Dissertations / Theses on the topic 'EEG rhythms'

Diese Dissertation zeigt, dass Hintergrundrhythmen mit Hilfe der gleichzeitigen Messung von EEG und fMRI Signalen untersucht werden können. Die Methodik dieses Ansatzes wurde durch den Einsatz einer speziellen fMRI Sequenz weiterentwickelt, und die Signalqualität durch visuell evozierte Potentiale überprüft. Der prominente okzipitale Alpha-Rhythmus und die vergleichsweise schwächeren rolandischen Rhythmen konnten in der elektromagnetisch störenden Umgebung des Magnetresonanztomografen, auch und gerade während der funktionellen Messsequenzen identifiziert werden. Durch den Einsatz der in dieser Arbeit vorgestellten Nachverarbeitungsmethoden kann die simultane Aufnahme von EEG und fMRI Signalen wertvolle Informationen über die neuronale Grundlage von Hirnrhythmen und ihrer hemodynamischer Korrelate liefern. Die hier vorgestellten Daten bekräftigen die Hypothese, dass die Amplitude der Hintergrundrhythmen mit spezifischen Deaktivierungen in sensorischen Hirnarealen einhergehen. Eine erhöhte Amplitude aller untersuchter Rhythmen war mit einem negativen BOLD Signal in sensorischen kortikalen Arealen verknüpft, was auf einen erniedrigten Energieverbrauch in Arealen mit höherer Synchronizität schliessen lässt. Der posteriore Alpha Rhythmus, ist invers mit dem hemodynamischen Signal in primären visuellen Arealen gekoppelt, während hämodynamische Korrelate der rolandischen Alpha und Beta Rhythmen in somatomotorischen Arealen lokalisiert wurden. Für den rolandischen Alpha und Beta Rhythmus wurden unterschiedliche regionale Netzwerke gefunden. Der rolandische Beta Rhythmus ist mit dem Motornetzwerk, während der rolandische Alpha Rhythmus mit einen somatosensorischen bzw. Assoziationsnetzwerk assoziert ist, was eine fundamentale Eigenschaft des Somatomotorischen Systems zu sein scheint. Die rolandischen Rhythmen könnten dadurch somatomotorische Areale während der Erhaltung oder Planung von Bewegungsabläufen funktional koppeln [Brovelli, et al., 2004]. Desweiteren wurde gezeigt, dass thalamische und cinguläre Strukturen mögliche Generatoren oder Modulatoren der hier untersuchten Hintergrundrhythmen sind. Die experimentellen Daten der hier vorgestellten Studien legen nahe, dass eine inverse Beziehung der Stärke eines Hintergrundrhythmus mit regional kortikalem Metabolismus und gleichzeitig eine „antagonistische“, positive Beziehung mit thalamischen oder cingulären Struktuen ein gernerelles orgnaisatorisches Prinzip des Gehirns zu sein scheint. Der Begriff der Grundaktivität des Gehirns [Gusnard, et al., 2001] müsste daher in verschiedene Netzwerke der Grundaktivität unterteilt werden, die elektrophysiologisch durch Hintergrundrhythmen definiert wären.
The data provided by this thesis show that imaging of brain rhythms can be achieved by simultaneous EEG-fMRI recordings. This methodology was developed further by implementing an adapted MR sequence and the EEG-fMRI signal quality was confirmed by means of visual evoked potentials. Together with the post processing methods applied in this work, simultaneous EEG-fMRI recordings can thus provide valuable information about the neuronal basis of brain rhythms and their regional hemodynamic correlates. The data further substantiate the hypothesis that ‘idling’ rhythms indicate distinct deactivated sensory cortical areas. Increased power of all examined rhythms was associated with negative BOLD signal in sensory cortical areas, indicating less energy consumption in those areas with higher synchronicity. The posterior alpha or so-called Berger rhythm is coupled inversely to the hemodynamics in primary visual areas, whereas rolandic alpha and beta rhythm could be localized to somatomotor areas. Different networks were found for rolandic alpha and beta rhythms. The rolandic beta rhythm is more associated with a motor-network whereas the rolandic alpha rhythm is more associated with a sensory and association network which represents a fundamental characteristic of the sensorimotor system. The rolandic oscillations may bind sensorimotor areas into a functional loop during pre-movement motor maintenance behaviour [Brovelli, et al., 2004]. Furthermore thalamic and cingulate structures were shown to be possible generative or modulatory structures for the brain rhythms examined in this study. The experimental data obtained in this work suggest that the inverse correlation of an ‘idling’ rhythm’s strength with the metabolism in ‘its cortical areas’, and the positive correlation with cingulate or thalamic areas are both general organizational principles. The notion of a default mode of the brain [Gusnard, et al., 2001] may perhaps be further subdivided into different networks with a “default mode”, each of them electro-physiologically defined by its “idle rhythm”.

Tato diplomová práce představuje koncept elektrického invalidního vozíku ovládaného lidskou myslí. Tento koncept je určen pro osoby, které elektrický invalidní vozík nemohou ovládat klasickými způsoby, jakým je například joystick. V práci jsou popsány čtyři hlavní komponenty konceptu: elektroencefalograf, brain-computer interface (rozhraní mozek-počítač), systém sdílené kontroly a samotný elektrický invalidní vozík. V textu je představena použitá metodologie a výsledky provedených experimentů. V závěru jsou nastíněna doporučení pro budoucí vývoj.

Submitted by (lucia.rodrigues@ufrpe.br) on 2016-06-09T14:34:56Z No. of bitstreams: 1 Renato Barros Moraes.pdf: 1461731 bytes, checksum: 72fe61b249cbff251455227ca064db5a (MD5)
Made available in DSpace on 2016-06-09T14:34:56Z (GMT). No. of bitstreams: 1 Renato Barros Moraes.pdf: 1461731 bytes, checksum: 72fe61b249cbff251455227ca064db5a (MD5) Previous issue date: 2010-02-09
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Over the last 25 years, major advances have occurred in the techniques of nonlinear analysis applied to time series. These techniques have helped us to understand how dynamic systems behave over time. The brain is considered the most complex dynamic system known for man, and as such, it presents great challenges to the understanding of their processes, both physiological and pathological. In this work, we try to better understand epilepsy, a brain disease that affects millions of individuals around the world. The records of electroencephalogram (EEG) and electrocorticogram (ECoG) are widely used in the clinic for diagnosis and monitoring of epilepsy, but the information contained in these records are underutilized, since they are generally analyzed by the clinical eye. It is known that is contained in the EEG and ECoG, some specific frequencies such as alpha (α), beta (β), theta (θ), delta (δ) and gamma (γ) and they have interesting properties for the diagnosis of some brain pathologies. Through the DFA (Detrended fluctuation Analysis) technique used to verify long-range correlation in time series, and a derivation of this, the Parabolicity index (b), we observed some differences in EEG and ECoG signals, to normal and epileptic conditions between different brain rhythms, both in an animal model and in human records.
Nos últimos 25 anos, grandes avanços têm ocorrido nas técnicas de análise não-linear aplicadas a séries temporais. Essas técnicas têm nos ajudado a entender como sistemas dinâmicos se comportam com o passar do tempo. O cérebro é considerado o sistema dinâmico mais complexo conhecido pelo homem, e como tal apresenta grandes desafios para a compreensão de seus processos, tanto fisiológicos quanto patológicos. Nesse trabalho, tentamos compreender melhor a epilepsia, uma patologia cerebral que afeta milhões de indivíduos em todo o mundo. Os registros de eletroencefalograma (EEG) e eletrocorticograma (ECoG) são bastante utilizados na clínica para o diagnóstico e acompanhamento da epilepsia, porém as informações contidas nestes registros são subutilizadas, uma vez que são analisadas geralmente pelo olho clínico. Sabe-se que estão contidas no EEG e ECoG, algumas freqüências específicas tais como alfa(α), beta(β), teta(θ), delta(δ) e gama(γ), e que elas possuem propriedades interessantes para diagnóstico de algumas patologias cerebrais. Através da DFA (Análise de Flutuação sem Tendência), técnica usada para verificar correlação de longo alcance em séries temporais, e de uma derivação dessa, o Índice de parabolicidade (b), conseguimos verificar algumas diferenças nos sinais de ECoG e EEG, para uma condição normal e epiléptico, entre as diferentes ondas cerebrais, tanto num modelo animal quanto em registros de humanos.

Menschliche Hirnsignale von der Kopfhaut bieten einen Einblick in die neuronalen Prozesse, denen Wahrnehmung, Denken und Verhalten zugrunde liegen. Rhythmen, die historisch den Grundstein für die Erforschung großflächiger Hirnsignale legten, sind ein häufiges Zeichen neuronaler Koordination, und damit von weitem Interesse für die kognitiven, systemischen und komputationalen Neurowissenschaften. Typischen Messungen von Rhythmizität fehlt es jedoch an Details, z. B. wann und wie lange Rhythmen auftreten. Darüber hinaus weisen neuronale Zeitreihen zahlreiche dynamische Muster auf, von denen nur einige rhythmisch erscheinen. Obwohl aperiodischen Beiträgen traditionell der Status irrelevanten „Rauschens“ zugeschrieben wird, attestieren neuere Erkenntnisse ihnen ebenfalls eine Signalrolle in Bezug auf latente Hirndynamik. Diese kumulative Dissertation fasst Projekte zusammen, die darauf abzielen, rhythmische und aperiodische Beiträge zum menschlichen Elektroenzephalogramm (EEG) methodisch zu dissoziieren, und ihre Relevanz für die flexible Wahrnehmung zu untersuchen. Projekt 1 ermittelt insbesondere die Notwendigkeit und Durchführbarkeit der Trennung rhythmischer von aperiodischer Aktivität in kontinuierlichen Signalen. Projekt 2 kehrt diese Perspektive um und prüft Multiscale Entropy als Index für die Unregelmäßigkeit von Zeitreihen. Diese Arbeit weist auf methodische Probleme in der klassischen Messung zeitlicher Unregelmäßigkeit hin, und schlägt Lösungen für zukünftige Anwendungen vor. Abschließend untersucht Projekt 3 die neurokognitive Relevanz rhythmischer und aperiodischer Zustände. Anhand eines parallelen multimodalen EEG-fMRT-Designs mit gleichzeitiger Pupillenmessung liefert dieses Projekt erste Hinweise dafür, dass erhöhte kognitive Anforderungen Hirnsignale von einem rhythmischen zu einem unregelmäßigen Regime verschieben und impliziert gleichzeitige Neuromodulation und thalamische Aktivierung in diesem Regimewechsel.
Non-invasive signals recorded from the human scalp provide a window on the neural dynamics that shape perception, cognition and action. Historically motivating the assessment of large-scale network dynamics, rhythms are a ubiquitous sign of neural coordination, and a major signal of interest in the cognitive, systems, and computational neurosciences. However, typical descriptions of rhythmicity lack detail, e.g., failing to indicate when and for how long rhythms occur. Moreover, neural times series exhibit a wealth of dynamic patterns, only some of which appear rhythmic. While aperiodic contributions are traditionally relegated to the status of irrelevant ‘noise’, they may be informative of latent processing regimes in their own right. This cumulative dissertation summarizes and discusses work that (a) aims to methodologically dissociate rhythmic and aperiodic contributions to human electroencephalogram (EEG) signals, and (b) probes their relevance for flexible cognition. Specifically, Project 1 highlights the necessity, feasibility and limitations of dissociating rhythmic from aperiodic activity at the single-trial level. Project 2 inverts this perspective, and examines the utility of multi-scale entropy as an index for the irregularity of brain dynamics, with a focus on the relation to rhythmic and aperiodic descriptions. By highlighting prior biases and proposing solutions, this work indicates future directions for measurements of temporal irregularity. Finally, Project 3 examines the neurocognitive relevance of rhythmic and aperiodic regimes with regard to the neurophysiological context in which they may be engaged. Using a parallel multi-modal EEG-fMRI design with concurrent pupillometry, this project provides initial evidence that elevated demands shift cortical dynamics from a rhythmic to an irregular regime; and implicates concurrent phasic neuromodulation and subcortical thalamic engagement in these regime shifts.

