Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

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This study investigated the relationship among anxiety, depression, and sleep disturbances and the treatment of these three disorders through neurotherapy. Research suggests that these conditions commonly co-occur in the general population and that central nervous system (CNS) arousal may play a primary role in the development and maintenance of these disorders. Several recent studies suggested that neurotherapy, a biofeedback-based treatment for CNS dysregulation, might be an effective treatment for comorbid conditions, particularly the ones of interest here, depression, anxiety, and sleep disturbances. This investigation used a clinical case-series design to assess pre/post neurotherapy changes on objective measures of anxiety, depression, and sleep and to determine whether changes in anxiety and depression then predict improvements in sleep quality. Data for 23 participants (10 males) were obtained from files of adults (Mage = 40.22 years, SD = 16.20) who received at least 15 neurotherapy sessions (M = 47.83 sessions, SD = 22.23) the University of North Texas Neurotherapy Lab. Matched pair t-tests revealed that symptoms of sleep disturbance, depression, and anxiety showed significant improvements following neurotherapy. Neurotherapy treatment effect sizes generally ranged from moderate to large (d = .414 - .849). Multiple regression analysis found that changes in self-reported anxiety symptoms, but not depressive symptoms, predicted observed improvements in sleep quality (adjusted R2 = .26). Last, the implications and limitations were discussed in relation to neurotherapy practice and the associated research.

Le vaste domaine de l’amélioration cognitive traverse les applications comportementales, biochimiques et physiques. Aussi nombreuses sont les techniques que les limites de ces premières : des études de pauvre méthodologie, des pratiques éthiquement ambiguës, de faibles effets positifs, des effets secondaires significatifs, des couts financiers importants, un investissement de temps significatif, une accessibilité inégale, et encore un manque de transfert. L’objectif de cette thèse est de proposer une méthode novatrice d’intégration de l’une de ces techniques, le neurofeedback, directement dans un paradigme d’apprentissage afin d’améliorer la performance cognitive et l’apprentissage. Cette thèse propose les modalités, les fondements empiriques et des données à l’appui de ce paradigme efficace d’apprentissage ‘bouclé’. En manipulant la difficulté dans une tâche en fonction de l’activité cérébrale en temps réel, il est démontré que dans un paradigme d’apprentissage traditionnel (3-dimentional multiple object tracking), la vitesse et le degré d’apprentissage peuvent être améliorés de manière significative lorsque comparés au paradigme traditionnel ou encore à un groupe de contrôle actif. La performance améliorée demeure observée même avec un retrait du signal de rétroaction, ce qui suggère que les effets de l’entrainement amélioré sont consolidés et ne dépendent pas d’une rétroaction continue. Ensuite, cette thèse révèle comment de tels effets se produisent, en examinant les corrélés neuronaux des états de préparation et de performance à travers les conditions d’état de base et pendant la tâche, de plus qu’en fonction du résultat (réussite/échec) et de la difficulté (basse/moyenne/haute vitesse). La préparation, la performance et la charge cognitive sont mesurées via des liens robustement établis dans un contexte d’activité cérébrale fonctionnelle mesurée par l’électroencéphalographie quantitative. Il est démontré que l’ajout d’une assistance- à-la-tâche apportée par la fréquence alpha dominante est non seulement appropriée aux conditions de ce paradigme, mais influence la charge cognitive afin de favoriser un maintien du sujet dans sa zone de développement proximale, ce qui facilite l’apprentissage et améliore la performance. Ce type de paradigme d’apprentissage peut contribuer à surmonter, au minimum, un des limites fondamentales du neurofeedback et des autres techniques d’amélioration cognitive : le manque de transfert, en utilisant une méthode pouvant être intégrée directement dans le contexte dans lequel l’amélioration de la performance est souhaitée. / The domain of cognitive enhancement is vast, spanning behavioral, biochemical and physical applications. The techniques are as numerous as are the limitations: poorly conducted studies, ethically ambiguous practices, limited positive effects, significant side-effects, high financial costs, significant time investment, unequal accessibility, and lack of transfer. The purpose of this thesis is to propose a novel way of integrating one of these techniques, neurofeedback, directly into a learning context in order to enhance cognitive performance and learning. This thesis provides the framework, empirical foundations, and supporting evidence for a highly efficient ‘closed-loop’ learning paradigm. By manipulating task difficulty based on a measure of cognitive load within a classic learning scenario (3-dimentional multiple object tracking) using real-time brain activity, results demonstrate that over 10 sessions, speed and degree of learning can be substantially improved compared with a classic learning system or an active sham-control group. Superior performance persists even once the feedback signal is removed, which suggests that the effects of enhanced training are consolidated and do not rely on continued feedback. Next, this thesis examines how these effects occur, exploring the neural correlates of the states of preparedness and performance across baseline and task conditions, further examining correlates related to trial results (correct/incorrect) and task difficulty (slow/medium/fast speeds). Cognitive preparedness, performance and load are measured using well-established relationships between real-time quantified brain activity as measured by quantitative electroencephalography. It is shown that the addition of neurofeedback-based task assistance based on peak alpha frequency is appropriate to task conditions and manages to influence cognitive load, keeping the subject in the zone of proximal development more often, facilitating learning and improving performance. This type of learning paradigm could contribute to overcoming at least one of the fundamental limitations of neurofeedback and other cognitive enhancement techniques : a lack of observable transfer effects, by utilizing a method that can be directly integrated into the context in which improved performance is sought.

