The purpose of this thesis is threefold: 1) A behavioral examination of the role of diacritics in Arabic, 2) A functional magnetic resonance imaging (fMRI) investigative study of diacritics in Arabic, and 3) An optimization algorithm for brain mapping and detecting brain function. Firstly, the role of diacritics in Arabic was examined behaviorally. The stimulus was a lexical decision task (LDT) that constituted of low, mid, and high frequency words and nonwords; with and without diacritics. Results showed that the presence of vowel diacritics slowed reaction time but did not affect word recognition accuracy. The longer reaction times for words with diacritics versus without diacritics suggest that the diacritics may contribute to differences in word recognition strategies. Secondly, an Event-related fMRI experiment of lexical decisions associated with real words with versus without diacritics in Arabic readers was done. Real words with no diacritics yielded shorter response times and stronger activation than with real words with diacritics in the hippocampus and middle temporal gyrus possibly reflecting a search from among multiple meanings associated with these words in a semantic store. In contrast, real words with diacritics had longer response times than real words without diacritics and activated the insula and frontal areas suggestive of phonological and semantic mediation in lexical retrieval. Both the behavioral and fMRI results in this study appear to support a role for diacritics in reading in Arabic. The third research work in this thesis is an optimization algorithm for fMRI data analysis. Current data-driven approaches for fMRI data analysis, such as independent component analysis (ICA), rely on algorithms that may have low computational expense, but are much more prone to suboptimal results. In this work, a genetic algorithm (GA) based on a clustering technique was designed, developed, and implemented for fMRI ICA data analysis. Results for the algorithm, GAICA, showed that although it might be computationally expensive; it provides global optimum convergence and results. Therefore, GAICA can be used as a complimentary or supplementary technique for brain mapping and detecting brain function by way of fMRI.

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This study investigated, in a small-scale, the extent to which the skill of mind-mapping improves conceptual learning in history in Standard eight. The study was carried out using two Standard eight classes. Each class had approximately 30 pupils. One group (8C) formed the experimental group while another (8D) formed the control group. The lesson planning and structure for the experimental group was carried out using Vygotsky's mediational teaching methodology. The design and construction of the pre-and post tests corresponded with each other with regard to the type of questions asked. Questions were designed to test the learner's ability to interpret and use mind maps as learning aids and the ability to recall with understanding. During the period between testing the groups received different types of intervention. The control group, 8D, received "normal" instruction (le. that which they usually received in their History lessons). This instruction consisted of eighteen lessons and the French revolution was the principal topic from which other topics were taken. This instruction was both teacher -centred and textbook-centred. The learners' participation was limited to answering of questions. Intervention in the experimental group ,8C, involved teaching in the normal way and also modelling how to interpret and use mind maps on simple non history at the beginning. Learners were given the opportunity to practice how to interpret and use mind maps as learning aids under controlled guidance until they were able to operate in an autonomous way. The same procedure was used to teach simple and complex history content. The tests results were analysed quantitatively and statistically. The results obtained supported the hypothesis that conceptual learning in History can be greatly improved through the use of the skill of mind mapping. The study ends by suggesting some recommendations for further research. / Thesis (M.Ed.)-University of Natal, Pietermaritzburg, 1997.

Thesis (Ph. D.)--University of California, San Diego, 2006. / Title from first page of PDF file (viewed July 11, 2006). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.

The present study aimed at quantifying the topographic distribution of spectral power as measured with electroencephalogram (EEG) in patients with opioid use disorder (OUD) across five broad band frequencies (δ, θ, α, β, and γ). Through comparative groups of healthy controls, patients with methamphetamine use disorder, and patients with alcohol use disorder, it was determined that OUD EEG spectral power was globally increased in the δ frequency, and more region-specific in others (frontal lobes in θ and β frequencies). α frequency was reduced in occipital lobes in OUD. The observed changes are discussed in terms of the microcircuit-level changes in the cortex. Based on these findings, EEG may prove to be a valuable tool for diagnostic and prognostic evaluation of OUD. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection

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It is well established that anticipation of the arrival of an expected stimulus is accompanied by rich ongoing oscillatory neurodynamics, which span and link large areas of cortex. An intriguing possibility is that these dynamic interactions may convey knowledge that is embodied by large-scale neurocognitive networks from higher level regions of multi-model cortex to lower level primary sensory areas. In the current study, using autoregressive spectral analysis, we establish that during the anticipatory phase of a visual discrimination task there are rich patterns of coherent interaction between various levels of the ventral visual hierarchy across the frequency spectrum of 8 - 90 Hz. Using spectral Granger causality we determined that a subset of these interactions carry beta frequency (14 - 30 Hz) top-down influences from higher level visual regions V4 and TEO to primary visual cortex. We investigated the functional significance of these top-down interactions by correlating the magnitude of the anticipatory signals with the amplitude of the visual evoked potential that was elicited by stimulus processing. We found that in one third of the extrastriate-striate pairs, tested in three monkeys, the amplitude of the visual evoked response is well predicted by the magnitude of pre-stimulus coherent top-down anticipatory influences. To investigate the dynamics of the coherent and topdown Granger causal interactions, we analyzed the relationship between coherence and top-down Granger causality with stimulus onset asynchrony. This analysis revealed that in an abundance of cases the magnitudes of the coherent interactions and top-down directional influences scaled with the length of time that had elapsed before stimulus onset. / Together these results reveal a complex network of coherent and top-down directional interactions that predict the amplitude of early components of the visual evoked potential in primary visual cortex and vary in strength on the basis of the length of the stimulus onset. / by Craig G. Richter. / Thesis (Ph.D.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.

