Rozprawy doktorskie na temat „Vestibular apparatus”
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Li, Chuan. "Spatial coding of gravitational input to the vestibuloolivary pathway and its refinement in development". Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B31539609.
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Lee, Son Gregory Martin. "Vestibular connectivity to soleus motor units during quiet stance". Thesis, University of British Columbia, 2007. http://www.oregonpdf.org.
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Manczak, Tiago. "Estimulador galvânico vestibular para fMRI". Universidade Tecnológica Federal do Paraná, 2012. http://repositorio.utfpr.edu.br/jspui/handle/1/406.
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Este trabalho apresenta o desenvolvimento de um estimulador galvânico vestibular para ser usado em experimentos de imageamento por ressonância magnética funcional (fMRI). Em experiências de fMRI é necessário a produção de estímulos somatossensoriais no paciente. Os estímulos devem ser sincronizados com a sequência de pulsos da fMRI. O estimulador foi dividido em circuitos analógicos (colocados dentro da sala do magneto) e circuitos digitais (sala de comando do sistema de MRI). A comunicação entre os circuitos é feita através de fibra óptica. Experimentos de fMRI realizados com voluntários demonstraram que o estimulador proposto é capaz de manter a sincronização com sistema de fMRI e pode ser usado para localizar as áreas do cérebro que são ativados pelo sistema vestibular.This work presents the development of a galvanic vestibular stimulator to be used in functional magnetic resonance imaging experiments (fMRI). In fMRI experiments it is required the production of somatosensory stimuli in the patient must be sincronized with the fMRI pulse sequence. The stimulator circuits were divided in analog circuits (placed within the magnet room) and digital circuits (placed in the MRI command room). The communication between the circuits is made through optical fiber. fMRI experiments performed with volunteers demonstrated that the proposed stimulator is able to keep the sincronization with the MRI system and can be used to locate the brain areas that are activated by the vestibular system.
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Li, Chuan, i 李川. "Spatial coding of gravitational input to the vestibuloolivary pathway and its refinement in development". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B31539609.
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Sansom, Andrew J., i n/a. "The role of calcium-dependent pathways in vestibular compensation". University of Otago. Department of Pharmacology & Toxicology, 2005. http://adt.otago.ac.nz./public/adt-NZDU20070418.145158.
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Damage to one vestibular apparatus (unilateral vestibular deafferentation, UVD) results in severe postural and ocular motor disturbances (such as spontaneous nystagmus, SN) that recover over time in a process known as vestibular compensation. However, the underlying neurochemical mechanisms of vestibular compensation are poorly understood. While UVD affects many areas in the CNS, attention has focused upon the partially deafferented second order neurons in the vestibular nuclei complex (VNC). Several converging lines of evidence suggest that Ca�⁺-permeable ion channels (N-methyl-D-aspartate receptors and L-type voltage-gated Ca�⁺-channels) and intracellular Ca�⁺-dependent protein kinases play an important role in vestibular compensation. However, the nature of this involvement and the locus of these changes are unknown. The aim of this thesis was to investigate the role of Ca�⁺ signalling pathways in the VNC during vestibular compensation in guinea pig. These issues were investigated in three separate experiments that utilised two methodological approaches: i) in vitro assays were used to determine the nature and extent of protein phosphorylation within the VNC at various stages of compensation; and ii) ion channel blockers or cell-permeable kinase inhibitors were injected directly into the VNC immediately before UVD to determine whether or not these systems were causally involved in compensation.
The results of experiment 1 (Chapter 5) showed that a bolus intra-VNC injection of an uncompetitive NMDA receptor antagonist, but not an L-type voltage-gated Ca�⁺ channel antagonist, temporarily reduced SN frequency at the earliest measurement time (6 hours post-UVD). These results suggested that the initial expression of SN required, in part, the activation of NMDA receptors in the VNC on the side of the UVD, and by inference, Ca�⁺ entry through the ion channel. The results of experiment 2 (Chapter 6) revealed that the medial VNC contains abundant Ca�⁺/calmodulin-dependent and Ca�⁺/phospholipid-dependent protein kinase activities. The same VNC tissue removed from animals at various times after UVD, showed that vestibular compensation is accompanied by specific changes in the phosphorylation of several major protein kinase C substrates. These included an unidentified 46-kDa band, and a 75-kDa band with similar characteristics to the myristoylated alanine-rich C kinase substrate (MARCKS). These results suggest that protein kinase C signalling pathways may be involved in vestibular compensation. The results of experiment 3 (Chapter 7) are consistent with these results showing that intra-VNC infusion of a protein kinase C inhibitor, but not a Ca�⁺/calmodulin-dependent protein kinase II inhibitor, significantly increased SN at the earliest measurement times (6 and 8 hours), but had no effect upon the time taken to achieve compensation or on postural compensation. These results suggest that the induction of SN compensation involves protein kinase C activity in the VNC. Taken together, these findings suggest that the mechanisms underlying the expression of SN (e.g., Ca�⁺ influx via NMDA receptors) are possibly distinct from those that initiate its compensation (e.g., PKC activation). The downstream effects of raised intracellular Ca�⁺ may involve protein kinase C-dependent phosphorylation of key intracellular proteins that initiate long-lasting changes in cellular function within the VNC.
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Goddard, Matthew John, i n/a. "Cognitive and emotional effects of vestibular damage in rats and their medial temporal lobe substrates". University of Otago. Department of Pharmacology & Toxicology, 2008. http://adt.otago.ac.nz./public/adt-NZDU20080923.091605.
