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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.
51

Adaptabilidade de respostas posturais reativas em função de restrição imposta por tarefa voluntária: efeito do envelhecimento e da doença de Parkinson / Adaptability of reactive postural responses as a function of voluntary task constraint: influence of aging and Parkinson´s disease

Pardini, Andréa Cristina de Lima 09 April 2013 (has links)
Neste estudo foi avaliado o efeito da restrição de estabilidade imposta por uma tarefa voluntária sobre a adaptação de respostas posturais reativas a perturbações externas em jovens, idosos sadios e idosos com doença de Parkinson (DP). No Experimento 1 participantes com DP e idosos sadios foram perturbados por meio de translação posterior da superfície de apoio, enquanto executavam duas versões de uma tarefa voluntária: segurando uma bandeja com um cilindro apoiado em sua base (BR) ou em seu lado circular (AR). A avaliação foi feita por meio de blocos alternados de baixa e alta restrição. Os resultados indicaram que ambos os grupos mostram menor velocidade da bandeja no contexto de AR em comparação ao de BR. A latência de resposta postural foi maior no contexto de AR apenas para indivíduos sadios. Indivíduos sadios apresentaram diferentes padrões de coordenação ombro-quadril em função da restrição da tarefa, enquanto idosos com DP apresentaram um padrão relativamente invariável. Estes resultados sugerem que a doença de Parkinson prejudica a capacidade de adaptar as respostas posturais às exigências impostas por uma tarefa voluntária. O Experimento 2 teve como objetivo comparar as respostas posturais reativas entre jovens e idosos sadios. O mesmo paradigma do Experimento 1, com exceção do tipo de perturbação, foi utilizado no Experimento 2. Ambos os grupos diminuíram a velocidade da bandeja no contexto de AR em comparação ao contexto de BR. Os resultados mais expressivos mostraram que, enquanto os jovens adaptaram a latência muscular, magnitude muscular, nível de coativação muscular e coordenação interarticular de acordo com a sequência, os idosos foram mais sensíveis ao contexto atual de restrição da tarefa voluntária. Estes resultados sugerem que o envelhecimento leva à mudança de uma adaptação mais generalizada para uma mais específica das respostas posturais reativas / This study assessed the effect of stability constraints imposed by a voluntary task on the adaptation of postural responses to an external perturbation in healthy adults and in elderly individuals with Parkinsons disease (PD). In Experiment 1 subjects with PD and age-matched controls were perturbed through a backward translation of the support surface while standing and performing two versions of a voluntary task: holding a tray with a cylinder placed with the flat side down (LC) or with the rolling round side down (HC). Participants performed alternating blocks of low and high constraint trials. Parkinsons disease participants accomplished the voluntary task as well as controls, showing slower tray velocity in the high, as compared with the low, constraint context. Latency of postural responses was longer in the high constraint context only for control subjects. Control subjects presented different patterns of hip-shoulder coordination as a function of task constraint, whereas PD subjects had a relatively invariable pattern. These results suggest that Parkinsons disease impairs the capacity to adapt postural responses to constraints imposed by a voluntary task. Experiment 2 aimed at comparing postural reactive responses between healthy young and elderly individuals in response to unexpected load release. Results showed that while the young group adapted muscular latency, muscular magnitude, coactivation level and interjoint coordination according to task-constraint sequence, the elderly group was more sensitive to the current context of voluntary task constraint. These results suggest that aging lead to more specific postural reactive responses adaptation
52

Efeitos de tarefas cognitivas no controle postural estático e dinâmico de adultas jovens e idosas caidoras e não-caidoras

