." Doctoral thesis, Universitat de Barcelona, 2011. http://hdl.handle.net/10803/50391.
Повний текст джерелаPallarés, Picazo Vicente. "Individual traits versus invariances of cognitive functions: a model-based study of brain connectivity." Doctoral thesis, Universitat Pompeu Fabra, 2019. http://hdl.handle.net/10803/666806.
Повний текст джерелаÉs conegut en la literatura de neuroimatge que les xarxes cerebrals funcionals reflecteixen trets personals. Aquestes característiques individuals podrien interferir en caracteritzar la cognició entesa com la manera en què les xarxes es coordinen per realitzar una tasca, com mantenir l'atenció, recordar o processar informació visual. Cóm aquests aspectes individuals coexisteixen amb mecanismes generals, és, per tant, una pregunta clau en recerca sobre connectivitat cerebral. Aquest treball estudia la relació entre marcadors de connectivitat específics tant de subjectes, com de tasques. Se centra en dues escales temporals: la variabilitat entre sessions, i les fluctuacions ràpides produïdes durant una sessió d'adquisició. Utilitzem tècniques de machine learning per separar quantitativament les contribucions d'informació del subjecte i de l'estat cognitiu a la connectivitat. La metodologia presentada ens permet extreure aquelles xarxes representatives d'ambdues dimensions, així com aprofundir en la seva evolució, suggerint les escales temporals rellevants en la cognició.
There is consistent evidence in the neuroimaging literature that functional brain networks reflect personal traits. Individual specificity may interfere with the characterization of cognition, in terms of coordination of brain networks to perform a task, such as sustained attention, memory retrieval or visual information processing. How individual traits coexist with invariant mechanisms is, therefore, a key question in brain connectivity research. This work aims to examine the relationship between subject- and task-specific connectivity signatures. It focuses on two different timescales: day-to-day variability and faster fluctuations exhibited within a scanning session. We adopt a machine learning approach to quantitatively disentangle the contribution of subject information and cognitive state to the connectivity patterns. The proposed methodology allows us to extract the specific brain networks that support each of the two dimensions, as well as to delve into their changes over time, suggesting the relevant timescales for cognition.
Liu, Xiaojin [Verfasser]. "Multi-modal Parcellation of the Human Striatum: Functions, Clinical Relevance and its Specific Connectivity / Xiaojin Liu." Düsseldorf : Universitäts- und Landesbibliothek der Heinrich-Heine-Universität Düsseldorf, 2021. http://d-nb.info/1239893752/34.
Повний текст джерелаAdar, Maia. "Step-Selection Functions for Modeling Animal Movement -- Case Study: African Buffalo." Scholarship @ Claremont, 2018. http://scholarship.claremont.edu/cmc_theses/1938.
Повний текст джерелаFuller, Joanne Elizabeth. "Analysis of affine equivalent boolean functions for cryptography." Thesis, Queensland University of Technology, 2003. https://eprints.qut.edu.au/15828/1/Joanne_Fuller_Thesis.pdf.
Повний текст джерелаFuller, Joanne Elizabeth. "Analysis of Affine Equivalent Boolean Functions for Cryptography." Queensland University of Technology, 2003. http://eprints.qut.edu.au/15828/.
Повний текст джерелаShin, Jaemin. "Characterization and compensation of physiological fluctuations in functional magnetic resonance imaging." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/44862.
Повний текст джерелаRahal, Line. "Imagerie fonctionnelle ultrasonore du cerveau pour l'étude, le suivi et le traitement de la douleur aiguë et chronique." Thesis, Paris Sciences et Lettres (ComUE), 2018. http://www.theses.fr/2018PSLET041.