A standard Neurofeedback approach to mitigate the working memory decline in some fragile groups (elderly, subjects affected by stroke or Alzheimer's disease) can be suboptimal for some patients. The goal of this research is to investigate which visual stimulus (among colour, geometrical shape, direction, and symbol) is the most suited for each of the six healthy participants and which brain areas are the most discriminative, during the maintenance of a presented stimulus in a retro-cue-based working memory experiment. In order to identify the most discriminative stimulus, the single-trial classification accuracies of some Support Vector Machines, trained on the theta, alpha and beta electroencephalography power bands, have been compared; while, in order to identify the most involved brain regions, three machine learning feature reduction techniques have been explored: the first based on a massive univariate analysis, the second based on multivariate filtering and wrapping, and the last one based on Frequency-based Common Spatial Pattern. The results have shown that the univariate approach, more than the others, managed to clearly identify for each participant at least one preferential type of stimulus and a brain region of discriminative electrodes during the maintenance of the stimulus. These promising results can be interpreted as a further step to optimize the Neurofeedback working memory enhancement through a personalised approach.

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O presente estudo avaliou a eficácia do equipamento de biofeedback Vertiguard®), que utiliza a informação vibrotátil como substituto sensorial (SS) de apoio ao sistema vestibular. Foram selecionados 13 pacientes com comprometimento severo do equilíbrio corporal e não obtiveram resultado satisfatório à terapia de reabilitação vestibular convencional. Os sujeitos foram randomizados entre dois grupos controle (GC), que utilizou o estímulo vibratório e estudo (GE), que treinou com o equipamento desligado. Os indivíduos foram treinados com o equipamento durante dez dias e foram orientados a corrigir o alinhamento corporal sempre que recebessem um estímulo vibrotátil de um cinto com quatro vibradores dispostos em ângulo de 90°entre eles, que informava o desvio corporal para aquele lado e o risco de queda. Para avaliação pré e pós tratamento foi utilizada o protocolo Teste de Integração Sensorial (TIS) da Posturografia Dinâmica Computadorizada (PDC) e duas escalas de auto percepção do equilíbrio: ABC (Activities-specific Balance Confidence) e DHI (Dizziness Handicap Inventory). O GE apresentou melhora estatisticamente significante em C5 (p=0,007) e C6 (p= 0,012) após treinamento. Na escala ABC houve diferença significante entre o início e o final do tratamento apenas no GE (p=0,04). No questionário DHI ocorreu diferença significante no aspecto físico nos GC e GE, e no aspecto funcional (p=0,0427) apenas no grupo GE. Os resultados observados demonstram que o estímulo de substituição sensorial vibratório oferecido pelo sistema Vertiguard®, propicia a melhor integração das redes neurais envolvidas na manutenção da postura, melhorando as estratégias utilizadas na recuperação do equilíbrio corporal / This study evaluated the effectiveness of biofeedback equipment Vertiguard® that uses vibrotactile information as sensory substitution (SS) of the vestibular system. We selected thirteen patients with severe impairment of balance who did not obtain enough improvement from conventional vestibular rehabilitation. A randomization list was used to distribute the patients in Control Group (CG), who received the vibrotactile stimulus and Study Group (SG), who trained without any stimulus. During ten days of training, the patients in both groups used the equipment attached to the waist. They were instructed to correct body alignment when vibrotactile stimulus received from one of the four vibrators arranged at an angle of 90° signaling the risk of f alling. The results of the treatment were evaluated by the protocol sensory organization test (SOT) of the computerized dynamic posturography (CDP), ABC scale (Activities-specific Balance Confidence) and DHI (Dizziness Handicap Inventory). After treatment the SG showed a statistically significant improvement in C5 (p = 0.007) and C6 (p = 0.012). In the ABC scale there was significant difference between the beginning and end of treatment only in the SG (p = 0.04). The Dizziness Handicap Inventory questionnaire (DHI) showed in the after training a significant difference in functional in both CG and SG, and in physical aspects (p = 0.0427) only in SG. The present findings show that sensory substitution using the vibrotactile stimulus of Vertiguard (R) system promotes the improvement of neural networks involved in maintaining posture, improving the strategies used in the recovery of body balance

