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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.
31

Efeitos da estimulação tátil adicional sobre a regularidade das flutuações do centro de pressão durante tarefas de controle postural bipedal e unipedal / Effects of light finger touch on the regularity of center of pressure fluctuations during quiet bipedal and single-leg postural tasks

Lara, Jéssica Rodriguez 26 February 2019 (has links)
Estudos demonstram que um toque efetuado pela ponta do dedo indicador sobre uma superfície externa rígida (a força exercida é mínima, não configurando um apoio mecânico) diminui consideravelmente a oscilação postural, o que indica que as informações sensoriais adquiridas pelos receptores táteis da ponta do dedo (i.e. relacionadas com as forças de contato entre o dedo e a superfície de apoio) fornecem ao sistema nervoso central informações relevantes que ajudam a manter a estabilidade postural. Esse efeito estabilizador proveniente do toque também tem sido associado a mecanismos supraposturais, como requisitos de precisão manual e demandas de atenção. A demanda atencional investida durante uma dada tarefa postural tem sido associada à regularidade das oscilações posturais, estimada pela entropia da amostra (SaEn) dos sinais do centro de pressão (CoP) (SaEnCoP). No entanto, nenhuma investigação anterior abordou se a regularidade das trajetórias do CoP é influenciada pelo toque suave do dedo (em inglês light touch LT) durante as tarefas posturais. Com base nos achados de estudos anteriores que sugeriram aumento da demanda atencional associada ao toque suave dos dedos (em comparação às condições de controle sem toque), a hipótese abordada foi de que a realização de tarefas posturais ao tocar levemente uma superfície externa rígida, além de atenuar a magnitude das oscilações posturais, estaria associada a níveis mais altos de regularidade do CoP (isto é, medidas baixas do SaEnCoP) em comparação com as condições de controle sem toque. Neste sentido, o objetivo do presente projeto foi investigar o efeito do toque suave do dedo sobre a regularidade das flutuações do CoP durante a manutenção da postura quieta bipedal e em uma tarefa de equilíbrio unipedal, de modo a analisar duas tarefas de controle postural com diferentes níveis de complexidade, associadas a diferentes níveis de demanda atencional. Sendo assim, 8 voluntários participaram dos experimentos na tarefa em postura quieta bipedal e 14 na tarefa de equilíbrio unipedal, ambas com e sem informação tátil adicional. Foram obtidos maiores valores de SaEnCoP na condição LT, tanto na tarefa de postura bipedal quanto em unipedal, sendo as diferenças significativas em relação a condição NT. Os resultados indicam que a presença de informações táteis adicionais levou a redução da instabilidade postural, mas não aumentou o grau de demanda de atenção na postura pelas flutuações do CoP mais irregulares (maiores valores de SaEnCoP), mesmo na tarefa mais complexa (equilíbrio unipedal). Isso sugere que, a automaticidade do controle postural foi maior, o que significa que a presença do toque tornou o controle postural mais efetivo (reduzindo as oscilações posturais), mas não o tornou mais cognitivamente dependente / Studies have been demonstrated that lightly touching an external rigid (the force exerted is minimal not setting a mechanical support) surface reduce the magnitude of postural oscillation. This decrease of postural sway indicates that the sensory information acquired by fingertip tactile receptors provides the central nervous system relevant information that aid to maintain postural stability. The stabilizing effect of light finger touch has been associated with sensory mechanisms involving enhanced proprioceptive feedback (e.g., from finger and hand muscles as well as from joint and cutaneous mechanoreceptors) and also with suprapostural mechanisms such as manual precision requirements and attentional demand. The attentional demand invested during a postural task has been associated with the regularity of the postural oscillations, as estimated by the sample entropy (SaEn) of center of pressure (CoP) signals (SaEnCoP). However, no previous investigation has addressed whether the regularity of CoP trajectories is influenced by light finger touch during postural tasks. Based on the previous findings that suggested an increased attentional demand associated with light finger touch (as compared to control conditions with no touch), the hypothesis addressed in the present study was that postural tasks performed when lightly touching an external rigid surface, besides attenuating the magnitude of postural oscillations, would be associated with higher levels of CoP regularity (i.e. lower measurements of SaEnCoP) as compared to control conditions with no touch. Therefore, the aim of this study was to investigate the effect of light finger touch on CoP regularity during two postural control tasks, quiet bipedal and single leg stance to investigate postural control tasks with different levels of complexity, which has been associated with different levels of attentional demand. We evaluated the CoP fluctuations in 8 volunteers during quiet bipedal posture and in 14 volunteers during single leg postural task, both with and without light finger touch. We obtained greater values os SaEnCoP in the LT condition in both bipedal and single leg posture tasks with significant differents compared to the NT condition. The findings indicate that light finger touch producing additional tactile informations that reduced postural instability did not increase the degree of attention demand in posture with the more irregular CoP fluctuations, even in the more complex task (single-leg stance). This suggests that the automaticity of postural control was greater which means that the presence of touch made postural control more effective (reducing postural oscillations), but did not made it more cognitively dependent
32

