Made available in DSpace on 2016-03-15T19:40:42Z (GMT). No. of bitstreams: 1 Vera Marcia Goncalves da Silva Pina.pdf: 744603 bytes, checksum: 091e0414715b177c9dcb799db54a7e03 (MD5) Previous issue date: 2009-08-13 / Despite extensive research seeking to understand the problems of reading and the causes underlying them, there are still some open aspects. Therefore, it was with this research examining the relationship between temporal processing and reading. For both were initially evaluated 184 children of 2, 3 and 4 grades of elementary school and, based on performance on a reading test, it was selected two groups with 26 children each, a group of good readers and a group of poor readers. These two groups were subjected to three tests to assess individual abilities of temporal processing, namely the rhythm (in terms of spontaneous motor production, reproduction of rhythmic structures and understanding of symbolic notation), the speed (readinf speed, picture naming speed and number naming speed) and sequencing (memory of verbal sounds and sequencing of daily activities). Analysis of variance was conducted to check possible differences between groups and school years. Overall, the group of poor readers showed lower performance on several tasks of temporal processing when compared with the group of good readers. This lower performance is more apparent in the tasks of reading speed and naming. There was also correlation between reading and various aspects of temporal processing. These results suggest that problems with reading are related to temporal deficits, especially on tasks involving verbal material, such as speed reading and naming. / Apesar das vastas pesquisas que buscam compreender os problemas de leitura e as causas a eles subjacentes, ainda há alguns aspectos em aberto. Por essa razão, buscou-se com a presente pesquisa analisar a relação entre o processamento temporal e a leitura. Para tanto inicialmente foram avaliadas 184 crianças de 2º, 3º e 4º anos do ensino fundamental e, com base nos desempenhos em uma prova de leitura, foram selecionados dois grupos com 26 crianças cada, um grupo de bons leitores e um grupo de maus leitores. Esses dois grupos foram submetidos a testes individuais para avaliar três habilidades de processamento temporal, a saber, o ritmo (em termos de produção motora espontânea, reprodução de estruturas ritmicas e compreensão de notação simbólica), a velocidade (de leitura, de nomeação de figuras e números) e o sequenciamento (memória de sons verbais e sequenciamento de atividades cotidianas). Análises de variância foram conduzidas para verificar possíveis diferenças significativas entre os grupos e os anos escolares. De forma geral, o grupo de maus leitores apresentou desempenho rebaixado em diversas tarefas de processamento temporal quando comparadas com ao grupo de bons leitores, sendo tal rebaixamento mais evidente nas tarefas de velocidade de leitura e de nomeação. Houve também correlação entre leitura e vários aspectos do processamento temporal. Tais resultados sugerem que problemas de leitura estão relacionados a déficits temporais, principalmente em tarefas que envolvem material verbal, tais como a velocidade de leitura e de nomeação.

Pessoas com fissura lábio palatina apresentam alterações na acuidade auditiva por um grande período de suas vidas, ou por toda vida, devido à constante disfunção tubária, que acarreta a otite média, impedindo assim uma recepção adequada dos sons da fala. Influência de otite média durante a infância é uma das características que está associada com o distúrbio de aprendizagem e transtornos de processamento auditivo. A consciência fonológica envolve o reconhecimento de que as palavras são formadas por diferentes sons que podem ser manipulados, abrangendo além da capacidade de reflexão (constatar e comparar), também a de operação com fonemas, sílabas, rimas e aliterações (contar, segmentar, unir, adicionar, suprimir, substituir e transpor). O objetivo principal deste trabalho foi estudar a associação entre a consciência fonológica e o processamento temporal em crianças com fissura labiopalatina. Foram avaliadas 41 crianças de ambos os sexos, com idades entre 7 anos e 10 anos e 11 meses, com fissura labiopalatina transforame unilateral, sem outras anomalias associadas ou síndromes. As crianças foram submetidas ao teste de processamento temporal Random Gap Detection Test (RGDT) e a avaliação de consciência fonológica CONFIAS adaptada com figuras. Os resultados indicaram não haver associação, nesta amostra, entre a consciência fonológica e o processamento temporal. Porem outros estudos devem ser realizados com um número maior de crianças na amostra. / Persons with cleft lip and palate presents alterations in the auditory sharpness by a big period of his lives, or by all life, because the constant tube dysfunction, that causes otitis media, stopping like this an adequate reception of the sounds of the speak. Influence of the otitis media during the childhood is one of the characteristics that is associated with the disturbance of learning and auditory process disorders. The phonological awareness involves the recognition of that the words are graduates by different sounds that can be manipulated, including beyond the capacity of reflection (establish and compare), also the operation with phonemes, syllables, rhymes and alliterations (count, segment, unite, add, suppress, replace and transpose). The main objective of this work was study the association between the phonological awareness and the temporal processing in childrens with cleft lip and palate.The work counted on 41 children of both sexes, with ages between 7 years and 10years and 11 monts, with cleft lip and palate, without other anomalies associated or syndromes. The children were submitted temporal processing test Random Gap Detection Test (RGDT) and the evaluation of the phonological awareness CONFIAS, adapted with figures. The results showed there isnt association, in this sample, bettween the phonological awareness and the temporal processing. But others studies should be realized with more children in the sample.