Pranke, Gabriel Ivan January 2015 (has links)
O controle postural vem sendo estudado há algum tempo com o intuito de entender o complexo funcionamento do sistema de controle postural, além de servir para evitar quedas em idosos. As quedas são eventos que ocorrem em aproximadamente um terço da população idosa e podem levar a consequências muito graves, o que dá importância para o tema. A dupla-tarefa com interferência cognitivo-motora pode afetar o desempenho dos idosos na tarefa de manter o equilíbrio e aumentar o risco de quedas. Logo, o objetivo desse estudo foi avaliar o efeito de tarefas cognitivas sobre o desempenho em tarefas de controle motor estático e dinâmico em adultas jovens (n=25) e idosas caidoras (n=20) e não-caidoras (n=21). Foram avaliados o controle postural estático em dois tipos de superfície (estável e instável) e também o desempenho na tarefa de marcha com transposição de obstáculos, durante dois tipos de tarefas cognitivas (teste de Stroop e contagem regressiva em etapas de três). ANOVAs de dois fatores foram usadas para avaliar as diferenças entre grupos e condições. O equilíbrio estático foi melhor para jovens em comparação com idosas, que não diferiram entre caidoras e não-caidoras. A tarefa de contagem regressiva piorou o equilíbrio, principalmente nas idosas. Na tarefa de ultrapassagem de obstáculos, a velocidade das idosas caidoras foi menor, mesmo sem tarefa cognitiva, sendo que a tarefa cognitiva influenciou o desempenho das idosas não-caidoras e jovens. As distâncias verticais na transposição do obstáculo foram maiores para o grupo de idosas caidoras, diferente do esperado, denotando uma segurança maior na tarefa nesses indivíduos e uma menor chance de cair nesses indivíduos. É possível que esse resultado seja relacionado ao medo de cair nesses idosas, o que levou os mesmos a realizarem uma tarefa mais cautelosa na transposição do obstáculo. Com relação às distâncias horizontais, as jovens afastaram mais o pé do obstáculo, denotando maior capacidade nessa tarefa que idosas não-caidoras e caidoras, não havendo efeito da tarefa cognitiva. Os resultados indicam que o desempenho em tarefas de controle postural estático e dinâmico é pior em idosas, sem grandes diferenças entre caidoras e não-caidoras. Na tarefa de transposição do obstáculo, as idosas optaram por uma tarefa mais cautelosa, mesmo quando nenhuma tarefa cognitiva era solicitada, ao passo que a tarefa cognitiva levou as jovens a realizar estratégia semelhante. O medo de cair que acomete o idoso pode ter levado a estratégias mais cautelosas. Conclui-se que o as tarefas cognitivas afetam o desempenho no controle postural estático em jovens e idosas e afetam o desempenho da tarefa dinâmica em jovens, principalmente. Durante a execução da tarefa de marcha com obstáculo, as idosas assumiram uma estratégia mais segura, possivelmente pelo medo de cair. Somente o teste de contagem regressiva aplicou demanda cognitiva suficiente para afetar a realização das tarefas motoras, enquanto que o teste de Stroop ajudou a tarefa motora em alguns casos. / Postural control has been studied in the last years to understand the hard behavior of the postural control system and to find ways to prevent falls in elderly. One third of the elderly people experiences falls during the live and falls can lead to serious consequences, being an important issue to study. Cognitive-motor interference in dual-task conditions can affect balance tasks performance on elderly and increase the risk of falls. Thus, this study aims to evaluate the effect of cognitive tasks on static and dynamic motor control tasks performances in young women (n = 25) and fallers (n = 20) and non-fallers (n = 21) older women. Static postural control in two surface conditions (stable and unstable) and obstacle negotiation task during walking were evaluated, while the subjects were performing two different cognitive tasks (Stroop task and counting backwards on steps of three) and without any cognitive task. Were performed ANOVAs with two factor to test differences between groups and conditions. Static balance was better in younger compared to old-aged, and non-fallers and fallers did not differ between themselves. Counting backward cognitive task impaired the balance especially in elderly. During obstacles negotiation tasks, the mean velocity was lower for fallers than the other groups, even without cognitive task. Cognitive tasks impaired performance of non-fallers and younger groups. Vertical distances on obstacle negotiation were higher for the fallers group, different than we expected. It means that this group performs the task safer than the others perform and has lower chance of falling. It is possible that these results are related to the elderly fear of falling, which led them to conduct a more cautious task during obstacle negotiation. Regarding to horizontal distances, young people distance more their foot from obstacle, showing increased capacity in this task than non-fallers and fallers, with no effect of cognitive task. Results indicate that static and dynamic performance on postural control tasks is worse in the elderly, without many differences between fallers and non-fallers. In obstacle negotiation task, elderly have opted for a more cautious task, even when no cognitive task was requested, while the cognitive tasks lead young people to perform similar strategy. Fear of falling that affect elderly people has led them to take more cautious strategies. We conclude that the cognitive tasks affect static postural control performances in young and old groups and affect dynamic task performance mainly in the young group. During the obstacle negotiation task, elderly have taken a safer strategy, possibly due to fear of falling in this task. Only the counting backwards task applied a sufficient cognitive demand to affect the proposed motor tasks while the Stroop task improved the performances for some variables.
53