Cortical and cerebellar motor processing changes subsequent to motor training and cervical spine manipulation

Daligadu, Julian 01 July 2012 (has links)
Chronic neck pain, including subclinical neck pain (SCNP), is a significant problem that places a burden on the healthcare system. Chiropractic manipulation has shown not only to be effective in treating symptoms of neck pain, but also in providing a neuromodulatory effect on the central nervous system. The motor cortex and cerebellum are thought to be important neural structures involved in motor learning and sensorimotor integration (SMI), and are therefore key structures to investigate how SMI is changed in a SCNP group following chiropractic care. Motor sequence learning (MSL) has also been shown to provide alterations in cerebellar projections to the motor cortex. Therefore, the studies in this thesis set out to determine if it was possible to induce both cortical and cerebellar learning, and if chiropractic care could alter motor output via transcranial magnetic stimulation measures to facilitate this learning. The study‟s results suggest that in a healthy group of subjects there is alteration in the intracortical inhibition of the motor cortex and no significant change in the cerebellum, following MSL. However, the results also suggest that in a SCNP group, there is a modulation of the cerebellar connections to the motor cortex but no effect specific to the motor cortex following both MSL and chiropractic manipulation. Therefore, these findings suggest that people with intermittent neck pain have concomitant changes in SMI and could manifest as clinical symptomology. / UOIT
33

Manifold Integration: Data Integration on Multiple Manifolds

Choi, Hee Youl 2010 May 1900 (has links)
In data analysis, data points are usually analyzed based on their relations to other points (e.g., distance or inner product). This kind of relation can be analyzed on the manifold of the data set. Manifold learning is an approach to understand such relations. Various manifold learning methods have been developed and their effectiveness has been demonstrated in many real-world problems in pattern recognition and signal processing. However, most existing manifold learning algorithms only consider one manifold based on one dissimilarity matrix. In practice, multiple measurements may be available, and could be utilized. In pattern recognition systems, data integration has been an important consideration for improved accuracy given multiple measurements. Some data integration algorithms have been proposed to address this issue. These integration algorithms mostly use statistical information from the data set such as uncertainty of each data source, but they do not use the structural information (i.e., the geometric relations between data points). Such a structure is naturally described by a manifold. Even though manifold learning and data integration have been successfully used for data analysis, they have not been considered in a single integrated framework. When we have multiple measurements generated from the same data set and mapped onto different manifolds, those measurements can be integrated using the structural information on these multiple manifolds. Furthermore, we can better understand the structure of the data set by combining multiple measurements in each manifold using data integration techniques. In this dissertation, I present a new concept, manifold integration, a data integration method using the structure of data expressed in multiple manifolds. In order to achieve manifold integration, I formulated the manifold integration concept, and derived three manifold integration algorithms. Experimental results showed the algorithms' effectiveness in classification and dimension reduction. Moreover, for manifold integration, I showed that there are good theoretical and neuroscientific applications. I expect the manifold integration approach to serve as an effective framework for analyzing multimodal data sets on multiple manifolds. Also, I expect that my research on manifold integration will catalyze both manifold learning and data integration research.
34

Sensory processing and integration and children with alcohol-related diognoses : an exploratory analysis /

Jirikowic, Tracy L. January 2003 (has links)
Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 134-144).
35