Although the mu rhythm is traditionally defined as a normal EEG variant, recent evidence suggests that mu may have functional significance in a variety of disorders such as autism, Parkinson's disease, and multiple sclerosis. While an increasing number of articles have focused on the blocking mechanism of mu in relation to various cognitive processes and disorders, few have examined the significance of a prominent mu rhythm in the background EEG. A few studies have examined the relationship between the mu rhythm and psychological disturbance, such as attentional and affective disorders. Increasing evidence suggests that EEG and qEEG variables may be useful in classifying psychiatric disorders, presenting a neurophysiological alternative to traditional symptom-based diagnosis and classification. Thus, the intention of the present study was to examine the relationship between neuropsychological variables, gathered from multiple assessment sources, and the presence of a prominent mu rhythm in the EEG. Results did not show a statistically significant difference between individuals with and without a prominent mu rhythm on the Test of Variables of Attention (TOVA); although individuals in the mu group showed a pattern of increased impulsivity and performance decrement over time. For adults, no significant differences were observed between groups on psychological variables measured by the Minnesota Multiphasic Personality Inventory-2 (MMPI-2). However, for children, the mu and control groups differed on several behavioral and emotional variables on the Child Behavior Checklist (CBCL). Results are examined in the context of other research and clinical implications are discussed.

This thesis addresses some theoretical issues generated by the results of recent analysis of EEG time series proving the brain dynamics are driven by abrupt changes making them depart from the ordinary Poisson condition. These changes are renewal, unpredictable and non-ergodic. We refer to them as crucial events. How is it possible that this form of randomness be compatible with the generation of waves, for instance alpha waves, whose observation seems to suggest the opposite view the brain is characterized by surprisingly extended coherence? To shed light into this apparently irretrievable contradiction we propose a model based on a generalized form of Langevin equation under the influence of a periodic stimulus. We assume that there exist two different forms of time, a subjective form compatible with Poisson statistical physical and an objective form that is accessible to experimental observation. The transition from the former to the latter form is determined by the brain dynamics interpreted as emerging from the cooperative interaction among many units that, in the absence of cooperation would generate Poisson fluctuations. We call natural time the brain internal time and we make the assumption that in the natural time representation the time evolution of the EEG variable y(t) is determined by a Langevin equation perturbed by a periodic process that in this time representation is hardly distinguishable from an erratic process. We show that the representation of this random process in the experimental time scale is characterized by a surprisingly extended coherence. We show that this model generates a sequence of damped oscillations with a time behavior that is remarkably similar to that derived from the analysis of real EEG's. The main result of this research work is that the existence of crucial events is not incompatible with the alpha wave coherence. In addition to this important result, we find another result that may help our group, or any other research group working on the analysis of brain's dynamics, to prove or to disprove the existence of crucial events. We study the diffusion process generated by fluctuations emerging from the same model after filtering out the alpha coherence, and we study the recursion to the origin. We study the survival probability of this process, namely the probability that up to a given time no re-crossing of the origin occurs. We find that this is an inverse power law with a power that depends on whether or not crucial events exist.

Обсяг звіту становить 57 сторінок, міститься 32 ілюстрації, 14 таблиць, 5 формул, 2 додатки. Загалом опрацьовано 36 джерел. Актуальність даної роботи полягаєу визначенні залежності біоелектричної активності головного мозку від амплітудно-частотних характеристик звукового сигналу. У наш час музика супроводжує наше життя, тому важливо визначити який вплив вона має на електричну активність головного мозку і як саме змінюються характеристики показників мозкової активності при прослуховуванні музичних сигналів. Мета:визначити ефективність впливу аудіо сигналів різного амплітудно-частотного складу на зміну інтегральної активності мозку. Для досягнення мети дипломної роботи було сформовано ряд наступних задач: 1. Проаналізувати амплітудно частотні характеристики обраних аудіо сигналів; 2. Дослідити зміну ЕЕГ-ритмів на фоні впливу обраних аудіо сигналів 3. Дослідити вплив частотних характеристик аудіо сигналу на інтегральну електричну активність мозку.
The scope of the report is 57 pages, contains 32 illustrations, 14 tables, 2 annexes. In total, 36 sources were used. The relevance of this work lies in determining the dependence of the bioelectric activity of the brain on the amplitude-frequency characteristics of the sound signal. Nowadays, music accompanies our life, so it is important to determine what impact it has on the electrical activity of the brain and how the characteristics of the indicators of brain activity change when listening to musical signals. Purpose: to determine the effectiveness of audio signal impact of different amplitude-frequency composition on the change of brain integral activity. To achieve the goal of the thesis, the following tasks were formed: 1. Analyze the amplitude-frequency characteristics of the selected audio signals; 2. Investigate the change in EEG rhythms against the background of the influence of selected audio signals; 3. Investigate the influence of frequency characteristics of the audio signal on the integrated electrical activity of the brain.

This thesis deals with evaluation EKG in terms of classification rhythm and analysis HRV. In theoretic part of work are described basics of heart physiology and its usual pathology, basics of electrocardiography, evaluation EKG and standard methods of HRV evaluation. In practical part are described algorithms used in created application. Mainly describes technique of rhythm evaluation, ectopic rhythms and delineation error elimination, data preparing for HRV evaluation, drift removal from DES and HRV evaluation methods. Created program was tested on CSE and MIT- BIH database records. For lack of suitable data and absence of tested data, it wasn’t possible to test all the classification rules of used algorithms. Tested part of program appears reliable and functional.

Segmentational grouping in music listening refers to the organisation of individual tones into tone groups that tend to be processed and subsequently recalled as perceptual units or chunks. Grouping of tones via this process tends to occur at natural breaks in structure of a tone sequence, so that relatively larger changes in pitch, amplitude or timing are perceived as boundaries which cue the segmentational grouping process. Segmentational grouping processes have been examined using behavioural research techniques; yet neurophysiological processes underlying the grouping process have received little attention, and are poorly understood. This study aimed to identify brain regions involved in the segmentational grouping process as cued by rhythmic information. Participants performed two auditory tasks while brain electrical activity responses were monitored using Steady-State Probe Topography (SSPT). Behavioural responses evoked in a task probing individuals' use of lengthened-duration tones to organise memory for pitch sequences indicated that longer-duration tones were used as cues to organise working memory representations of the musical patterns. Examination of dynamic SSPT responses during the encoding phase of a probe recognition task indicated that greater use of rhythmic cues to organise working memory representations was associated with activation of a network of left hemisphere frontal, temporal and parietal regions. During the lengthened tone, activation of left central and vertex regions and progressive activation of left temporal and temporoparietal regions were linked with use of the deviant status of the lengthened tone to update temporal expectations for the sequence. Excitatory responses observed in left posterior frontal and temporal regions to a tone following the lengthened tone were proposed to reflect temporal allocation of attention to this point in time, whereas sustained excitatory activation of left temporal, and temporoparietal regions reflected the role of these regions in supporting representations of the tone events in working memory. Finally, late inhibitory responses to the tone following the lengthened tone in left frontal, temporal, temporoparietal, and parietal regions were linked with the manipulation and closure of the working memory trace in association with the grouping process. Together, these findings support the activation of a network of left frontal, temporal and parietal regions underlying rhythmic grouping of pitch sequences.

Anxiety disorder is prevalent and costly. But its diagnosis is underdeveloped and treatment ad hoc. This could be corrected if the neural mechanisms of anxiety were known. All anxiolytic medications produce a decrease in rodent hippocampal theta rhythm - so hippocampal theta could underlie some types of anxiety. But, a review (Chapter 2) showed that ethanol and other anxiolytics increase FM-theta in the human scalp EEG and have other properties unlike hippocampal theta. The experiments in this thesis, therefore, tested for other potential homologues (Chapter 3) of hippocampal theta in the human EEG. The phase of hippocampal theta activity is reset in a working memory task and not an equivalent reference memory task in rats. Furthermore, low doses ethanol increases and high dose ethanol (and other anxiolytics) decrease theta activity. So, EEG was recorded from 15 scalp sites while participants performed non-verbal working memory and reference memory tasks before and after ethanol administration and assessed for the presence of phase-reset and ethanol-related changes in 5-7Hz and 8-11Hz spectral power (chapter 4 and 5). There was little general evidence for stimulus-induced phase-resetting of the ongoing EEG activity (Chapter 6). Increased post-stimulus synchronization in the theta frequency range was accompanied by increases in post-stimulus spectral power - suggesting that the synchronised activity was evoked rather than reset. Across 3 experiments (Chapter 7), low dose ethanol (54.5-146.6[mu]g/l) increased 5-7Hz theta, while the highest dose (307[mu]g/l) reduced task-related-increases in 5-7Hz activity. These effects were noted across electrode locations including frontal-midline sites and particularly at the beginning of the delay period. The suppression of 5-7Hz activity also coincided with an impairment in working memory performance. The dose-response curve for 5-7Hz theta was as predicted from rat hippocampal work. This particular component, linked to high working memory load or task difficulty, is a potential of homologue hippocampal theta. A clear decrease in theta with high dose ethanol, of this type, has not been reported previously. Activity in the 8-11Hz range typically increased with all doses of ethanol. It is clearly not a homologue of hippocampal theta. This is consistent with previous reports of increased alpha with high doses of ethanol - although these have been accompanied by increased, not decreased, theta. There is a potential homologue of hippocampal theta that can be detected in the human EEG (chapter 8); but the observed changes in 5-7Hz activity cannot be localised and may not be related to the hippocampus. It is clear there is more than one type of theta within the human EEG - with opposing sensitivities to ethanol. Critically, these types were detected at a single site and apparently in phase with one another. The current data, together with the previous literature, suggest that theta can be generated concurrently in distinct networks that, under specific task demands, can become coherent and so produce synchonised activity. Future studies need to test higher doses of ethanol and other anxiolytics and use different experimental paradigms to further differentiate the theta systems in the human EEG. Human EEG could be useful for differentiating sub-types of anxiety, and the choice and effectiveness of interventions delivered.

