Context: Despite an association between foot structure and the incidence of lower limb injury in sport, few studies have measured the effects of neutral, pronated and supinated foot structures during dynamic activity. Furthermore, despite its widespread use as an injury prevention method, the effects of athletic taping on individuals with pronated and supinated foot structures are unclear. Objectives: To explore whether individuals with pronated and supinated foot structures have poorer lower limb neuromuscular control as measured by postural stability and muscle reaction time in comparison to those with neutral feet. Additionally, the effects of athletic taping on individuals with neutral, pronated and supinated foot structures on aspects of lower limb neuromuscular control are also examined. Subjects: All subjects used in this thesis were aged from 18 – 30 years and took part in at least two hours of exercise each week. Subjects were categorised in to groups according to navicular drop height measures; neutral 5 – 9 mm; pronated ≥ 10 mm; supinated ≤ 4 mm. Methods: Neuromuscular control was analysed in subjects with neutral, pronated and supinated feet using dynamic postural stability and muscular reaction time measures. These measures were then repeated with four athletic taping conditions (arch tape, ankle tape, proprioceptive tape and no-tape) both before and after a period of exercise. Results: Individuals with pronated and supinated foot structures were shown to have reduced postural stability in comparison to those with neutral foot structures during some dynamic tasks. Pronated and supinated foot structures also resulted in slower muscle reaction times in comparison to those with neutral feet during a tilt platform perturbation. No differences were identified between dominant and non-dominant limbs on subjects with neutral, pronated or supinated foot structures; however the high incidence of foot structure asymmetry did appear to result in differences between contralateral limbs in both postural stability and reaction time parameters. Arch and ankle taping resulted in increased neuromuscular control after application, yet these effects diminished after a period of exercise. Conclusions: The results of this thesis provide evidence to suggest that foot structure does affect lower limb neuromuscular control as measured by postural stability and muscle reaction time. In addition athletic taping has been shown to affect neuromuscular control on subjects with neutral, pronated and supinated foot structures both before and after exercise. These findings may have wide implications in sport where individuals with pronated and supinated feet may be more susceptible to injury in comparison to those with neutral feet.

Uma sequência melódica não depende apenas de eventos discretos, mas também da tonalidade, uma estrutura holística que hierarquiza a expectativa dos ouvintes para as notas que devem ocorrer. Para melhor compreender o funcionamento dos mecanismos cognitivos responsáveis por essa hierarquia, dois experimentos foram propostos. O primeiro experimento verificou se o tempo de resposta simples de um participante a uma nota é influenciado pelas suas características em relação a tonalidade da música, não encontrando nenhuma relação entre os tempos de resposta e as características melódicas dos estímulos. O segundo experimento verificou os tempos de resposta dos participantes para discriminarem uma determinada altura como igual ou diferente a uma altura apresentada em um momento anterior ao momento da coleta. Os resultados mostraram que os participantes são capazes de realizar a tarefa, e apresentaram um tempo de resposta menor para uma nota um tom abaixo da nota esperada, um achado novo. / A melodic sequence not only depends of discrete events, but also of the tonality, a holistic structure that hierarchize the listener expectancy to notes that should occur. To better understand the cognitive mechanisms responsible for this hierarchy, two experiments were developed. The first experiment tested if the simple reaction time of the participants in response to a note is influenced by its tonal characteristics, did not find any correlation between the collected reaction times and the melodic characteristics of the stimuli. The second experiment tested if the participants choice reaction time to discriminate a relative pitch presented in a different moment than a pitch presented earlier to the gathering. The results show that the participants, independently of musical training, are capable of performing the task, and present a smaller reaction time to the note one tone bellow the expected note, a new finding that didnt match the expected characteristics used to guide the participant reaction.

