Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 121-136).

Thesis (Ph. D.)--University of Texas at El Paso, 2009. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (Ph. D.)--University of California, San Diego, 2009. / Title from first page of PDF file (viewed September 16, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.

Thesis--University of Jyväskylä, 1997. / Added t.p. with thesis statement inserted.

Thesis (Ph.D.)--University of Delaware, 2005. / Principal faculty advisor: Hoffman, James E., Dept .of Psychology. Includes bibliographical references.

Thesis (PhD) - Swinburne University of Technology, Brain Sciences Institute, 2008. / A thesis submitted for the degree of Doctorate of Philosophy, Brain Sciences Institute, Swinburne University of Technology - 2008. Typescript. Includes bibliographical references (p. 98-133)

Event related potentials (ERPs) are obtained from noninvasive electroencephalograms (EEG) which measure neuronal activity of brain on the scalp. However, conventional ERPs derived by averaging of single EEG trials have strong latency variability and are smeared, resulting in blurred scalp topography, especially in late components of ERP. The smearing problem had been addressed by reconstructing ERPs after latency correction with a new EEG analysis method Residue Iteration Decompo¬sition (RIDE), which was demonstrated in a face priming paradigm to improve distinctness in scalp topography (Ouyang et al., 2011). This thesis aims to (1) extend the benefits of RIDE to neural source space by localizing the neural generators of ERPs, thereby developing an integrated RIDE framework for improvement in source localization and causal modeling of effective source networks, and (2) apply the framework to the face priming paradigm for famous faces, to explore the dynamics of face processing and priming. We localized sources through brain electrical source analysis for both conventional ERP and RIDE derived ERPs (RERPs). RERPs allowed localization of an additional motor execution source (Premotor Cortex, PMC), apart from 5 other common sources, of which 2 (Occipital Lobe, OL; Fusiform Gyrus, FG) were obtained from early activity (< 250 ms) and 3 (Mediotemporal lobe, MTL; Prefrontal Cortex, PFC; Anterior Temporal Lobe, ATL) from late activities (> 250 ms) of RERPs respectively. Priming effects, i.e., the difference between primed famous (PF) and unprimed famous (UF) face conditions in source waveforms (SWFs), were extended and enhanced in RERPs, especially for late sources. The priming effects revealed (1) the role of sources in each hemisphere that play in perception, memory and execution, (2) parallel processing of information in sources, (3) early processing in the right hemisphere, and (4) predominance of the right hemisphere in face recognition. Results confirmed SWFs of RERPs as better choice for the dynamic causal model (DCM). Two candidate DCM models, forward (F) and forward-backward (FB) were outlined on each hemisphere with SWFs from PF and UF conditions of RERP data. Priming has tendency to facilitate the FB model in the left hemisphere. On the other hand, independent of model preference, priming strengthened a bidirectional connection between FG and PFC in both hemispheres; this indicates a strong role of FG in structural representation and of PFCs in controlling decisions about face familiarity. Priming modulates the pathway FGMTLPFC differently in the two hemispheres, strengthening the involvement of MTL in the left hemisphere and weakening in the right hemisphere. This indicates proficiency of the left and right MTL in processing different aspects of facial information. Further, a backward connection ATLPFC in the left hemisphere was found to be functionally relevant for both conditions in speeding up response time in individual subjects, reinforcing the role of PFC in executive functioning and ATL in naming of famous faces. Thus, an integrated framework of source localization and DCM with RERPs allows a novel, comprehensive understanding of time resolved dynamics in face recognition and priming, thereby piloting prospects of its application to other experimental paradigms.

Proprioception is an ability to perceive the position and speed of body parts that is important for construction of the body schema in the brain. Proper updating of the body schema is necessary for appropriate voluntary movement. However, the mechanisms mediating such an updating are not well understood. To study these mechanisms when the body part was at rest, electroencephalography (EEG) and evoked potentials studies were employed, and when the body was in motion, kinematic studies were performed. An experimental approach to elicit proprioceptive P300 evoked potentials was developed providing evidence that processing of novel passive movements is similar to processing of novel visual and auditory stimuli. The latencies of the proprioceptive P300 potentials were found to be greater than those elicited by auditory, but not different from those elicited by the visual stimuli. The features of the functional networks that generated the P300s were analyzed for each modality. Cross-correlation networks showed both common features, e.g. connections between frontal and parietal areas, and the stimulus-specific features, e.g. increases of the connectivity for temporal electrodes in the visual and auditory networks, but not in the proprioceptive ones. The magnitude of coherency networks showed a reduction in alpha band connectivity for most of the electrodes groupings for all stimuli modalities, but did not demonstrate modality-specific features. Kinematic study compared performances of 19 models previously proposed in the literature for movements at the shoulder and elbow joints in terms of their ability to reconstruct the speed profiles of the wrist pointing movements. It was found that lognormal and beta function models are most suitable for wrist speed profile modeling. In addition, an investigation of the blinking rates during the P300 potentials recordings revealed significantly lower rates in left-handed participants, compared to the right-handed ones. Future work will include expanding the experimental and analytical methodologies to different kinds of proprioceptive stimuli (displacements and speeds) and experimental paradigms (error-related negativity potentials), and comparing the models of the speed profiles produced by the feet to those of the wrists, as well as replicating the observations made on the blinking rates in a larger scale study.