Повний текст джерелаThose thesis works aimed at demonstrating the value of functional ultrasound imaging for the definition and the tracking of acute and chronic pain therapeutic treatments. As part of a common project intertwining wave physics, imaging, neurosciences and pain, we demonstrated that this young imaging technology can be applied to pain imaging on the anesthetized small animal, at different levels of the nervous system.With the aim of obtaining an adapted anaesthesia, stable, reproducible from one animal to another, and containing as less pain modulating agents as possible, we compared six different anaesthetics protocols. This study was concluded by the use of the ketamine and medetomidine mixture as the best compromise for our future experiments in pain.The first study on pain processes has focused on the formaline test, a well characterized model of short term inflammatory pain (1h). Indeed, our wish was to start with an acute pain model as short as possible which may be performed on the anesthetized animal. With this model, we didn’t observe any significant change of functional connectivity in the brain of the injected rats. We then chose to turn to more ongoing models of inflammatory pain.The second study of this thesis dealt with the study of the functional connectivity and brain states alterations in two models of inflammatory pain: a short term model, induced by unilateral injection of Freund’s adjuvant, and a long term model, which is adjuvant induced polyarthritis (four weeks of bilateral inflammation). While we didn’t obtain significant results of functional alterations in the short term model, the long term model gave us ample information on the central nervous system alterations during the chronification process.Finally, the last study concerns the ultrasound functional imaging of the trigeminal ganglions, peripheral nervous system structures, both small and deeply located. We tried to characterize the vascular response of those ganglions following mechanical and chemical nociceptive stimulations of the cornea on the anesthetized rat. This study allowed us to confirm the observations obtained by immunohistochemistry of the proto-oncogene c-fos and to validate the functional ultrasound imaging as a modality for the imaging of the trigeminal ganglions in the anesthetized rat, for the study of trigeminal pain
Senouci, Mustapha. "De l'usage de la théorie des fonctions de croyance dans le déploiement et le contrôle de réseaux de capteurs sans fil." Thesis, Paris Est, 2014. http://www.theses.fr/2014PEST1045.
Повний текст джерелаThis dissertation is an in-depth investigation of the Wireless Sensor Networks (WSNs) deployment problems that follows three general directions: (1) random deployment, (2) deterministic deployment, and (3) self-deployment. First, we present a survey and taxonomy of random node placement in WSNs and we devise a practical random deployment strategy. Second, we analyze the uncertainty-aware deterministic WSNs deployment problem where sensors may not always provide reliable information. We discuss sensor coverage models and placement algorithms found in the literature and we investigate the evidence theory to design better deployment strategies. We devise evidence-based sensor coverage models and we propose several polynomial-time uncertainty-aware deployment algorithms. Third, we explore the published self-deployment strategies and we devise a lightweight and comprehensive two-phase protocol, for ensuring area coverage employing a mobile WSN. Experimental results based on synthetic data sets, data traces collected in a real deployment, and an experimental test, show that the proposed approaches outperform the state-of-the-art deployment strategies
Van, Der Werf Steven Martijn. "Architecture and performance of multi-hop wireless ad-hoc routing protocol (MultiWARP)." Thesis, Curtin University, 2010. http://hdl.handle.net/20.500.11937/1989.
Повний текст джерелаJagger, Audreyana. "DEFAULT MODE NETWORK (DMN) AND CENTRAL EXECUTIVE NETWORK (CEN) RESTING-STATE CONNECTIVITY AND THEIR RELATIONSHIP TO HOT AND COOL EXECUTIVE FUNCTIONS IN A MIXED CLINICAL GROUP." OpenSIUC, 2016. https://opensiuc.lib.siu.edu/theses/1916.
Повний текст джерелаBarbalat, Guillaume. "Architecture du contrôle cognitif au sein du cortex cérébral dans la schizophrénie." Phd thesis, Université Claude Bernard - Lyon I, 2009. http://tel.archives-ouvertes.fr/tel-00617958.
Повний текст джерелаEdde, Manon. "Approche multimodale de connectivité fonctionnelle et structurelle pour l’analyse du déclin cognitif au cours du vieillissement : étude au sein de la cohorte des 3Cités." Thesis, Paris Sciences et Lettres (ComUE), 2019. http://www.theses.fr/2019PSLEP011.
Повний текст джерелаAging is associated with changes in the brain, the heterogeneity of which partly explains the inter-individual variability of cognitive decline. These changes concern both the structural and functional aspects. Multimodal brain imaging has provided some insights into the structure-function relationship, but this has been little studied in the context of aging. In this work, functional rest (CF) and structural (CS) connectivity from native space were explored in 120 elderly subjects (cohort 3C) to study their relationship to cognitive trajectories modeled on the 12 years of follow-up. In our sample, elevated interhemispheric CF levels are associated with global changes in cerebral parenchyma (gray matter atrophy and white matter injury burden) and episodic memory decline. The diffusion parameters corrected for free-water, extracted from the cingulum tract are associated with the decline in verbal fluency. On the other hand, high CF and low CS between posterior ventral cingulate cortex (vPCC) and precuneus A7m are associated with episodic memory decline, regardless of hippocampal volume. Finally, the elderly subjects present a deficit of short-term reorganization of the rest-functional architecture after a learning task. Thus, cerebral aging is associated with different patterns of CF changes (increase, decrease, short-term reorganization deficit) thus providing to the brain a more complex response repertoire than CS
Kabbara, Aya. "Estimation des réseaux cérébraux à partir de l’EEG-hr : application sur les maladies neurologiques." Thesis, Rennes 1, 2018. http://www.theses.fr/2018REN1S028/document.