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Psychiatric disorders and cognitive impairment are increasingly being described in patients with vestibular pathology. Yet frameworks that describe the link between emotion, memory and the vestibular system have yet to reach maturity, partly because studies have not yet provided detailed accounts of behavioral changes in experimental animals, or in man. One of the goals of this thesis was to use experimental psychology to define changes in memory and emotional behaviour in rats given bilateral vestibular deafferentation (BVD, n=18) or sham surgery (Sham, n=17). In an elevated-plus maze task, BVD rats made up to 166% greater open arm entries and spent up to 42% more time in the open arms compared to Sham rats. In an elevated-T maze task, BVD rats failed to develop a normal learned inhibition response to open space. In an open field maze BVD rats consistently showed 50-60% greater movement velocity, spent on average 35% more time in the inner most aversive part of the arena, and failed to show the normal boundary-seeking behaviour (thigmotaxis) typical of untreated or Sham rats. In a social interaction test BVD rats spent up to 34% less time engaged in social contact compared to Sham rats. In a hyponeophagia test, BVD rats� latency to eat was 70% greater than Sham rats at 3-weeks post-op., however this difference disappeared at 3- and 5-months. These findings suggest that BVD treatment may in some cases disrupt normal behavioral inhibition. Memory performance was also affected. In a T-maze task BVD rats achieved 40-60% correct arm entries, compared to 90-100% for Sham controls. In a foraging task carried out in darkness, BVD rats� initial homing angle was random, homing paths were ~70% longer, and reference memory errors were ~56% greater compared to Sham rats. To elucidate possible neurochemical substrates for these behavioral changes, western blot assays on monoamine proteins were carried out on tissue from a naïve set of rats (BVD n=6; Sham n=6). In BVD rats, serotonin transporter protein expression was 39% lower in CA1 hippocampus and 27% lower in the forebrain region, despite forebrain tryptophan hydroxylase expression being 34% upregulated. Tyrosine hydroxylase expression in the forebrain region was 27% lower in BVD rats. Proteins related to synaptogenesis were also investigated. In the dentate gyrus SNAP-25 was 37% upregulated in BVD rats, while in area CA2/3 of the hippocampus neurofilament-L was 13% upregulated. Forebrain and entorhinal cortex drebrin expression was 28% and 38% downregulated in BVD rats. Neurofilament-L was also 31% downregulated in the forebrain region of BVD rats. To test whether any of these behavioral or biochemical changes may have been attributable to chronic physiological stress, a corticosterone assay was carried out at the conclusion of behavioral testing; however, the no significant between treatment differences were found. In conclusion, vestibular information appears to be needed for the acquisition of spatial and reference memory as well as the normal expression of emotional behaviour. The neurochemical changes described herein point toward possible substrates for these behaviors, however their full significance has yet to be determined.
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Lau, Yau-pok. "Postnatal development of thalamic neurons in response to vertical movement /". View the Table of Contents & Abstract, 2007. http://sunzi.lib.hku.hk/hkuto/record/B3834810X.
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劉友璞 i Yau-pok Lau. "Postnatal development of thalamic neurons in response to vertical movement". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B45011369.
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Knox, Craig A. "A model for morphological change in the hominid vestibular system in association with the rise of bipedalism". Virtual Press, 2007. http://liblink.bsu.edu/uhtbin/catkey/1371468.
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This study re-examines the morphological data and conclusions of Spoor, Wood, and Zonneveld concerning the morphology of the vestibular apparatus in relation to locomotor behavior in hominids (1994). The pedal and labyrinthine morphology of early hominid taxa are functionally analyzed for classification as either obligate bipeds or habitual bipeds with primarily arboreal locomotion. The bony labyrinth is investigated since the anatomy of the semicircular canals of the vestibular auditory system can be determined in fossil crania through computed tomographical analysis. It is thought that a relationship exists between semicircular canal size and locomotor behavior. Functionally modern pedal morphology precedes modern vestibular morphology in the fossil record. Complete modern pedal morphology, however, appears concurrently with modern vestibular morphology first at Homo erectus. A comparison of the genes involved in the development of both pedal and labyrinthine morphology was undertaken. It was found that only fibroblast growth factor 8 (FgfS) and sonic hedgehog (Shh) are shared between these systems in the determination of positional information. It is found that the function of Fgf8 in otic induction and in limb bud formation is very different. It is also found that the function of Shh in vestibular and pedal morphogenesis is different. Therefore, it is unlikely for alteration in the function or in the expression of either gene to result in the observed differences in pedal and vestibular morphology between early hominid taxa: Australopithecus afarensis, Australopithecus africanus, Homo habilis; and Homo erectus. My examination of the data on the timing of changes in pedal morphology rejects Spoor, Wood, and Zonneveld's conclusion. Moreover I find no gene mutation which could account for simultaneous change in the shape of the semicircular canals and the proportions of the metatarsals and pedal phalanges. Instead, it is postulated that the change to modern vestibular morphology at Homo erectus is in response to a concurrent enlargement in cranial capacity. It is also postulated that persistence of panid vestibular morphology in the semicircular canals of hominid taxa: Australopithecus afarensis, Australopithecus africanus, and Homo habilis is a functionally neutral trait in regard to bipedal locomotor capability.Department of Anthropology
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Moravec, William J. "Tuning in vestibular hair cells of a turtle Trachemys scripta /". Ohio : Ohio University, 2006. http://www.ohiolink.edu/etd/view.cgi?ohiou1149291414.
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Macdougall, Hamish G. "The human eye-movement response to maintained surface galvanic vestibular stimulation". Phd thesis, School of Psychology, 2003. http://hdl.handle.net/2123/10402.
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Gliddon, C. M., i n/a. "An attempt to elucidate the role of GABAA receptors in vestibular compensation". University of Otago. Department of Pharmacology & Toxicology, 2006. http://adt.otago.ac.nz./public/adt-NZDU20070427.150754.
