Dissertations / Theses on the topic 'Visual pathways'
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Nicholas, Julian Jesuratnam. "Information processing in #parallel' visual pathways." Thesis, University of Oxford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386633.
Full textGillett-Cooper, Anita M. "Development and degeneration in visual pathways." Thesis, University of Oxford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670398.
Full textMaeda, Satomi. "Attentional Limitations and the Visual Pathways." Wright State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=wright1244773263.
Full textLaBonte, Christopher Edward. "Visual pathways and specific reading disabilities /." Digital version accessible at:, 2000. http://wwwlib.umi.com/cr/utexas/main.
Full textCardin, V. Maria de la Paz. "The form pathways in the visual brain." Thesis, University College London (University of London), 2008. http://discovery.ucl.ac.uk/1444134/.
Full textMahajan, Supriya M. "Do visual pathways for action and perception respond differently to the Ebbinghaus Illusion? /." Connect to online version, 2006. http://ada.mtholyoke.edu/setr/websrc/pdfs/mhc/2006/182.pdf.
Full textCecere, Roberto <1981>. "Residual visual processing following real or virtual lesions to primary visual pathways." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5896/1/Cecere_Roberto_tesi.pdf.
Full textUna lesione alla via visiva primaria (genicolo-striata) causa cecità nel campo visivo controlesionale. Ciononostante, studi precedenti suggeriscono che, mediante vie visive alternative che non coinvolgono la corteccia striata, i pazienti con deficit di campo visivo potrebbero ancora riuscire ad elaborare implicitamente la valenza affettiva degli stimoli emotivi non visti (affective blindsight) e di sfruttare meccanismi multisensoriali (audio-visivi), cosicchè la stimolazione uditiva migliori la detezione visiva di stimoli non percepiti quando presentati da soli (crossmodal blindsight). Nella presente tesi si sono indagate l’elaborazione emotiva implicita e l’integrazione multisensoriale osservabili quando l’elaborazione visiva cosciente è impedita da lesioni reali o virtuali della via genicolo-striata, in modo da chiarire sia la natura di tali processi sia gli aspetti funzionali dei circuiti neurali sottostanti. Le evidenze sperimentali qui presentate dimostrano che, in assenza di elaborazione corticale, le vie visive alternative sottocorticali consentono l’elaborazione implicita del contenuto emotivo delle espressioni facciali, ma che tale abilità è limitata alle espressioni di paura. Questo suggerisce l’esistenza di un sistema sottocorticale specializzato nella detezione di segnali di pericolo a partire da segnali visivi grezzi, permettendo dunque il rapido reclutamento di risposte comportamentali di lotta o fuga già prima che possa avvenire un riconoscimento conscio e dettagliato delle potenziali minacce. Inoltre, la presente tesi estende le conoscenze riguardo ai fenomeni di “crossmodal blindsight”, dimostrando che, a differenza della detezione visiva, la discriminazione di orientamento di linee non può essere migliorata dalla presentazione di suoni quando la corteccia striata non è funzionante. Questo dato suggerisce da un lato che la corteccia striata ha un ruolo causativo nel miglioramento “cross-modale” della sensibilità visiva all’orientamento e, dall’altro, che le vie visive sottocorticali che non coinvolgono la corteccia striata, anche se permettono l’integrazione di segnali audio-visivi e il miglioramento della semplice detezione, non possono potenziare abilità visive complesse, come la discriminazione di orientamento
Cecere, Roberto <1981>. "Residual visual processing following real or virtual lesions to primary visual pathways." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5896/.