Influência da visão e da dupla tarefa no controle postural de idosas com perdas urinárias

Ribeiro, Joane Severo January 2015 (has links)
A Sociedade Internacional de Continência (ICS) define que toda queixa de perda involuntária de urina é considerada incontinência urinária (IU), sendo que a IU é um processo natural do envelhecimento que afeta de 25 a 45% das mulheres brasileiras. Portadores de IU podem apresentar alterações no controle postural, pois a musculatura do assoalho pélvico é responsável pela estabilização das estruturas da pelve, possuindo assim íntima relação com o controle postural estático. Em virtude disto, o presente estudo tem por objetivo comparar o controle postural de mulheres idosas com relato de perdas urinárias e idosas continentes, nas condições de olhos abertos, supressão da visão e durante teste de dupla tarefa cognitiva e visual. Trata-se de um estudo do tipo observacional de caráter transversal, quantitativo realizado com 46 mulheres idosas, sendo 26 com incontinência urinária com média de idade 68,31 ± 5,79 anos e 20 continentes com média de idade 69,3 ± 6,87 anos. Foi utilizado um questionário de anamnese, para identificar aspectos gerais de saúde das idosas, onde incluía auto relato de perda urinária. A análise do controle postural foi realizada utilizando-se uma plataforma de força para a obtenção dos dados referentes ao centro de pressão (COP). As idosas foram avaliadas nas situações: olhos abertos, olhos fechados e teste de dupla tarefa stroop color. Os dados foram analisados utilizando-se o programa estatístico SPSS 17.0. A normalidade foi verificada através do teste de Shapiro-Wilk e após, realizado teste t de Student e o nível de significância adotado foi de 5%. Os resultados não apresentaram diferenças estatisticamente significativas em todas as variáveis do COP na situação de olhos abertos, nem nas variáveis COPap e COPml de olhos fechados bem como no COPap, COPml e COPvel na dupla tarefa. E as variáveis COPvel e COPelp na situação de olhos fechados e COPelp na dupla tarefa, apresentaram diferenças estatisticamente significativas com p<0,05. Concluiu-se que as mulheres idosas com relato de perdas urinárias apresentaram um pior desempenho do controle postural estático no que se refere a velocidade média de oscilação e a área de oscilação, quando comparadas as idosas continentes. / The International Continence Society (ICS) defines that every complaint involuntary loss of urine are considered urinary incontinence (UI). The UI is a natural process of aging and affects 25-45% of Brazilian women. IU carriers may show changes in postural control, because the pelvic floor muscles is responsible for stabilization of pelvic structures, thus having intimate relationship with the static postural control. This study analyzed and compared the postural control of elderly women with urinary incontinence and continent. The data collection conditions were with eyes open, suppression of vision and with dual cognitive and visual task. It is an observational study of transversal, quantitative conducted with 46 elderly women, 26 UI with a mean age 68.31 ± 5.79 years and 20 continent with a mean age 69.3 ± 6.87 years. The anamnesis questionnaire was used to identify general aspects of health of older, which included urinary loss self-reported. The analysis of postural control was performed using a force plate to obtain data on the center of pressure (COP). The elderly were evaluated in situations: eyes open, eyes closed and dual task Stroop color test. Data were analyzed using SPSS17.0 statistical software, data normality was verified using the Shapiro-Wilk test and after, performed t Student test, and Statistical significance was set at a p-value< 0.05. The results no significant differences for all variables to COP in open eyes, COPap and COPml in closed eyes situations, and COPap, COPml e COPvel in dual task. The results were statistically significant with p<0,05 for variables COPvel and COPelp in closed eyes situations and COPelp in dual task. It was concluded that older women reporting urinary losses showed a worse performance of the static postural control COPvel and COPelp in relation to continent women.
54

Aprendizagem em tarefas duais: variação de desempenho e demanda atencional / Dual task learning: variation of performance and attention demand.