Large scale neural dynamics of rhythmic sensorimotor coordination and stability /

Borrell, Joseph W. Jantzen, Kelly J. January 2010 (has links)
Thesis (M.S.)--Western Washington University, 2010. / Includes bibliographical references (leaves 30-35). Also issued online.
36

Brain mechanisms underlying sensory motor adatations /

Lee, Jihang, January 2002 (has links)
Thesis (Ph. D.)--University of Oregon, 2002. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 195-205). Also available for download via the World Wide Web; free to University of Oregon users.
37

Synthesis and analysis of a physical model of biological rhythmic motor control with sensorimotor feedback

Simoni, Mario F. 05 1900 (has links)
No description available.
38

Confirmatory models of sensory/motor and cognitive constructs

Decker, Scott L. January 2002 (has links)
This study examined the relationship between neuropsychological constructs of sensory-motor functioning and cognitive ability constructs in the Cattell-Horn-Carroll (CHC) (Carroll, 1993) theory. Two studies were conducted For the first study, the Dean-Woodcock Sensory Motor Battery (SMB) (Dean & Woodcock, 1999) was administered to 800 individuals. A factor analysis and a confirmatory factor analysis were used to investigate and develop a factor structure of the SMB. Results from this study suggest sensory and motor tests significantly share common variance and a hierarchical, multifactorial model that included a higher-order factor of both sensory and motor tests best fit the data. The second study examined the SMB model, developed in the first study, in relation to the CHC (Cattell-Horn-Carroll) model of cognitive abilities, as measured by the Woodcock-Johnson Revised Tests of Cognitive Abilities (WJ-R) (McGrew, Werder, & Woodcock, 1991). For this study, the SMB and the WJ-R was administered to 411 individuals. A confirmatory model was tested that included the higher-order factor of the SMB as a broad ability within the CHC model. Results from this analysis suggest the higher order factor of the SMB does have a significant relationship with overall measures of cognitive ability of a similar level to other broad abilities in the CHC model, and significantly improves the fit of CHC model. These results support Roberts, Pallier, and Goffs (1999) argument for the inclusion of an additional broad ability in the CHC taxonomy that represents sensory and motor functioning. Additionally, this study provides empirical support for the utility of including neuropsychological tests of sensory and motor functioning in a comprehensive assessment of cognitive abilities (Dean & Woodcock, 1999). The implications for neuropsychological and psychometric assessment are discussed. / Department of Educational Psychology
39

Predicting closed head injury using a standardized measure of sensory-motor functioning

Hall, John J. January 2007 (has links)
The main purpose of the present study was to identify sensory-motor deficits caused by closed head injury (CHI) when individuals with CHI are compared to a normal sample. The study also investigated lower-level sensory-motor functioning, such as gait, balance, and coordination and its relation to neurological impairment related to CHI. Additionally, the study determined if age significantly influenced sensory-motor functioning.Archival data was utilized to complete the study. Data was collected from a large, Midwestern neurology clinic (CHI) as well as from a normative sample of individuals with no reported history of neurological impairment. Preliminary analyses were completed to identify outliers. Samples were then randomly selected from the impaired group (CHI) and matched with randomly selected subjects from the normative sample based upon age.Three separate analyses were completed. The first analysis focused on age and if age significantly influences sensory motor functioning. The second analysis was completed using an adult's only sample based upon the results that age significantly influenced sensory-motor performance. Finally, the third analysis utilized all age groups to determine how dramatically age had an impact on distinguishing between individuals with CHI versus a normative sample.Results demonstrated that age had a significant influence on sensory-motor performance. Measures of subcortical and cortical motor function, motor speed, motor coordination and tactile examination were able to accurately classify individuals with head injury from a normative sample to a clinically significant degree (78%). The study argues that the D-WSMB is a reliable and valid measure to utilize when evaluating individuals with CHI. / Department of Educational Psychology
40

Predicting depression using the Dean-Woodcock Sensory Motor Battery

Vaux, Fleeta R. January 2009 (has links)
Access to abstract permanently restricted to Ball State community only / Access to thesis permanently restricted to Ball State community only / Department of Educational Psychology

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