O presente estudo avaliou a eficácia do equipamento de biofeedback Vertiguard®), que utiliza a informação vibrotátil como substituto sensorial (SS) de apoio ao sistema vestibular. Foram selecionados 13 pacientes com comprometimento severo do equilíbrio corporal e não obtiveram resultado satisfatório à terapia de reabilitação vestibular convencional. Os sujeitos foram randomizados entre dois grupos controle (GC), que utilizou o estímulo vibratório e estudo (GE), que treinou com o equipamento desligado. Os indivíduos foram treinados com o equipamento durante dez dias e foram orientados a corrigir o alinhamento corporal sempre que recebessem um estímulo vibrotátil de um cinto com quatro vibradores dispostos em ângulo de 90°entre eles, que informava o desvio corporal para aquele lado e o risco de queda. Para avaliação pré e pós tratamento foi utilizada o protocolo Teste de Integração Sensorial (TIS) da Posturografia Dinâmica Computadorizada (PDC) e duas escalas de auto percepção do equilíbrio: ABC (Activities-specific Balance Confidence) e DHI (Dizziness Handicap Inventory). O GE apresentou melhora estatisticamente significante em C5 (p=0,007) e C6 (p= 0,012) após treinamento. Na escala ABC houve diferença significante entre o início e o final do tratamento apenas no GE (p=0,04). No questionário DHI ocorreu diferença significante no aspecto físico nos GC e GE, e no aspecto funcional (p=0,0427) apenas no grupo GE. Os resultados observados demonstram que o estímulo de substituição sensorial vibratório oferecido pelo sistema Vertiguard®, propicia a melhor integração das redes neurais envolvidas na manutenção da postura, melhorando as estratégias utilizadas na recuperação do equilíbrio corporal / This study evaluated the effectiveness of biofeedback equipment Vertiguard® that uses vibrotactile information as sensory substitution (SS) of the vestibular system. We selected thirteen patients with severe impairment of balance who did not obtain enough improvement from conventional vestibular rehabilitation. A randomization list was used to distribute the patients in Control Group (CG), who received the vibrotactile stimulus and Study Group (SG), who trained without any stimulus. During ten days of training, the patients in both groups used the equipment attached to the waist. They were instructed to correct body alignment when vibrotactile stimulus received from one of the four vibrators arranged at an angle of 90° signaling the risk of f alling. The results of the treatment were evaluated by the protocol sensory organization test (SOT) of the computerized dynamic posturography (CDP), ABC scale (Activities-specific Balance Confidence) and DHI (Dizziness Handicap Inventory). After treatment the SG showed a statistically significant improvement in C5 (p = 0.007) and C6 (p = 0.012). In the ABC scale there was significant difference between the beginning and end of treatment only in the SG (p = 0.04). The Dizziness Handicap Inventory questionnaire (DHI) showed in the after training a significant difference in functional in both CG and SG, and in physical aspects (p = 0.0427) only in SG. The present findings show that sensory substitution using the vibrotactile stimulus of Vertiguard (R) system promotes the improvement of neural networks involved in maintaining posture, improving the strategies used in the recovery of body balance

The research entails the early identification of neuropsychological learning disabilities in grade 1 learners. The researcher used the definition, criteria and characteristics of the DSM-IV for the identification of neuropsychological learning disabilities. The section of Learning Disabilities or Disorders includes Reading Disorders, Mathematic Disorder, Disorder of Written Expression and Learning Disorder Not Otherwise Specified. Learning Disabilities are diagnosed when the learner’s achievement on individually administrated, standardized tests in reading, mathematics or written expression is substantially below that expected for age, schooling and the level of intelligence. The learning problems, such as unsatisfied reading, mathematical or writing skills, significantly interfere with the learner’s academic achievement. Mathematic Disorder and Disorder of Written Expression most commonly occur as early as in the beginning or first grade, when formal reading instruction usually begin. Neuropsychological learning disabilities have a negative influence on the learner’s scholastic achievement, social development and emotional functioning. The research is focused on the grade 1 learners only. There is no differentiation regarding gender. In the literature study, the researcher observed five important components regarding neuropsychological learning disabilities, namely:- -- Definition, criteria and characteristics; -- Classification; -- Causes; -- The localization of the cortical areas of the brain associated with neuropsychological abilities; and -- The Neurofeedback. The Neurofeedback is based on the tenents that brain electrical activity reflects mental status and that the activity can be trained. The researcher also observed in the literature study certain risk factors regarding neuropsyhological learning disabilities, namely phonological awareness, analysis, synthesis, word recognition and syntax. The researcher considered these components in conjunction with the compilation of the neuropsychological test battery. The researcher could determine the follow findings with the assistance of the neuropsychological test battery:- -- The developmental delays which are present. -- The brain areas in which the cognitive abilities, associated with the developmental delays, are located. -- The limited functioning of brain wave activities which are associated with the cognitive abilities and developmental delays. -- The early idenitification of neuropsychological learning disabilities in grade 1 learners. The researcher found that the Neurofeedback programme is a useful contribution for the early identification of neuropsychological learning disabilities in grade 1 learners. / Thesis (PhD (Learning Support, Guidance and Counselling))--University of Pretoria, 2006. / Educational Psychology / unrestricted