Claudio, Ana Paula Kogake 31 October 2011 (has links)
O presente estudo teve como objetivo avaliar a aprendizagem em uma tarefa dual em comparação à aprendizagem de tarefas singulares e a respectiva variação de demanda atencional em função da prática. Participaram do estudo 27 estudantes universitários destros, divididos em três grupos de acordo com a tarefa praticada: prática da tarefa singular de traçar uma estrela com a mão esquerda recebendo feedback invertido (EST), prática da tarefa singular de toques sequenciais dos dedos da mão direita (TOQ) e prática dual consistindo na prática simultânea das duas tarefas singulares (T+E). A demanda atencional foi mensurada por meio do tempo de reação probatório, com estímulo auditivo e resposta vocal. As tarefas foram praticadas em 200 tentativas, distribuídas em 4 sessões executadas em diferentes dias. O efeito de aprendizagem foi avaliado após um dia e após uma semana a última sessão de prática. Os resultados mostraram que a demanda atencional foi maior na tarefa dual em comparação com as tarefas singulares e houve diminuição persistente da demanda atencional após o período de prática somente para a tarefa dual. A análise da fase de aquisição mostrou que o ganho proporcional de desempenho do grupo T+E foi equivalente ao encontrado para os grupos singulares, apesar de ter havido vantagem de desempenho favorável aos grupos singulares. A avaliação da retenção revelou que a prática na tarefa dual induziu resultados equivalentes à prática nas tarefas singulares quando avaliado o desempenho em cada tarefa motora separadamente. Para desempenho na tarefa dual, o grupo T+E atingiu valores superiores ao grupo EST e valores equivalentes ao grupo TOQ nas respectivas tarefas praticadas por estes dois grupos. Tais resultados mostram que o compartilhamento dos recursos atencionais durante a tarefa dual não prejudicou a aprendizagem motora em comparação com a prática com atenção focal em uma tarefa singular / This study aimed to evaluate learning of a dual task in comparison to learning of single tasks and the respective variation of attentional demand as a function of practice. Twenty-seven right-handed university students participated of the study. They were assigned to one of three groups: practice of a single task requiring drawing of a star based on inverted visual feedback with the left hand (EST); practice of a single task requiring fast sequential fingers movements with the right hand (TOQ); and practice of a dual task requiring performance of both single tasks simultaneously (T+E). To evaluate attentional demand we used a probe reaction time task, consisting of auditory stimuli and vocal responses. The experimental tasks were practiced for 200 trials, during four sessions distributed on different days. The learning effect was evaluated after one day and after one week the last practice session. Results showed that attentional demand was higher when performing the dual task in comparison with the two single tasks and reduced attentional demand persisted after the practice period only for the dual task. Analysis of the acquisition phase showed that the proportional performance gain of the T+E group was equivalent to that found for groups practicing single tasks, despite the performance advantage favoring the latter. Evaluation of the retention phase showed that practice of the dual task led to similar results to practicing single tasks when performance was measured on each motor task separately. For performance on the dual task, the T+E group was superior in comparison with the EST group and equivalent to the TOQ group on the specific tasks practiced by these two groups. The results evidenced that sharing attentional resources in the practice of a dual task did not hinder motor learning in comparison to situations of focused attention to the practice of a single task
55

Integração de informações visuais e verbais na memória de trabalho / Integration of visual and verbal information in working memory