The goal of this investigation was to explore the efficacy of implementing a rehabilitation robot controlled by a noninvasive brain-computer interface (BCI) to influence brain plasticity and facilitate motor learning. The motivation of this project stemmed from the need to address the population of stroke survivors who have few or no options for therapy. A stroke occurs every 40 seconds in the United States and it is the leading cause of long-term disability [1-3]. In a country where the elderly population is growing at an astounding rate, one in six persons above the age of 55 is at risk of having a stroke. Internationally, the rates of strokes and stroke-induced disabilities are comparable to those of the United States [1, 4-6]. Approximately half of all stroke survivors suffer from immediate unilateral paralysis or weakness, 30-60% of which never regain function [1, 6-9]. Many individuals who survive stroke will be forced to seek institutional care or long-term assistance. Clinicians have typically implemented stroke rehabilitative treatment using active training techniques such as constraint induced movement therapy (CIMT) and robotic therapy [10-12]. Such techniques restore motor activity by forcing the movement of weakened limbs. That active engagement of the weakened limb movement stimulates neural pathways and activates the motor cortex, thus inducing brain plasticity and motor learning. Several studies have demonstrated that active training does in fact have an effect on the way the brain restores itself and leads to faster rehabilitation [10, 13-15]. In addition, studies involving mental practice, another form of rehabilitation, have shown that mental imagery directly stimulates the brain, but is not effective unless implemented as a supplemental to active training [16, 17]. Only stroke survivors retaining residual motor ability are able to undergo active rehabilitative training; the current selection of therapies has overlooked the significant population of stroke survivors suffering from severe control loss or complete paralysis [6, 10]. A BCI is a system or device that detects minute changes in brain signals to facilitate communication or control. In this investigation, the BCI was implemented through an electroencephalograph (EEG) device. EEG devices detect electrical brain signals transmitted through the scalp that corresponded with imagined motor activity. Within the BCI, a linear transformation algorithm converted EEG spectral features into control commands for an upper-limb rehabilitative robot, thus implementing a closed-looped feedback-control training system. The concept of the BCI-robot system implemented in this investigation may provide an alternative to current therapies by demonstrating the results of bypassing motor activity using brain signals to facilitate robotic therapy. In this study, 24 able-bodied volunteers were divided into two study groups; one group trained to use sensorimotor rhythms (SMRs) (produced by imagining motor activity) to control the movement of a robot and the other group performed the 'guided-imagery' task of watching the robot move without control. This investigation looked for contrasts between the two groups that showed that the training involved with controlling the BCI-robot system had an effect on brain plasticity and motor learning. To analyze brain plasticity and motor learning, EEG data corresponding to imagined arm movement and motor learning were acquired before, during, and after training. Features extracted from the EEG data consisted of frequencies in the 5-35Hz range, which produced amplitude fluctuations that were measurably significant during reaching. Motor learning data consisted of arm displacement measures (error) produced during an motor adaptation task performed daily by all subjects. The results of the brain plasticity analysis showed persistent reductions in beta activity for subjects in the BCI group. The analysis also showed that subjects in the Non-BCI group had significant reductions in mu activity; however, these results were likely due to the fact that different EEG caps were used in each stage of the study. These results were promising but require further investigation. The motor learning data showed that the BCI group out-performed non-BCI group in all measures of motor learning. These findings were significant because this was the first time a BCI had been applied to a motor learning protocol and the findings suggested that BCI had an influence on the speed at which subjects adapted to a motor learning task. Additional findings suggested that BCI subjects who were in the 40 and over age group had greater decreases in error after the learning phase of motor assessment. These finding suggests that BCI could have positive long term effects on individuals who are more likely to suffer from a stroke and possibly could be beneficial for chronic stroke patients. In addition to exploring the effects of BCI training on brain plasticity and motor learning this investigation sought to detect whether the EEG features produced during guided-imagery could differentiate between reaching direction. While the analysis presented in this project produced classification accuracies no greater than ~77%, it formed the basis of future studies that would incorporate different pattern recognition techniques. The results of this study show the potential for developing new rehabilitation therapies and motor learning protocols that incorporate BCI.

El temps és un component estructural de la música. A cada cultura, els sons de la música es produeixen i es perceben com patrons rítmics que posseeixen una pulsació isocrònica subjacent. Aquesta pulsació isocrònica s'organitza mitjançant el compàs en patrons que jerarquitzen posicions fortes i febles. Ambdós, la pulsació isocrònica i el compàs, són constructes cognitius que funcionen com a punts de referència temporal per categoritzar i predir esdeveniments, fet que permet sincronitzar moviments (entre altres coses). Aquesta tesi pretén explorar les bases biològiques de la pulsació isocrònica i del compàs jeràrquic des d'un enfocament neurofisiològic i comparatiu. Els estudis electrofisiològics amb humans han revelat que les poblacions neuronals poden sincronitzar-se amb estímuls periòdics visuals i auditius; i amb el compàs ternari, sigui imaginat en la modalitat visual o marcada per característiques auditives espacials. A més, la formació musical i l'atenció interaccionen amb el processament del ritme i reforcen la sincronia neural amb les periodicitats de la pulsació i el compàs. Els estudis conductuals amb rates han revelat que altres animals són capaços de reconèixer l'estructura rítmica subjacent a una cançó familiar i que poden detectar isocronia en seqüències auditives presentades a diversos tempos, independentment de la durada absoluta dels tons. A diferència dels humans, les rates no tenen habilitats d'aprenentatge vocal, les quals semblen no ser necessàries per processar aquests dos components temporals del ritme. En conjunt, aquestes troballes assenyalen que alguns aspectes rítmics de la música van més enllà de la modalitat auditiva en els humans i que els seus orígens es poden trobar en altres espècies.

Orientador: João Lima Sant'Anna Neto
Banca: Margarete Cristiane de Costa Trindade Amorim
Banca: José Tadeu Garcia Tommaselli
Banca: Inês Moresco Danni-Oliveira
Banca: Emerson Galvani
A análise dos modos de atuação dos mecanismos atmosféricos é uma das bases da ciência climatológica, pois, através dessas, os pesquisadores estão aptos a fazer as diagnoses regionais, as prognoses climáticas, avaliar o possível impacto de variações climáticas e desenvolver projetos para mitigá-los. Seguindo essa lógica, foi elaborada a análise de adversidade climática do oeste paulista e do norte do Paraná. Para a efetuação dessa tarefa, foi utilizada a técnica de análise rítmica de Monteiro, sendo pesquisados os anos de 1997, 1998 e 2001 nas localidades de Presidente Prudente, Maringá e Londrina. Além da pesquisa dos dados diários desses três anos, em que foram criados 108 gráficos de análise rítmica e 108 gráficos de eventos climáticos, foram analisados 27 anos de dados mensais e anuais (1976- 2003) que possibilitaram a elaboração de 54 figuras, 67 tabelas, 102 gráficos e 9 organogramas, em que foram analisadas as características atmosféricas regionais, observando possíveis tendências de alterações climáticas futuras. Foram constatados, ao longo da análise, que a área de estudo está passando por um processo de aquecimento de até 1ºC, além de um processo de fortalecimento sazonal, com as estações mais secas e chuvosas tornando-se mais bem definidas, o que pode causar, futuramente, uma maior quantidade de eventos extremos e adversidades climáticas, que, por sua vez, podem afetar as cidades e a produção agrícola.
Analyzing how the atmospheric mechanisms act is a great base of the climate science because it allows the researches to know about the regional weather aspects, to discuss the possible impact of climatic variations and to develop projects in order to protect the region against these possible variations in the soon future. Following this idea, we elaborated an analysis about hazards in the Western Sao Paolo State and the North Parana State in Brazil. We based on the Monteiro rhythm analysis method to study the cities Presidente Prudente, Maringa and Londrina in the years 1997, 1998 and 2001. Through the search of diary weather statistics we created 108 rhythm analysis graphics and 108 climatic event graphics. Besides them, we studied 27 years of mensal and annual statistics (1976 - 2003) which allowed the creation of 54 figures, 67 tables, 102 graphics and 9 examples. Through these we analyzed regional climatic aspects, searching for future tendencies of climate variations. It was verified by the analysis a warming of one Celsius degree at the studied areas and also a process of sazonalization which showed more clearly the division of wet and dry seasons. We see that it could result in the future more cases of hazards that could affect the cities and the agricultural production. The thesis revels that the climatic rhythms study, the interpretation of regional climatic variation and the study of the necessary actions to protect the areas against hazards are complex questions which involve great series of variables that, sometimes, the statistical techniques are not able to solve, despite its powerful and recognition in science. Because of that, it is extremely important the careful interpretation of climatic aspects by rhythm paradigm, mainly linking it with statistical techniques as well.
Doutor

Abstract The purpose of the present study was to gain more insight into the blood oxygen level-dependent (BOLD)-contrast functional MRI (fMRI) in the brain and its connection to EEG, both in global and local scales of their temporal and spatial relations. BOLD signal changes were studied during hyperventilation (HV) induced EEG reactivity of intermittent rhythmic delta activity (IRDA). The BOLD signal in gray matter decreased 30% more in subjects with IRDA (N = 4) than in controls (N = 4), during the first two minutes of HV. This difference disappeared during IRDA in EEG. BOLD signal changes may provide additional information about dynamic hemodynamic changes relative to HV induced EEG reactivity. BOLD signal changes were investigated during sudden deepening of thiopental anesthesia into EEG burst-suppression level in pigs (N = 5). Positive (6–8%) or negative (-3– -8%) group average BOLD signal changes correlated to the thiopental bolus injection were seen. Positive and negative responses covered 1.6% and 2.3% of the brain voxels, respectively. BOLD signal changes in brain are associated with sudden deepening of thiopental anesthesia into EEG burst-suppression level, but they are spatially inconsistent and scarce. Somatosensory BOLD response was studied in brain before and after globally induced methotrexate (MTX) exposition in pigs (N = 4). After the MTX exposure, reduced (from 2–4% to 0–1%) or negative (-2% to -3%) BOLD responses were detected. Somatosensory BOLD-contrast response shows a slight difference in brain before and after globally induced MTX exposition. An experimental epilepsy model for development of simultaneous EEG and BOLD-contrast fMRI in the localization of epilepsy was developed and tested. Dynamic penicillin induced local epilepsy was applied in deep isoflurane anesthesia in pigs (N = 6). Relatively high (10–20%) and localized BOLD signal increase was found. The dynamic penicillin induced focal epilepsy model in deep isoflurane anesthesia with simultaneous EEG and BOLD-contrast fMRI is feasible for the development of these methods for localization of epileptic focus or foci. In conclusion, with careful experimental design and analysis, BOLD-contrast fMRI with EEG provides a potential tool for monitoring and localising functional changes in the brain.

