Real-time simulation of complex audio-visual scenes remains challenging due to the technically independent but perceptually related rendering process in each modality. Because of the potential crossmodal dependency of auditory and visual perception, the optimization of graphics and sound rendering, such as Level of Details (LOD), should be considered in a combined manner but not as separate issues. For instance, in audition and vision, people have perceptual limits on observation quality. Techniques of perceptually driven LOD for graphics have been greatly advanced for decades. However, the concept of LOD is rarely considered in crossmodal evaluation and rendering. This thesis is concentrated on the crossmodal evaluation of perception on audiovisual LOD rendering by psychophysical methods, based on that one may apply a functional and general method to eventually optimize the rendering. The first part of the thesis is an overview of our research. In this part, we review various LOD approaches and discuss concerned issues, especially from a crossmodal perceptual perspective. We also discuss the main results on the design, rendering and applications of highly detailed interactive audio and graphical scenes of the ANR Topophonie project, in which the thesis took place. A study of psychophysical methods for the evaluation on audio-visual perception is also presented to provide a solid knowledge of experimental design. In the second part, we focus on studying the perception of image artifacts in audio-visual LOD rendering. A series of experiments was designed to investigate how the additional audio modality can impact the visual detection of artifacts produced by impostor-based LOD. The third part of the thesis is focused on the novel extended-X3D that we designed for audio-visual LOD modeling. In the fourth part, we present a design and evaluation of the refined crossmodal LOD system. The evaluation of the audio-visual perception on crossmodal LOD system was achieved through a series of psychophysical experiments. Our main contribution is that we provide a further understanding of crossmodal LOD with some new observations, and explore it through perceptual experiments and analysis. The results of our work can eventually be used as the empirical evidences and guideline for a perceptually driven crossmodal LOD system.

This study aims at explaining the significance of the &ldquo / field&rdquo / concept in contemporary architecture and urbanism, in reference to the technical definitions of the term in different disciplines. In this context, it investigates the concepts of &ldquo / field&rdquo / in physics, psychology, art theory and criticism. It highlights the reinterpretation of the &ldquo / field&rdquo / concept in physics by eminent Gestalt psychologists, and its consequences for architecture and urbanism. Starting from the definitions of the concept of &ldquo / field&rdquo / by Kurt Koffka and Kurt Lewin, and from the Gestalt Theory that constitutes the basis of these definitions, it brings into discussion a group of related notions that have been employed in art and architectural theory and criticism: &ldquo / psychophysical field,&rdquo / &ldquo / psychological life space,&rdquo / &ldquo / figure-ground,&rdquo / &ldquo / figure-field,&rdquo / and &ldquo / field-field.&rdquo

Il est courant de faire remonter l’origine du «problème corps-esprit» à Descartes et à sa distinction radicale des substances pensante et étendue. La question est bien connue : comment l’esprit, n’étant pas corporel, pourrait-il agir sur le corps et le mouvoir, et comment le corps pourrait-il agir en retour sur l’esprit, en causant ses sentiments et ses passions ? Si Descartes ne voyait là aucune difficulté qui aurait mérité d’abandonner la distinction des substances, ou au contraire la thèse d’une interaction causale réelle entre l’esprit et le corps, tel n’aura pas été le cas de ses lecteurs et interprètes. Ces derniers n’ont eu de cesse de faire valoir l’incohérence de son «dualisme interactionniste», souvent invoquée pour rendre compte de l’abandon, à l’âge classique, des relations causales entre l’esprit et le corps, et à l’époque contemporaine, du dualisme des substances au profit d’une ontologie physicaliste. Dans ce travail, nous revenons sur les difficultés engendrées par le cartésianisme concernant les rapports de l’esprit et du corps, en combinant trois perspectives qui associent réceptions classiques et contemporaines : celle des premiers objecteurs de Descartes ; celle de ses successeurs cartésiens, en s’intéressant à leur traitement de la difficulté liée à l’interaction âme-corps ; et celle des philosophes de l’esprit contemporains, dans le cadre de leur réflexion autour du Mind-body problem. Les problèmes