京都大学 / 新制・課程博士 / 博士(人間健康科学) / 甲第23125号 / 人健博第87号 / 新制||人健||6(附属図書館) / 京都大学大学院医学研究科人間健康科学系専攻 / (主査)教授 林 悠, 教授 稲富 宏之, 教授 村井 俊哉 / 学位規則第4条第1項該当 / Doctor of Human Health Sciences / Kyoto University / DFAM

Many living organisms have the ability to execute complex behaviors and cognitive processes that are reliable. In many cases, such tasks are generated in the absence of an ongoing external input that could drive the activity on their underlying neural populations. For instance, writing the word "time" requires a precise sequence of muscle contraction in the hand and wrist. There has to be some patterns of activity in the areas of the brain responsible for this behaviour that are endogenously generated every time an individual performs this action. Whereas the question of how such neural code is transformed in the target motor sequence is a question of its own, their origin is perhaps even more puzzling. Most models of cortical and sub-cortical circuits suggest that many of their neural populations are chaotic. This means that very small amounts of noise, such as an additional action potential in a neuron of a network, can lead to completely different patterns of activity. Reservoir computing is one of the first frameworks that provided an efficient solution for biologically relevant neural networks to learn complex temporal tasks in the presence of chaos. We showed that although reservoirs (i.e. recurrent neural networks) are robust to noise, they are extremely sensitive to some forms of structural perturbations, such as removing one neuron out of thousands. We proposed an alternative to these models, where the source of autonomous activity is no longer originating from the reservoir, but from a set of oscillating networks projecting to the reservoir. In our simulations, we show that this solution produce rich patterns of activity and lead to networks that are both resistant to noise and structural perturbations. The model can learn a wide variety of temporal tasks such as interval timing, motor control, speech production and spatial navigation.