Godoy, Juliana Pardo Moura Campos 05 March 2010 (has links)
O paradigma de tarefas duplas foi utilizado para investigar o envolvimento da atenção na conjunção da informação verbal e visual na memória de trabalho, e o papel específico desses componentes quando integrados. Em dois experimentos os sujeitos (33) memorizaram seqüências de Faces, Nomes, ou Conjunções face-nome. No experimento 1 essas condições foram realizadas, em blocos separados, isoladamente ou junto com uma contagem regressiva de três em três (CR3). No experimento 2 essas condições foram realizadas, em blocos separados, com uma supressão articulatória (SA) e com um ruído visual dinâmico (RVD). A CR3 provocou um prejuízo maior na condição de conjunção do que nas de faces e nomes (Exp 1). A SA e o RVD têm efeitos iguais e mais acentuados sobre a conjunção; a SA tem um efeito mais pronunciado do que o RVD nas condições de face e nome (Exp 2). O prejuízo maior da CR3 sobre a conjunção, em comparação com nomes e faces sugere que a integração de características visuais e verbais exigiu o envolvimento da atenção. Além disso, o efeito diferenciado da SA no armazenamento das características visuais e verbais isoladas sugere que estas podem ser armazenadas de maneira diferente quando integradas. / The dual tasks paradigm was used to investigate the involvement of attention in the binding of verbal and visual information in working memory, and the specific role of these components when they are integrated. Two experiments were carried out, with 33 subjects, who memorized sequences of faces, names, or face-name conjunctions. In the Experiment1, these conditions were performed in separate blocks, either alone or with a backward counting in threes (CR3). In experiment2, these conditions were performed in separate blocks, with Articulatory Suppression (AS) and Dynamic Visual Noise (DVN). The CR3 caused greater loss in the conjunction than in the faces and names condition (Exp.1). The SA and the DVN have equivalent effect and they show more relevant effects in the conjunction condition. The SA revealed more relevant effect than the DVN in the face and name conditions (Exp.2). The greater prejudice of CR3 in binding, compared to that obtained in names and faces suggested that the integration of visual and verbal features demanded the involvement of attention. Moreover, the differential effect of SA towards DVN in the storage of isolated visual and verbal features, suggests that they may be stored in different ways when integrated.
56

En träningsstudie om barn och balans : effekter av Tai Chi liknande rörelser på flickors och pojkars balans / An intervention study of postural control in children : effects of Tai Chi like exercises on postural control in girls and boys

Nilsson, Kerstin January 2009 (has links)
<p>Syfte</p><p>Tidigare forskning har visat att Tai Chi träning förbättrar balansen hos äldre. Syftet med denna studie var att undersöka om barns balans påverkades av träning som utfördes i ett långsamt tempo liknande Tai Chi träning.</p><p>Studien syftade också till att utreda om det förelåg någon skillnad i balans mellan pojkar och flickor och om något av könen tog till sig träningen bättre. Studien syftade även till att undersöka hur balansen påverkades då barnen utförde olika kognitiva uppgifter.</p><p>Metod</p><p>Studien fullföljdes av 41 barn i åldern 9-10 år. En interventionsgrupp, 19 barn tränade Tai Chi liknande rörelser dagligen under åtta veckor och denna jämfördes med en kontrollgrupp, 22 barn som inte fick denna träning.</p><p>Balansövningar utfördes på en kraftplatta samt på en metallprofil. Från övningarna på kraftplattan mättes standardavvikelse och amplitud av tryckcentrums mediolaterala och anterioposteriora förflyttning. Från övningarna på metallprofilen mättes antalet nedtramp.</p><p>Resultat</p><p>Många parametrar mättes men endast en uppvisade en signifikant träningseffekt. Pojkarna minskade standardavvikelsen på tryckcentrums mediolaterala förflyttning vid stående med öppna ögon.</p><p>Studien uppmätte vissa skillnader i balans mellan pojkar och flickor.</p><p>Mätningar av tryckcentrums förflyttning då barnen utförde olika uppgifter uppmätte en signifikant skillnad vid stående med öppna ögon jämfört med stående då ögonen var stängda (med eller utan utförande av en samtida kognitiv uppgift).</p><p>Övningarna på metallskenan förbättrades lika mycket i tränings- som kontrollgrupp.</p><p>Slutsats</p><p>Studien ger indikationer att träningsformen i viss utsträckning var effektiv då daglig träning under åtta veckor gav signifikant förbättring i en av de testade parametrarna.</p><p>Dessa fynd är i linje med de fåtal studier som finns på träning av balans hos barn.</p><p> </p> / <p>Aim.</p><p>Previous studies have shown that Tai Chi exercises improve postural control in elderly people. The primary aim of this study was to investigate if similar Thai Chi like training affects postural control in children. Secondary aims of the study was 1) to investigate if any such effects from training differs between boys and girls and 2) to investigate whether performing a cognitive task during balance testing had any effect on postural control in these children.</p><p>Method.</p><p>In the balance tests, different tasks were performed on a force plate and on a metal profile. From the tasks performed on the force plate, the standard deviations and amplitudes of the mediolateral and anterioposterior displacements of center of pressure were measured. From the tasks performed on the metal profile, the number of clampdowns were counted.</p><p>The study was conducted over an eight week period with 41 children in the ages 9-10 years old. The children were divided into two groups; children in the training group (n=19) who participated in Tai Chi like training every day, and children in the control group (n=22) who did not participate in this training.</p><p>Results.</p><p>The study also showed some differences in postural control between boys and girls.</p><p>When comparing the displacement in center of pressure between different two-legged tasks performed on the force plate, significantly less displacement was found in the task involving standing with open eyes compared to all tasks involving standing with closed eyes (with or without a concurrent cognitive task).</p><p>The number of clampdowns from the metal profile were reduced after the training period, to a similar extent in the control and the training groups.</p><p>Several different aspects of the postural control were measured in the study. Only one of these improved significantly with training. Boys in the intervention group showed a decrease in the standard deviation of the mediolateral displacement of the center of pressure when standing with open eyes.</p><p>Conclusion.</p><p>These results are also consistent with similar studies on postural control among children.</p><p>This study indicates that slow motion training, similar to Tai Chi, has a small but positive effect on postural control, for boys 9-10 year old, when conducted every day over an eight week period, as one of the tested parameters shows an improvement.</p><p> </p>
57