philosophiques ainsi mis au jour sont utilisés pour relire les thèses de Descartes et proposer une nouvelle évaluation des doctrines sur la base des phénomènes psychophysiques qu’elles permettent ou non d’expliquer. / It is common to trace back the origin of the “mind-body problem” to Descartes and to his radical distinction between extended and thinking substance. The question is well known: how can the immaterial mind act on the body and move it, and how can the body, in turn, act on the mind by causing its feelings and passions? While Descartes did not regard this as the source of any difficulties that might have necessitated the rejection of the distinction between substances or, inversely, of the theory of real causal interaction between mind and body, his readers and interpreters did. They constantly insisted on the inconsistency of his “interactionist dualism,” which is often invoked as a reason for discarding the theory of causal relation between mind and body in the classical period, and for replacing substance dualism with a physicalist ontology in the contemporary period.In this work, we return to the difficulties generated by Cartesian philosophy about the relationship between mind and body from three interrelated perspectives, which combine classical and contemporary receptions of Descartes: that of the first objectors to Descartes; that of his successors, with special consideration of their treatment of the difficulties involved in explaining mind-body interaction; and that of contemporary philosophers of mind, whose reflections on the mind-body problem are examined. Our approach to the philosophical issues thus brought to light allows us to revisit Descartes’s theses, and to propose a new evaluation of the doctrines on the basis of the psychophysical phenomena that they are capable of accounting for or not.

Made available in DSpace on 2015-05-14T13:16:34Z (GMT). No. of bitstreams: 1 arquivototal.PDF: 1526331 bytes, checksum: 38e40aec6b111371aebd1a5cba081a3c (MD5) Previous issue date: 2009-04-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Epilepsy is a brain dysfunction characterized by the repeated tendency of the brain to cause epileptic crisis and by the neurobiological, cognitive, psychological and social consequences of this condition. In these terms, the aim of this work is to determine the visual sensory threshold of children and adolescents who have and who do not have epilepsy, analyzing possible alterations in the form related to this dysfunction. The sensory threshold is defined as the smallest intensity of incentive a human being is capable of detecting. The contrast sensitivity function (CSF) is the inverse of the threshold curve of contrast (1/CSF). This way, the CSF is a tool that allows us to label the answer of SV to visual patterns in low, medium and high levels of contrast and evaluate possible sensorial alterations associated with the visual processing. The main idea is that the elevation or reduction of the CSF can happen deem to sensorial, cognitive and behavioral alterations. Twenty volunteers participated on this study, from both genders, between 7 and 17 years of age, 10 of whom nonepileptic and 10 epileptic (tonic-clonic crisis). All of them presented either normal or corrected visual accuracy and were distributed in groups that were equivalent in age. The resolutions were taken from the psychophysical forced-choice method, using the static sine wave gratings with spatial frequencies of 0.25, 2.0 and 8.0 cpd (cycles per degree of visual angle). During each experimental session, there were stimulus pares presented randomly (test stimulus and neutral), and the task of the participants was to choose always the test stimulus with one of the frequencies above. The criterion used was the one of three consecutive correct answers to low the contrast in one unity and just one mistake to increase the contrast in the same unity (20%). After each session, a sheet of results with the experimental situation was released and the six values of contrast were calculated by the reversions. The values of contrast obtained to each frequency were grouped in spreadsheets separated by condition (with or without epilepsy) and the big average was used as an estimative of the sensory threshold or of the sensibility to the contrast due to each spatial frequency tested. The analysis of variance (ANOVA) to repeated measures showed significant differences between the groups [F(1,238) = 11.80); p<0.01]. The analysis obtained with the help of the test posthoc Tukey HSD revealed a relevant dissimilarity only in the 0.25cpg (p<0.01)]. In other words, the results indicated an expressive alteration in the visual perception children and adolescents with epilepsy have. / A epilepsia