Повний текст джерелаThe human brain is a very complex network. Cerebral function therefore does not imply activation of isolated brain regions but instead involves distributed networks in the brain (Bassett and Sporns, 2017, McIntosh, 2000). Therefore, the analysis of the brain connectivity from neuroimaging data has an important role to understand cognitive functions (Sporns, 2010). Thanks to its excellent spatial resolution, fMRI has become one of the most common non-invasive methods used to study this connectivity. However, fMRI has a low temporal resolution which makes it very difficult to monitor the dynamics of brain networks. A considerable challenge in cognitive neuroscience is therefore the identification and monitoring of brain networks over short time durations(Hutchison et al., 2013), usually <1s for a picture naming task, for example. So far, few studies have addressed this issue which requires the use of techniques with a very high temporal resolution (of the order of the ms), which is the case for magneto- or electro-encephalography (MEG or EEG). However, the interpretation of connectivity measurements from recordings made at the level of the electrodes (scalp) is not simple because these recordings have low spatial resolution and their accuracy is impaired by volume conduction effects (Schoffelen and Gross, 2009). Thus, during recent years, the analysis of functional connectivity at the level of cortical sources reconstructed from scalp signals has been of increasing interest. The advantage of this method is to improve the spatial resolution, while maintaining the excellent resolution of EEG or MEG (Hassan et al., 2014; Hassan and Wendling, 2018; Schoffelen and Gross, 2009). However, the dynamic aspect has not been sufficiently exploited by this method. The first objective of this thesis is to show how the EEG connectivity approach source "makes it possible to follow the spatio-temporal dynamics of the cerebral networks involved either in a cognitive task or at rest. Moreover, recent studies have shown that neurological disorders are most often associated with abnormalities in cerebral connectivity that result in alterations in wide-scale brain networks involving remote regions (Fornito and Bullmore, 2014). This is particularly the case for epilepsy and neurodegenerative diseases (Alzheimer's, Parkinson's) which constitute, according to WHO, a major issue of public health.In this context, the need is high for new methods capable of identifying Pathological networks, from easy to use and non-invasive techniques. This is the second objective of this thesis
Corell, Hanna. "Applications of ocean transport modelling." Doctoral thesis, Stockholms universitet, Meteorologiska institutionen (MISU), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-75344.
Повний текст джерелаAt the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Submitted. Paper 3: Submitted. 4: Manuscript.
Emeriau, Samuel. "Caractérisation des réseaux multi-sujets en IRMf : apport du clustering basé sur la connectivité fonctionnelle." Thesis, Reims, 2011. http://www.theses.fr/2011REIMS018/document.
Повний текст джерелаThe comprehension of cerebral operations is in constant evolution since the rise of the neurosciences.New methods of imagery made it possible to highlight an architecture of our brain in complex networks.The purpose of my work is to develop a method to find the most representative networks of a group of subjects in Functional MRI.In the first step, I developed a method to reduce the fMRI data size based on clustering. I introduced a new characterization of functional information by the profile of connectivity. This one makes it possible to reduce the variance induced by the noise present within the data of Functional MRI.Moreover this profile does not require a priori information on the data contrary to the traditional inferential methods.In the second step, I developed a method to identify common networks on a group of subjects while taking into account of spatial and functional inter-subjects variability. The networks obtained can then be characterized by their spatial organization but also by their inner connectivity links.This method also allows the comparison of the networks of various groups of subjects, making it possible to highlight the implications of different networks according to different stimulations or pathological states
Quidé, Yann. "Etat de stress post-traumatique : corrélats cérébraux, neuropsychologiques, biologiques et thérapeutiques." Thesis, Tours, 2013. http://www.theses.fr/2013TOUR4043/document.
Повний текст джерелаPosttraumatic stress disorder (PTSD) is an anxiety, stress-related disorder, often seen in soldiers returning from armed conflict, victims of war or natural disasters, but can also occur after exposure to more « common » situations in Western countries, such as motor vehicle accidents or sexual assault. PTSD is characterized by executive functioning impairments (attention, working memory) associated with morphological and functional brain abnormalities. This thesis aimed to characterize the morphological and functional effects of different treatments currently recognized as first line for anxiety disorders and major depressive disorder, indicating a « top-down » effect of normalization of frontal areas for psychotherapeutic treatments, while pharmacological treatments seem to lead to a « bottom-up » normalization effect in limbic areas. In addition, in a second study, we demonstrated the importance of the study of brain networks involved in the performance of cognitive tasks such as memory tasks. These networks are deregulated in PTSD, leading to their inefficiency, and therefore to PTSD patient’s inability to perform the required task correctly. Finally, we have set up an ambitious longitudinal (1 month and 6 months) clinical research protocol, investigating early stages of PTSD development in victims of sexual assault. This study combines neuropsychological measures of executive functions, biological measures of the hypothalamic-pituitary-adrenal axis (salivary cortisol) and measures of structural (MRI, DTI) and functional imaging (fMRI, ASL), including measures of brain connectivity (structural, functional)
Radhakrishnan, Rupa M. D. "Altered Functional Activation and Network Connectivity Underlies Working Memory Dysfunction in Adolescents with Epilepsy." University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1515514289145094.