Full textUna lesione alla via visiva primaria (genicolo-striata) causa cecità nel campo visivo controlesionale. Ciononostante, studi precedenti suggeriscono che, mediante vie visive alternative che non coinvolgono la corteccia striata, i pazienti con deficit di campo visivo potrebbero ancora riuscire ad elaborare implicitamente la valenza affettiva degli stimoli emotivi non visti (affective blindsight) e di sfruttare meccanismi multisensoriali (audio-visivi), cosicchè la stimolazione uditiva migliori la detezione visiva di stimoli non percepiti quando presentati da soli (crossmodal blindsight). Nella presente tesi si sono indagate l’elaborazione emotiva implicita e l’integrazione multisensoriale osservabili quando l’elaborazione visiva cosciente è impedita da lesioni reali o virtuali della via genicolo-striata, in modo da chiarire sia la natura di tali processi sia gli aspetti funzionali dei circuiti neurali sottostanti. Le evidenze sperimentali qui presentate dimostrano che, in assenza di elaborazione corticale, le vie visive alternative sottocorticali consentono l’elaborazione implicita del contenuto emotivo delle espressioni facciali, ma che tale abilità è limitata alle espressioni di paura. Questo suggerisce l’esistenza di un sistema sottocorticale specializzato nella detezione di segnali di pericolo a partire da segnali visivi grezzi, permettendo dunque il rapido reclutamento di risposte comportamentali di lotta o fuga già prima che possa avvenire un riconoscimento conscio e dettagliato delle potenziali minacce. Inoltre, la presente tesi estende le conoscenze riguardo ai fenomeni di “crossmodal blindsight”, dimostrando che, a differenza della detezione visiva, la discriminazione di orientamento di linee non può essere migliorata dalla presentazione di suoni quando la corteccia striata non è funzionante. Questo dato suggerisce da un lato che la corteccia striata ha un ruolo causativo nel miglioramento “cross-modale” della sensibilità visiva all’orientamento e, dall’altro, che le vie visive sottocorticali che non coinvolgono la corteccia striata, anche se permettono l’integrazione di segnali audio-visivi e il miglioramento della semplice detezione, non possono potenziare abilità visive complesse, come la discriminazione di orientamento
Beaudet, Luc. "Adaptation mechanisms in the salmonid visual system." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0002/NQ32704.pdf.
Full textVierck, Esther, and n/a. "Direct selection by colour for visual encoding." University of Otago. Department of Psychology, 2005. http://adt.otago.ac.nz./public/adt-NZDU20070427.145655.
Full textZhang, Wenjian, and 張文劍. "Magnetic resonance imaging investigation of the auditory and visual functions." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/208023.
Full textpublished_or_final_version
Electrical and Electronic Engineering
Doctoral
Doctor of Philosophy
Parkyn, Daryl Charles. "Visual biology of salmonids with special reference to polarised light sensitivity." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ34280.pdf.
Full textHayduk, Steven J. "Evidence against a transient system deficit in specific reading disability." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=69559.
Full textRitchie, Kay Laird. "Visual attention and awareness : lessons from the damaged and intact brain." Thesis, University of Aberdeen, 2012. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=192179.
Full textRebotier, Thomas P. "Vision and imagery : the role of cortical attractor dynamics /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1998. http://wwwlib.umi.com/cr/ucsd/fullcit?p9908500.
Full textGonzalez, Alvaro J. "Alpha stable human visual system models for digital halftoning." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 58 p, 2007. http://proquest.umi.com/pqdweb?did=1251904881&sid=3&Fmt=2&clientId=8331&RQT=309&VName=PQD.
Full textPerens, Gregory S. "NMDA Receptor-mediated Synaptic Plasticity in Developing Mammalian Visual Pathways." VCU Scholars Compass, 1995. https://scholarscompass.vcu.edu/etd/5246.
Full textLee, Chak-pui Terence. "Unified percepts in three-dimensional space derived from motion in depth or rotation in depth." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/hkuto/record/B37943741.
Full textLee, Chak-pui Terence, and 李澤沛. "Unified percepts in three-dimensional space derived from motion in depth or rotation in depth." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B37943741.
Full textBaldwin, David Hugh. "The role of visual subsystems in Drosophila phototaxis /." Thesis, Connect to this title online; UW restricted, 2000. http://hdl.handle.net/1773/5135.
Full textSzmajda, Brett A. "Subcortical pathways for colour vision /." Connect to thesis, 2006. http://eprints.unimelb.edu.au/archive/00003165.
Full textTypescript. Includes bibliographical references (leaves 95-111).
Zhou, Yi-Xiong. "Responses to envelope patterns in visual cortical neurons." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=41806.
