O potencial visual evocado (PVE) é um sinal elétrico de baixa intensidade originado no córtex visual em resposta a uma estimulação visual periódica. O potencial visual evocado de varredura é um procedimento de PVE modificado para medir acuidade visual de grades em pacientes pré-verbais e não-verbais. Este biopotencial está imerso em uma grande quantidade de ruído eletroencefalográfico e artefato relacionado ao movimento. A relação sinal-ruído tem um papel dominante na determinação de erros sistemáticos e estatísticos. O propósito deste estudo é apresentar um método baseado na transformada wavelet para filtrar e extrair o potencial evocado visual de varredura. Grades de luminância de onda senoidal moduladas em 6 Hertz foram usadas como estímulo para se determinar os limiares de acuidade. A amplitude e a fase da 2ª. harmônica (12 Hertz) do padrão de resposta foram analisadas usando-se a transformada rápida de Fourier após a filtragem por wavelet. O método da transformada wavelet discreta foi usado para decompor o PVE em coeficientes wavelet, determinando-se quais destes representavam uma atividade significativa. Em um passo seguinte somente os coeficientes relevantes foram considerados, zerando-se os demais e reconstruindo-se, assim, o sinal PVE. Isto resultou na filtragem das demais freqüências que foram consideradas ruído. Simulações numéricas e análises com dados de PVE humanos mostraram que este método forneceu maior relação sinal-ruído quando comparado com o método clássico dos mínimos quadrados recursivo (RLS) e ainda uma análise de fase mais apropriada / Visually evoked potential (VEP) is a very small electrical signal originated in the visual cortex in response to periodic visual stimulation. Sweep-VEP is a modified VEP procedure used to measure grating visual acuity in non-verbal and preverbal patients. This biopotential is buried in a large amount of electroencephalographic noise and movement related artifact. The signal-to-noise ratio (SNR) plays a dominant role in determining both systematic and statistic errors. The purpose of this study is to present a method based on wavelet transform technique for filtering and extracting steady-state sweep-VEP. Counter-phase sine-wave luminance gratings modulated at 6 Hertz were used as stimuli to determine sweep-VEP grating acuity thresholds. The amplitude and phase of the second-harmonic (12 Hertz) pattern reversal response were analyzed using the fast Fourier transform after the wavelet filtering. The wavelet transform method was used to decompose the VEP signal into wavelet coefficients by a discrete wavelet analysis to determine which coefficients yield significant activity at the corresponding frequency. In a subsequent step only significant coefficients were considered and the remaining was set to zero allowing a reconstruction of the VEP signal. This procedure resulted in filtering out other frequencies that were considered noise. Numerical simulations and analyses of human VEP data showed that this method has provided higher SNR when compared with the classical recursive least squares (RLS) method. An additional advantage was a more appropriate phase analysis showing more realistic second-harmonic amplitude value during phase brake

Doctor of Philosophy / Department of Psychological Sciences / Lester C. Loschky / Visual resolution (i.e., blur or clarity) is a natural aspect of vision. It has been used by film makers to direct their audience’s attention by focusing the depth of field such that the critical region in a scene is uniquely clear and the surrounding is blurred. Resolution contrast can focus attention towards unique clarity, as supported by previous eye tracking and visual search research (Enns & MacDonald, 2013; Kosara, Miksch, Hauser, Schrammel, Giller, & Tscheligi, 2002; & McConkie, 2002; Peterson, 2016; Smith & Tadmor, 2012). However, little is known about how unique blur is involved in guiding attention (e.g., capture, repel, or be ignored). Peterson (2016) provided reaction time (RT) evidence that blur is ignored by selective attention when resolution is not task-relevant. Perhaps visual resolution is a search asymmetry where unique clarity can be used to guide selective attention during search, but unique blur cannot guide attention. Yet, perhaps the RT evidence was not sensitive enough with Peterson’s (2016) methodology to observe unique blur capturing or repelling attention. Eye movements (e.g., letter first fixated) may be more sensitive than RT as it measures blur and clarity’s influence on guiding attention earlier in a trial. The current study conducted three experiments that investigated: a) how visual resolution guides attention when it is task-irrelevant (Exp. 1), b) whether visual resolution is a search asymmetry, by manipulating resolution’s task-relevance (Use Blur, Use Clarity, Do Not Use Unique Blur or Clarity, & No Instructions) (Exp. 2), and c) whether blur and/or clarity are processed preattentively or require attention (Exp. 3). Experiments 1 and 2 manipulated blur and clarity (Exp. 1 Resolution = Task-irrelevant & Exp. 2 Resolution = Task-relevant), during a rotated L and T visual search measuring RT and eye movements. Experiment 1 found with the more sensitive eye movement measures that unique clarity strongly captured attention while unique blur weakly repelled attention towards nearby clarity (or clarity, especially that close to blur, captured attention). Experiment 2 found evidence that visual resolution is not a search asymmetry because the influence of resolution on selective attention was contingent upon its task-relevance, which theoretically supports the presence of a reconfigurable resolution feature detector. Experiment 3 used a feature search for either blur or clarity (i.e., resolution was task-relevant) and compared RT x Set Size search slopes. Both blurred and clear target present RT x Set Size search slopes were ~ 1 msec/item. The results strongly supported that blur and clarity are both processed preattentively, and provided additional evidence that resolution is not a search asymmetry. Overall, the current studies shed light on how visual resolution is processed and guides selective attention. The results revealed that visual resolution is processed preattentively and has a dynamic relationship with selective attention. Predicting how resolution will guide attention requires knowledge of whether resolution is task relevant or irrelevant. By increasing our understanding of how resolution contrast guides attention, we can potentially apply this knowledge to direct viewers’ attention more efficient using computer screens and heads-up displays.