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Loss of sensory input from one vestibular labyrinth by unilateral vestibular deafferentation (UVD) results in a severe ocular motor (i.e., spontaneous nystagmus (SN)) and postural syndrome (i.e., yaw head tilt, (YHT) and roll head tilt (RHT)) which compensates over time in a behavioural recovery process known as vestibular compensation. It is generally accepted that the UVD-induced neuronal imbalance in the resting activity between the two vestibular nuclear complexes (VNCs) generates the ocular motor and postural syndrome and that the restoration of the resting activity in the ipsilateral VNC plays a causal role in the compensation of the static symptoms. γ-Aminobutyric acid (GABA) and the GABAA and GABAB receptors within the VNC are involved in normal vestibulo-ocular and --spinal pathways and it has been suggested that modification of GABAergic inhibition may be a mechanism responsible for the recovery of resting activity in the ipsilateral VNC. Behavioural, western blotting, and immunoassay techniques were used to address the role of the GABAA receptor in the VNC during vestibular compensation.
The first study involved the characterization of SN, YHT, and RHT compensation in guinea pigs that had been anaesthetized with isoflurane during the UVD. These animals compensated rapidly (i.e., 30 hrs) and the time to compensate was independent of the duration of the anaesthesia. Using the 30 hrs time frame, the effects of the chronic infusion of the GABAA receptor agonist (muscimol) / antagonist (gabazine) into either the ipsilateral or the contralateral VNC on the compensation of SN, YHT, and RHT, were determined. Infusion of muscimol (250, 500, and 750 ng) into the contralateral VNC and gabazine (31.25, 62.5 and 125 ng) into the ipsilateral VNC significantly affected YHT and RHT (p < 0.05), but not their rate of compensation (p > 0.05). Interestingly, the effects of muscimol and gabazine on YHT and RHT were consistent throughout the first 30 hrs post-UVD. At 30 hrs post-UVD, the pumps were disconnected. In both experimental groups, the value and direction of the YHT and RHT returned to vehicle levels. Infusion of muscimol (62.5, 125, and 250 ng) into the ipsilateral VNC and gabazine (125, 375, and 750 ng) into the contralateral VNC had little effect on YHT and RHT, or their rate of compensation. At 30 hrs post-UVD, the pumps were disconnected. In both experimental groups, the value and direction of the YHT and RHT returned to vehicle levels. These results suggest that the ipsilateral gabazine and contralateral muscimol infusions were modifying the expression of the symptoms without altering the mechanism of compensation. Furthermore, the mechanism responsible for vestibular compensation can cope with the both the GABAA receptor-mediated and the UVD-induced decrease in resting activity. Results from the western blotting study indicated that compensation of SN, YHT, and RHT is not associated with changes in the protein levels of the GABAA receptor α₁, β₂, or γ₂ subunits. Compensation of SN, YHT, and RHT is associated with an elevation in cortisol salivary levels. Overall, the results suggest that the GABAA receptors are involved in the expression of YHT and RHT, but not in the mechanism that is responsible for their compensation.
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Sun, Bing, i 孫冰. "Vestibular influence on central cardiovascular regulation in the rat: functional and anatomical aspects". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B31244774.
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Wood, Noel. "The efficacy of Vestibular Rehabilitation: A Meta-analysis". Honors in the Major Thesis, University of Central Florida, 2000. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/680.
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This item is only available in print in the UCF Libraries. If this is your Honors Thesis, you can help us make it available online for use by researchers around the world by following the instructions on the distribution consent form at http://library.ucfB.S.
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15
Thurtell, Matthew James. "Effect of eye position on the three-dimensional kinematics of saccadic and vestibular-evoked eye movements". Thesis, The University of Sydney, 2005. http://hdl.handle.net/2123/1665.
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Saccadic and vestibular-evoked eye movements are similar in that their three-dimensional kinematic properties show eye position-dependence. When the line of sight is directed towards an eccentric target, the eye velocity axis tilts in a manner that depends on the instantaneous position of the eye in the head, with the magnitude of tilt also depending on whether the eye movement is saccadic or vestibular-evoked. The mechanism responsible for producing eye velocity axis tilting phenomena is not well understood. Some authorities have suggested that muscle pulleys in the orbit are critical for implementing eye velocity axis tilting, while others have suggested that the cerebellum plays an important role. In the current study, three-dimensional eye and head rotation data were acquired, using the magnetic search coil technique, to confirm the presence of eye position-dependent eye velocity axis tilting during saccadic eye movements. Both normal humans and humans with cerebellar atrophy were studied. While the humans with cerebellar atrophy were noted to have abnormalities in the two-dimensional metrics and consistency of their saccadic eye movements, the eye position-dependent eye velocity axis tilts were similar to those observed in the normal subjects. A mathematical model of the human saccadic and vestibular systems was utilized to investigate the means by which these eye position-dependent properties may arise for both types of eye movement. The predictions of the saccadic model were compared with the saccadic data obtained in the current study, while the predictions of the vestibular model were compared with vestibular-evoked eye movement data obtained in a previous study. The results from the model simulations suggest that the muscle pulleys are responsible for bringing about eye position-dependent eye velocity axis tilting for both saccadic and vestibular-evoked eye movements, and that these phenomena are not centrally programmed.
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Thurtell, Matthew James. "Effect of eye position on the three-dimensional kinematics of saccadic and vestibular-evoked eye movements". Faculty of Medicine, 2005. http://hdl.handle.net/2123/1665.