Full textSullivan, Thomas Joseph. "Computational models of feedforward and feedback pathways in the visual cortex /." Diss., Connect to a 24 p. preview or request complete full text in PDF formate. Access restricted to UC campuses, 2006. http://wwwlib.umi.com/cr/ucsd/fullcit?p3236624.
Full textDaniels, Rebecca. "Electrophysiological studies of the visual pathways in Alzheimer's and Parkinson's disease." Thesis, Aston University, 1994. http://publications.aston.ac.uk/14612/.
Full textHathibelagal, Amithavikram Rugvedi. "The role of noise on rod signaling in the visual pathways." Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/122230/1/Amithavikram%20Rugvedi_Hathibelagal_Thesis.pdf.
Full textFung, Chun Him. "A biomimetic active stereo head with torsional control /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?ECED%202006%20FUNG.
Full textMorgan, J. E. "The organization of the retinogenuculate pathways in normal and neonatally enucleated pigmented and albino ferrets." Thesis, University of Oxford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.371563.
Full textPeng, Xiaozhe, and 彭晓哲. "Visual path information on the active control of heading." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B41633817.
Full textPeng, Xiaozhe. "Visual path information on the active control of heading." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B41633817.
Full textRoy, Sujata. "Segregation within afferent pathways in primate vision." Connect to thesis, 2009. http://repository.unimelb.edu.au/10187/4913.
Full textThe spatial, temporal, chromatic and orientation preferences of neurons in the dLGN of the macaque were investigated by electrophysiological methods. The physiological findings of cells with S-cone inputs were compared to cells with opponent inputs from the long and medium wavelength sensitive cones (L-cones & M-cones, respectively). The cells receiving S-cone inputs (blue-yellow or B-Y cells) preferred lower spatial frequencies than the cells with opponent L-cone and M-cone inputs (red-green or R-G cells). Orthodromic latencies from optic chiasm stimulation were measured where possible to distinguish differences in conduction velocity between the cell groups. Although the B-Y cells usually had longer latencies than R-G cells, there wasconsiderable overlap between the cell groups.
The recorded cells were localised through histological reconstruction of dLGN sections stained for Nissl substance. The distribution of B-Y cells within the dLGN was compared to the distribution of R-G cells. The majority of B-Y cells were located within the intercalated koniocellular layers as well as the koniocellular bridges (extensions of the koniocellular layers into the adjacent parvocellular layers). The B-Y cells were also largely segregated within the middle dLGN layers (K3, P3, K4 & P4). The R-G cells were mainly concentrated within the parvocellular layers (P3, P4, P5 & P6) and were evenly distributed throughout the middle and outer layers of the dLGN.
The study also included recordings from the extra-striate middle temporal area (MT) to determine whether a fast S-cone input exists from the dLGN to area MT which bypasses V1. The pattern of cone inputs to area MT neurons was investigated before and during inactivation of V1. The inactivation was done through reversible cooling with a Peltier thermocouple device or focal inactivation with y-amino butyric acid (GABA) iontophoresis. Precise inactivation of V1 to the topographically matching visual fields of the recording sites in area MT revealed a preservation of all three coneinputs in many cells. The subcortical sources of these preserved inputs are discussed with their relevance to blindsight, which is the limited retention of visual perception after V1 damage. Analysis of the latencies of area MT cells revealed a rough segregation into latencies faster or slower than 70 ms. Cells both with and without a significant change in response during V1 inactivation were present in each group. The findings reported in this thesis indicate that some of the preserved inputs in area MT during V1 inactivation may be carried by a direct input from the dLGN which bypasses V1.
Nassi, Jonathan J. "Contributions of early parallel pathways to extrastriate visual cortex in macaque monkey." Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2007. http://wwwlib.umi.com/cr/ucsd/fullcit?p3258528.
Full textTitle from first page of PDF file (viewed June 1, 2007). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
Chatterjee, Soumya. "Early visual pathways in the Macaque monkey : cone contributions and cortical targets /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2004. http://wwwlib.umi.com/cr/ucsd/fullcit?p3144320.