This thesis examines the labour that is made visible by the individual on-screen performances of five distinct postfeminist identities from contemporary popular culture. Each chapter focuses on one of three texts: the English-language film adaptation of The Girl with the Dragon Tattoo (2011); The Hunger Games film adaptations (2012-2015); and HBO’s cable-television series, Girls (2012-2017); as well as the girl figures at the centre of them: Lisbeth Salander; Katniss Everdeen/ Jennifer Lawrence; and Lena Dunham/Hannah Horvath. In these analyses I identify two marked strands of work acting as a conceptual thread that harnesses the potential of these gendered performances: firstly, the narrative, thematic, aesthetic, and representational work of the texts, which complicate current ideological and conceptual understandings of girlhood, feminism, and postfeminism; secondly, the cultural and ideological work of the magnetic identities of the girls at the centre of these texts, who help to bring these politics to the surface. The texts and the performances that inform my analyses are often associated with feminism, although the value of this work is often contradictory in nature, both questioned and reinforced by virtue of the performative, creative labour that underpins their authentic, yet commodified, representations. In the case of Lawrence and Dunham, this concerns their work as celebrities and how they mediate feminist ideas through their branded performance. The main objective of this thesis, then, is to demonstrate how each of the identities in this corpus effectively open out the tensions involved in performing feminism in twenty-first century culture, and thus to render the gendered labour attendant with this as politically imperative towards current understandings. This is an interdisciplinary study, drawing on scholarship from film, media, celebrity, gender, and cultural studies in order to grapple with the complexities and myriad meanings of contemporary feminism in the broader context of media culture.

La Web 2.0 es un fenómeno que cada día atrae a más usuarios, y cuyo elevado desarrollo ha convertido a los cibernautas en los constructores y protagonistas de sus propios espacios en la red. De forma individual o colectiva, todos tienen la oportunidad de vivir diversas experiencias en un sitio web, expresar sus opiniones, mostrar su diario vivir e integrarse voluntariamente a la amplia vitrina que ofrece un Internet libre y sin fronteras. La presente investigación indaga en el uso de este medio y específicamente en los portales web y las redes sociales, cuyos fundamentos serán aplicados en la creación de una nueva comunidad online, dedicada a una etnia reconocida a nivel nacional y mundial por la gran riqueza cultural que posee, y que aumenta su valor dada la distancia que la separa del continente. Isla de Pascua, tanto en su espacio real como virtual convoca a miles de turistas cada año; sin embargo, también puede ser parte de una iniciativa que reúna en línea a sus propios habitantes.

Abstract This research paper examines the ways in which the autobiographical impulse is constructed in selected artworks of Tracey Emin (b1963-) and Claudette Schreuders (b1973-). It is situated within contemporary discourses around notions of the self, namely postmodernist, feminist and post colonialist frameworks. This critical discussion of notions of the self, as evidenced in these selected artworks, leads into discourses of Authenticity, of Histories, personal and collective and of the role Identity formation plays in the performing self. In conducting this research I have drawn on a wide range of theoretical frameworks including philosophy, psychoanalysis and literary theory, including magical realism. The first part of my study presents the theoretical frameworks of Authenticity, History and Identity regarding the autobiographical impulse. The second section of this paper examines the selected works of Emin and Schreuders. I chose these two artists because of their different strategies in performing themselves rather than their similarities, which allows for an interrogation of a broader framework of contemporary artistic practices. The concluding chapter examines my practical artwork during the period of my Masters degree. My work comes from an autobiographical base and I create a ‘self-portrait’ through my accumulation, production and display of objects. My exhibition took the form of an installation whereby I created an uncomfortable atmosphere through various methods including stimulating the olfactory sense in a predominant way.

During scene viewing, visual working memory (VWM) is used to retain information from recently attended and fixated objects. In the present study, I examined whether and how people can strategically control the content of VWM during scene viewing, prioritizing task-relevant objects for retention even as the eyes are directed to subsequent objects. Participants viewed a set of real-world objects presented serially within a 3-D rendered scene. One object in the sequence was cued by a tone as to-be-remembered. At the end of the sequence, memory for the visual form of one object was tested. Participants exhibited tight control over the content of VWM, implementing prioritization after the encoding of an object into VWM, protecting that item from subsequent interference. Participants also successfully reallocated protection to subsequent objects, regardless of the duration of prioritization of the original item. Such strategic maintenance of objects in VWM is likely to play an important role in real-world visual behavior, especially when object information must be maintained across shifts of attention and the eyes to other objects (such as when comparing two spatially separated objects).

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