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Master of Science in MedicineSaccadic and vestibular-evoked eye movements are similar in that their three-dimensional kinematic properties show eye position-dependence. When the line of sight is directed towards an eccentric target, the eye velocity axis tilts in a manner that depends on the instantaneous position of the eye in the head, with the magnitude of tilt also depending on whether the eye movement is saccadic or vestibular-evoked. The mechanism responsible for producing eye velocity axis tilting phenomena is not well understood. Some authorities have suggested that muscle pulleys in the orbit are critical for implementing eye velocity axis tilting, while others have suggested that the cerebellum plays an important role. In the current study, three-dimensional eye and head rotation data were acquired, using the magnetic search coil technique, to confirm the presence of eye position-dependent eye velocity axis tilting during saccadic eye movements. Both normal humans and humans with cerebellar atrophy were studied. While the humans with cerebellar atrophy were noted to have abnormalities in the two-dimensional metrics and consistency of their saccadic eye movements, the eye position-dependent eye velocity axis tilts were similar to those observed in the normal subjects. A mathematical model of the human saccadic and vestibular systems was utilized to investigate the means by which these eye position-dependent properties may arise for both types of eye movement. The predictions of the saccadic model were compared with the saccadic data obtained in the current study, while the predictions of the vestibular model were compared with vestibular-evoked eye movement data obtained in a previous study. The results from the model simulations suggest that the muscle pulleys are responsible for bringing about eye position-dependent eye velocity axis tilting for both saccadic and vestibular-evoked eye movements, and that these phenomena are not centrally programmed.
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Penberthy, Marie Louise. "The identification of vestibular processing dysfunction in disorders of sensory integration". Master's thesis, University of Cape Town, 1985. http://hdl.handle.net/11427/26447.
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Schwartz, Robert Lee. "Vestibular and Electromagnetic Stimulation: Their Effects on Intellectual Performance and Mood State". Thesis, University of North Texas, 1991. https://digital.library.unt.edu/ark:/67531/metadc332751/.
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In the present study, the Electromechanical Therapeutic Apparatus was examined to determine the extent to which its repeated use can influence intellectual performance and mood state. The Electromechanical Therapeutic Apparatus is a device designed to mildly stimulate the body and brain, while facilitating relaxation. Its three components include a rotating platform-bed; a weak, extremely-low-frequency, external-electric field; and music. In the present study, three groups were contrasted, a music-only group which served as a placebo; a group which combined motion-vestibular stimulation and music; and a group which combined motion-vestibular stimulation and music with an externalelectric field. The sample included 33 randomly selected men and women whose average age was 34.6 years.
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Rülander, Britta Angela. "Galvanic vestibular stimulator for fMRI research". Universidade Tecnológica Federal do Paraná, 2016. http://repositorio.utfpr.edu.br/jspui/handle/1/1843.
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CAPESThis master thesis presents the further development of a galvanic vestibular stimulator for use in fMRI examinations developed in a previous thesis (MANCZAK, 2012). This thesis amends the GVS by circuits to measure feedback values and implements the stimulation circuit with digital components, such as a microcontroller and flyback integrated circuits. The microcontroller is used in order to control the current source and process the measured values. The communication between the PC, which allows user interaction through a graphical user interface, and the microcontroller is implemented through optical communication, which is defined by a communication protocol specification. The digital circuitry is designed to be placed within the MRI room, meeting the requirements imposed by strong magnetic fields and radio frequency pulses. The underlying hypothesis of the thesis is that the device can be placed within the MRI room without having a negative impact on the MRI image quality. Laboratory tests without the MRI confirmed the correct design of the galvanic vestibular stimulator.
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Justina, Hellen Mathei Della. "Interação entre as áreas funcionais do sistema visual e do sistema vestibular: estudo com RMF e EGV". Universidade Tecnológica Federal do Paraná, 2014. http://repositorio.utfpr.edu.br/jspui/handle/1/850.
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CAPES, CNPqO equilíbrio estático corporal é comandado por três sistemas sensoriais: o sistema vestibular, responsável pelas informações sobre a posição e os movimentos da cabeça; o sistema visual, que informa a posição espacial dos objetos em relação ao nosso corpo; e o sistema proprioceptivo, que controla a postura e a movimentação corporal. Estes três sistemas devem funcionar sempre em sintonia, caso contrário, o indivíduo apresentará problemas de equilíbrio. Dessa forma, é importante caracterizar as regiões corticais, bem como suas interações, envolvidas neste processo. Para isto, é necessário a utilização de técnicas de neuroimagem funcional, sendo a ressonância magnética funcional (RMf) uma das técnicas mais utilizadas neste campo nos dias de hoje. Entretanto, uma grande parte dos experimentos de RMf requer o uso de aparelhos eletrônicos para produzir estimulações somatosensoriais no corpo humano, onde a principal dificuldade é o seu ambiente hostil aos circuitos eletrônicos. A estimulação galvânica vestibular é um dos métodos mais utilizados para estimular o sistema vestibular. Esta consiste em fornecer uma corrente de baixa amplitude diretamente nas aferências vestibulares, a qual atua no disparo dos neurônios vestibulares primários atingindo principalmente as aferências otolíticas e as fibras dos canais semicirculares. O objetivo deste trabalho é analisar e avaliar as áreas cerebrais envolvidas com as estimulações visual e galvânica vestibular e suas interações, utilizando a técnica de RMf e um estimulador galvânico vestibular. Para tanto, como primeira etapa desta pesquisa, validou-se in vivo um estimulador galvânico vestibular. O estimulador elétrico não interferiu de forma significativa na qualidade das imagens de ressonância magnética e pode ser utilizado com segurança nos experimentos de RMf. Testes foram realizados para determinar um eletrodo suficientemente confortável para o voluntário durante a estimulação galvânica vestibular e que não causasse artefato nas imagens. Após estas etapas concluídas, 24 voluntários foram selecionados para realizarem três tarefas: uma puramente visual (um tabuleiro de xadrez piscante no centro da tela), uma puramente vestibular (pela aplicação da estimulação galvânica vestibular) e uma simultânea, com a apresentação em conjunto dos estímulos visual e vestibular. A estimulação puramente visual mostrou ativação dos córtices visual primário e associativo, enquanto que a estimulação puramente vestibular levou a ativação das principais áreas envolvidas com a função multimodal do sistema vestibular, como o córtex parietoinsular vestibular, o lóbulo parietal inferior, o giro temporal superior, o giro pré-central e o cerebelo. A estimulação simultânea dos sistemas visual e vestibular resultou na ativação dos giros frontal médio e inferior. Além do padrão de interação visual-vestibular inibitório recíproco ter sido mais evidente durante a condição simultânea, observou-se que as regiões frontais (córtex dorsomedial pré-frontal e giro frontal superior) estão envolvidas com o processamento da função executiva quando existem informações conflitantes dos sistemas visual e vestibular.