Hearing loss of various types is increasingly plaguing our modern world (Geneva: World Health Organization 2018). As the life expectancy increased in the industrialized world, age-related hearing loss (ARHL) has become more prevalent. The wars and terrorism of the modern world also created a significant body of blast-induced hearing loss (BIHL) patients. Both types of hearing loss present significant challenges for listeners even at suprathreshold sound levels. However, increasing bodies of clinical and laboratory evidence have suggested that the difficulties in the processing of time-varying auditory features in speech and other natural sounds may not be sufficiently diagnosed by threshold changes and simple auditory electrophysiological measures (Snell and Frisina 2000; Saunders et al. 2015; Bressler et al. 2017; Guest et al. 2018).<br>Studies have emphasized that excitatory/inhibitory neurotransmission imbalance plays important roles in ARHL (Caspary et al. 2008) and may also be key in BIHL, as hinted by the strong presence of GABA regulation in non-blast TBI (O’Dell et al. 2000; Cantu et al. 2015; Guerriero et al. 2015). The current studies focus on age-related and blast-induced hearing deficits by examining changes in the processing of simple, brief stimuli and complex, sustained, temporally modulated sounds.<br>Through post hoc circular analysis of single-unit, in vivo recording of young and aged inferior colliculus (IC) neurons responding to amplitude modulation (AM) stimuli and modulation depth changes, we observed evidence of central compensation in the IC manifesting as increased sensitivity to presynaptic input, which was measured via local field potentials (LFPs). We also found decreased sensitivity to decreasing modulation depth. Age-related central gain in the IC single units, while preserving and even overcompensating for temporal phase coding in the form of vector strength, was unable to make up for the loss of envelope shape coding.<br>Through careful, longitudinal measurements of auditory evoked potential (AEP) responses towards simple sounds, AM and speech-like iterated rippled noise (IRN), we documented the development and recovery of BIHL induced by a single mild blast in a previously established (Song et al. 2015; Walls et al. 2016; Race et al. 2017) rat blast model over the course of two months. We identified crucial acute (day 1-4 post-exposure) and early recovery (day 7-14) time windows in which drastic changes in electrophysiology take place. Challenging conditions and broadband, speech-like stimuli can better elucidate mild bTBI-induced auditory deficits during the sub-acute period. The anatomical significance of the aforementioned time windows was demonstrated with immunohistochemistry methods, showing two distinct waves of GABA inhibitory transmission changes taking place in the auditory brainstem, the IC, and the auditory thalamus. These changes were in addition to axonal and oxidative damage evident in the acute phase. We examined the roles and patterns of excitatory/inhibitory imbalance in BIHL, its distinction compared to that of ARHL, and demonstrated the complexity of its electrophysiological consequences. Blast traumatizes the peripheral auditory system and auditory brainstem, evident through membrane damage and acrolein-mediated oxidative stress. These initial traumas kickstart a unique, interlocking cascade of excitatory/inhibitory imbalances along the auditory neuraxis that is more complex and individually varied than the gradual, non-traumatic degradations in ARHL. Systemic treatment with the FDA-approved acrolein scavenger Hydralazine (HZ) was attempted with limited effects.<br>Taken together, the current study provided insights into the similarities and distinctions between the mechanisms of ARHL and BIHL and called for innovative and individual diagnostic and therapeutic measures.<br>

The primary purpose of this investigation was to determine whether temporal coding in the auditory system was the same for younger and older listeners. Temporal coding was assessed by amplitude-modulated auditory steady-state responses (AM ASSRs) as a physiologic measure of phase-locking capability. The secondary purpose of this study was to determine whether AM ASSRs were related to behavioral speech understanding ability. AM ASSRs showed that the ability of the auditory system to phase lock to a temporally altered signal is dependent on modulation rate, carrier frequency, and age of the listener. Specifically, the interaction of frequency and age showed that younger listeners had more phase locking than old listeners at 500 Hz. The number of phase-locked responses for the 500 Hz carrier frequency was significantly correlated to word-recognition performance. In conclusion, the effect of aging on temporal processing, as measured by phase locking with AM ASSRs, was found for low-frequency stimuli where phase locking in the auditory system should be optimal. The exploration, and use, of electrophysiologic responses to measure auditory timing analysis in humans has the potential to facilitate the understanding of speech perception difficulties in older listeners.