Повний текст джерелаBaronnet-Chauvet, Flore. "IRM fonctionnelle au repos après un accident ischémique : de la connectivité fonctionnelle au handicap." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066229/document.
Повний текст джерелаResting-state functional MRI is increasingly used to investigate brain networks in stroke patients. Most studies focused specifically on motor, attentional and language deficits. Here we have investigated the relationships between global post-stroke disability and functional connectivity of seven major cortical networks in subacute ischemic stroke patients. We have studied 50 patients with first-ever unilateral hemispheric stroke (29 men, 22 left strokes, 57 ± 14 years) with a median post-stroke delay of 4.5 weeks and 75 healthy volunteers (27 men, 55 ± 15 years). Seven cortical networks were characterized with a seed-based approach and for each network we distinguished inter-hemispheric, ipsi- and contra-lesional functional connectivity. The 22 patients without disability (modified Rankin’s scale 0-1) had normal functional connectivity in all networks whereas the 28 disabled patients had widespread and bilateral decreases in functional connectivity explaining 22 % of the variance. Secondary analyses showed that abnormalities mainly differentiate no disability from mild disability and may predominate in default-mode and top-down control networks. We have computed for each subject a functional connectivity index that summarizes all these abnormalities. This simple tool was strongly predictive of residual disability with a specificity of 91% and a sensitivity of 86%. In conclusion, widespread and bilateral alterations in cortical connectivity occur in disabled subacute stroke patients, whereas normal indicate excellent global outcome
Nylén, Jan. "Exploring Ways of Visualizing Functional Connectivity." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-141182.
Повний текст джерелаGoldstone, Aimée. "Functional connectivity of the ageing brain." Thesis, University of Birmingham, 2017. http://etheses.bham.ac.uk//id/eprint/7651/.
Повний текст джерелаMerz, Susanne. "Functional connectivity in disorders of consciousness." Thesis, University of Aberdeen, 2013. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=211209.
Повний текст джерелаNauhaus, Ian Michael. "Functional connectivity in primary visual cortex." Diss., Restricted to subscribing institutions, 2008. http://proquest.umi.com/pqdweb?did=1692099811&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
Повний текст джерелаGhumman, Sukhmanjit. "Functional connectivity in patients with brain tumours." Mémoire, Université de Sherbrooke, 2018. http://hdl.handle.net/11143/12001.
Повний текст джерелаLe mode de fonctionement par défaut du cerveau est un réseau cérébral associé à la rêverie et à l’introspection. Des études récentes sur ce réseau ont découvert qu’il est perturbé dans plusieurs pathologies cérébrales. Par example, le mode de fonctionnement par défaut est modulé en démence, TDAH, dépression, schizophrénie et plusieurs autres maladies liés au cerveau. Ceci a mené à l’hypothèse que le mode de fonctionnement par défaut pourrait avoir un rôle dans la physiopathologie des maladies du système nerveux, ou pourrait être un marqueur utile du fonctionnement cérébral. Par contre, très peu d’études ont investigué l’effet de lésions chirurgicaux comme les tumeurs cérébrales sur le mode de fonctionnement par défaut. Par conséquent, le but de ce projet était de caractériser l’importance de l’histologie, de la localisation et de plusieurs autres paramètres de l’effet d’une tumeur cérébrale sur le mode de fonctionnement par défaut.
Boisgontier, Jennifer. "Corrélats anatomo - fonctionnels de la vulnérabilité aux troubles du spectre autistique." Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC0074/document.