A epilepsia do lobo temporal (ELT) é a forma mais comum de epilepsia e a mais resistente ao tratamento medicamentoso. Existem diversos tipos de drogas anti-epilépticas usadas no controle das crises. Entretanto, em alguns casos, esse tipo de tratamento não é eficaz e a cirurgia para remoção da zona epileptogênica (ZE) pode ser uma alternativa recomendada. A ZE é definida como aquela onde as crises são originadas. Trata-se de um conceito teórico e, atualmente, não existem técnicas capazes de delimitá-la precisamente. Na prática, exames de EEG, vídeo-EEG, MEG, SPECT, PET e diversas técnicas de MRI, em especial as funcionais, têm sido usados para mapear zonas relacionadas à ZE. Contudo, em alguns casos, os resultados permanecem não convergentes e a determinação da ZE inconclusiva. Desse modo, é evidente a importância do surgimento de novas metodologias para auxiliar a localização da ZE. Assim, pois, o objetivo deste trabalho foi desenvolver dois métodos para a avaliação da ZE, ambos baseados na imagem funcional por ressonância magnética. No primeiro, investigamos possíveis alterações da resposta hemodinâmica (HRF) quando da modulação da pressão parcial de CO2. Para tanto, fizemos um estudo sobre 22 pacientes com ELT e 10 voluntários assintomáticos modulando a pressão parcial de CO2 sanguíneo cerebral por um protocolo de manobra de pausa respiratória e outro de inalação passiva de CO2/ar. Os resultados mostram que o tempo de onset da HRF tende a ser maior e a amplitude da HRF tende a ser menor em áreas do lobo temporal de pacientes com ELT quando comparados com os dados de voluntários assintomáticos. Além disso, os resultados mostram mapas de onset individuais coincidentes com exames de SPECT ictal. O segundo estudo foi baseado em medidas de EEG-fMRI simultâneo. Neste, avaliamos a relação entres as potências dos ritmos cerebrais alfa e teta (EEG) e o contraste BOLD (fMRI) de 41 pacientes com ELT e 7 voluntários assintomáticos em estado de repouso. A análise da banda alfa mostrou correlações negativas nos lobos occipital, parietal e frontal tanto nos voluntários quanto nos pacientes com ELT. As correlações positivas nos voluntários foram dispersas e variáveis em ambos hemisférios cerebrais. Por outro lado, encontramos forte correlação positiva no tálamo e ínsula dos pacientes com ELT. Na análise da banda teta observamos correlações positivas bilaterais nos giros pré e pós central de voluntários. Ainda, foram observados clusters no cíngulo anterior, tálamo, ínsula, putamen, em regiões parietais superior, frontais e giros temporais. Também, utilizamos um cálculo de índice de lateralização (IL) no lobo temporal em confrontos entre pacientes com ELT à direita, pacientes com ELT à esquerda e voluntários assintomáticos. Verificamos que os ILs, utilizando os clusters obtidos nas análises em teta, foram coincidentes com o diagnóstico clínico prévio da localização da ZE em todas as análises dos grupos de pacientes com ELT à direita, e na maioria do grupo de pacientes com ELT à esquerda. De forma geral, verificamos que o método de hipercapnia se mostrou ferramenta interessante na localização da ZE comprovada pelos coincidentes achados pela avaliação de SPECT. Inferimos que o maior tempo de onset e menor amplitude da HRF observadas nos pacientes em relação a voluntários possam estar relacionados a um stress vascular devido à recorrência de crises. Já o método de ritmicidade alfa e teta proposto parece promissor para ser usado na determinação da lateralização da ZE em pacientes com ELT.
Temporal lobe epilepsy (TLE) is the most common and resistant form of epilepsy to anti-epileptic drug. There are several types of anti-epileptic drugs used in seizure control. However, in some cases drug treatment is not effective and surgery to remove the epileptogenic zone (EZ) is a recommended alternative. EZ is a theoretical concept and there are many techniques that have been applied to enclose it precisely. In practice, EEG, video-EEG, MEG, SPECT, PET and various MRI techniques, especially functional MRI (fMRI), have been used to map areas related to EZ. However, in some cases, the results remain non-convergent and the EZ, undefined. Therefore, the use of new methodologies to assist the location of EZ have been proposed. Herein, our goal was to develop two methods for assessing the EZ. The first one was designed to access changes in the hemodynamic response (HRF) of the EZ in response to hypercapnia. 22 patients with TLE and 10 normal volunteers were evaluated by modulating the partial pressure of CO2 during the acquisition of fMRI in a breathing holding and a passive inhalation CO2/air protocols. The results show increased onset times and decreased amplitude of the HRF in the temporal lobe of TLE patients compared with asymptomatic volunteers. Moreover, most patients had onset maps coincident with ictal SPECT localizations. The second proposed study was based on simultaneous EEG-fMRI acquisitions. The relationship between powers of alpha and theta bands (EEG) and BOLD contrast (fMRI) was investigated in 41 TLE patients and 7 healthy controls. Alpha band results show a consistent negative correlation in the occipital, parietal and frontal lobes both in controls and TLE patients. In addition, controls show disperse positive correlations in both hemispheres. On the other hand, TLE patients presented strong positive correlations in the thalamus and insula. Theta band analysis, in controls, primarily show positive correlations in bilateral pre-and post-central gyri. In patients, robust positive correlations were observed in the anterior cingulate gyrus, thalamus, insula, putamen, superior parietal, frontal and temporal gyri. Moreover, the lateralization index (LI) indicates a coincidence between the side of the EZ evaluated by clinical diagnosis and clusters detected in the theta band. In conclusion, the hipercapnia study showed to be an interesting tool in locating EZ and the results are similar to SPECT findings. The longer onset and lower amplitude of the HRF observed in patients may be related to a vascular stress due to the recurrence of seizures. Furthermore, alpha and theta rhythms may be a promising tool to be used in determining the lateralization of EZ in patients with TLE.

This work focuses on a theoretical explanation of heart rhythm disorders and the possibility of their automatic detection using deep learning networks. For the purposes of this work, a total of 6884 10-second ECG recordings with measured eight leads were used. Those recordings were divided into 5 groups according to heart rhythm into a group of records with atrial fibrillation, sinus rhythms, supraventricular rhythms, ventricular rhythms, and the last group consisted of the others records. Individual groups were unbalanced represented and more than 85 % of the total number of data are sinus rhythm group records. The used classification methods served effectively as a record detector of the largest group and the most effective of all was a procedure consisting of a 2D convolutional neural network into which data entered in the form of scalalograms (classification procedure number 3). It achieved results of precision of 91%, recall of 96% and F1-score values of 0.93. On the contrary, when classifying all groups at the same time, there were no such quality results for all groups. The most efficient procedure seems to be a variant composed of PCA on eight input signals with the gain of one output signal, which becomes the input of a 1D convolutional neural network (classification procedure number 5). This procedure achieved the following F1-score values: 1) group of records with atrial fibrillation 0.54, 2) group of sinus rhythms 0.91, 3) group of supraventricular rhythms 0.65, 4) group of ventricular rhythms 0.68, 5) others records 0.65.

Orientador: João Lima Sant'Anna Neto
Banca: José Tadeu Tommaselli
Banca: Margarete Cristiane de Costa Trindade Amorim
Banca: José Bueno Conti
Banca: Luci H. Nunes
Resumo: Esta pesquisa objetivou analisar a dinâmica climática e a variabilidade pluviométrica para a determinação do padrão de precipitação predominante em diferentes escalas de análise e estabelecer a atuação dos sistemas atmosféricos e sua participação na geração de chuvas através da metodologia de análise rítmica proposta por Monteiro (1971). A bacia do rio Ivaí ocupa uma área de 35.845km2, sendo a segunda maior no território paranaense. Na primeira etapa do trabalho foi realizada a caracterização da pluviosidade através dos dados pluviométricos de 60 postos no período de 1976 a 2001. Foram calculadas as médias mensais, sazonais e anuais e os totais anuais para toda série histórica. Para alguns anos considerados atípicos (secos e chuvosos) foram calculados os desvios-padrão em relação à média. A segunda etapa do trabalho consistiu na aplicação da análise rítmica para os anos eleitos como "padrão" - 1998 (chuvoso), 1999 (seco) e 2001 (habitual) para Guarapuava e Maringá. Como resultado, constatou-se que a distribuição espacial da pluviosidade, para todas as escalas de análise, apresentou um padrão com os valores mais elevados a montante, devido ao efeito orográfico e ao clima subtropical predominante nessa porção, enquanto os menores valores foram observados a jusante, por estar ela numa área de clima tropical e baixas altitudes. No que se refere à análise rítmica, foi constatado, no ano de 1998, que os maiores valores precipitados sob atuação dos sistemas frontais ocorreram no outono para Guarapuava e no inverno para Maringá, e que somente a frente polar atlântica gerou 57% da pluviosidade para cada localidade em relação ao total anual. Para o ano de 1999 os sistemas frontais geraram valores pluviométricos semelhantes tanto no verão quanto na primavera, para Guarapuava e Maringá... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: This research analyzes both the climate dynamics and the rainfall variability. It is aimed to determine the dominant rainfall pattern at different scales of analysis, to define the atmospheric systems and how they influence the rainfall generation. This research was performed according to the rhythm analysis methodology proposed by Monteiro (1971). The Ivaí River Basin drains an area of 35.845 kmø. It is the second largest river basin in the Paraná State. The first step of this research was to characterize rainfall regime based on 60 different rain gauge stations data, collected from 1976 to 2001. This basin monthly, seasonal, yearly averages and yearly totals were calculated based on its historic rainfall records. Atypical years (dry and rainy years) had their standard deviation calculated from mean values. During the second step of this research, rhythm analysis was performed for those years considered "atypical" - 1998 (rainy), 1999 (dry) and 2001 (typical) both for Guarapuava and Maringá. Each analysis scale showed that rainfall spatial distribution has a pattern of higher levels in the upstream basin. This is true because of the dominant subtropical climate and the orographic effects occurring in this area. Lower values occurred in the downstream basin because of the low altitude and its tropical climate. As far as rhythm analysis is concerned, it was evident that rainfall higher values under frontal systems occurred during the fall of 1998 in Guarapuava city and during the winter time in Maringá city, and also that the Atlantic polar front was responsible for 57% of rainfall measures for each locality in relation to the yearly total. In 1999, frontal systems values were similar in the summer and in the spring time, both in Guarapuava and in Maringá... (Complete abstract click electronic access below)
Doutor

The master´s thesis presents the problems of EEG biofeedback and its application to relax people. The first part discusses the properties of EEG signal , the requirements of the standard EEG and also distribusion signal into different frequency bands. The main essence of the work is the design and realization of Alfa Monitor – a device for relaxation , that for implamanting EEG biofeedback uses acoustic form and sensing of electrical activity of brain in the region of alpha waves. The second half of the work is t focused on circuit design, using integrated circuits with component values of relevant calculations . Further, it analyzes the practical implementation of alfa monitor. The last chapter is devoted to the testing the functionality of this device.