Com intuito de avaliar o processo cognitivo cerebral e o desempenho de médicos veterinários especializados em radiologia, este estudo proporcionou, através de um sistema computacional, tarefas de questões radiológicas. Os 29 voluntários foram divididos por gênero: homens (n=13) e mulheres (n=16); e por tempo de especialidade: iniciantes (n=13), experientes (n=8) e seniores (n=8). Quatorze casos foram selecionados com diferentes níveis de dificuldade a partir de imagens radiográficas de cães e gatos e foram escaneadas e colocadas em um programa chamado Enscer®, adaptado para a realização deste estudo. Os casos eram divididos em três partes, nomeadas, história clínica, imagem radiográfica e decisão diagnóstica. Durante as etapas, foram realizados eletroencefalogramas dos voluntários, que resultaram em mapeamentos cerebrais. Além disso, foi feita avaliação das respostas corretas, incorretas e dos tempos utilizados para as tarefas. Através das avaliações estatísticas dos resultados foi possível concluir que radiologistas veterinários com maior tempo de especialidade foram estatisticamente mais rápidos nas tarefas e tiveram melhor desempenho diagnóstico; voluntários com maior tempo de especialidade ativaram áreas cerebrais diferentes dos menos experientes; o desempenho diagnóstico foi quantitativamente igual em voluntários de ambos os gêneros e o mapeamento cerebral do grupo masculino foi diferente do grupo feminino, mesmo com desempenho igual nas atividades / With intention to evaluate the cerebral cognitive process and the performance of medical veterinarians specialized in radiology, this study provided, through a computerized system, tasks of radiological questions. The 29 volunteers were divided by gender: man (n=13) and woman (n=16); and by time of experience: beginners (n=13), experienced (n=8) and seniors (n=8). Fourteen cases were selected with different levels of difficulty from radiographic images of dogs and cats and had been scanned and processed by a software called Enscer®, adapted for the accomplishment of this study. The cases were divided into three parts, namely, clinical history, radiographic image and diagnostic decision. During the stages the electroencephalography was carried through, which resulted in the cerebral mapping. Moreover, evaluation of the correct and incorrect answers and of the times used for the tasks was made. Through the statistical evaluations of the results it was possible to conclude that radiologists veterinarians with more time of experience had been statistically faster in the tasks and had had better diagnostic performance; volunteers with more time of experience had activated different cerebral areas than volunteer with less experience; the diagnostic performance was quantitatively equal in volunteers of both genders and the cerebral mapping of the masculine group was different of the feminine group, even with equal performance in the activities

Research presented in this dissertation has the central aim of applying a novel method of source localization called beamforming to neuromagnetic recordings for characterizing dynamic spatiotemporal activity of sensorimotor brain processes in subjects during rhythmic auditory stimulation, self-paced movement, and two sensorimotor coordination (synchronization and syncopation) tasks known to differentiate on the basis of behavioral stability. Each experimental condition was performed at different rates resulting in 26 experimental runs per subject. Event-related neural responses were recorded with a whole-head MEG system and characterized in terms of their phase-locked (evoked) and non-phase-locked (induced) activity within the brain using both whole-brain analysis and region of interest (ROI) analysis. The analysis of the auditory conditions revealed that neural activity within extraauditory areas throughout the brain, including sensorimotor cortex, is modulated by rhythmic auditory stimulation. Additionally, the temporal profile of this activity was markedly different between sensorimotor and auditory cortex, possibly revealing different physiological processes, entrained within a common network for representing isochronic auditory events. During self-paced movements cycle-by-cycle dynamics of induced neural activity was measured and consistent neuro-modulation in the form of event-related desynchronization (ERD) and synchronization (ERS) was observed at all rates investigated (0.25 - 1.75Hz). ERD and ERS modulations exhibited dynamic scaling properties on a cycle-by-cycle basis that depended on the period of movement. Activity in the beta- and mu-bands also exhibited patterns of phase locking between sensorimotor locations. Phase locking patterns exhibited abrupt decreases with increases in movement rate. / During sensorimotor coordination tasks, the effect of temporal positioning of the auditory stimulus was apparent within sensorimotor cortical sites. This finding offers direct source level support for previous sensor level analysis revealing a differentiation of functional specificity for mu- and beta-band activity (Chen, Ding, Kelso, 2003; Jantzen, Fuchs, Mayville et al., 2001; Mayville, Fuchs, Ding et al., 2001), and may be reflective of specific coupling mechanisms between auditory and sensorimotor networks. The beamformer analysis applied within this dissertation successfully characterized large-scale neural networks during a variety of rhythmic perceptual, motor, and sensorimotor tasks resulting in the general message that information processes across disparate parts of the brain from different sensory, motor, and cognitive modalities appear to have the ability for widespread integration. / by Paul Ferrari. / Thesis (Ph.D.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.

This study examined the topography of prefrontal molds of human endocasts using three-dimensional laser scanning and geographic information systems (GIS) in order to carry out intra-species comparisons. Overall brain topography can indicate when major reorganizational shifts in brain structure happened in our evolutionalry history, and these shifts may indicate major shifts in cognition and behavior. Endocasts are one of the sole sources of information about extinct hominin brains ; they reproduce details of the brain's external morphology. Analysis of endocast morphology has never been done using GIS methodology. The use of GIS helps to overcome previous obstacles in regards to endocast analysis. Since this methodology is new, this research focuses on only one species, Homo sapiens and the area of focus is narrowed to the frontal lobe, specifically Broca's cap. This area is associated with speech in humans and is therefore of evolutionary significance. The variability in lateralization of this feature was quantified. / by Melissa Boas. / Thesis (M.A.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.