Повний текст джерелаAutism Spectrum Disorder (ASD) are neurodevelopmental disorders highly heritable.In parallel, the underconnectivity theory of ASD assumes that fronto-posterior brain disconnectivity is at the core of its pathophysiology. Our goal was to assess long-range structural and functional connectivity in unaffected parents of subjects with ASD to better understand the contributions of familial factors to heightened risk of ASD. We performed a diffusion weighted imaging (DWI) based whole brain tractography to compare generalized fractional anisotropy (gFA) in the main deep long white matter tracts in 85 adults: 39 unaffected parents, 18 probands compared to 28 controls. After corrections for multiple comparisons, we identified a significant decrease in gFA in the bilateral inferior frontal occipital fasciculus (IFOF) in both probands with ASD and unaffected parents when compared to controls. To understand the functional implication of fronto – occipital anatomical disconnectivity, we assessed the functional connectivity between the regions linked by IFOF exhibiting significant alterations in gFA. We also showed that both probands and unaffected parents exhibited a significantly increased functional connectivity between the frontal and occipital regions linked by the IFOF. In order to better understand and extend this interesting results, to evaluate the global functional connectivity of our sample in order to be able to interpret the increase of fronto-occipital functional connectivity would be an important perspective. These findings highlight an altered fronto-occipital connectivity in subjects with ASD and unaffected parents suggesting that fronto-occipital disconnectivity may be an endophenotype of ASD
Kopal, Jakub. "Usage de la connectivité pour étudier les (dys)fonctions cérébrales." Thesis, Toulouse 3, 2021. http://www.theses.fr/2021TOU30020.
Повний текст джерелаWe picture the brain as a complex network of structurally connected regions that are functionally coupled. Brain functions arise from the coordinated activity of distant cortical regions. Connectivity is used to represent the cooperation of segregated and functionally specialized brain regions. Whether it is the analysis of anatomical links, statistical dependencies, or causal interactions, connectivity reveals fundamental aspects of brain (dys)function. However, estimating and applying connectivity still faces many challenges; therefore, this work is devoted to tackling them. The first challenge stems from the detrimental effect of systematic noise (such as head movements) on connectivity estimates. We proposed an index that depicts connectivity quality and can reflect various artifacts, processing errors, and brain pathology, allowing extensive use in data quality screening and methodological investigations. Furthermore, connectivity alterations play an invaluable role in understanding brain dysfunction. Investigating the mechanisms of epilepsy, we show that connectivity can track gradual changes of seizure susceptibility and identify driving factors of seizure generation. Identifying critical times of connectivity changes could help in successful seizure prediction. Finally, how the brain adapts to task demands on fast timescales is not well understood. We present a combination of intracranial EEG and state-of-art measures to investigate network dynamics during recognition memory. Understanding how the brain dynamically faces rapid changes in cognitive demands is vital to our comprehension of the neural basis of cognition. In conclusion, the modest goal of this thesis is to at least partially answer some of the many challenges that current neuroscience is facing
Narayanan, Ananth. "Pharmacological Modulation of Functional Connectivity in Neuropsychological Disorders." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1353086436.
Повний текст джерелаFauvet, Maxime. "Mécanismes centraux de contrôle de la motricité saine et altérée : rôle fonctionnel de la dynamique des couplages cortico-musculaires." Thesis, Toulouse 3, 2022. http://www.theses.fr/2022TOU30065.
Повний текст джерелаThe control of voluntary movement is a most discussed issue for those people interested in how the human locomotion or other daily acts are controlled and find answers in two apparently separate fields of research: biomechanics on the one hand and motor control on the other. Verified theories, which model some of the mechanisms involved in motor control at either muscles or brain levels, exist in both fields. However, we still miss a unifying theory that would bridge the gap existing between biomechanics and motor control and would offer a model including all levels of observation: from central nervous system to muscle activity. The present work has been actually designed to partly answer this issue: we propose to study the dynamics of communications occurring during a movement between the different nodes of the motor network through connectivity analyses. Hence, we pursued three main goals: i) develop a dynamic analysis of connectivity measures, ii) apply this analysis to the comparison of functional connectivity between healthy subjects and stroke patients performing elbow extensions and iii) complete the previous analyses with effective connectivity studies of the same paradigm. Thus, this is a multidisciplinary work involving neurosciences, biomechanics and signal processing. Our results show that high inter-variability and intra-variability are less influential in connectivity analysis with our method. Compared analyses between healthy subjects and stroke patients reveal a specific alteration of functional connectivity between antagonist muscles and motor cortex in stroke patients and varying levels of connectivity measures during movement. Finally, the development of effective connectivity analyses and the associated parameters selection will allow us to figure out the direction of communications within the motor network during movement. The overall results of this work show that the analyses of connectivity dynamics can complete existing motor control theories and provide a basis for the constitution of a new dynamic model including the communications between the nodes of the motor network involved in movement control and finally reunite biomechanics and motor control
Rizkallah, Jennifer. "Characterization of neocortical networks from high-resolution EEG : application to disorders of consciousness." Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1S095.