Orientador: Zélia Lopes da Silva
Banca: Antonio Celso Ferreira
Banca: Norval Baitello Junior
Banca: Eda Maria Goes
Banca: Maria Teresa Santos Cunha
Resumo: Este trabalho se fundamenta na importância crescente das imagens no século vinte, as quais podem ser entendidas em duplo sentido: como estimulantes dos olhares e como aparências investidas de potencial comunicativo. É privilegiado o uso que a mídia efetuou do universo do olhar. As imagens, em sua ambigüidade, são instrumentos adequados ao uso publicitário em um século em que, paulatinamente, a notícia e a informação são consideradas mercadorias pelos grandes grupos de comunicação. As fontes da pesquisa são as capas de revistas brasileiras de sucesso de mercado. O mercado da informação está fundamentalmente ligado ao exercício da política, eis porque o período de análise corresponde ao final da década de sessenta (início da censura governamental à imprensa) e da década de oitenta (primeira eleição direta para presidente da República após o fim da censura), sendo lícito questionar de que forma a comunicação foi empreendida enquanto entrávamos e saíamos da ditadura militar. As capas são signos do funcionamento da chamada grande imprensa e, ao mesmo tempo, são signos de um olhar que se estrutura no decorrer do século: olhar que busca informação rápida e concisa. Estratégias comuns utilizadas nas imagens de capa são analisadas, como o uso dos códigos das cores e das expressões corporais, assim como os temas que tiveram destaque nas capas das revistas e que mostram a constituição de sentidos propostos à massa de fatos que os próprios meios de comunicação oferecem. As sínteses compostas em imagens estabelecem pautas de discussões, tornando-as importantes e exercendo um poder excludente. As capas das... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The thesis is based on the increasing importance of pictures in the 20th century. Pictures may be understood as (1) gaze stimulating and as (2) appearances charged with communicative potentiality. The use that the media make of the gaze is extremely conspicuous. Even in their ambiguity, pictures are veritable publicity instruments in a century during which news and information became gradually commercial goods in the hands of great communication groups. Our research sources are covers of best selling Brazilian magazines. Since the information market is intimately linked to politics and the analyzed period ranges from the late 60s (the starting point of press censorship by the government) to the late 80s (the first true election for the presidency of Brazil after censorship), it is important to problematize the communication theme as Brazil alternated from censorship and dictatorship to democracy. Magazine covers are performance signs of the big press and, at the same time, of the gaze structuring itself throughout the century: the gaze that seeks precise and fast information. Common strategies in magazine covers, uses of color, body expression codes, underlined themes which show the constitution of meanings suggested to the great amount of photos by the same communication media, are analyzed. Picture-composed synthesis establishes discussions, giving great importance to pictures since they exercise an excluding stance. Magazine covers allure the magazines' target public, or consumers. Beneath the magazines' syntheses lie... (Complete abstract, click electronic access below)
Doutor

Resumo: A restrição alimentar é uma técnica muito difundida no meio científico e produtivo, usada para contenção de gastos e exploração do ganho compensatório. Entretanto, há escassez de pesquisas que retratem as suas possíveis consequências ao comportamento e bem-estar dos animais. Este estudo teve por objetivo verificar os possíveis efeitos que a restrição alimentar causa no bem-estar de cabritos mantidos em gaiolas individuais, detectado por possíveis alterações na expressão de seus comportamentos. No estudo do ritmo circadiano, utilizou-se três cabritos Saanen machos, e no segundo experimento utilizou-se 27 cabritos Saanen (machos, fêmeas e castrados) entre 30 e 40 dias de vida, e em ambos os estudos os animais eram submetidos a 3 diferentes níveis nutricionais (sem restrição, restrição intermediária e restrição severa), com consumo individual controlado diariamente. As observações foram realizadas de forma direta e contínua, com uso de câmeras de vídeo, utilizando como variáveis a frequencia e a duração dos comportamentos, perfazendo 702 horas de observação. Através da análise do ritmo circadiano, foi possível verificar alterações na alocação temporal dos comportamentos realizados pelos cabritos e na condição de bem-estar desses animais, sendo que todos os animais apresentaram desenvolvimento de estereotipias. Os cabritos desta pesquisa apresentaram consumo de matéria seca sólida aquém do esperado para a idade em estudo, e os animais dos diferentes sexos reagiram de forma distinta. O presente estudo contribuiu com informações relevantes para os pesquisadores que trabalham com animais em condições restritivas, mostrando que existem custos para os animais e que estes respondem de alguma forma a estas imposições. Entretanto mais esforços dirigidos a esta área se fazem necessários, especialmente com a espécie caprina, ainda pouco estudada
Abstract: Feed restriction is a common practice in scientific studies and in the animal husbandry. It is used to minimize the production costs and to explore compensatory growth. However, there are few studies that measure their possible consequences in the behavior and welfare of the animals. The aim of this study was verify the possible effects that food restriction causes in the welfare of penned goat kid, detected by possible changes in the expression of their behaviors. For the rhythm study, three male Saanen kids were used. In the second one, 27 goat kids were used from different gender (males, females, castrates), that had between 30 and 40 days of life, and in both studies the animals were subjected to 3 different nutrition levels of diets (without restriction, intermediate restriction and severe restriction), and the individual feed intake was daily controlled. The observations were made on direct way, using video cameras on continuous recording, using the frequency and the length of the behaviors as variables, totalizing 702 hours of observation. By the analyses of the circadian rhythms, it was observed changes in temporal allocation in the behavior and in the welfare conditions of the kids, whereas all animals showed development of behavior stereotypes. The dry matter intake of the solid ratio was below for what was expected from kids with this age, and animals of different sexes reacted in a distinct way. This study contributed with relevant information to researchers who works with animals in a restrictive condition, showing that are costs to the animals and they respond somehow for this charges, however, further studies has to be done for this area, especially with goats, which are still very little studied
Orientadora: Izabello Auxiliadora Molina de Almeida Teixeira
Coorientador: Mateus José Rodrigues Paranhos da Costa
Banca: Kleber Tomás de Resende
Banca: Carla Forte Maiolino Molento
Mestre

Orientador: Florivaldo Menezes Filho
Banca: Alexandre Roberto Lunsqui
Banca: Silvio Ferraz Mello Filho
Resumo: Este trabalho detém-se sobre o conceito de periodicidade generalizada, desenvolvida pelo compositor belga Henri Pousseur (1929-2009), com intuito de investigar algumas das mais notáveis transformações ocorridas na organização rítmica e temporal da música do século XX, especialmente na produção ligada à experiência do serialismo integral no pós-guerra europeu. A periodicidade também será abordada do ponto de vista da Teoria da Informação, de acordo com as formulações do teórico francês Abraham Moles (1920-1992), referência fundamental para o trabalho deste compositor. Segue-se, então, a exposição teórica da periodicidade generalizada, complementada por um caso prático de aplicação composicional por meio de uma análise da obra Apostrophe et six réflexions, escrita por Henri Pousseur na época da formulação deste conceito.
Abstract: This work is centered on the concept of generalized periodicity as proposed by Belgian composer Henri Pousseu (1929-2009), aiming to investigate some of the most remarkable transformations in rhythmic and temporal organization in 20th century concert music, specifically concerning the experience of serialism in post-war Europe. Periodicity is also approached through Information Theory, accordingly to the developments made by French theorist Abraham Moles (1920-1992), fundamental reference for Pousseur's work. After a conceptual presentation of the generalized periodicity, a case study of its compositional application is provided by an analysis of the work Apostrophe et six réflexions (1964-1966), written by the Belgian composer by the time this concept was formulated.
Mestre

Orientador: João Afonso Zavattini
Banca: José Bueno Conti
Banca: Lúcia Helena de Oliveira Gerardi
Resumo: A sociedade contemporânea sofre intensos efeitos negativos e degradantes causados pela emissão de substâncias diversas na atmosfera. Doenças, redução das aptidões físicas, desconforto térmico, transformação de paisagens e mudanças climáticas que envolvem escalas do nível local ao global são apenas alguns exemplos da ação dos poluentes atmosféricos. Na Região Metropolitana de São Paulo (RMSP), expoente maior das áreas metropolitanas na América do Sul, o uso intenso dos veículos, congestionamentos e grandes percursos no espaço intra-urbano induzem episódios de grande poluição do ar. Nesta pesquisa é desenvolvido e apresentado um roteiro metodológico, baseado no paradigma do ritmo climático, para o estudo da poluição do ar causada por veículos automotores em áreas metropolitanas, confrontando episódios de intensa poluição e os tipos de tempo reinantes com uso da técnica de análise rítmica. O roteiro metodológico, aplicado à Região Metropolitana de São Paulo, com dados da estação Ibirapuera (CETESB) nos invernos de 2001, 2002, 2003 e 2004, mostrou que os episódios representativos de intensa poluição por monóxido de carbono (CO), material particulado (MP10) e dióxido de nitrogênio (NO2) foram caracterizados por ação anticiclonal que impediu as invasões frontais, com dias de calmarias que não dispersaram a poluição produzida dentro da RMSP. Os processos de tropicalização da MPA e de continetalização MPV, que influenciaram o aumento das temperaturas e a queda da umidade, representaram os dias de aumento de poluição do ar. Já os episódios de intensa poluição por ozônio (O3) foram caracterizados principalmtente pela influência de massas tropicais atlânticas e massas tropicais continentalizadas, com dias bastante ensolarados e com ventos que tiveram grande influência no transporte do ozônio e de seus precursores, trazidos das... (Resumo completo, clicar acesso eletrônico abaixo).
Abstract: The cotemporary society suffers many negative effects caused by the emission of substances in the atmosphere. Illnesses, reduction of the physical aptitudes, thermal discomfort, climatic transformation of landscapes and changes that involve scales of the local level to the global one are only some examples of the atmospheric pollutants action. At São Paulo Metropolitan Region (RMSP), the most important exponent of South American metropolitan areas, the intense use of motor vehicles, traffic jam and long distances in the urban space induce air pollution episodes. In this research it is developed and presented a methodology, based on the climate rhythm paradigm, for the study of the air pollution caused vehicles in metropolitan areas, collating episodes of intense pollution and types of weather using rhythmic analysis technique. The methodology was applied to the RMSP with the Ibirapuera station data (CETESB) in the 2001, 2002, 2003 and 2004 winters, showing that the representative episodes of intense pollution for carbon monoxide (CO), particulate matter (MP10) and nitrogen dioxide (NO2) had been characterized by stagnating anticyclones action that hindered the frontal invasions, with days of calmnesses that had not exhausted the produced pollution of the RMSP. The processes of tropicalization of the Atlantic Polar Air Mass (MPA), that had influenced the increase of the temperatures and the decrease of the humidity, had represented the days with high level of pollutants in the air. Already the episodes of intense pollution for ozone (O3) had been characterized mainly by the influence of Atlantic Tropical Air Mass (MTA) and Continental Tropical Air Mass (MTC) masses, with sufficiently sunny and hot days, winds that had great influence in the transport of ozone and its precursors from the industrial areas of ABCD region and Cubatão into the central area of the RMSP.
Mestre