Ces travaux de recherche ont eu pour objectif d’évaluer les capacités de discrimination des réponses des neurones et leur robustesse dans le bruit à chaque étage du système auditif. Nous avons ainsi quantifié la capacité de discrimination neuronale entre quatre vocalisations cibles conspécifiques masquées par un bruit stationnaire depuis le noyau cochléaire jusqu’au cortex auditif secondaire chez le cobaye anesthésié. La discrimination des vocalisations cibles par les populations neuronales a été fortement diminuée par le bruit dans toutes les structures, mais les populations du colliculus inférieur et du thalamus ont montré de meilleures performances que les populations corticales. La comparaison avec les réponses neuronales obtenues avec les vocalisations vocodées (38, 20 ou 10 bandes de fréquences) a révélé que la réduction des capacités de discrimination neuronale était principalement due à l'atténuation des modulations d'amplitude lente (< 20 Hz). En outre, nous avons quantifié la robustesse des réponses neuronales grâce à une méthode de classification automatique réalisée sur l’ensemble des données obtenues en présence du bruit stationnaire et d’un autre bruit appelé chorus. Cela a mis en évidence cinq catégories de comportements neuronaux (des plus robustes aux plus sensibles) et leurs proportions respectives sur l’ensemble du système auditif ainsi qu’au sein de chaque structure auditive. Cette analyse a montré également qu’il existait des neurones robustes à tous les étages du système auditif, bien qu’une proportion plus importante soit retrouvée au niveau du colliculus inférieur et du thalamus. Par ailleurs, la proportion de neurones robustes est plus faible dans le bruit chorus ce qui laisse suggérer que ce dernier est plus pénalisant que le bruit stationnaire. Il est important de souligner qu’une proportion non négligeable de neurones sous-corticaux et corticaux changent de comportement d’un bruit à l’autre de sorte que le comportement de ces neurones dans un bruit particulier est peu prédictible. Ces résultats démontrent donc que la discrimination neuronale en situation de dégradation acoustique est principalement déterminée par l’altération des modulations lentes d'amplitude à la fois au niveau sous-cortical et cortical et suggèrent que les structures sous-corticales contribuent de façon importante à la perception robuste d’un signal cible dans le bruit. / This research aimed at evaluating the discrimination abilities of neuronal responses and their robustness to noise at each stage of the auditory system, from the cochlear nucleus to the secondary auditory cortex. We quantified the neuronal discrimination performance between four conspecific vocalizations masked by a stationary noise in anesthetized guinea pig. Discrimination of target vocalizations by neuronal populations was significantly reduced by noise in all structures, but collicular and thalamic populations displayed better performance than cortical populations. The comparison with neuronal responses obtained with vocoded vocalizations (using 38, 20 or 10 frequency bands) revealed that the reduction in discrimination performance was mainly due to the attenuation of slow amplitude modulations (<20 Hz). In addition, we quantified the robustness of neuronal responses using an automatic classification method performed on the whole database obtained in presence of stationary noise and of another noise called “chorus” noise. This highlighted five categories of neural behavior (from robustness to sensitivity) and their respective proportions across the auditory system as well as within each auditory structure. This analysis demonstrated that robust neurons do exist at all stages of the auditory system, although a higher proportion was found in the inferior colliculus and thalamus. Moreover, the proportion of robust neurons is lower in the chorus noise, which suggests that the latter is more penalizing than the stationary noise. It is worth to point out that a significant proportion of subcortical and cortical neurons changed category from one background noise to another, so that the behavior of these neurons in a particular noise was unpredictable. These results provide clear evidence that neuronal discrimination in degraded acoustic conditions is mainly determined by alterations of slow amplitude modulations both at the subcortical and cortical level, and suggest that the subcortical structures significantly contribute to the robust perception of a target signal in noise.

No description available.

The experiments described in this thesis use psychophysical techniques and human observers to investigate temporal processing in the millisecond range. The thesis contains five main sections. Introductory chapters provide a brief overview of the visual and auditory systems, before detailing our current understanding of duration processing. During the course of this review, several important questions are highlighted. The experiments detailed in Chapters 8-11 seek to address these questions using the psychophysical techniques outlined in Chapter 7. The results of these experiments increase our understanding of duration perception in several areas. Firstly, Experiments 1 and 2 (Chapter 8) highlight the role of low level stimulus features: even when equated for visibility stimuli of differing spatial frequency have different perceived durations. Secondly, a psychophysical hypothesis arising from the ¿duration channels¿ or ¿labelled lines¿ model of duration perception is given strong support by the adaptation experiments detailed in Chapter 9 and 10. Specifically, adaptation to durations of a fixed temporal extent induces repulsive duration aftereffects that are sensory specific and bandwidth limited around the adapted duration. Finally Chapter 11 describes the results of experiments designed to probe the processing hierarchy within duration perception by measuring the interdependency of illusions generated via duration adaptation and via multisensory cue combination. The results of these experiments demonstrate that duration adaptation is a relatively early component of temporal processing and is likely to be sub served by duration selective neurons situated in early sections of the visual and auditory systems.

No description available.