é um distúrbio cerebral caracterizado pela predisposição persistente do cérebro para gerar crises epilépticas e pelas conseqüências neurobiológicas, cognitivas, psicológicas e sociais desta condição. Algumas pesquisas demonstram que distúrbios visuais são bastante freqüentes em pessoas com epilepsia. Nestes termos, o objetivo deste trabalho foi determinar o limiar sensório visual de crianças e adolescentes com e sem epilepsia, verificando possíveis alterações na percepção visual da forma relacionadas a este transtorno. O limiar sensório é definido como a menor intensidade de um estímulo que um ser humano é capaz de detectar. A função de sensibilidade ao contraste (FSC) é o inverso da curva de limiar de contraste (1/FSC). Assim, a FSC é uma ferramenta que permite caracterizar a resposta do SV para padrões visuais em níveis baixos, médios e altos de contraste e avaliar possíveis alterações sensoriais relacionadas ao processamento visual. A idéia principal é que a elevação ou redução da FSC pode está relacionada a alterações sensoriais, cognitivas e comportamentais. Participaram deste estudo, 20 voluntários de ambos os sexos com idades entre 7 e 17 anos, sendo 10 sem epilepsia e 10 com epilepsia (crises tônicoclônicas). Todos apresentavam acuidade visual normal ou corrigida e foram distribuídos pelos grupos atendendo ao critério de equivalência de idade. As medidas foram realizadas com o método psicofísico da escolha forçada, utilizando grade senoidal vertical estática com freqüências espaciais de 0,25; 2,0 e 8,0 cpg (ciclos por grau de ângulo visual). Durante cada sessão experimental, foram apresentados aleatoriamente pares de estímulos (estímulo de teste e neutro), e a tarefa dos participantes foi escolher sempre o estímulo de teste com uma das freqüências acima. O critério adotado foi o de três acertos consecutivos para diminuir o contraste em uma unidade, e apenas um erro para aumentar o contraste na mesma unidade (20%). Após cada sessão, o programa produzia uma folha de resultados com a situação experimental e os seis valores de contraste conseguidos pelas reversões. Os valores de contraste obtidos para cada freqüência foram agrupados em planilhas por condição (com e sem epilepsia) e a grande média foi utilizada como estimativa do limiar sensório ou da sensibilidade ao contraste em função de cada freqüência espacial testada. A análise de variância (ANOVA) para medidas repetidas mostrou diferenças significantes entre os dois grupos [F(1, 238) =11,80); p < 0,01]. Já a análise com o teste post-hoc Tukey HSD revelou diferença significante apenas na faixa de freqüências de 0,25 cpg (p < 0,01). Em termos gerais, os resultados demonstraram alteração significante na percepção visual da forma de crianças e adolescentes com epilepsia.

A fruição estética envolve um processo ativo de percepção visual e interpretação de informação capaz de evocar sensações, emoções, e sentimentos. A estética experimental busca entender como artistas utilizam elementos visuais em suas obras e como esses elementos são processados à nível consciente no indivíduo. Diversos experimentos psicológicos e pesquisas recentes em neuroestética permitiram acesso quantitativo sobre julgamento estético. O presente trabalho realizou dois experimentos psicofísicos que permitiram medir julgamento emocional em obras de arte abstrata. Experimento 1. Objetivo: realizar uma tarefa de ordenamento de obras de arte para adjetivos de emoção. 55 participantes (55% sexo feminino, idade média: 31; SD: 11). Foram calculadas as correlações entre as emoções, podendo compará-las com o modelo circular afetivo, e os resultados se mostraram satisfatórios. Experimento 2. Objetivo: desenvolver uma escala psicofísica utilizando o caso V da lei do julgamento comparativo a fim de estabelecer as distâncias subjetivas dos julgamentos emocionais para obras de arte abstrata. 39 participantes (52% sexo feminino, idade média: 28; SD: 10). A formulação psicofísica feita idealmente para julgamento discriminatório de estímulos físicos simples pôde ser aplicada em julgamento discriminatório subjetivo e de bastante complexidade. O uso do escalonamento psicofísico permitiu um eficiente acesso quantitativo das distâncias dos julgamentos das emoções em cada obra de arte. 10 Espera-se que o trabalho proposto permita, através de uma reconciliação interdisciplinar entre neurociência e psicologia, novas abordagens e métodos livres de vieses subjetivos para o estudo de julgamento estético / Aesthetic appreciation involves a process of visual perception and interpretation capable of evoking sensations, emotions and feelings. Experimental aesthetics seeks to understand how artists use elements in their works and how these elements are processed in the individual in a conscientious level. Several psychological experiments and recent researches in neuroesthetics allowed quantitative access on aesthetic judgment. The present work carried out two psychophysical experiments that allow measuring emotional judgment in works of abstract art. Experiment 1. Objective: to carry out a task of ordering works of art for adjectives of emotion. 