Orientador: Gladis Massini-Cagliari
Banca: Gisela Collischonn
Banca: Flaviane Romani Fernandes Svartman
Banca: Rosane de Andrade Berlinck
Banca: Marcia Valeria Zamboni Gobbi
Resumo: Esta tese de doutorado tem por objetivo confirmar a possibilidade de uma conexão entre a música e a linguística no desenvolvimento de uma nova metodologia para o estudo da prosódia de línguas mortas ou de períodos anteriores de línguas vivas. Tal metodologia baseia-se, resumidamente, na observação das proeminências musicais de textos poéticos musicados, na observação das proeminências linguísticas do texto dos poemas, junto com a observação da estrutura métrica dos mesmos. Sendo assim, partiu-se da ideia de que o tempo forte do compasso musical (o primeiro tempo) marca preferencialmente uma proeminência no nível linguístico, podendo servir de base para a localização das sílabas tônicas das palavras do texto, o que poderia fornecer pistas para o estudo do acento lexical de palavras em línguas que já não possuem falantes, nem registros orais. O corpus utilizado na pesquisa que sustenta essa tese constitui-se de um recorte das cem primeiras Cantigas de Santa Maria de Afonso X, tomadas a partir das suas versões transcritas por Anglés (1943) para a notação musical atual. Os dados foram coletados por meio da elaboração de fichas de análise, as quais mostram, de maneira clara, as coincidências entre proeminências nos níveis musical e linguístico. Vale ressaltar que foram coletadas trinta e oito mil e dezoito palavras, por meio das quais foi possível analisar a atribuição do acento lexical nas três pautas prosódicas existentes no português arcaico (oxítonas, paroxítonas e proparoxítonas), além e abrirmos uma discussão a respeito da tonicidade de monossílabos e o status prosódico de clíticos; também foi possível analisar a ocorrência do acento secundário, uma das maiores contribuições deste trabalho para a descrição da prosódia dessa língua. Dialogando com os trabalhos de... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: This thesis aims to confirm the possibility of a connection between Music and Linguistics on the development of a new methodology applied to the study of the prosody of dead languages or ancient periods of living languages. This methodology is based on the observation of musical prominences of poetic texts with musical notation, and on the observation of linguistic prominences of the texts, considering their metrical structure. There is a great probability of the musical stresses (the first beat of the measure) to coincide with the stressed syllable of the words. This fact provides clues for the study of lexical stress in past periods of the language. The corpus used for this research is composed by the first hundred Cantigas de Santa Maria, which were compiled by Alfonso X and transcribed for the contemporary musical notation by Anglés (1943). The data were collected by means of the elaboration of boards which show the coincidences between prominences at musical and linguistic levels. It is important to point out that thirty eight thousand and eighteen words were collected; this fact enabled the analysis of the attribution of the lexical stress in Medieval Portuguese. Moreover it was possible to discuss the prominence grade of monosyllables and to analyze the occurrence of secondary stresses, maybe the largest contribution of this research in the description of the prosody of that language. Dialoguing with previous researches such as Massini-Cagliari (1995, 1999, 2005) and Costa (2006) - regarding the attribution of the lexical stress in Medieval Portuguese - and Collishonn (1994) - regarding the secondary stress in Brazilian Portuguese - we could verify that the methodology developed in this thesis brought significant contributions for the description of the Medieval Portuguese phonological component as it allowed the analysis of... (Complete abstract click electronic access below)
Doutor

This project added to the sparse body of research on the neural underpinnings of turn-taking with an electroencephalography (EEG) investigation of spontaneous conversation. Eighteen participants (3 male, 15 female, mean age 29.79), recruited and participating in pairs, underwent EEG hyperscanning as they conversed on a freely chosen topic for 45 minutes. In line with previous research, it was predicted that a time-frequency analysis of the EEG might reveal either increased power at around 10 Hz (the location of one of two components of the mu rhythm, an oscillation possibly involved in motor preparation for speech), or reduced alpha (8-12 Hz) power (reflecting non-motor aspects of turn preparation) prior to taking one’s turn. Increased power between 8-12 Hz was observed around 1.5 and 1 second preceding turn-taking, but similar power increases also occurred prior to turn-yielding and the conversation partner continuing after a pause, and a reduction in alpha power was found in turn-taking relative to listening to the other speaker continue after a pause. It is unclear whether this activity reflected motor or non-motor aspects of turn preparation, but the spontaneous conversation paradigm proved feasible for investigating brain activity coupled to turn-taking despite the methodological obstacles.
Detta forskningsprojekt bedrar till ett ämne där relativt få studier har genomförts med en elektroencefalografi- (EEG-) undersökning av hjärnaktivitet som är kopplad till turtagning i spontant samtal. Arton deltagare (3 män, 15 kvinnor, medelålder 29,79) som rekryterades och deltog i par, genomgick EEG-hyperscanning medan de pratade om ett fritt valt ämne i 45 minuter. Det förutsades att en tidsfrekvensanalys av EEG kan avslöja antingen ökad effekt vid cirka 10 Hz (vilket motsvarar en av två komponenter i mu-rytmen, en oscillation som eventuellt är involverad i motoriska förberedelser för tal) eller reducerad alfaeffekt (8 -12 Hz) (vilket möjligen återspeglar icke-motoriska aspekter av turtagningsförberedelser) innan man tar sin tur. Ökad effekt mellan 8-12 Hz observerades ungefär 1,5 och 1 sekund före turtagning, men liknande ökningar inträffade också innan samtalspartnern tog sin tur eller fortsatte efter en paus, och en minskning av alfaeffekt observerades när turtagning jämfördes till kontexter där försökspersonerna lyssnade när den andra talaren fortsatte efter en paus. Det är oklart om denna aktivitet återspeglade motoriska eller icke-motoriska aspekter av turtagningsförberedelser, men det visar sig vara möjligt att undersöka hjärnaktivitet kopplad till spontant samtal på ett rimligt sätt trots paradigmens metodologiska svårigheter.
Hidden events in turn-taking

The aim of this work is describe common methods of biological feedback therapy that is used to treat some psychosomatic diseases. Subsequently, the description is focused on minimal brain dysfunction treatment by the help of EEG biofeedback. Properties and technical requirements for this therapy are concretized. The last part of this thesis is dedicated to the design and realization of practical software tool for EEG biofeedback therapy which is made in LabView 7.1. The M535 acquisition unit and NI USB-6221 measuring device are used for hardware solution.

Les 2 populations etudiees sont de chize (deux-sevres) et de julliac (massif central). Les durees d'activite journaliere et annuelle, selon le sexe, sont precisees. Le domaine vital est de 14 m**(2) chez les males, 7 m**(2) chez les femelles. Le comportement alimentaire est decrit, la ration alimentaire s'estime d'apres le poids des individus. La densite de population est plus elevee et plus stable a juillac. La proportion des pontes et les taux de survie sont fournis

碩士
國立中央大學
電機工程學系
101
This study aims to analyze movement-related sensorimotor Mu rhythm when leukoaraiosis patients and semi-paralyzed stroke patients were performing self-paced finger movement task. The investigation of differences between patients and normal subjects were also performed. Leukoaraiosis is a descriptive term used to describe neuroimaging findings of diffuse hemispheric white matter abnormalities mainly characterized by loss of myelin and/or ischemic injury. Leukoaraiosis is a major risk factor and prognostic factor for stroke. Similar to leukoaraiosis, we found the sensorimotor Mu rhythm in stroke patients are also affected in performing finger movement task. Since EEG signals are weak (μv) and stochastic, the use of traditional digital filter may be unable to well extract the stochastic sensorimotor rhythms which could result in the pitfall of underestimating subject’s responses. Accordingly, a novel tool, multivariate empirical mode decomposition (MEMD), was adopted in this study to exact the sensorimotor Mu rhythm in human brain. The MEMD decomposes multi-channel EEG into sets of multi-channel intrinsic mode functions (IMF). Each set contains IMFs with similar frequency range across different channels, and each IMF is analytic, band-limited, and self-organized. The superiority of MEMD enables its capability in extracting stochastic signals. This study recruited ten stroke patients and ten leukoaraiosis patients. The stroke patients were asked to continuously perform the self-paced index finger tapping tasks, and the leukoaraiosis patients were asked to perform the movement once seven seconds. Our results demonstrated that the suppressed post-movement beta event-related desynchronizations (post-movement beta ERS) were found both in stroke and leukoaraiosis patients while performing finger movement tasks. It might be expected the measure of post-movement beta ERS could be a plausible index for evaluating patients’ motor function in future clinical applications.

碩士
國立成功大學
電機工程學系碩博士班
95
In the course of studying the Electroencephalogram (EEG), many researches have been using different algorithms to analyze the EEG signals in time- or frequency-domain. The purpose of our research is to find out the characteristics of rhythm on normal and abnormal (ex. epilepsy waves) EEG signals. The abnormal discharge of γ, β, α, θ and δ rhythms can be observed from the characteristics. And it can help the researcher or doctor to discriminate the EEG signals more accurately. In this study, the wavelet transform decomposition is employed to investigate the normal EEG and epilepsy EEG signals. On the basis of property of different EEG signal rhythms, double wavelet transform (DWT) decomposition is used for designing filters with different frequency characteristics to detect the features in power spectrum of different EEG rhythms, which are used to form the dynamic map of brain activity. In order to examine the dynamic characteristics of all sorts of rhythms which were generated by epilepsy patients, two kinds of clinical EEG data from normal person and epilepsy patient are analyzed and compared. The experimental results indicate that when compared with normal person, the γ, β, α, θ and δ rhythms of epilepsy patients are quite different under conscious state without any load.

碩士
國立成功大學
電機工程學系碩博士班
97
Electroencephalogram (EEG) is a kind of physiological signal of the human body. Several research institutions are interested in EEG study, because it has the potential to provide much more unknown information in the human brain. When the EEG reveals abnormal discharges (eg. Epilepsy), abnormal EEG signals can be distinguished by their unusual rhythm powers. Various algorithms have been applied to analyze the EEG signals. In our laboratory, on the basis of property of different EEG signal rhythms, double wavelet transform decomposition was used for designing filters with different frequency characteristics to detect the features in power spectrum of different EEG rhythms, namely α, β, θ and δ rhythms, which are used to form the dynamic map of brain activity. The aim of the present investigation is to implement the algorithm on a digital signal processor (TMS320C6713 DSP, Texas Instruments) for analyzing the distribution of the ratio of the power of rhythms on normal and abnormal EEG signals. The results of this study can be used to help researchers and doctors to analyze the distribution of the rhythm powers and thus identify abnormal EEG signals.

