No description available.

Aims: The aims of this study were to identify school-aged children who exhibit spatial stream segregation deficits by using the Listening in Spatialized Noise – Sentences (LiSN-S) test, and to determine the effectiveness of personal FM systems as an intervention for these children. Method: Participants consisted of 22 children between the age of 7;0 and 11;11 years with normal hearing thresholds. Based on their performance on the LiSN-S test, participants with normal and impaired spatial stream segregation ability were assigned to the control group (n=12) and the FM group (n=10) respectively. Participants from the latter group were provided with and required to use the personal ear-level FM devices during school time for a period of eight weeks. The impact of the FM systems was determined by both quantitative and qualitative data, which were gathered at three sampling points: (1) Before FM trial; (2) At the end of the FM trial (i.e. after eight weeks of use); and finally (3) At eight weeks following withdrawal of the FM systems. Results: Results revealed children with APD improved on their ability to segregate spatial streams following the use of personal FM devices, whereas control participants did not exhibit this change. The personal FM devices seemed to provide the greatest benefit to the younger participants. Qualitative measures, including individualised Goal Attainment Scales (GAS), indicated positive improvements in auditory behaviours following the use of FM devices in all participants. In addition, teachers anecdotally reported positive behavioural changes in the FM participants during the FM trial. Conclusion: Personal FM systems appear to be an effective management strategy for school age children who exhibit difficulty in spatial stream segregation.

Head direction cells signal the orientation of the head in the horizontal plane. This thesis shows how some of the known head direction cell response properties might develop through learning. The research methodology employed is the computer simulation of neural network models of head direction cells that self-organize through learning. The preferred firing directions of head direction cells will change in response to the manipulation of distal visual cues, but not in response to the manipulation of proximal visual cues. Simulation results are presented of neural network models that learn to form separate representations of distal and proximal visual cues that are presented simultaneously as visual input to the network. These results demonstrate the computation required for a subpopulation of head direction cells to learn to preferentially respond to distal visual cues. Within a population of head direction cells, the angular distance between the preferred firing directions of any two cells is maintained across different environments. It is shown how a neural network model can learn to maintain the angular distance between the learned preferred firing directions of head direction cells across two different visual training environments. A population of head direction cells can update the population representation of the current head direction, in the absence of visual input, using internal idiothetic (self-generated) motion signals alone. This is called the path integration of head direction. It is important that the head direction cell system updates its internal representation of head direction at the same speed as the animal is rotating its head. Neural network models are simulated that learn to perform the path integration of head direction, using solely idiothetic signals, at the same speed as the head is rotating.

The ability to self-localize and navigate in both stable and changing environments is crucial for the survival of many species. Research conducted on the non-human mammalian hippocampus and surrounding brain structures has uncovered several classes of spatial related cells. These cells provide the rest of the brain with knowledge of the animal’s location and direction—knowledge that is subsequently used in spatial navigation. This thesis provides an overview of three types of cells underlying this ability in rodents. First, place cells located in the hippocampus encode the animal’s specific location in the environment. Second, head direction cells found throughout the Papez circuit convey the angular direction of the animal’s head. Last, grid cells in the medial entorhinal cortex generate a regular triangular grid spanning the entire explored setting. The focus of this review lies on the most salient features of these types of cells. It is also considered how the cells respond to manipulations of external and internal information, as well as how different lesions affect their activity.

This thesis presents a series of human psychophysical experiments designed to examine the interaction between the reliability of spatial form information and the neural mechanisms responsible for the processing of sub-second durations. Duration discrimination sensitivity was found to be lower when event durations were defined by stimulus characteristics that caused reductions in spatial form sensitivity. This form-duration sensitivity coupling persisted across stimuli defined both by crossed and uncrossed retinal disparity and within monocularly visible texture-defined stimuli. The interaction was also observed when spatial form was degraded by physical instability within shape borders, and when physically stable borders became perceptually unstable. These effects could not be attributed to artefacts of stimulus visibility, temporal coherence or stimulus size. Adaptation experiments generated aftereffects of perceived duration within stimuli whose durations were defined solely by retinal disparity, providing the first demonstration of duration selectivity within exclusively cortical duration encoding mechanisms. The selectivity of these aftereffects was then investigated using adapting and testing durations defined by matching or opposing retinal disparities. Duration aftereffects were maximal when adapt and test disparities were matched. However, there was partial transfer of duration aftereffects across large changes in retinal disparity, implicating contributions from higher-level extra-striate mechanisms. Collectively, these experiments provide support for duration processing mechanisms that are inextricably linked to the mechanisms underpinning spatial processing across multiple levels of the visuo-spatial hierarchy.