55 participants (55% female, mean age: 31; SD: 11). They were calculated as correlations between emotions, being able to compare them with the affective circular model, and the results were satisfactory. Experiment 2. Objective: to develop a psychophysical scale using case V the law of comparative judgment in order to establish as subjective distances from emotional judgments to abstract works of art. 39 participants (52% female, mean age: 28; SD: 10). A psychophysical formulation ideally made for discriminatory judgment of simple physical stimuli was applied in subjective and complex discriminatory judgment. The use of psychophysical scaling allowed an efficient access to the distances of the judgments of the emotions in each work of art. It is expected that the proposed work will allow, through an interdisciplinary reconciliation between neuroscience and psychology, new approaches and methods free of bias for the study of aesthetic judgment.

Název diplomové práce: Mysl a vědomí u zvířat Vedoucí práce: prof. Karel Thein, Ph.D. Vypracovala: Bc. Klaudie Richterová Abstrakt v anglickém jazyce This thesis examines the issue of cognition, mind, and consciousness of living beings other than humans. What complicates the whole issue is the essential inwardness of the conscious experience. We objectivize this inwardness per our aim to know, and thus deprive it of its essence. Thereby, very often, we lose sight of what we want to examine. This problem is related to the theme of speech as a form of communication that plays an ambivalent role here. Speech in the sense of articulated form of communication can easily become a barrier that separates human beings from other living creatures; the so-called less articulated forms of communication may, on the other hand, be an opportunity to overcome this barrier. Part of the thesis thus offers a critical reflection on the scientific research whose focus is on animal abilities, but which forgets to take into account the human element contained in the apparently scientific method. The final part of the thesis deals with modern research of a canine abilities and offers a reflection on the influence of the domestication process on what we call intelligence.

When portraying a character in a fictional world the actor is faced with many challenges. To circumvent these challenges, he must become congruent with the reality of the fictional world. In order to do so, the actor has to ‘believe’ in the circumstances of the unfolding scene and live ‘in the moment’. These external circumstances act as stimuli which the actor uses to create and consequently ‘believe’ in the environment that the character inhabits. However, the use of green screen technology in special effects limits or eliminates these stimuli and the external circumstances. Green screen is a technique used in film and television that allows the filmmaker to film an actor in combination with a green screen and then replace the ‘green’ with anything the filmmaker requires. This allows for compositing to occur and the filmed reality to be manipulated. However, this technology challenges the actor’s ‘belief’ and behaviour, thus affecting congruence with and the (photo)realism of the created fictional world. In a green screen environment the actor is challenged to imagine, experience and act in line with the circumstances of the fictional world that will replace the green screen, instead of the green environment in which he finds himself. One acting strategy that elicits imagination, action and feeling is Stanislavsky’s notion of the magic if. Accordingly, this dissertation proposes that this strategy can assist the actor in circumventing the challenges that arise when working with green screen technology. Stanislavsky developed his acting principles by observing human behaviour in an attempt to use the mind–body paradigm in circumnavigating the acting moment. The field of cognitive neuroscience has also investigated human behaviour and the mind–body paradigm and recent discoveries have increased understanding of the fields. These discoveries have validated the notion of the magic if and the components it incorporates. Yet, the discoveries surrounding the notion of the magic if and, subsequently, the increased understanding of the concept have not to date been applied to acting with green screen technology. It is therefore hypothesised that, by triangulating the challenges of ‘green screen acting’, the principles of the magic if and the knowledge gained from cognitive neuroscience, an acting strategy can be developed that will assist the actor in the green screen environment and thus create verisimilitude with the fictional world. This hypothesis has led to the theoretical development of explorations that will strengthen the skills the actor needs in order to apply the notion of the magic if; as well as an acting strategy to assist the actor when entering the green screen environment. / Dissertation (MA)--University of Pretoria, 2013. / gm2014 / Drama / Unrestricted