This dissertation explores the neural coding and mechanisms associated with consciousness by analyzing electrical rhythms of the brain under altered states of consciousness, namely epilepsy and anesthesia. First, transformation of neural coding under epileptogenic conditions is examined by computing the Volterra kernels in a rodent epilepsy model, where the epileptogenic condition is induced by altering the concentrations of Mg2+ and K+ of the perfusate for different levels of excitability. Principal dynamic modes (PDMs) are further deduced from the Volterra kernels to compare the changes in neural dynamics under epileptogenic conditions. The integrating PDMs are shown to dominate at all levels of excitability in terms of their relative contributions to the overall response, whereas the dominant frequency responses of the differentiating PDMs shift to higher ranges under epileptogenic conditions, from ripple activities (75 - 200 Hz) to fast ripple activities (200 - 500 Hz). Second, markers of anesthetic states are explored by analyzing amplitude and phase of brain rhythms as well as their interaction and modulation, utilizing electroencephalogram (EEG) recorded from patients undergoing anesthesia. Anesthesia shifts the power to low frequency rhythms, especially alpha rhythms. Additionally anesthesia increases the coupling between alpha rhythms and gamma rhythms while disrupting the coupling between alpha rhythms and ripples (70 - 200 Hz). The results also indicate that the dose responses (i.e. depth of anesthesia) are not necessarily monophasic or linear. The commonality and differences of the changes in brain rhythms associated with these conditions are discussed to elucidate on the possible underlying mechanisms involved in producing consciousness.

Percevoir et synchroniser ses mouvements à une pulsation régulière en musique est une capacité largement répandue chez l’Homme, et fondamentale aux comportements musicaux. La pulsation et la métrique en musique désignent généralement une organisation temporelle périodique perçue à partir de stimuli acoustiques complexes, et cette organisation perceptuelle implique souvent une mise en mouvement périodique spontanée du corps. Cependant, les mécanismes neuraux sous-tendant cette perception sont à l’heure actuelle encore méconnus. Le présent travail a donc eu pour objectif de développer une nouvelle approche expérimentale, inspirée par l’approche électrophysiologique des potentiels évoqués stationnaires, afin d’explorer les corrélats neuraux à la base de notre perception de la pulsation et de la métrique induite à l’écoute de rythmes musicaux. L’activité neurale évoquée en relation avec la perception d’une pulsation a été enregistrée par électroencéphalographie (EEG) chez des individus sains, dans divers contextes : (1) dans un contexte d’imagerie mentale d’une métrique appliquée de manière endogène sur un stimulus auditif, (2) dans un contexte d’induction spontanée d’une pulsation à l’écoute de patterns rythmiques musicaux, (3) dans un contexte d’interaction multisensorielle, et (4) dans un contexte de synchronisation sensorimotrice. Pris dans leur ensemble, les résultats de ces études corroborent l’hypothèse selon laquelle la perception de la pulsation en musique est sous-tendue par des processus de synchronisation et de résonance de l’activité neurale dans le cerveau humain. De plus, ces résultats suggèrent que l’approche développée dans le présent travail pourrait apporter un éclairage significatif pour comprendre les mécanismes neuraux de la perception de la pulsation et des rythmes musicaux, et, dans une perspective plus générale, pour explorer les mécanismes de synchronisation neurale.
The ability to perceive a regular beat in music and synchronize to it is a widespread human skill. Fundamental to musical behavior, beat and meter refer to the perception of periodicities while listening to musical rhythms, and usually involve spontaneous entrainment to move on these periodicities. However, the neural mechanisms underlying entrainment to beat and meter in Humans remain unclear. The present work tests a novel experimental approach, inspired by the steady-state evoked potential method, to explore the neural dynamics supporting the perception of rhythmic inputs. Using human electroencephalography (EEG), neural responses to beat and meter were recorded in various contexts: (1) mental imagery of meter, (2) spontaneous induction of a beat from rhythmic patterns, (3) multisensory integration, and (4) sensorimotor synchronization. Our results support the view that entrainment and resonance phenomena subtend the processing of musical rhythms in the human brain. Furthermore, our results suggest that this novel approach could help investigating the link between the phenomenology of musical beat and meter and neurophysiological evidence of a bias towards periodicities arising under certain circumstances in the nervous system. Hence, entrainment to music provides an original framework to explore general entrainment phenomena occurring at various levels, from the inter-neural to the inter-individual level.
Thèse de doctorat réalisé en cotutelle avec l'Université catholique de Louvain, Belgique (Faculté de médecine, Institut de Neuroscience)

Tese de mestrado integrado, Engenharia Biomédica e Biofísica (Engenharia Clínica e Instrumentação Médica) Universidade de Lisboa, Faculdade de Ciências, 2017
Decoding arm movement trajectory from brain signals would allow motor impaired people to control an arm prosthetic. Studies show that we can estimate a vector that points in the direction of arm movements based on single motor neuron activity - the population vector. This type of recording requires the surgical insertion of electrodes in the cerebral cortex. Although such invasive recordings would offer high spatial resolution, noninvasive recording have the advantage of high temporal resolution and no need for surgery. Researchers have managed to decode movement properties from noninvasive brain signals with similar accuracy as from invasive recordings. But can we find a noninvasive analogous of the population vector, a vector that points in the direction of the arm movement? This was the motivation for this thesis. To approach this question we acquired EEG, EOG and kinematic data from 12 healthy subjects while they performed a rhythmic circular right arm movement. We analyzed the data in the time and frequency domains. In the time domain we explored mainly the data averaged over cycles. We found a pattern that looked as if the potentials in the scalp rotated with the arm. To better visualize this rotation, we fit one dipole per time-stamp in the averaged cycle data of each subject to describe the scalp’s potentials. The dipoles rotated along the cycle for all subjects, most of them in the same direction and plane of rotation, with exception for two subjects whose rotation was opposite and three subjects with a slightly different rotation plan. In the frequency domain, we used the Source Power Comodulation algorithm (SPoC), an algorithm that searches for components whose power correlates with a target variable, in our case, the arm kinematics. By applying this algorithm to 20-24 Hz band-pass filtered data, we found two components per subject, each calculated with different kinematic target variables. The results show components that when applied to the non band-pass filtered data, created signals whose power spectrum highly correlated with the given targets (the average of the absolute correlations being 85.5%). The physiological reason for both these phenomena is not entirely understood. To find the analogous of the population vector there is still a long way to go, and we hope this thesis was a first step towards it.
O cérebro controla direta ou indiretamente todas as ações do corpo humano, entre elas o nosso movimento. O movimento é uma capacidade fundamental ao ser humano e, por essa mesma razão, indivíduos que sofram de incapacidades motoras têm uma redução considerável da sua qualidade de vida. Uma interface cérebro-computador (mais conhecida pelo seu nome em inglês brain-computer interface (BCI)) é um sistema que permite o controlo de dispositivos externos usando sinais cerebrais. Esta tecnologia é particularmente interessante para pessoas com incapacidade motora uma vez que não necessita de input físico e poderia ser usada para controlar uma neuroprótese ou um braço robótico. Existem várias estratégias que possibilitam o controlo destes sistemas, mas para o controlo de uma prótese do braço seria preferível usar uma estratégia natural, que não implicasse uma aprendizagem exaustiva por parte do utilizador. Para esse fim, é necessário descodificar vários parâmetros motores de acordo com a intenção do utilizador, como por exemplo, a direção do braço. A possibilidade de um dia conseguir descodificar sinais cerebrais para o controlo de dispositivos externos já começa a ganhar forma, mas ainda não é possível a um nível suficientemente eficaz. Usando métodos invasivos de aquisição de sinais cerebrais que requerem cirurgia para implantar elétrodos no córtex cerebral, Georgopoulos et al. conseguiram distinguir entre movimentos direcionais (em 8 direções num plano horizontal) em macacos. Nessas experiências criou o conceito de vetor de população (population vector) que é um vetor calculado a partir da atividade de neurónios motores que tem a particularidade de apontar na direção do movimento executado. Já no campo dos métodos de aquisição não-invasivos podemos destacar o eletroencefalograma (EEG) e o magnetoencefalograma (MEG) que adquirem sinais elétricos e magnéticos (respetivamente) com sensores colocados fora do crânio. Vários investigadores usaram estes métodos de aquisição para descodificar sinais cerebrais durante tarefas de movimento direcionais usando regressões lineares em sinais de baixa frequência, e modulações em frequência para sinais na gama dos 50-90 Hz (banda de frequência ϒ) e em frequência mais baixas para os 10-30 Hz (bandas de frequência α e β). Algo que ainda não foi estudado é a possibilidade de encontrar um análogo ao vetor população usando métodos não-invasivos. Este não teria os mesmos princípios do vetor de Georgopoulos, uma vez que nos é impossível inferir a atividade de neurónios singulares em métodos não-invasivos, mas teria o mesmo objetivo: apontar na direção do movimento executado. Para explorar este conceito realizámos aquisição de dados EEG, eletrooculograma (EOG) e dados cinéticos do braço direito de 12 sujeitos saudáveis, enquanto estes executavam um movimento rítmico, circular, no sentido dos ponteiros do relógio num plano vertical à sua frente. Durante a aquisição, os sujeitos focaram o seu olhar numa cruz mostrada através de um monitor colocado a sua frente, de forma a minimizar os movimentos oculares. Adicionalmente, uma divisória foi colocada perto do lado direito da face de cada sujeito impedindo os mesmos de observarem o seu braço enquanto realizavam o movimento requisitado, não obtendo assim qualquer feedback visual do seu membro superior. Os dados cinéticos foram adquiridos com um sensor Kinect para a Xbox 360 que ao longo da experiência localizou as junções do braço direito dos sujeitos. Os dados cinéticos foram filtrados com um passa-banda 0.3-0.8 Hz e, ao longo dos ciclos do braço, os pontos extremos do braço (i.e., os máximos e mínimos nas coordenadas vertical e horizontal) foram anotados nos dados para possibilitar a associação dos sinais cerebrais com a trajetória do braço em cada ciclo. Para cada sujeito os canais EEG ruidosos foram interpolados, os dados foram referenciados à média comum de todos os canais, e os sinais foram filtrados numa banda de frequência 0.25-100 Hz e com um filtro tapa banda nos 50 e nos 100 Hz, este último para rejeitar o ruído de fundo. Os sinais de EEG e EOG foram separados em épocas conforme a posição do braço, sendo que cada época passou então a consistir num ciclo do braço completo que começa no ponto mais alto da coordenada vertical. Cada época foi depois temporalmente distorcida para que todas tivessem a mesma duração. As épocas com artefactos foram rejeitadas da análise usando métodos automáticos de rejeição. Independent Component Analysis (ICA) foi utilizada para identificar e posteriormente rejeitar componentes independentes referentes a movimentos musculares e oculares. Por fim, os dados foram explorados em ambos os domínios de tempo e frequência. No domínio do tempo, estudámos mais especificamente a média das épocas de EEG e EOG durante os ciclos do braço. Uma vez que sinais não-invasivos são muito sujeitos a ruído, a média elimina artefactos singulares e acentua os sinais que aparecem constantemente nos dados. Os sinais do ciclo médio mostraram um padrão interessante para todos os sujeitos; um comportamento rotacional ao longo da rotação do braço direito. Para acompanhar a rotação dos potenciais, procurámos por um dipolo que descrevesse a distribuição topográfica a cada ponto do tempo. A rotação dos potenciais do EEG ao longo do ciclo médio foram verificados com a rotação da direção do dipolo ao longo do ciclo. A grande maioria dos sujeitos obteve um dipolo a rodar no mesmo sentido no mesmo plano (segundo a regra da mão direita, com um vetor de rotação a apontar para a zona frontal esquerda do cérebro). Cinco sujeitos foram a exceção, 2 desses cujo dipolo rodava no sentido contrário, e os restantes 3 sujeitos cujo dipolo rodava no mesmo sentido, mas num plano ligeiramente diferente. Em todos os sujeitos o dipolo ajustado rodava, de forma relativamente uniforme. No domínio da frequência, estudámos em particular a banda de frequência dos 20 aos 24 Hz. Escolheuse esta banda de frequência pois demonstrou os resultados mais interessantes e já tinha sido utilizada em estudos prévios. Usámos um algoritmo chamado SPoC (Source Power Comodulation) que encontra componentes de atividade cerebral cuja amplitude em frequência correlacione com uma variável alvo. Como variável alvo usámos os dados cinéticos do braço direito, e como input os dados cerebrais filtrados por um filtro passa-banda (20-24 Hz). Os resultados traduziram-se numa série de componentes cuja amplitude correlacionava ou anti-correlacionava com o movimento do braço, muitas delas com projecções topográficas consistentes com as áreas cerebrais motoras. Encontraram-se algumas semelhanças entre os padrões de ativação das componentes do SPoC dos vários sujeitos, ainda que os resultados variassem entre cada um. Ao projetar as componentes aos dados não-filtrados pelo passa-banda, verificamos que as modelações em frequência de facto correlacionam com as variáveis-alvo como esperado, com uma média da norma das correlações de todos os sujeitos a 85,5%. No domínio temporal, ainda que recorrendo à média de todos os ciclos (épocas), este é o primeiro estudo que demonstra de forma não-invasiva, a existência de um dipolo com comportamento rotacional ao longo da rotação do braço. Para o seu uso em tecnologias de BCI, é necessário encontrar o mesmo fenómeno em épocas únicas, tornando possível uma classificação em single-trial e em tempo real. No que toca aos resultados no domínio da frequência, a procura por componentes cuja fonte poderia estar envolvida na criação do movimento circular foi também bem-sucedida. Este estudo abriu portas para uma série de investigações futuras. Para trabalhos posteriores destaco a necessidade de uma análise estatística, de usar mais do que um dipolo para descrever a distribuição de potenciais no domínio temporal, de explorar os dados em cada movimento e não apenas a sua média, e de explorar paradigmas semelhantes durante o movimento do braço esquerdo. Os resultados desta tese serviram, portanto, como primeiro passo na direção de encontrar o análogo não-invasivo do vetor de população.