The static body equilibrium is controlled by three sensory systems: the vestibular system, responsible for informing the position and the movements of the head; the visual system, which informs the spatial objects position relative to the body; and the proprioceptive system, which controls posture and body movements. These three systems must always work in harmony, otherwise the individual will present balance problems. Thus, it is important to characterize the cortical regions, as well as their interactions, involved in this process. For this it is necessary to use functional neuroimaging techniques, the functional magnetic resonance imaging (fMRI) is one of the most used techniques in this field nowadays. However, a large fMRI experiments require the use of electronic devices for producing somatosensory stimulation in the human body, where the main difficulty is its hostile environment for electronic circuits. The galvanic vestibular stimulation is one of the most used methods to stimulate the vestibular system. This stimulation consist of applying a low current amplitude directly on vestibular afferents, which acts firing the primary vestibular neurons, affecting the otolithic afferents and the semicircular canals fibers. The objective of this work is to evaluate and analyze the brain areas involved with visual and galvanic vestibular stimulations and their interactions using fMRI. Therefore, as a first step of this research, a galvanic vestibular stimulator was validated in vivo. The electrical stimulator did not interfere in a significance way on magnetic resonance images quality and could be safely used in fMRI experiments. Tests were performed to select an electrode sufficiently comfortable for the volunteer during the galvanic vestibular stimulation and that do not cause artifacts in the images. After completed these steps, 24 subjects were selected to perform three tasks: a purely visual (a flashing checkerboard in the center of the screen), a purely vestibular (with application of galvanic vestibular stimulation) and a simultaneous, presenting the visual and vestibular stimuli together. The purely visual stimulation showed activation of the primary and associative visual cortices, while the purely vestibular stimulation led to activation of areas involved in multimodal function of the vestibular system, such as the parieto-insular vestibular cortex, the inferior parietal lobe, the superior temporal gyrus, the precentral gyrus and the cerebellum. The simultaneous stimulation of visual and vestibular systems resulted in activation of the middle and inferior frontal gyri. In addition to the reciprocal inhibitory visualvestibular interaction pattern had been more evident during the simultaneous condition, it was observed that frontal regions (dorsomedial prefrontal cortex and superior frontal gyrus) are involved with the executive function processing when there is conflicting information of visual and vestibular systems.
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Brown, Michael Patrick. "Effect of Ototoxic Drugs on the Amphibian Auditory System: Injection of Gentamicin Sulfate into Anuran Otic Capsules and Recovery of Thresholds". PDXScholar, 1995. https://pdxscholar.library.pdx.edu/open_access_etds/4858.
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Hair cell trauma from aminoglycosides, which may lead to permanent loss of hair cells in mammals, was studied physiologically in frogs by measuring an auditory evoked potential (AEP) in Rana pipiens. The AEP was evaluated in order to measure threshold shift (TS) and recovery from TS after the administration of the aminoglycoside antibiotic, gentamicin. To obtain an AEP, chronic electrodes were implanted into the cranium near the cochlear nucleus. The frogs were then exposed to frequency-specific narrow band ~clicks" which included a single period 1 kHz sinewave, and a computer synthesized high frequency and low frequency click. Amphibians have two hearing organs, the amphibian and basilar papillae, sensitive to low (150-1500) and high (1500-2000) frequencies, respectively. The low (AP) and high (BP) frequency clicks were created to stimulate specifically the corresponding papillae. After normal thresholds were recorded for each frog, gentamicin sulfate, 200 μM, 300 μM, or 400 μM, was injected bilaterally into the otic capsules. Thresholds were recorded until the TS had disappeared, allowing the threshold recovery period to be measured. The injections of 200 μM yielded a 10 dB change in one animal and no change in two others. The injection of 300 μM into 10 frogs and 400 μM into 20 frogs yielded at least a 10 dB change in 60% and 93% of the frogs, respectively, with the concentration of 400 μM producing threshold shifts of 20 dB. Thus, the threshold shifts were dose-dependent. Recovery times varied between six and fourteen days. No apparent differences between thresholds for the high frequency click, low frequency click and sinewave clicks were observed.
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Xue, Jingbing. "Morphometry of Hair Cell Bundles and Otoconial Membranes in the Utricle of a Turtle, Trachemys scripta". Ohio : Ohio University, 2006. http://www.ohiolink.edu/etd/view.cgi?ohiou1155672444.
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Janky, Kristen L. "Unilateral centrifugation effects of age, translation method and vestibular disease on ocular torsion and SVV /". 2009. http://proquest.umi.com/pqdweb?did=1826156721&sid=5&Fmt=2&clientId=14215&RQT=309&VName=PQD.