No description available.

Background: Research suggests that musculoskeletal injury (MSI) influences cognitive functioning. Cognitive functioning following MSI in athletes is not evaluated currently. Purpose and Method: To examine cognitive deficit in athletes following musculoskeletal injuries, the Automated Neuropsychological Assessment Metric (ANAM) was administered to 22 varsity athletes prior to competition and following MSI. A healthy comparison group of 22 athletes was also tested at time intervals matched with the injured group. Results: A 2 (Group) X 2 (Time) repeated measures ANOVA revealed significant main effects for time on ANAM subtests of Delayed Code Substitution and Simple Reaction Time. Post-hoc Paired t-Tests revealed significant improvements in both groups for Simple Reaction Time, and a significant improvement for the comparison group on Match-to-Sample. Implications: Athletes with musculoskeletal injuries did not show cognitive deficit post-injury; however, the apparent absence of practice effects on a test of spatial processing and working memory requires further examination.

Background: Research suggests that musculoskeletal injury (MSI) influences cognitive functioning. Cognitive functioning following MSI in athletes is not evaluated currently. Purpose and Method: To examine cognitive deficit in athletes following musculoskeletal injuries, the Automated Neuropsychological Assessment Metric (ANAM) was administered to 22 varsity athletes prior to competition and following MSI. A healthy comparison group of 22 athletes was also tested at time intervals matched with the injured group. Results: A 2 (Group) X 2 (Time) repeated measures ANOVA revealed significant main effects for time on ANAM subtests of Delayed Code Substitution and Simple Reaction Time. Post-hoc Paired t-Tests revealed significant improvements in both groups for Simple Reaction Time, and a significant improvement for the comparison group on Match-to-Sample. Implications: Athletes with musculoskeletal injuries did not show cognitive deficit post-injury; however, the apparent absence of practice effects on a test of spatial processing and working memory requires further examination.

A presente pesquisa centra-se no estudo das relações entre memória de curto prazo, memória de trabalho, velocidade de processamento, processamento visuoespacial, funções executivas, atenção seletiva e alternada e desempenho matemático, uma vez que essas relações podem esclarecer as diferenças entre os alunos na aprendizagem da matemática. O trabalho teve como objeto de observação crianças da 2ª série do ensino fundamental. Consiste em um estudo com base correlacional e comparativa. A amostra desta pesquisa é composta por 40 alunos, com idade entre 8 e 9 anos. A investigação envolvendo o funcionamento neuropsicológico e o desempenho cognitivo na aprendizagem matemática é relevante, pois para desenvolver habilidades de cálculo matemático é fundamental que o aluno tenha construído o conceito de número e esta construção está vinculada ao desenvolvimento das funções neuropsicológicas. O desempenho matemático é avaliado através da Prova de Aritmética de Capovilla, Montiel e Capovilla (2007) e as funções neuropsicológicas, através de quatro subtestes da Escala Wechsler WISCIII, que são: Memória de Curto Prazo – teste de Dígitos de Ordem Direta; Memória de Trabalho – Dígitos de Ordem Inversa; Velocidade de Processamento - Procurar Símbolos e Códigos; Percepção Visuoespacial – teste de Cubos. A Função Executiva é avaliada através do Teste das Trilhas de Montiel e Capovilla (2007) e a Atenção, através do Teste de Atenção por Cancelamento de Montiel e Capovilla (2007). Observa-se uma correlação significativa entre Desempenho Matemático e Memória de Curto Prazo, Velocidade de Processamento, Função Executiva e Atenção. Neste estudo, não se encontrou uma correlação estatisticamente significativa entre as funções Memória de Trabalho e Processamento Visuoespacial. / This paper approaches the relationship amongst neuropsychological functions –Short Term Memory (STM), Working Memory (WM), Speed Processing (SP), Visual Spatial Perception (VSP), Executive Functions (EF), Attention (A) and Math Performance (MP) in 2nd grade children at a public Elementary School from Porto Alegre. It is a comparative and correlation study. The sample of this research is composed for 40 pupils with are between 8 and 9 years. Research involving neuropsychological functioning and cognitive performance in mathematics is pertinent, for it is essential that the student build the notion of number in order to develop mathematical skills and such construction relies on the expansion of neuropsychological functions. The mathematical performance is measured by the Arthmetic Test of Capovilla, Montiel and Capovilla (2007) and the neuropsychological functions are verified by subtests Wechsler WIS CIII; Short Term Memory is assessed by the Digits in Direct Order, while the Working Memory is established by the Digits in Reverse Order. The speed processing is assessed through the use of Find Symbols and Codes activities, and spatial perception is confirmed by the utilization of cubes. The Executive Function is assessed by the Trail Making of Montiel and Capovilla (2007) and attention is assessed by the Attention Test for Cancellation of Montiel and Capovilla (2007). There is a momentous correlation amid math performance and Short-Term Memory, speed processing, executive function and attention. This study one did not mett, however, the establishment of a statistically significant correlation between the Working Memory functions and the Visual Spatial Processing.