Difficulty understanding speech in background noise is the most common hearing complaint. Elucidating the neurophysiological mechanisms underlying speech intelligibility in everyday environments with multiple sound sources and distortions is hence important for any technology that aims to improve real-world listening. Using a combination of behavioral, electroencephalography (EEG), and computational modeling experiments, this dissertation provides insight into how the brain analyzes such complex scenes, and what roles different acoustic cues play in facilitating this process and in conveying phonetic content. Experiment #1 showed that brain oscillations selectively track the temporal envelopes (i.e., modulations) of attended speech in a mixture of competing talkers, and that the strength and pattern of this attention effect differs between individuals. Experiment #2 showed that the fidelity of neural tracking of attended-speech envelopes is strongly shaped by the modulations in interfering sounds as well as the temporal fine structure (TFS) conveyed by the cochlea, and predicts speech intelligibility in diverse listening environments. Results from Experiments #1 and #2 support the theory that temporal coherence of sound elements across envelopes and/or TFS shapes scene analysis and speech intelligibility. Experiment #3 tested this theory further by measuring and computationally modeling consonant categorization behavior in a range of background noises and distortions. We found that a physiologically plausible model that incorporated temporal-coherence effects predicted consonant confusions better than conventional speech-intelligibility models, providing independent evidence that temporal coherence influences scene analysis. Finally, results from Experiment #3 also showed that TFS is used to extract speech content (voicing) for consonant categorization even when intact envelope cues are available. Together, the novel insights provided by our results can guide future models of speech intelligibility and scene analysis, clinical diagnostics, improved assistive listening devices, and other audio technologies.

碩士
正修科技大學
資訊工程研究所
105
Due to the increasing of aging population in Taiwan, the incidence of dementia becomes a concern. The treatment of dementia includes drug and non-drug therapy. Music therapy is one of the non-drug therapies. The benefit of the music therapy is that no side effect has been found. As music therapy has been developed in Western countries for many years and widely been used in clinical. In this study, EEG is referred for creating music spectrum by Labview software and converted the messy EEG into rhythm and melody. The slow wave frequency and the fast wave band of EEG have been revealed by PSD (power spectral density) of EEG spectrum. The analysis result shows that the EEG of patients with dementia after music therapy could be feedback modified. The slow wave increases but fast wave decreases in the presents of EEG spectrum. Music can thus be revealed as a good tool for the therapy and diagnosis of dementia as well.

碩士
國立交通大學
電控工程研究所
103
This thesis is aimed to investigate the temporal evolution of spatial microstates of 30-channel Chan-Ding and resting EEG (electroencephalograph). Two different schemes of microstate analysis are developed in this study. The first scheme, CWT-NSAD, is based on spatial distribution of alpha power. The EEG signal is first decomposed into five EEG rhythms (∆, θ, α, β, and γ) by continuous Wavelet Transform (CWT). The percentage of  power is used to identify whether a 0.25-second epoch is α-dominant. For all the -dominant EEG epochs, the feature vectors composed of 30 normalized-to-unity (NU) alpha powers are classified by NSAD (normalized sum of absolute difference) based strategy. The strategy proposed in this thesis successfully classifies the EEG brain mappings of NU alpha powers. Performance of NSAD-based strategy is superior to FCM (fuzzy C-means) clustering. Finally, the classification results can be employed in long-term EEG interpretation and analysis of microstate behaviors. The second scheme, PMC (mass center of peak), directly evaluates the mass center of the brain electrical-potential field constructed for the major peaks of channel Fz. Channel Fz often picks up eye-motion artefacts that cause serious baseline drift. We apply linear regression to EEG baseline-drift correction. After the baseline correction, peak detection is employed to identify the major positive and negative peaks of substantial amplitude. The PMC microstate analysis is conducted on the major peaks. Each instantaneous microstate is quantified by the spatially geometric coordinates of centers of mass evaluated for major positive and negative peaks (positive and negative PMCs). Finally, we may explore the microstate behaviors from the spatial transition of positive and negative PMC in five regions (frontal, left temporal, right temporal, central, and posterior region). In our preliminary results, CWT-NSAD reveals the extraordinarily consistent -power level through the entire Chan-Ding EEG record, particularly in the frontal region. PMC discloses the rapid and frequent microstate transitions between frontal and central regions (68 FC or CF in one minute) in Chan-Ding EEG compared with the resting EEG (46 transitions in one minute). In addition, Chan-Ding positive PMC visits the posterior region (probability of 2.3%) less often than resting PMC (5.3%).

Thesis (Ph. D.)--University of Tennessee, Knoxville, 2001.
Title from title page screen. Document formatted into manuscript-like pagination: xi, 136 leaves : ill. Vita. Includes bibliographical references (leaves 103-112).

碩士
東南科技大學
電機工程研究所
101
The main function of the heart is to pump blood to various parts of the body; it is one of the key components with human organs to maintain normal operation. Electrocardiogram (ECG) recording is a reference to investigate the heart is normal or not. Most conventional electrocardiographs are bulky; it shall be operated by health care professionals and explained by a doctor. ECG machine for home use is getting more popular recently; however most of those machines presented waveform and beat frequency and few of the analysis and determine the abnormal condition. Therefore, this paper attempts to create a precise, lightweight, easy to operate and full-featured ECG measurement system. The main purpose of this paper is development an ECG measurement system with remote synchronization control and analysis of abnormal heart rhythm, including ECG instrument hardware development, and writing software programs to determine abnormal heart rhythm. Unlike conventional 12-lead method, the system uses the hand holding the metal ball and the foot with metal plates to retrieve the ECG, is a 1-lead method. In determine the function of the abnormal heart rhythm, taking sinus P wave and R wave to analyze, and write a software program for heart rhythm abnormalities judgments. In the man-machine interface development, this system uses LabVIEW software as the windows user interface development tools, the interface design were also considering the needs of patients and medical staffs have different functions displayed. In order to make research with practical features, we have normal and abnormal heart rate tests respectively to verify system performance. Experimental results show, this research has the accuracy, easy to use, easy portability and low cost advantages. In addition, considering the future telemedicine care, the system combined with remote WEB function. It not only can be applied to health care institutions or home care, can also provide medical and care staff as a basis for subsequent processing.

碩士
東南科技大學
電機工程研究所
99
Since a long time, most of the research and development of medical electronic equipment focused on the hardware circuit design, the physiological signal acquisition and data transmission, few of the analysis and determine the abnormal condition. In this context, this paper proposed a windowing interface ECG measurement system; this system has to determine the function of sinus rhythm abnormalities, including ECG instrument hardware development, and writing software programs to determine abnormal heart rhythm. Unlike conventional 12-lead method, the system uses the hand holding the metal ball and the foot with metal plates to retrieve the ECG, is a 1-lead method. In determine the function of the abnormal heart rhythm, taking sinus P wave and R wave to analyze, and write a software program for heart rhythm abnormalities judgments. In the man-machine interface development, this system uses LabVIEW software as the windows user interface development tools, the interface design were also considering the needs of patients and medical staffs have different functions displayed. In order to make research with practical features, we have normal and abnormal heart rate tests respectively to verify system performance. Experimental results show, this research has the accuracy, easy to use, easy portability and low cost advantages. It not only can be applied to health care institutions or home care, can also provide medical and care staff as a basis for subsequent processing.

The aim is to determine the importance of photoperiod for oviposition of Peruphasma schultei. The theoretical part covers common description of the reproduction and embryonic development of phasmid. Included the climatic factors affecting physiological action and brief description of the biological clock of insects. Experimental individuals were are kept in three different photoperiods with constant temperature of 25 °C. Control and collection of eggs ran at intervals of two hours. It was shown the influence of photoperiod, time and their interaction on the number of eggs and imposed the difference in putting across time.