Повний текст джерелаThe human brain is a complex network. Cognitive function is guaranteed when the brain dynamically reconfigures its network organization over time. Studies have showed that most brain disorders, including neurodegenerative and mental diseases, are characterized by changes in the structural and/or functional brain networks. Thus, there is a strong demand for new, non-invasive, network-based and easy-to-use methods to identify these pathological networks. Electroencephalography (EEG) source connectivity method enables the tracking of large scale brain networks dynamics with an excellent temporal resolution. It is in this context that my thesis was carried out. My work here extends the methodological and clinical developments of our research team on functional connectivity at cortical level. The aim of my thesis work is twofold: i) to progress on the methodological aspects of the EEG source connectivity method and ii) to use this method in a clinical application related to the disorders of consciousness. My thesis is divided into two main parts, with two studies realized in each part. In the first part (methodological aspects), I approached, in a first study, the capacity of the EEG source connectivity method to track the brain network dynamic alterations during a fast cognitive task. Then in a second study, I tested the effect of the spatial leakage problem on the reconstructed functional brain networks. In the second part (clinical applications), I analyzed brain networks alterations in patients with disorders of consciousness, using static analysis in the first study and dynamic analysis in the second one
Ing, Alex. "Comparing functional connectivity across the whole brain." Thesis, University of Aberdeen, 2014. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=225661.
Повний текст джерелаStringer, Michael S. "Functional connectivity approaches to focal neurological conditions." Thesis, University of Aberdeen, 2016. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=231782.
Повний текст джерелаBjörnfot, Cecilia. "Multiband functional magnetic resonance imaging (fMRI) for functional connectivity assessments." Thesis, Umeå universitet, Institutionen för fysik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-149906.
Повний текст джерелаAlmashaikhi, Talal. "Electrical brain stimulation and human insular connectivity." Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10174/document.
Повний текст джерелаThe insular cortex is the fifth lobe of the brain and is in charge of the integration of many cognitive functions, underpinned by a rich cytoarchitectonic organization and a complex connectivity. Our work aims to evaluate the insular functional connectivity of the human brain using intracerebral electrical stimulation and recording of cortico-cortical evoked potentials (CCEPs) in patients investigated with stereoelectroencephalography (SEEG) for refractory partial epilepsy. We first developed an automated protocol to stimulate successively all intracerebral recorded bipoles (two contiguous leads of the same electrode) available in patients undergoing SEEG. Two sets of 20 monophasic stimulation of 1 ms duration and 1mA intensity were delivered at a frequency of 0.2 Hz at each bipole (105 on average, producing a total of about 11,000 recordings per patient). We then develop a reliable and objective statistical method to detect significant CCEPs as a complement to visual analysis, and validate this approach on a sample of 33017 recordings in three patients. The analysis was performed over four distinct post-stimulus epochs: 10-100 ms, 100-300 ms, 300-500 ms, 500-1000 ms. In the second part of our thesis, we applied these methods to the study of intrainsular connections on a sample of 10 patients with at least two intra-insular electrodes. The last part of our work used the same approach to investigate insular efferents in a sample of 11 patients. The study of CCEPs provides novel and important findings regarding the human brain functional connectivity, with unmatched spatial and temporal resolutions as compared to neuroimaging techniques. The complex management of large volume of data in each patient can be solved by automated statistical analysis procedures with satisfactory sensitivity and specificity. The pattern of connections within and outside the insula revealed by this approach provides a better understanding of the physiology of the Human insula as well as of the propagation of epileptic discharges involving this lobe
Osher, David Eugene. "Function follows form : how connectivity patterns govern neural responses." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/81731.
Повний текст джерелаThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references.
Connectivity restricts and defines the information that a network can process. It is the substance of information processing that underlies the patterns of functional activity in the brain. By combining diffusion-weighted imaging or DWI, with fMRI, we are able to non-invasively measure connectivity and neural responses in the same individuals and directly relate these two measures to one another. In Chapter 2, I first establish the proof-of-principle that anatomical connectivity alone can predict neural responses in cortex, specifically of face-selectivity in the fusiform gyrus. I then extend this novel approach to the rest of the brain and test whether connectivity can accurately predict neural responses to various visual categories in Chapter 3. Finally, in Chapter 4, I compare and contrast the resulting models, which are essentially networks of connectivity that are functionally-relevant to each visual category, and demonstrate the type of knowledge that can be uncovered by directly integrating structure and function.
by David Eugene Osher.