Made available in DSpace on 2015-07-22T20:50:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-24 / Objetivo: Padronizar as respostas do Potencial Evocado Auditivo de Tronco Encefálico por meio de um novo equipamento desenvolvido no Brasil. Métodos: Análise das latências absolutas, interpicos e das amplitudes das ondas I e V, utilizando um novo equipamento desenvolvido para estudar o grupo experimental 1 (76 indivíduos normo-ouvintes); análise do PEATE no equipamento padrão ouro do mercado EP15 / Interacoustis nos grupos ouro 1 (15 indivíduos normo-ouvintes) e ouro 2 (15 indivíduos com perda auditiva neurossensorial); análise do PEATE no novo equipamento desenvolvido no mesmo indivíduo do grupo ouro 1 para estudar o grupo experimental 2 e no mesmo indivíduo do grupo ouro 2 para estudar o grupo experimental 3, para possibilitar a análise da efetividade do teste com o novo equipamento. O estímulo utilizado para a obtenção das respostas evocadas foi o clique não filtrado, com duração de 100 μs, num total de 2.000 estímulos, na polaridade negativa (rarefeita) a uma frequência de estimulação de 13,1 cliques/s, na intensidade de 80 dB nNA, com um período de análise de 10 milissegundos e filtro passa-banda configurado entre 100 e 3000Hz. Os dados foram analisados estatisticamente considerando um nível de significância de 0,05. Resultados: As médias das latências absolutas e interpicos encontradas no novo equipamento desenvolvido foram: onda I=1,50, III=3,57, V=5,53, I-III=2,06, III-V=1,96 e I-V=4,02. Ao separar os dados por gênero houve diferença estatisticamente significante para as latências absolutas das ondas III (p=0,000) e V (p=0,000) e nos interpicos I-III (p=0,007) e I-V (p=0,001). O valor médio da amplitude da onda I foi 0,384 μV e da onda V foi 0,825 μV. Não existiu diferença estatisticamente significante ao se comparar as latências absolutas e interpicos entre dois equipamentos no mesmo indivíduo, normo-ouvinte e com perda auditiva neurossensorial. Conclusões: Os componentes do Potencial Evocado Auditivo de Tronco Encefálico mensurados com o novo equipamento em adultos ouvintes normais foram similares quanto às orelhas, com latências menores estatisticamente significantes nas mulheres do que nos homens. As latências do Potencial Evocado Auditivo de Tronco Encefálico no mesmo indivíduo, normo-ouvinte e com perda auditiva neurossensorial com o Novo Equipamento Desenvolvido foram semelhantes às obtidas com o EP15 / interacoustic, padrão ouro do mercado. Nas perdas auditivas de grau leve a moderado o achado mais frequente no PEATE foi a presença das Ondas I, III, V com latências absolutas e interpicos dentro da normalidade. Foram obtidos os valores de referência de normalidade para o PEATE em adultos ouvintes normais. / Objective: To validate responses of the Auditory Brainstem Response (ABR) using a new equipment developed in Brazil. Method: The annalyses of the absolute latencies, inter slopes, and magnitude of the waves I and V, using a new equipment developed to asses the Experimental Group 1 (76 participants with normal hearing). Analysis of the ABR using the gold-standard equipment, EP15/Interacoustis, where performed in Gold Group 1 (15 participants with normal hearing) and Gold Group 2 (15 participants with sensorineural hearing loss). In order to assess the validity of the new equipment, analysis of the ABR were performed using the new equipment with participants of the Gold Group 1 to compare with participants from the Experimental Group 2, and with participants from the Gold Group 2 to compare with participants from the Experimental Group 3. The stimulus used to obtain the evocated responses was a non-filtrated click sound, with a duration of 100 μs and a total of 2,000 stimuli. All stimuli were given in the negative (rarefaction wave) polarities in a stimulation frequency of 13.1 clicks, with an intensity of 80 dB Nan, an interval of 10 milliseconds and a filter band-pass set between 100 and 3000Hz. The results were statistically analyzed considering a significance level of 0.05. Results: The means for the absolute latencies and inter slopes for the specific waves using the new equipment were: I=1.50, III=3.57, V=5.53, I-III=2.06, III-V=1.96 e I-V=4.02. Statistically significant gender differences were observed for the absolute latencies in wave III (p=0,000) and V (p=0,000) as well as for the inter slopes I-III (p=0,007) and I-V (p=0,001). The mean magnitude values for wave I and V were 0.384 μV and 0.825 μV, respectively. No statistically significant differences between the new equipment and the gold-standard were observed when comparing the results for absolute latencies and inter slopes in the same individual (with normal hearing or with sensorineural hearing loss). Conclusions: The components of the ABR assessed in adults with no hearing impairments using the new equipment were similar for both ears, with latencies significantly lower for women than for men. Moreover, the latencies of the ABR in the same individual (either normal or with sensorineural hearing loss) did not differ between the new equipment and the gold-standard equipament. In hearing loss of mild to moderate degree the most frequent finding on the ABR was the presence of Waves I, III, V and absolute latencies and inter slopes within normal limits. The referent values of normality for the ABR were obtained in adults with normal hearing. / TEDE / BV UNIFESP: Teses e dissertações