Full textColavincenzo, Justin. "Myelin debris clearance along the goldfish visual paths during Wallerian degeneration." Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=21529.
Full textOliveira, Elaine Aparecida de. "Desenvolvimento e avaliação de uma ferramenta para diagnostico da literacia visual, contextualizada no estudo de vias metabolicas." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314741.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-15T17:08:58Z (GMT). No. of bitstreams: 1 Oliveira_ElaineAparecidade_M.pdf: 4028860 bytes, checksum: 12a75ba90b00d8eded4dc1107cc6168a (MD5) Previous issue date: 2010
Resumo: Representações externas são muito utilizadas no ensino de bioquímica. As vias metabólicas constituem um tipo de representação externa e envolvem habilidades visuais; estão, portanto, intimamente relacionados à literacia visual (capacidade de interpretar imagens). Há uma preocupação crescente em diagnosticar a dificuldade dos estudantes com a bioquímica. Este tipo de diagnóstico é importante para poder propor soluções pedagógicas que possam facilitar o aprendizado. O presente trabalho tem como objetivo descrever o desenvolvimento e a aplicação de um teste informatizado para diagnosticar a literacia visual, relacionada ao estudo de vias metabólicas, de estudantes de cursos das áreas biológica e da saúde. Inicialmente foram desenvolvidos testes piloto com itens (modelos e questões) que contemplavam habilidades visuais para a compreensão de vias metabólicas mais frequentemente representadas em livros didáticos de bioquímica. Os testes piloto foram aplicados em 2007 e 2008 com turmas de graduação de cursos da área biológica e da saúde. Os resultados obtidos serviram de subsídio para que alguns itens fossem reformulados e outros adicionados. Os resultados obtidos foram tratados com uso do modelo de Rasch, tanto no processo de equalização dos testes piloto (para definir os itens do teste final), como para o tratamento dos resultados obtidos com a calibração de itens-respondentes após as aplicações do teste final. Três grupos participaram da aplicação do teste final e compreenderam 79 estudantes distribuídos entre os cursos de educação física (UNICAMP), enfermagem (UNICAMP) e fisioterapia/nutrição (FAJ). A partir dos dados obtidos utilizou-se o processo de calibração de itens-respondentes, proposta pelo modelo de Rasch, obtendo-se a dificuldade dos itens e as habilidades visuais apresentadas pelos grupos. Os resultados observados sugerem que entre as dificuldades apresentadas pelos estudantes no aprendizado de metabolismo pode ser incluída a dificuldade em se compreender as representações externas de vias metabólicas. Essa dificuldade pode ser minimizada com explicações dos modelos antes de se entrar nos conteúdos específicos. O teste produzido permite o diagnóstico de estudantes ou de grupos. A necessidade de desenvolver práticas de visualização para melhorar a compreensão de conceitos bioquímicos pelos estudantes mostrou-se um aspecto importante no estudo de vias metabólicas
Abstract: External representations are used in teaching of biochemistry. The metabolic pathways are a type of external representation and involve visual skills, are therefore closely related to visual literacy (ability to interpret images). There is an increasing concern regarding the diagnosis of students with difficulty to the biochemistry, this type of diagnosis is important to be able to propose solutions that would facilitate learning. This paper aims to describe the development and implementation of a computerized test to diagnose the visual literacy, related to the study of metabolic pathways for undergraduate students enrolled in courses in the biological and health. Initially, pilot tests have been developed with (models and items) that looked visual skills for the understanding of metabolic pathways most often represented in textbooks of biochemistry. The pilot tests were applied in 2007 and 2008 on undergraduate classes of various courses in the biological and health. The results served as a subsidy for some items were reformulated and others added. The results are processed using the Rasch model, both in the process of equalizing the pilot tests (for set of the final test) and for the treatment of the results obtained with calibration of items-respondents the applications for the final test. Three groups participated in the implementation of the final test and included 79 students distributed among the courses of physical education (UNICAMP), nursing (UNICAMP) and physiotherapy/nutrition (FAJ). From the data we used the calibration of items-respondents proposed by Rasch model resulting in the difficulty of items and visual skills presented by the groups. The results suggest that among the difficulties presented by the students in the learning of metabolism may be included the difficulty in understanding the external representations of metabolic maps. This difficulty can be minimized with the explanations of the models before they enter the specific content. The test produced allows the diagnosis of students or groups. The need of developing imagery to improve the understanding of biochemical concepts by students were an important aspect in the study of metabolic pathways
Mestrado
Bioquimica
Mestre em Biologia Funcional e Molecular
Bruce, Freyja Mairi. "Determining the roles of DSCAM and SDK proteins in vertebrate visual system development." Thesis, University of Aberdeen, 2012. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=185643.