Název diplomové práce: Mysl a vědomí u zvířat Vedoucí práce: prof. Karel Thein, Ph.D. Vypracovala: Bc. Klaudie Richterová Abstract This thesis examines the issue of cognition, mind and consciousness of living beings other than humans. It starts with the attitudes of two contemporary thinkers: Thomas Nagel and Daniel C. Dennett. In connection with their opinions, this thesis examines a certain number of questions: Might there be something like a subjective experience of life or being? How can one know that others have mental states that are like one's own? How important is a fact that nonhuman animals cannot describe their mental states in language? Is it possible to connect the observable characteristics of animals (behavioral or neurological) to consciousness? Nagel assumes that individuals have a proprietary perspective on their own perceptual, cognitive and emotive processes. Dennett argues that consciousness is essentially an illusion created by language, which is why he concludes that consciousness is uniquely human. What complicates the whole issue is the essential inwardness of the conscious experience. We objectivize this inwardness per our aim to know, and thus deprive it of its essence. Thereby, very often, we lose sight of what we want to examine.

Sensory feedback possesses the possibility of adding a new dimension to many applications, including, but not limited to, prosthetics and surgical robots for improved control, virtual reality for incorporation of another sense, and phantom limb pain reduction for amputees. Electrotactile stimulation provides a compact, light-weight, energy efficient, highly responsive, and non-invasive option for sensory feedback; however, it has been found to commonly elicit unnatural or uncomfortable sensations for the user. To address this issue, this thesis was designed to test the impact of the different electrotactile stimulus parameters – current amplitude and polarity, pulse width, frequency, and waveform – on the user’s perceived sensation and afferent neural response. The relationship between sensation and neural response was also analysed. The aim of this thesis was to create guidelines to assist in the design and use of electrotactile stimulation. Neural data and matching psychophysical data from one healthy subject and purely psychophysical data from three others were gathered while applying electrotactile stimulations of different parameter combinations on the dorsal side of the hand or lower arm. Significant (p &lt; 0.05) correlations and differences were found in all three relationships between electrotactile stimulus parameters, primary afferent response, and perceived sensation. Current (specifically negative) or pulse width control in monophasic waveforms were deemed most appropriate in applications that relay information through varying intensity. However, monophasic waveforms produced more discomfort, rendering biphasic waveforms more suitable when mild, local, and more natural sensations are of greater importance. Surprisingly, the data also suggested higher sensitivity to positive currents. While lower values of current amplitude and pulse width increased neural spike count, stimulus frequency could reliably control neural firing at all tested frequencies. Spike counts were moderately to strongly correlated with perceived intensity; however, practically identical neural responses could elicit different sensations. High current pulses at low frequencies induced spikes with the shortest latency – but with greater risk of discomfort. Due to limitations in sample size, generalisability is limited, and this thesis should be considered a pilot study to guide future investigations. The results suggest that recording from single and multiple afferent nerve fibres simultaneously would improve the understanding of the neural population response to electrotactile stimuli. Moreover, the one-to-one neural response to electrotactile stimuli raised the question of whether an electrotactile stimulation based on a natural spike pattern could replicate the original sensation. A future study testing this hypothesis may find a new