Ph.D.in Neuroscience
Brown, Christopher A. "THE DEFAULT MODE NETWORK AND EXECUTIVE FUNCTION: INFLUENCE OF AGE, WHITE MATTER CONNECTIVITY, AND ALZHEIMER’S PATHOLOGY." UKnowledge, 2017. http://uknowledge.uky.edu/neurobio_etds/18.
Повний текст джерелаSpencer, Matthew. "Evolving complex network models of functional connectivity dynamics." Thesis, University of Reading, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.590143.
Повний текст джерелаAkram, Harith. "Application of MRI connectivity in stereotactic functional neurosurgery." Thesis, University College London (University of London), 2018. http://discovery.ucl.ac.uk/10052005/.
Повний текст джерелаOrban, Csaba. "Amygdala resting state functional connectivity in alcohol dependence." Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/59191.
Повний текст джерелаSavva, Androula. "Assessment of Functional Connectivity Impairment in Rat Brains." Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-247593.
Повний текст джерелаDjurmodeller med gnagare (råtta och mus) har länge använts i hjärnforskning. Men ännu finns det ingen standardiserad rutin för analys och utvärdering av bilddata från sådana sjukdomsmodeller. Detta arbete använder en råttmodell av sjukdomen ensidig hörselgångsatresi, som innebär att yttre hörselgången är igensatt på ena sidan. Detta görs genom att mjukvaruverktyg som utvecklats för att analysera bilddata från magnetkameraundersökning av den mänskliga hjärnan anpassas för att användas på motsvarande bilddata från råtta för att studera hur ensidig hörselgångsatresi påverkar hjärnans funktionella konnektivitet, dvs hur mönstren i hjärnaktivering samvarierar mellan olika delar av hjärnan (rs-fMRI). Vi visar att det är möjligt att använda mjukvara avsedd för människans hjärna för att förbehandla bilder av råtthjärna. Med hjälp av etablerade arbetsflöden och särskilda procedurer för rs-fMRI kunde den utvecklade proceduren implementera de viktigaste stegen i analysen. För varje individ avgränsades hjärnan med programmet Mialite, rörelsekorrigering och korrigering av rumsdistorsion gjordes med FSL, och rörelseartefakter avlägsnades med ICA-AROMA. Sedan brus tagits bort, och bilddata standardiserats till en standardanatomi och genomgått filtrering i rum och tid, gjordes analys på två grupper, med och utan artificiell hörselgångsatresi. En univariat, hypotesdriven metod och en multivariat, data-driven metod användes för gruppjämförelse och statistisk analys. Frö-baserad korrelationsanalys (SCA) gav inga signifikanta resultat, men oberoende-komponent-analys (ICA) påvisade två anatomiska områden med aktivering relaterad till skillnader mellan grupperna.
McRae, Kateri Lynne. "Functional and Effective Connectivity of Effortful Emotion Regulation." Diss., The University of Arizona, 2007. http://hdl.handle.net/10150/194032.
Повний текст джерелаGoparaju, Balaji. "High level motion: neural correlates and functional connectivity." Thesis, Boston University, 2012. https://hdl.handle.net/2144/21157.
Повний текст джерелаThis thesis uses functional magnetic resonance imaging (fMRI) data to investigate: 1. The neural substrate of high level visual motion 2. The functional connectivity between a behavioral task and resting state. In chapter 1, we find the neural substrate of a set of psychophysical high level motion tasks. Specifically, we used tasks of visually guided navigation, such as heading from optic flow, landmarks, motion parallax, and collision detection. We also used tasks underlying the ability to perform object recognition from motion cues alone such as 3D Structure From Motion (SFM) and Biological Motion (BM). fMRI data was analyzed with Brain Voyager and activated anatomical areas were delineated using Matlab scripts developed in the laboratory. Several regions within the dorsal visual system elicited significant BOLD activity: the dorsal-occipital (BA19) and parietal lobes (BA 37, 40, 7). The ventral areas (BA 20, 21, 22, 38) showed significant BOLD activity only in BM and SFM and in heading tests using landmarks or motion parallax. We generated a schematic map with the overlapping areas among high level motion tasks, which can aid in diagnosis and rehabilitation of motion deficits in neurological patients. In chapter 2, we computed the functional brain connectivity between the brain areas in a resting state (subject performs no task), and during task (subject performs a visual motion task). In the resting state, we found connectivity using correlations between the posterior cingulate cortex (PCC), precuneus, medial prefrontal cortex (MPFC), lateral parietal cortex, and the hippocampal formation, which have been reported as the default mode network (DMN) since it represents correlated neural activity during a state of rest. We used bivariate correlations to compute functional connectivity using the CONN fMRI toolbox and in-house Matlab scripts. We computed a whole-brain analysis and compared network statistics in both, resting state and during task to investigate measures of integration such as path length and global efficiency, regional measures such as degree (number of connections) and betweenness centrality (number of shortest paths), and global measures such as small-worldness. The DMN and graph theoretical measures connectivity during task was stronger as compared with the resting state. We also computed these measures in task using a similar frequency spectrum as rest (0.009 Hz < f < 0.08 Hz), and in the full frequency spectrum. We find that on the whole, the connectivity measures in the DMN and the graph theoretical measure are stronger in the fullband signal processing analysis as compared to the bandpass version of the analysis.