Objetivo: Caracterizar as respostas do Mismatch Negativity (MMN) em crianças com limiares auditivos dentro dos padrões de normalidades e sem queixas auditivas. Métodos: Estudo do tipo transversal. Participaram desta pesquisa crianças de cinco a onze anos, sem queixas auditivas. Todos os participantes realizaram avaliação audiológica periférica com medidas de imitância acústica, audiometria tonal e audiometria vocal previamente à realização do MMN. Para a execução do procedimento eletrofisiológico, MMN, foi utilizado o equipamento Masbe ATC Plus da marca Contronic. Os eletrodos foram fixados nas posições Fpz (eletrodo ativo), M1 e M2 (eletrodos referência) e na fronte (eletrodo terra). A intensidade utilizada para evocar o potencial foi de 80 dBNA, o estímulo frequente utilizado foi de 1.000 Hz e o estímulo raro de 2.000 Hz. Os estímulos foram apresentados em ambas as orelhas de modo monoaural. As crianças realizaram a avaliação sentadas e foram condicionadas a assistirem a um vídeo sem som, no tablet, enquanto o procedimento era realizado. Resultados: Para o grupo feminino, a média das latências e amplitudes foi de 177,3 ms e 5,01 μV na orelha direita e de 182,4 ms e 5,39 μV na orelha esquerda. Quanto ao grupo masculino, a média das latências foi de 194,4 ms na orelha direita e 183,6 ms na orelha esquerda, com amplitude de 5,11 μV na orelha direita e 5,83 μV na orelha esquerda. Não houve diferença estatisticamente significante nos valores de latência e amplitude entre orelhas (p=0,867 e p=0,178), idade (p>0,20) e sexo dos participantes (p>0,05). Conclusão: Os valores encontrados nas latências e amplitudes do potencial MMN são semelhantes aos observados na literatura científica compulsada, em crianças com desenvolvimento típico e sem queixas auditivas. / Aim: To characterize the answers of Mismatch Negativity (MMN) in children with hearing thresholds within the normality patterns and without auditory complaints. Methods: Transversal type study. Children between 5 and 11 years old without auditory complaints have participated in this research. All the participants have done peripheral audiological evaluation with acoustic immittance measures, tonal audiometry and vocal audiometry previously to MMN execution. To perform the electrophysiological procedure, MMN, it was used Masbe ATC Plus equipment from Contronic brand. The electrodes were fixed in Fpz (active electrode), M1 and M2 (reference electrodes) and front (earth electrode) positions. The intensity used to evoke the potential was 80 dBNA, the frequent stimulus used was 1.000 Hz and the rare stimulus was 2.000 Hz. The stimuli were presented in both ears monoaurally. Children performed the assessment sat and they were conditioned to watch a video without sound, on a tablet computer, while the procedure was performed. Results: For the female group, the average of the latencies and amplitudes was 177,3 ms and 5,01 μV for the right ear and 182,4 ms and 5,39 μV for the left ear. Regarding the male group, the average of latencies was 194,4 ms for the right ear and 183,6 ms for the left ear, with an amplitude of 5,11 μV for the right ear and 5,83 μV for the left ear. There was no significant statistically difference for the values of latency and amplitude among ears (p=0,867 and p=0,178), age (p>0,20) and gender of the participants (p>0,05). Conclusion: The values found in the latencies and amplitudes of MMN potential are similar to those observed in the scientific literature examined, in children with typical development and without auditory complaints.