A atenção encontra-se incluída no grupo de funções psíquicas, agrupadas sob o nome de funções cognitivas que subsidiam o processo de aprendizagem escolar. Em relação à atenção visual, a literatura vem apontando a existência de diferenças no tempo de reação a estímulos visuais entre escolares com e sem distúrbios de aprendizagem (DA). Neste sentido, o objetivo deste estudo foi caracterizar a função atencional visual em escolares com DA. Participaram deste estudo 50 escolares, sendo 25 com o diagnóstico de distúrbio de aprendizagem, formando o grupo de estudo (GE), e 25 crianças sem queixas escolares, formando o grupo controle (GC), com faixa etária entre oito e 14 anos de idade. Os instrumentos utilizados foram o Teste de Atenção Visual (TAVIS4), um teste computadorizado composto por três tarefas para avaliar a capacidade atentiva de sustentar, selecionar e mudar o foco de atenção para estímulos visuais e da impulsividade motora, e a Escala de Conners na forma abreviada para professores, apropriado para discriminar crianças com problemas de comportamento e com sintomas de TDAH. Os resultados evidenciaram que o tempo de reação médio (TRM) do GC foi significativamente menor que o do GE na tarefa de atenção sustentada. O GE também apresentou diferença estatística significativa na atenção alternada, com menor número de acertos (NA), maior número de erros por omissão (EO) e maior número de erros por ação (EA). Na Escala de Conners a pontuação do GE foi maior do que do GC. Houve correlação entre os testes nas tarefas de atenção alternada e nas tarefas de atenção sustentada para o número de acertos (NA), erros por omissão (EO) e erros por ação (EA). Podemos inferir que as crianças com DA apresentam déficit dos processos atencionais, embora não possam ser caracterizadas com o TDAH. No subgrupo dos adolescentes houve diferença significativa na atenção seletiva para o número de erros por omissão (EO), no TRM da atenção sustentada e na atenção alternada para número de erros por omissão (EO) e erros por ação (EA). Houve correlação entre os testes, neste subgrupo do GE e GC na atenção seletiva para o número de acertos (NA), erros por omissão (EO) e erros por ação (EA). Portanto, os maiores índices apontados na escala (déficit atencional) estão associados aos piores resultados dos participantes nas tarefas de atenção alternada e sustentada. Pode-se observar que quanto maior a idade dos participantes, melhor é a capacidade de atenção seletiva, sustentada e alternada. Desta maneira, o TMR mais baixo do subgrupo dos adolescentes em comparação com o grupo geral pode evidenciar a melhora da atenção com o desenvolvimento. Porém, os adolescentes do GE apresentaram melhor desempenho do que as crianças, ou seja, algumas alterações notadamente persistem quando comparadas ao GC sugerindo uma disfunção dos mecanismos neuropsicológicos subjacentes ao processamento da atenção visual nos adolescentes com DA. / Attention is included in the group of psychic functions, grouped under the name of cognitive functions, and that support the learning process in school. Regarding the visual attention, literature has pointed to the existence of differences in reaction time to visual stimuli between students with and without learning disabilities (LD). In this sense, the purpose of this study was to characterize the visual attentional function in children with LD. A total of 50 students, including 25 with learning disorders without signs of Attention Deficit Disorder and Hyperactivity Disorder (ADHD), forming the study group (SG), and 25 children without impairments, forming the control group (CG) , aged between eight and 14 years old. The instruments used were the Test of Visual Attention (TAVIS4), computerized test consists of three tasks to assess the ability to sustain attentional, select and change the focus of attention to visual stimuli and motor impulsivity, and the Scale of the Conners abbreviated form for teachers, appropriate to discriminate children with behavior problems and ADHD signs. The results showed that the hit reaction time (HRT) of the CG was significantly less than the SG in the sustained attention task. SG also showed statistically significant differences in the alternating attention, with less number of right answers (RA), higher number of omission errors (OE) and higher number of commissions errors (CE). Scale of the Conners scores of GE was higher than the GC. There was a correlation between tests in alternating attention tasks and sustained attention tasks to the number of right answers (RA), omission errors (OE) and commission errors (CE). We may deduce that children with LD have deficits of attentional processes, although they cannot be characterized with ADHD. In the subgroup of adolescents was significant difference in selective attention to the number of omission errors (OE), the HRT of sustained attention and alternating attention to the number of omission errors (OE) and commission errors (CE). There was a correlation between tests, this subgroup of SG and CG in selective attention to the number of right answers (RA), omission errors (EO) and commissions errors (CE). So, the highest rates indicated on the scale (attentional deficits) are associated with worse outcomes of participants in the tasks of sustained and alternating attention. It can be observed that the higher the age of the participants, the better the ability of selective attention, sustained attention and alternating attention. That way, the HMT less subgroup of adolescents compared with the overall group may show an improvement in attention to development. However, adolescents SG improved their attentional capacity, but some changes persist especially when compared to CG suggesting a dysfunction of neuropsychological mechanisms underlying the processing of visual attention in adolescents with LD.