A presente pesquisa centra-se no estudo das relações entre memória de curto prazo, memória de trabalho, velocidade de processamento, processamento visuoespacial, funções executivas, atenção seletiva e alternada e desempenho matemático, uma vez que essas relações podem esclarecer as diferenças entre os alunos na aprendizagem da matemática. O trabalho teve como objeto de observação crianças da 2ª série do ensino fundamental. Consiste em um estudo com base correlacional e comparativa. A amostra desta pesquisa é composta por 40 alunos, com idade entre 8 e 9 anos. A investigação envolvendo o funcionamento neuropsicológico e o desempenho cognitivo na aprendizagem matemática é relevante, pois para desenvolver habilidades de cálculo matemático é fundamental que o aluno tenha construído o conceito de número e esta construção está vinculada ao desenvolvimento das funções neuropsicológicas. O desempenho matemático é avaliado através da Prova de Aritmética de Capovilla, Montiel e Capovilla (2007) e as funções neuropsicológicas, através de quatro subtestes da Escala Wechsler WISCIII, que são: Memória de Curto Prazo – teste de Dígitos de Ordem Direta; Memória de Trabalho – Dígitos de Ordem Inversa; Velocidade de Processamento - Procurar Símbolos e Códigos; Percepção Visuoespacial – teste de Cubos. A Função Executiva é avaliada através do Teste das Trilhas de Montiel e Capovilla (2007) e a Atenção, através do Teste de Atenção por Cancelamento de Montiel e Capovilla (2007). Observa-se uma correlação significativa entre Desempenho Matemático e Memória de Curto Prazo, Velocidade de Processamento, Função Executiva e Atenção. Neste estudo, não se encontrou uma correlação estatisticamente significativa entre as funções Memória de Trabalho e Processamento Visuoespacial. / This paper approaches the relationship amongst neuropsychological functions –Short Term Memory (STM), Working Memory (WM), Speed Processing (SP), Visual Spatial Perception (VSP), Executive Functions (EF), Attention (A) and Math Performance (MP) in 2nd grade children at a public Elementary School from Porto Alegre. It is a comparative and correlation study. The sample of this research is composed for 40 pupils with are between 8 and 9 years. Research involving neuropsychological functioning and cognitive performance in mathematics is pertinent, for it is essential that the student build the notion of number in order to develop mathematical skills and such construction relies on the expansion of neuropsychological functions. The mathematical performance is measured by the Arthmetic Test of Capovilla, Montiel and Capovilla (2007) and the neuropsychological functions are verified by subtests Wechsler WIS CIII; Short Term Memory is assessed by the Digits in Direct Order, while the Working Memory is established by the Digits in Reverse Order. The speed processing is assessed through the use of Find Symbols and Codes activities, and spatial perception is confirmed by the utilization of cubes. The Executive Function is assessed by the Trail Making of Montiel and Capovilla (2007) and attention is assessed by the Attention Test for Cancellation of Montiel and Capovilla (2007). There is a momentous correlation amid math performance and Short-Term Memory, speed processing, executive function and attention. This study one did not mett, however, the establishment of a statistically significant correlation between the Working Memory functions and the Visual Spatial Processing.