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Thesis (Ph.D.)--University of Nebraska-Lincoln, 2009.Title from title screen (site viewed January 12, 2010). PDF text: v, 128 p. : ill. ; 1 Mb. UMI publication number: AAT 3360500. Includes bibliographical references. Also available in microfilm and microfiche formats.
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White, Owen Bruce. "Vestibular projections to motor cortex in cat and monkey". Phd thesis, 1989. http://hdl.handle.net/1885/143033.
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Zikovitz, Daniel C. "Self-motion perception through visual optic flow and vestibular cues". 1998. http://wwwlib.umi.com/cr/yorku/fullcit?pMQ39249.
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Thesis (M. Sc.)--York University, 1998.Typescript. Includes bibliographical references (leaves. Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pMQ39249.
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Berry, Natanya Lee. ""It's been a helluva year": the experience of vestibular disorders on the significant other's quality of life". Thesis, 2017. https://hdl.handle.net/10539/23835.
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A dissertation on a study presented to
the Discipline of Speech Pathology and Audiology
,
School of Human and Community Development
,
Faculty of Humanities
,
University of the Witwatersrand
,
In fulfilment of the requirements
for the degree M.A. Audiology
,
March 2017In health care, there appears to be greater consideration for the biopsychosocial model of disability and viewing disability in terms of functional health. Recently, the effect of impairment on the significant other’s (SO’s) quality of life (QOL) has been explored. In audiology, there appear to be very few published studies in this area, particularly related to vestibular disorders. The purpose of this study was to investigate the experiences of vestibular disorders on the SO’s QOL. A qualitative research design was employed, including 11 interviews and two focus groups. Participants were SO’s of individuals with chronic vestibular disorders, and were recruited from a private audiology practice in Gauteng through purposive sampling strategies. Data were analysed using thematic analysis. Eight primary themes emerged in the data analysis: social implications, financial implications, searching for a diagnosis, emotional effects, changes in family dynamics, support systems, comparison-oriented coping mechanisms, and referrals for psychological services. Findings suggested that SO’s experienced third-party vestibular disability; however, having the appropriate support systems, including family and friends, was pertinent. It was also indicated that the relationship with the audiologist was essential in providing better understanding of the condition and prognosis thereof, resulting in less frustration and improved adaptation to the reported changes. A key finding was the lack of referral for psychological or counselling services. These findings suggest the need to account for third-party vestibular disability in clinical, theoretical, and academic settings, and they call for the inclusion of third-party disability in policy-making.
MT 2018
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McElhinney, Sarah-Anne. "A comparison of ocular and cervical vestibular evoked myogenic potentials in the evaluation of different stages of clinically certain Ménière's disease : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Audiology in the Department of Communication Disorders at the University of Canterbury /". 2009. http://hdl.handle.net/10092/3217.
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Hammam, Elie. "Physiological studies of the vestibulosympathetic reflex in humans". Thesis, 2014. http://handle.uws.edu.au:8081/1959.7/uws:33178.
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I have previously shown that sinusoidal galvanic vestibular stimulation (sGVS), a means of selectively modulating vestibular afferent activity, can cause partial entrainment of sympathetic outflow to muscle and skin in human subjects. However, GVS influences the firing of afferents from the entire vestibular apparatus, including the semicircular canals. To further identify the source of vestibular input in the generation of vestibulosympathetic reflexes, I conducted a series of studies using sinusoidal linear acceleration of seated subjects (head vertical) to physiologically stimulate the vestibular system. In Study I & II, I tested the hypotheses that selective activation of one set of otolithic organs - those located in the utricle, which are sensitive to displacement in the horizontal axis - could entrain muscle sympathetic nerve activity (MSNA) and skin sympathetic nerve activity (SSNA). Cross-correlation analysis revealed for the 10 subjects in Study I a marked entrainment of SSNA for all types of movements: vestibular modulation was 97±3 % for movements in the X-axis and 91±5 % for displacements in the Y-axis. Furthermore, Study II revealed partial entrainment of MSNA to the sinusoidal stimulus: vestibular modulation was 32±3 % for displacements in the X-axis and 29±3 % in the Y-axis; these were significantly smaller than those evoked in SSNA. In addition, in Study III I examined the capacity for the vestibular utricle to modulate muscle sympathetic nerve activity (MSNA) during sinusoidal linear acceleration at amplitudes below perceptual threshold. Subjects (n=16) were exposed to a range of amplitudes presented in a quasi-random order (1.25, 2.5, 5, 10, 20 and 30 mG), at a constant frequency of 0.2 Hz. Cross-correlation analysis revealed potent sinusoidal modulation of MSNA even at accelerations subjects could not perceive (1.25-5 mG). The modulation index showed a positive linear increase with acceleration amplitude, such that the modulation was significantly higher (25.3 ± 3.7 %) at 30 mG than at 1.25 mG (15.5 ± 1.2 %). Finally, in Study IV I sought to better understand how the brain differentiates between head-only movements that do not require changes in vasomotor tone in the lower limbs from body movements that do require vasomotor changes. As a result, I tested the hypothesis that neck movements modulate MSNA in the lower limbs of humans. Subjects (n=10) lay supine, at rest, during sinusoidal stretching of neck muscles (100 cycles, 35o peak to peak at 0.37 ± 0.02 Hz) and during a ramp-and-hold (17.5o for 54 ± 9 s) static neck muscle stretch, while their heads were held fixed in space. Cross-correlation analysis revealed cyclical modulation of MSNA during sinusoidal neck muscle stretch (modulation index 45.4 ± 5.3%), which was significantly less than the cardiac modulation of MSNA at rest (78.7 ± 4.2%). Overall, by using slow sinusoidal physiological stimuli, evidence accumulated throughout my doctoral candidature emphasizes the role of the utricle, through the vestibulosympathetic reflex, in control of the peripheral vasculature. Moreover, these vestibulosympathetic reflexes can be evoked below perceptual threshold. In addition, through dynamic stimuli of neck proprioceptors my findings also indicate that sensory endings in the neck, as well as vestibular inputs, contribute to cardiovascular control in awake humans via their projections to the vestibular nuclei.