approach to designing painless electrotactile stimulations for sensory feedback use. / Sensorisk återkoppling har möjlighet att drastiskt förbättra många användningsområden, t.ex. genom att bidra till enklare kontroll av proteser och kirurgiska robotar, mer verklighetstrogna VR-spel, och minskade fantomsmärtor hos patienter med amputeringar. Elektrisk hudstimulering erbjuder ett kompakt, lätt, energisnålt, hög-responsivt och icke-invasivt alternativ för sensorisk återkoppling – dock framkallar denna metod ofta onaturliga och obehagliga förnimmelser för användaren. Detta examensarbete bemöter detta problem genom att undersöka effekten av stimuleringsparametrar som strömstyrka, pulsbredd, frekvens och vågform på försökspersonens upplevda förnimmelse samt den afferenta nervresponsen. Även relationen mellan förnimmelse och nervrespons analyserades. Examensarbetets ändamål var att skapa riktlinjer för att förenkla designen och användandet av elektrisk hudstimulering. Nervdata med matchande psykofysiska data samlades från en frisk försöksperson, samt enbart psykofysiska data från tre andra, under olika elektriska hudstimuleringar (med varierande parametervärden) på handens dorsala sida eller på underarmen. Signifikanta (p &lt; 0.05) korrelationer och skillnader fanns i alla tre relationer mellan parametrarna för elektrisk hudstimulering, primärafferent respons och upplevd förnimmelse. Kontroll av ström (i synnerhet negativ) eller pulsbredd i monofasisk vågform visade sig vara mest fördelaktigt i applikationer där information kommuniceras till användaren genom att variera den upplevda intensiteten. Dock skapade denna vågform mer obehag, och bifasiska vågformer bedömdes mer passande då milda, lokala, och mer naturliga förnimmelser är av högre värde. Positiv ström upplevdes, förvånande, starkare än negativ. Vid låga värden på ström och pulsbredd var dessa faktorer viktiga gällande antalet aktionspotentialer (AP), men stimuleringsfrekvensen kunde kontrollera antalet AP vid alla frekvenser. Mängden AP var måttligt till starkt korrelaterad med upplevd intensitet – samtidigt kunde praktiskt taget identiska nervresponser vara kopplade till olika förnimmelser. Lågfrekvent stimulering med hög ström hade kortast latenstid, men högre risk för obehag. P.g.a. lågt antal försökspersoner är generaliserbarheten begränsad och detta examensarbete bör beaktas som en förstudie för att guida framtida forskning. Resultaten från denna studie antyder att en tydligare bild av populationsresponsen skulle kunna skapas genom samtidig läsning av ett flertal enskilda nervfibrer samtidigt. Det faktum att varje stimulering kunde ge upphov till en AP väckte frågan: kan ett stimuleringsmönster baserat på en naturlig nervrespons återskapa den ursprungliga förnimmelsen? En studie som testar denna hypotes har möjligheten att finna ett nytt tillvägagångssätt för att skapa smärtfri elektrisk hudstimulering för sensorisk återkoppling.

The Meisner Technique emerged as a part of the realist, modern theatre of the early-Twentieth Century and extended its influence through the rest of that century, including the 1960s and 1970s when there was an explosion of various forms of postmodern performance. This work will demonstrate that while Meisner’s Technique is a part of the paradigm of modern, realist theatre, it simultaneously challenges this ideology with disruptive processes of the sort that postmodern performance instigates. It is the thesis of this work that the Meisner Technique operates according to a set of phenomenologically-aligned imperatives that create strong resonances with certain forms of postmodern performance. This establishes the dynamic wherein the Meisner Technique is able to enter into discourse with instances of the postmodern paradigm of performance. In the first three chapters I will conduct in-depth analyses of Meisner actors’ relationships with their environment, their fellow performers, and their actions from a range of phenomenological perspectives. In the fourth chapter I will apply the conclusions of these analyses to the operation of the Meisner Technique within the paradigm of modern, realist theatre. In the fifth chapter I will set a backdrop to the postmodern field and suggest the issues from this tradition with which the Meisner Technique might resonate. Chapters Six, Seven, and Eight each take one example of an artist from the postmodern field, Richard Foreman, Michael Kirby, and Robert Wilson respectively, establishes their own particular context, and suggests those processes relating to acting/performing technique that might provoke the most productive exchanges. This juxtaposition suggests the places between the practices where discourse might take root and suggests the beginnings of such dialogues.