Full textGhinescu, Rodica. "A modeling-based approach for investigating multiple processing pathways in simple visual tasks /." free to MU campus, to others for purchase, 2004. http://wwwlib.umi.com/cr/mo/fullcit?p3164509.
Full textSchnell, Bettina. "Structure, Function and Input Pathways of Motion-sensitive Visual Interneurons in Drosophila melanogaster." Diss., lmu, 2010. http://nbn-resolving.de/urn:nbn:de:bvb:19-125189.
Full textDavidson, Miriam. ""Catching time" : pathways to engagement in the elementary classroom through the visual arts." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0019/NQ54391.pdf.
Full textFarivar-Mohseni, Reza. "Object recognition by integration of information across the dorsal and ventral visual pathways." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=21982.
Full textLe cerveau décompose l'informations visuelle en ses composants de forme et de mouvement, et les traite de manière indépendante par deux voies anatomiques distinctes‹l¹information ayant attrait au mouvement et à la relation spatiale par la voie dorsale qui se termine dans le lobe pariétal et l¹information ayant attrait à la forme par la voie ventrale qui se termine dans le cortex inférotemporal. Certaines informations de profondeur, tel que la structure-par-mouvement 3-D (SPM), sont presque entièrement analysées par la voie dorsale; toutefois, les objets décris par la SPM sont aussi reconnus par les voies ventrales. Cette thèse débute par une discussion théorique décrivant la manière dont l¹information de profondeur calculée par la voie dorsale peut contribuer aux machinismes de reconnaissance des objets (voie ventrale). Les résultats des expériences psychophysiques et neuropsychologiques indiquent que l¹information de SPM peut permettre la reconnaissance des objets complexes, même des visages peu familiers, et cela peut constituer un case d¹intégration entre les deux voies indépendantes. De plus, les résultats des expériences neuropsychologiques présentées suggèrent que la perception de forme-par-mouvement 2-D est dissociable de celle de structure par mouvement 3-D. Finalement, par le biais d'imagerie par résonance magnétique fonctionnelle, nous avons démontré que les objets décris par SPM n¹activent pas le même méchanisme cérébral que des photos de ces mêmes objets. Ensemble, les résultats présentés ci-après suggèrent que la reconnaissance des objets visuels peut être distribuée entre les deux voies visuelles.
Kogan, Cary. "The expression of neurofilament protein and mRNA levels in the lateral geniculate nucleus and area V1 of the developing and adult vervet monkey (Ceorcopithicus aethiops) /." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0028/MQ50807.pdf.
Full textXing, Kai, and 邢锴. "Functional magnetic resonance imaging (fMRI) of rodent visual and auditory system." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B47849939.
Full textpublished_or_final_version
Electrical and Electronic Engineering
Master
Master of Philosophy
Ghali, Rodney. "Non-neuronal cell response to axonal damage in the visual paths of goldfish." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=24005.
Full textLowenger, Elizabeth. "Studies of early neural regeneration in the visual system of the goldfish." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66031.
Full textLytle, Grace E. "Effects of various nitric oxide synthase inhibitors on the choroidal and growth responses in emmetropization in chicks /." Adobe Acrobat Reader required to view document, 2008. http://www.neco.edu/library/theses/LytleThesisJune08.pdf.
Full textDurán, Gabriela. "Effects of concurrent task performance on object processing." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2009. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
Full textSvoboda, Hanno. "The role of protein synthesis in branching and synaptogenesis in the visual system." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610032.