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Hill, Patricia M. "Vestibular dysfunction associated with chronic traumatic brain injury in amateur rugby players". 2005. http://www.oregonpdf.org.
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Thesis (M.S)--Texas State University, San Marcos, 2005.Includes bibliographical references (leaves 158-166). Also available online (PDF file) by a subscription to the set or by purchasing the individual file.
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Fu, Siu-ngor. "Postural disturbance in subjects with multiple ankle sprains the role of somatosensory and vestibular systems /". 2003. http://www.oregonpdf.org.
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Thesis (Ph. D.)--Hong Kong Polytechnic University, 2003.Includes bibliographical references (leaves 199-216). Also available online (PDF file) by a subscription to the set or by purchasing the individual file.
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Foster, Monique. "The effects of low-frequency sinusoidal linear acceleration on skin sympathetic nerve activity in humans". Thesis, 2017. http://hdl.handle.net/1959.7/uws:45938.
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Motion sickness, caused by actual or apparent motion, is a common disorder that is yet to be fully understood. It is a complex disorder that transcends the most common symptoms of nausea and vomiting, with several of the symptoms or symptom-complexes being under-researched or not well understood. One of these symptom-complexes is centred around the drowsiness, lethargy and irritability associated with typical motion sickness, is known as sopite syndrome. It has previously been shown that sopite syndrome can be caused by exposure to low-frequency motion over a longer duration. Additionally, it is known that the vestibular apparatus, being activated by motion, plays an important role in the pathogenesis of motion sickness, as robust vestibular modulation of skin sympathetic nerve activity (SSNA) has been demonstrated. However, there is currently no research quantifying the physiological changes that occur during sopite syndrome. Therefore, this study aims to quantify the physiological effects of low-frequency motion on SSNA, skin blood flow and heart rate variability (HRV), while also measuring self-reported sleepiness in subjects. The techniques used to obtain these measurements were: microneurography to record SSNA, infrared plethysmography to record skin blood flow, ECG to analyse and determine HRV and the Karolinska Sleepiness Scale to compare sleepiness before and after motion. Subjects were seated upright and exposed to a randomised sequence of five slow, sinusoidal motions on a motorised platform: 0.03 Hz at 0.5 mg, 0.05 Hz at 0.5 mg, 0.1 Hz at 0.5 mg, 0.1 Hz at 5 mg and 0.2 Hz at 5 mg. Cross-correlation analysis was used to calculate the vestibular modulation of SSNA, which was present at all frequencies and ranged from 30.7 ± 3.8 (0.2 Hz) to 37.2 ± 4.4 (0.1 Hz at 5 mg). There was no significant difference in the modulation indices when the magnitude of vestibular modulation was compared across all frequencies. However, the vestibular modulation of SSNA was greater than cardiac modulation at all frequencies, and the cardiac modulation during each frequency was less than the baseline value. Additionally, the skin blood flow was lower than the baseline at all frequencies and there was no statistical change in any of the HRV indices. Thus, it has been shown that very low-frequency sinusoidal motion can be used to activate the vestibular system causing modulation of SSNA. However, even though subjects reported feeling relaxed or drowsy upon completion of the protocol, with some even falling asleep throughout, it didn’t appear that the motion stimulus applied caused the onset of physiological relaxation.
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Rezlerová, Pavlína. "Vyšetření dynamické zrakové ostrosti u zdravých jedinců". Master's thesis, 2017. http://www.nusl.cz/ntk/nusl-369082.
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In this study we examined dynamic visual acuity as a functional testing of the vestibulo- ocular reflex. Two groups were examined: 22 healthy seniors and 22 healthy young people as controls. We used two types of situations for testing: while walking on a treadmill at a speed of 2, 4 and 5 kmph, and with a subject's head passively moved in yaw and pitch plane. Visual acuity was measured with optotype charts (for the walking test it was a standard Snellen optotype chart at 6 m distance, for the test of head moves it was a Jaeger chart at 30 cm distance). The values obtained in these ways we related to values of a subject's static visual acuity, measured in the same conditions, just before the dynamic situations were examined. We found significant difference of dynamic visual acuity in senior group within each condition tested. We also found a significant decline as for difference of dynamic visual acuity in the senior group compared to young subjects - in the walking test at 4 and 5 kmph and in both head-moving conditions. These results indicate age-related impairment in function of vestibulo-ocular reflex. Based on our results, the test of passive head moves appears to be more suitable for ordinary clinical examination of dynamic visual acuity.
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Hlaváčková, Anna. "Využití virtuální reality ke zhodnocení dynamické posturální stability u hráčů beachvolejbalu". Master's thesis, 2017. http://www.nusl.cz/ntk/nusl-353286.