En träningsstudie om barn och balans : effekter av Tai Chi liknande rörelser på flickors och pojkars balans / An intervention study of postural control in children : effects of Tai Chi like exercises on postural control in girls and boys

Nilsson, Kerstin January 2009 (has links)
Syfte Tidigare forskning har visat att Tai Chi träning förbättrar balansen hos äldre. Syftet med denna studie var att undersöka om barns balans påverkades av träning som utfördes i ett långsamt tempo liknande Tai Chi träning. Studien syftade också till att utreda om det förelåg någon skillnad i balans mellan pojkar och flickor och om något av könen tog till sig träningen bättre. Studien syftade även till att undersöka hur balansen påverkades då barnen utförde olika kognitiva uppgifter. Metod Studien fullföljdes av 41 barn i åldern 9-10 år. En interventionsgrupp, 19 barn tränade Tai Chi liknande rörelser dagligen under åtta veckor och denna jämfördes med en kontrollgrupp, 22 barn som inte fick denna träning. Balansövningar utfördes på en kraftplatta samt på en metallprofil. Från övningarna på kraftplattan mättes standardavvikelse och amplitud av tryckcentrums mediolaterala och anterioposteriora förflyttning. Från övningarna på metallprofilen mättes antalet nedtramp. Resultat Många parametrar mättes men endast en uppvisade en signifikant träningseffekt. Pojkarna minskade standardavvikelsen på tryckcentrums mediolaterala förflyttning vid stående med öppna ögon. Studien uppmätte vissa skillnader i balans mellan pojkar och flickor. Mätningar av tryckcentrums förflyttning då barnen utförde olika uppgifter uppmätte en signifikant skillnad vid stående med öppna ögon jämfört med stående då ögonen var stängda (med eller utan utförande av en samtida kognitiv uppgift). Övningarna på metallskenan förbättrades lika mycket i tränings- som kontrollgrupp. Slutsats Studien ger indikationer att träningsformen i viss utsträckning var effektiv då daglig träning under åtta veckor gav signifikant förbättring i en av de testade parametrarna. Dessa fynd är i linje med de fåtal studier som finns på träning av balans hos barn. / Aim. Previous studies have shown that Tai Chi exercises improve postural control in elderly people. The primary aim of this study was to investigate if similar Thai Chi like training affects postural control in children. Secondary aims of the study was 1) to investigate if any such effects from training differs between boys and girls and 2) to investigate whether performing a cognitive task during balance testing had any effect on postural control in these children. Method. In the balance tests, different tasks were performed on a force plate and on a metal profile. From the tasks performed on the force plate, the standard deviations and amplitudes of the mediolateral and anterioposterior displacements of center of pressure were measured. From the tasks performed on the metal profile, the number of clampdowns were counted. The study was conducted over an eight week period with 41 children in the ages 9-10 years old. The children were divided into two groups; children in the training group (n=19) who participated in Tai Chi like training every day, and children in the control group (n=22) who did not participate in this training. Results. The study also showed some differences in postural control between boys and girls. When comparing the displacement in center of pressure between different two-legged tasks performed on the force plate, significantly less displacement was found in the task involving standing with open eyes compared to all tasks involving standing with closed eyes (with or without a concurrent cognitive task). The number of clampdowns from the metal profile were reduced after the training period, to a similar extent in the control and the training groups. Several different aspects of the postural control were measured in the study. Only one of these improved significantly with training. Boys in the intervention group showed a decrease in the standard deviation of the mediolateral displacement of the center of pressure when standing with open eyes. Conclusion. These results are also consistent with similar studies on postural control among children. This study indicates that slow motion training, similar to Tai Chi, has a small but positive effect on postural control, for boys 9-10 year old, when conducted every day over an eight week period, as one of the tested parameters shows an improvement.
58