2031-01-01
Lee, Pamela Wen-Hsin. "Mutual information derived functional connectivity of the electroencephalogram (EEG)." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/219.
Повний текст джерелаGoldhacker, Markus [Verfasser], and Elmar [Akademischer Betreuer] Lang. "Frequency-resolved dynamic functional connectivity and scale stability of connectivity-states / Markus Goldhacker ; Betreuer: Elmar Lang." Regensburg : Universitätsbibliothek Regensburg, 2017. http://d-nb.info/1124679944/34.
Повний текст джерелаBerkström, Charlotte. "Ecological connectivity in East African seascapes." Doctoral thesis, Stockholms universitet, Systemekologiska institutionen, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-75194.
Повний текст джерелаAt the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Submitted. Paper 4: Submitted.
Twomey, T. "Ventral occipito-temporal cortex function and anatomical connectivity in reading." Thesis, University College London (University of London), 2013. http://discovery.ucl.ac.uk/1417085/.
Повний текст джерелаMakewita, Sumedha M. "Investigating the generic information seeking function of organisational decision makers : perspectives on improving organisational information systems." Thesis, University of Southampton, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246832.
Повний текст джерелаRieubland, S. C. S. "Functional and anatomical connectivity patterns in the cerebellar cortex." Thesis, University College London (University of London), 2013. http://discovery.ucl.ac.uk/1400297/.
Повний текст джерелаHabberfield, Michael William. "Functional connectivity for wildlife populations across spatially complex landscapes." Thesis, State University of New York at Buffalo, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10163822.
Повний текст джерелаIntegrating animal movement information with the spatial analysis of landscape structure is critical for restoring biological communities in spatially-structured landscapes. This integration can be accomplished by focusing on functional connectivity—a landscape’s potential for the movement of organisms among resource patches—in relation to the spatial and structural connectivity of landscape elements. I carried out three investigations in order to examine how landscape structure interacts with the ecological factors associated with animal movement processes, and thereby produce actionable outcomes for the restoration of wildlife populations. This work combined population- and individual-level data of dispersing wildlife to better resolve the influence of spatial structure on functional connectivity. First, I used a meta-analysis to quantify the relationship between structural and functional connectivity for a broad scope of animal species. Second, I assessed the influence of landscape position and habitat density on colonization, movement, and population dynamics of wood frogs (Lithobates sylvatica) within a network of restored vernal pools. Third, I experimentally evaluated dispersal and habitat selection of green frogs (Lithobates clamitans) within this vernal pool system.
The meta-analysis demonstrated that universal scaling relationships of species and the landscapes they are moving through interact as key drivers mediating the level of functional connectivity afforded to wildlife by structural connectivity. Mark-recapture data revealed rapid colonization of the restored vernal pool network by wood frogs, with subsequently moderate levels of frog movement among neighboring pools. Local pool density interacted with the colonization process and terrestrial habitat availability to limit wood frog productivity within a pool cluster. Experimental dispersal data for green frogs artificially translocated within the pool network showed key differences between movement in familiar and novel environments. Differing movement behaviors and habitat selection patterns indicated that a habitat patch for this species is on the scale of a pool cluster rather than an individual pool. Together, the observed spatial dynamics of these vernal pool amphibians contribute a framework for improving amphibian dispersal modeling, potential responses to rapid environmental changes, and predicting colonization and subsequent population dynamics in restored systems. The results of this dissertation improve our understanding of how spatial structure interacts with organism-specific factors to produce observed patterns of functional connectivity.
Joules, Richard Bryan. "Functional connectivity and machine learning for psychiatric drug development." Thesis, King's College London (University of London), 2015. http://kclpure.kcl.ac.uk/portal/en/theses/functional-connectivity-and-machine-learning-for-psychiatric-drug-development(23f2637e-2604-4b82-82e2-619e084cd6d3).html.
Повний текст джерела