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Title: Use of virtual reality to evaluate the dynamic postural stability in beachvoleyball players Objectives: The aim of the study was to evaluate if the dynamic postural stability of trained beachvoleyball players is affected by training. Also I tried to evaluate, if the final score of equilibrium will be higher, than in regular population. For testing was also used virtual reality to stimulate vestibular apparatus. Virtual reality was used as a disturbing element. NeuroCom Smart Equi Test was used as an evaluation factor of dynamic postural stbility. Methods: The research involved a total of 20 females - 10 beachvoleyball players and 10 healthy persons performing activities of daily living. We investigated dynamic postural stability on device called NeuroCom Smart Equi Test. For evaluation of dynamic postural stability was used Head Shake Test - Sensory Organisation Test. This test was taken twice, second time after intervetion by virtual reality. Data were analyzed by statistical t-test method. Result: Statisticly significant result was found only in the case of a Sensory Organisation Test condiition 5 and 6 in comparison between both groups and Head Shake test-SOT2 in latero- lateral movement of the head at the controle group. The results confirmed the effect of playing beachvoleyball on...
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Pakan, Janelle. "General principles of cerebellar organization : correlating anatomy, physiology and biochemistry in the pigeon vestibulocerebellum". Phd thesis, 2009. http://hdl.handle.net/10048/530.
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Thesis (Ph.D.)--University of Alberta, 2009.A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy, Centre for Neuroscience. Title from pdf file main screen (viewed on August 25, 2009). Includes bibliographical references.
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Claassens, Heidi. "Persepsie van grondslagfase-onderwysers en ouers aangaande die effektiwiteit van vestibulere oefeninge om sensoriese en motoriese ontwikkeling te bevorder". Diss., 2020. http://hdl.handle.net/10500/27175.
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Abstracts in Afrikaans and EnglishInklusiewe onderrig ondersteun die insluiting van alle leerders met verskillende behoeftes en vaardighede in klaskamers, wat baie keer te groot, of te verskillend vir doeltreffende onderrig is. Beweging as deel van ‘n vroeë leerervaring is noodsaaklik vir optimale neurale ontwikkeling. Dit beïnvloed organisasie en stimuleer die spesifieke neurologiese sisteme nodig vir optimale funksionering en ontwikkeling van die brein. Sensoriese integrasie disfunksie word gesien as die wortel van baie leerprobleme. Die vestibulêre sisteem is direk verbind met die sensoriese en motoriese sisteme. ‘n Sensoriese integrasie disfunksie het ‘n duidelike invloed op die vestibulêre sisteem. Die vestibulêre sisteem het baie interkonneksies met baie dele in die brein, byvoorbeeld propriosepsie en die tassisteem. Doeltreffende funksionering van die sensoriese, motoriese en vestibulêre sisteme word verlang vir ‘n hoë vlak van prestasieverrigting in sport en akademie. Wanneer die vestibulêre sisteem gestimuleer word, het dit ‘n direkte positiewe invloed op die sensoriese en motoriese ontwikkeling van leerders. Die doel van hierdie studie was om te bepaal wat die persepsie van grondslagfase-onderwysers en ouers is oor die rol en voordele wat vestibulêre oefeninge te weeg kan bring in die motoriese en sensoriese ontwikkeling van leerders. Leerders in graad 1 van ‘n privaatskool, asook van grade 2 en 3 van ‘n plaasskool is gekies as deelnemers in die studie. Die keuse van leerders was op grond van die bereidwilligheid van hulle en hul ouers om aan die studie deel te neem. Leerders het ‘n vestibulêre oefenprogram drie maal per week gedoen vir die tydperk van agt weke. Observasie-vraelyste is deur onderwysers en ouers ingevul na afloop van die derde sessie elke week. Vir die vraelys het ouers en onderwysers gekyk na die verbetering in aandagspan, konsentrasie, luistervaardigheid, oogkontak, sosiale interaksie en samewerking. Onderhoude is met ouers en onderwysers gedoen na aanleiding van die observasievraelyste wat vir die agt weke voltooi is. Transkripsies van die onderhoude is gedoen en afleidings is gemaak deur analise van die observasie-vraelyste en die getranskribeerde onderhoude. Al ses die ontwikkelingsareas by beide skole het verbetering getoon oor die agt weke. Dit dui daarop dat vestibulêre oefeninge wel ‘n invloed op die sensoriese en motoriese ontwikkeling het.
Inclusive education promotes the inclusion of learners with different needs and capabilities in classes which are often too big and diverse for effective teaching. Movement as an early learning experience is necessary for optimal neural development. It influences organisation and stimulates the specific neurological systems required for optimal functioning and development of the brain. Sensory integrative dysfunction is believed to be at the root of many learning disorders. The vestibular system is directly connected with the sensory and motor systems. The vestibular system will be directly affected when a sensory integrations dysfunction presents. In fact, the vestibular system has many interconnections with almost every other part of the brain like proprioception and the tactile system. Proper functioning of the sensory, motor and vestibular systems is required for higher level performance in sport and academics. When the vestibular system is stimulated, it will result in a positive influence on the sensory and motor development of learners. The aim of this study is to determine the perceptions of foundation phase teachers and parents regarding the role or benefits of vestibular exercises in promoting learners’ motor and sensory development. Learners in Grade 1 of a private school and Grade 2 and 3 learners of a farm school in the northern Free State were selected as participants in the research. Learners were selected on the basis of the willingness of them and their parents to participate in the research. The participants did exercise sessions three times a week for thirty minutes over a period of eight weeks. Observation sheets were completed for all eight weeks, for the duration of the exercise program, by teachers and parents. These sheets were completed weekly after the third sessions in that week. The observation sheets listed concentration, attention span, listening, eye contact, cooperation, social interaction and self-esteem as developmental areas. Interviews were done after the period of eight weeks with the parents and teachers. The interviews conducted with both parties were taped and meticulously transcribed. This helped the researcher to get a better understanding of the study and to analise data and draw conclusions.All six areas of development showed improvement at both schools over the period of eight weeks. This indicates that stimulating the vestibular system promotes sensory and motor development.
Inclusive Education
M. Ed. (Inklusiewe Onderwys)