Investigating Training and Transfer in Complex Tasks with Dual N-Back

Jonasson, Lars January 2011 (has links)
No clear consensus exists in the scientific community of what constitutes efficient dual-tasking abilities. Moreover, the training of executive components has been given increased attention in the literature in recent years. Investigating transferability of cognitive training in a complex task setting, thirty subjects practiced for five days on a Name-Tag task (controls) or a Dual N-Back task (experimental), subsequently being tested on two transfer tasks; the Automated Operation Span and a dual task (Trail Making task + Mathematical Addition task). Dual N-Back training previously transferred to unrelated intelligence tests and in this study is assumed to rely primarily on executive attention. Executive attention, functioning to resolve interference and maintaining task-relevant information in working memory, has previously been linked to fluid intelligence and to dual-tasking. However, no transfer effects were revealed. The length of training may have been too short to reveal any such effects. However, the three complex tasks correlated significantly, suggesting common resources, and therefore having potentials as transfer tasks. Notably, subjects with the highest task-specific improvements performed worse on the transfer tasks than subjects improving less, suggesting that task-specific gains do not directly correlate with any transfer effect. At present, if transfer exists in these settings, data implies that five days of training is insufficient for a transfer to occur. Important questions for future research relates to the necessary conditions for transfer to occur, such as the amount of training, neural correlates, attention, and motivation.
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Practice effects, emotion, and mechanisms of dual-task interference in driving and cell phone research

Lightman, Erin 18 May 2010 (has links)
Decades of research suggest that talking on a cell phone interferes with driving performance, but the underlying mechanisms of this interference remain poorly understood. Driving and cell phone research often generalizes easy, novice laboratory tasks to the well practiced task of driving, and it frequently ignores important factors like emotion in tasks used to represent cell phone conversation. This experiment sought to address these issues. Participants performed a tracking task and two verbal tasks over 7 one-hour sessions. At some times the tasks were performed individually, and at others the tracking task was performed concurrently with one of the verbal tasks. Participants watched an anger-inducing film clip at the beginning of the 7th session and were instructed to either down-regulate or maintain that anger. Results challenged the validity of generalizing easy novice task performance to driving performance.
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Dual-Task Performance During Traverse Climbing: Human Factors Implications for Emergency-Response Organisations

Green, Alexander Louis January 2012 (has links)
Two experiments were conducted to investigate how performance on a primary rock climbing task is affected by the inclusion of a secondary word memory task. In Experiment 1, twelve experienced rock climbers completed a dual traverse climb and word memory task, with participants’ performance analysed relative to their single task performance (climbing alone and word memory alone). Participants’ climbing efficiency and word recall were significantly lower in the dual-task condition. Experiment 2 examined the effects of emotional content on climbing performance. Fifteen experienced rock climbers completed two dual-tasks, in which they were asked to recall negatively valenced or neutral words. Climbing efficiency, climbing distance, and word recall were all significantly lower in the dual-task conditions, relative to the single-task conditions. Climbing efficiency and climbing distance were also significantly lower in the negative word dual-task, relative to the neutral word dual-task. The findings from these two experiments have important human factors implications for occupational settings that require climbing-like operations, including search and rescue and fire-fighting.

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