A atenção encontra-se incluída no grupo de funções psíquicas, agrupadas sob o nome de funções cognitivas que subsidiam o processo de aprendizagem escolar. Em relação à atenção visual, a literatura vem apontando a existência de diferenças no tempo de reação a estímulos visuais entre escolares com e sem distúrbios de aprendizagem (DA). Neste sentido, o objetivo deste estudo foi caracterizar a função atencional visual em escolares com DA. Participaram deste estudo 50 escolares, sendo 25 com o diagnóstico de distúrbio de aprendizagem, formando o grupo de estudo (GE), e 25 crianças sem queixas escolares, formando o grupo controle (GC), com faixa etária entre oito e 14 anos de idade. Os instrumentos utilizados foram o Teste de Atenção Visual (TAVIS4), um teste computadorizado composto por três tarefas para avaliar a capacidade atentiva de sustentar, selecionar e mudar o foco de atenção para estímulos visuais e da impulsividade motora, e a Escala de Conners na forma abreviada para professores, apropriado para discriminar crianças com problemas de comportamento e com sintomas de TDAH. Os resultados evidenciaram que o tempo de reação médio (TRM) do GC foi significativamente menor que o do GE na tarefa de atenção sustentada. O GE também apresentou diferença estatística significativa na atenção alternada, com menor número de acertos (NA), maior número de erros por omissão (EO) e maior número de erros por ação (EA). Na Escala de Conners a pontuação do GE foi maior do que do GC. Houve correlação entre os testes nas tarefas de atenção alternada e nas tarefas de atenção sustentada para o número de acertos (NA), erros por omissão (EO) e erros por ação (EA). Podemos inferir que as crianças com DA apresentam déficit dos processos atencionais, embora não possam ser caracterizadas com o TDAH. No subgrupo dos adolescentes houve diferença significativa na atenção seletiva para o número de erros por omissão (EO), no TRM da atenção sustentada e na atenção alternada para número de erros por omissão (EO) e erros por ação (EA). Houve correlação entre os testes, neste subgrupo do GE e GC na atenção seletiva para o número de acertos (NA), erros por omissão (EO) e erros por ação (EA). Portanto, os maiores índices apontados na escala (déficit atencional) estão associados aos piores resultados dos participantes nas tarefas de atenção alternada e sustentada. Pode-se observar que quanto maior a idade dos participantes, melhor é a capacidade de atenção seletiva, sustentada e alternada. Desta maneira, o TMR mais baixo do subgrupo dos adolescentes em comparação com o grupo geral pode evidenciar a melhora da atenção com o desenvolvimento. Porém, os adolescentes do GE apresentaram melhor desempenho do que as crianças, ou seja, algumas alterações notadamente persistem quando comparadas ao GC sugerindo uma disfunção dos mecanismos neuropsicológicos subjacentes ao processamento da atenção visual nos adolescentes com DA. / Attention is included in the group of psychic functions, grouped under the name of cognitive functions, and that support the learning process in school. Regarding the visual attention, literature has pointed to the existence of differences in reaction time to visual stimuli between students with and without learning disabilities (LD). In this sense, the purpose of this study was to characterize the visual attentional function in children with LD. A total of 50 students, including 25 with learning disorders without signs of Attention Deficit Disorder and Hyperactivity Disorder (ADHD), forming the study group (SG), and 25 children without impairments, forming the control group (CG) , aged between eight and 14 years old. The instruments used were the Test of Visual Attention (TAVIS4), computerized test consists of three tasks to assess the ability to sustain attentional, select and change the focus of attention to visual stimuli and motor impulsivity, and the Scale of the Conners abbreviated form for teachers, appropriate to discriminate children with behavior problems and ADHD signs. The results showed that the hit reaction time (HRT) of the CG was significantly less than the SG in the sustained attention task. SG also showed statistically significant differences in the alternating attention, with less number of right answers (RA), higher number of omission errors (OE) and higher number of commissions errors (CE). Scale of the Conners scores of GE was higher than the GC. There was a correlation between tests in alternating attention tasks and sustained attention tasks to the number of right answers (RA), omission errors (OE) and commission errors (CE). We may deduce that children with LD have deficits of attentional processes, although they cannot be characterized with ADHD. In the subgroup of adolescents was significant difference in selective attention to the number of omission errors (OE), the HRT of sustained attention and alternating attention to the number of omission errors (OE) and commission errors (CE). There was a correlation between tests, this subgroup of SG and CG in selective attention to the number of right answers (RA), omission errors (EO) and commissions errors (CE). So, the highest rates indicated on the scale (attentional deficits) are associated with worse outcomes of participants in the tasks of sustained and alternating attention. It can be observed that the higher the age of the participants, the better the ability of selective attention, sustained attention and alternating attention. That way, the HMT less subgroup of adolescents compared with the overall group may show an improvement in attention to development. However, adolescents SG improved their attentional capacity, but some changes persist especially when compared to CG suggesting a dysfunction of neuropsychological mechanisms underlying the processing of visual attention in adolescents with LD.