Full textMedrado, Ramon Gomes. "Formalização de uma linguagem visual para descrição de sistemas biológicos." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2009. http://hdl.handle.net/10183/27661.
Full textBiological pathways represent interactions between complex chemical entities (proteins, substrates, metabolites, etc.) that occur at the molecular level of cells. The representation and comprehension of biological pathways behavior is the main target of research in the field of Systems Biology. This area investigates the construction of mathematical models that can simulate in silico (computationally) the behavior of biological systems checked in vivo (experimentally). From a computational view point it is clear that such systems are too complex to analyze and describe in an intuitiveway. Models with predictive value are needed, describing the behaviors that are experimentally verifiable. There are some graphical notations to describe biological pathways. Among them, process diagrams have been widely used. A process diagram is essentially a graph in which vertices and edges represent biological components, and there is a graphical notation associated with each element. In this master thesis we give a formal foundation for biological process diagrams, by defining their (concrete and abstract) syntax and semantics using a formalism called graph grammars. We first build a graph called BioProc Graph, describing the meta-model of process diagrams. Instances of this BioProc graph are concrete process diagrams modeling biological pathways. To describe the semantics we proposed a translation of BioProc diagrams to generalized stochastic Petri networks (GSPNs) already widely used in modeling biological processes. The use of graph grammar formalism as a basis for translation enables the syntatic verification to check the valid types that can be defined for each reaction after the simulation of Petri net and before that to explore structural and stochastic properties of the model. In addition it serves as the basis for model evolution proposed. This is relevant because models are often built incrementally to adapt to new requirements and/or include new features.
Carvajal, Carlos. "Dynamic interplay between standard and non-standard retinal pathways in the early thalamocortical visual system : A modeling study." Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0209/document.
Full textUnderstanding the behavior of the retino-thalamo-cortico-collicular (i.e. early) visual system in a natural images situation is of utmost importance to understand what further happens in the brain. To understand these behaviors, neuroscientists have looked at the standard Parvocellular and Magnocellular pathways for decades. However, there is also the non-standard Koniocellular pathway, which plays an important modulating role in the local, global, and intermingled processing carried out to achieve such behaviors. Particularly, the standard motion analysis carried out by the Magno pathway is alternated with rapid reactions, like fleeing or approaching to specific motions, which are hard-wired in the Konio pathway. In addition, studying a fixation task in a real situation, e.g., when a predator slowly approaches its prey, not only involves a motion mechanism, but also requires the use of the Parvo pathway, analyzing, at least, the image contrast. Here, we study in a bio-inspired computational neural model how these pathways can be modeled with a minimal set of parameters, in order to provide robust numerical results when doing a real task. This model is based upon an important study to integrate biological elements about the architecture of the circuits, the time constants and the operating characteristics of the different neurons. Our results show that our model, despite operating via local computations, globally shows a good network behavior in terms of space and time, and allows to analyze and propose interpretations to the interplay between thalamus and cortex. At a more macroscopic scale, the behaviors emerging from the model are reproducible and can be qualitatively compared to human-made fixation measurements. This is also true when using natural images, where just a few parameters are slightly modified, keeping the qualitatively human-like results. Robustness results show that the precise values of the parameters are not critical, but their order of magnitude matters. Numerical instability occurs only after a 100% variation of a parameter. We thus can conclude that such a reduced systemic approach is able to represent attentional shifts using natural images, while also being algorithmically robust. This study gives us as well a possible interpretation about the role of the Konio pathway, while at the same time allowing us to participate in the debate between low and high-roads in the attentional and emotional streams. Nevertheless, other information, such as color, is also present in the early visual system, and should be addressed together with more complex cortical mechanisms in a sequel of this work
Chan, Chuen-wing, and 陳泉榮. "In vivo MRI study of the visual system in normal, developing and injured brains." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B44904769.
Full textpublished_or_final_version
Electrical and Electronic Engineering
Doctoral
Doctor of Philosophy
Darcy, Natasha [Verfasser]. "Effects of stimulus degradation on neural object processing in the two visual pathways / Natasha Darcy." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2020. http://d-nb.info/1206180846/34.
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