The ability to navigate with limited vision is a skill that is often employed in our daily lives. Navigating without vision to a remembered target has previously been studied. However, not much is known about the attention required to perform blind navigation. We examined the effect of aging and presence of obstacles on the attentional demands of blind navigation. We evaluated reaction time, navigation errors and average walking speed in an 8 meter walking path, with or without obstacles, in the absence of vision. Results showed that older participants had increased reaction time and increased linear distance travelled as opposed to young participants, that obstacles increased reaction time and decreased average walking speed in all participants, and that emitting the reaction time stimulus early in the trial increased the linear distance travelled. Interpretation of the results suggests that aging and presence of obstacles augments the attentional demands of blind navigation.

I investigated the effects of probability on visual search. Previous work has shown that people can utilize spatial and sequential probability information to improve their performance on visual attention tasks. My task was a simple visual search in which the target was always present among a field of distractors, and could take one of two colors. The absolute probability of the target being either color was 0.5; however, the conditional probability – the likelihood of a particular color given a particular cue combination – varied from 0.1 to 0.9. I found that participants searched more efficiently for high conditional probability targets and less efficiently for low conditional probability targets. This modulation of efficiency was reduced or abolished when participants were not explicitly informed of the cue-target relationships. After establishing this effect, I investigated its mechanism using eye tracking methods. Early in trials, participants fixated preferentially, but not exclusively, on areas of the screen which contained predominantly stimuli of the color to which they had been cued. As the trial progressed, this color bias shifted to the target color. I conclude that search efficiency is modulated by the conditional probability of target features and that this is a top-down process that benefits from explicit knowledge of the probabilistic relationship between cues and targets, and that the modulation is a result of more efficient eye movements towards stimuli with a greater probability of being the target of search.

Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 296-306). Also available on the Internet.

Issued also as Thesis (Ph. D.)--Columbia University. / Bibliography: p. 79-81.

Issued also as Thesis (Ph. D.)--Columbia University. / Bibliography: p. 38.

Issued also as thesis, Catholic University of America. / Bibliography: p. 52.