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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

How the lived experiences of black women can be understood through devised theatre informed by psychophysical actor training: an adaptation of the Tadashi Suzuki actor training technique

Makgabutlane,Linda 09 September 2022 (has links) (PDF)
In this study I aim to use my body as a tool to derive themes for use in performance making and to underpin this in theory. I focus on aspects of Tadashi Suzuki (1986) actor training (referred to as Suzuki training), free writing and the body. I use black feminism, cognitive neuroscience and body theory to account for my lived body, which I then use in performance. Practice and theory informed each other in a cyclical manner in accordance with Practice as Research as a methodology. Therefore, elements that emerged from my practice determined the theory included in the study, as practice was considered a way of knowing. I work to establish a relationship between race, subjugation and some of the multiple implications thereof on the body in the urban context: I draw on limited notions of culture and the body to interrogate how these can materialise in performance. The study also addresses aspects of the performing body to support why I derive value in Suzuki (1986) training as one psychophysical actor training tool. I theoretically discuss this technique as developing expressive abilities in young performers. The primary purpose of this research is to create work that is rooted in the tradition of devising. My research moves between the physical body and the body in performance in a South African context as I worked to conceptually account for the body in both instances. Although limited, this research includes theories that account for the performing body engaged in somatic foot-based practices where these interact with my practice. I further discuss the devising process I undertook with a cast, as a performance maker, my findings and reflection on this process.
52

Automated Machine Learning Framework for EEG/ERP Analysis: Viable Improvement on Traditional Approaches?

Boshra, Rober January 2016 (has links)
Event Related Potential (ERP) measures derived from the electroencephalogram (EEG) have been widely used in research on language, cognition, and pathology. The high dimensionality (time x channel x condition) of a typical EEG/ERP dataset makes it a time-consuming prospect to properly analyze, explore, and validate knowledge without a particular restricted hypothesis. This study proposes an automated empirical greedy approach to the analysis process to datamine an EEG dataset for the location, robustness, and latency of ERPs, if any, present in a given dataset. We utilize Support Vector Machines (SVM), a well established machine learning model, on top of a preprocessing pipeline that focuses on detecting differences across experimental conditions. A hybrid of monte-carlo bootstrapping, cross-validation, and permutation tests is used to ensure the reproducibility of results. This framework serves to reduce researcher bias, time spent during analysis, and provide statistically sound results that are agnostic to dataset specifications including the ERPs in question. This method has been tested and validated on three different datasets with different ERPs (N100, Mismatch Negativity (MMN), N2b, Phonological Mapping Negativity (PMN), and P300). Results show statistically significant, above-chance level identification of all ERPs in their respective experimental conditions, latency, and location. / Thesis / Master of Science (MSc)
53

The Cognitive and Neural Mechanisms of Curiosity

Cohanpour, Michael January 2023 (has links)
Curiosity, the intrinsic desire for information, is a significant but underexplored driver of human exploration, learning, and discovery. This dissertation seeks to uncover the cognitive and neural mechanisms of curiosity, in addition to investigating its impact on memory, contributing to our understanding of this fundamental aspect of human cognition. Chapter 2 uses a novel paradigm involving texforms, distorted visual stimuli, to probe the neural basis of curiosity. The findings reveal a negative, quadratic relationship between curiosity and confidence. Furthermore, the findings suggest a neural mechanism in which multivariate certainty in occipitotemporal cortex is translated into univariate confidence in the ventromedial prefrontal cortex (vmPFC) to facilitate curiosity. In Chapter 3, we delve deeper into the cognitive underpinnings of curiosity, demonstrating that confidence mediates the relationship between various cognitive variables — such as the vividness of imagery, guess specificity, and semantic similarity — and curiosity. This extension of the established mechanism from Chapter 2 reinforces the central role of confidence in curiosity. Shifting focus to the consequences of curiosity, Chapter 4 explores its influence on memory. Despite prior research demonstrating curiosity's enhancement of memory for trivia answers, our results reveal that curiosity does not affect memory for the stimuli that evoke curiosity itself, or 'questions'. This nuanced finding underscores the complexity inherent in the relationship between curiosity and memory. In sum, this dissertation creates a novel experimental framework for studying curiosity, highlights the pivotal role of confidence in curiosity, enhances our understanding of perceptual curiosity's mechanisms, and illuminates the intricate relationship between curiosity and memory. These results together provide a solid platform for future research in these areas.
54

Obsessive-Compulsive Disorder and Identity: The Role of Ego-Dystonicity

Mullin, Andrea B 01 January 2023 (has links) (PDF)
Obsessive Compulsive Disorder (OCD) has been linked to a dysmorphic construction of self that is closely tied to mental illness (Bhar & Kyrios, 2007). Although associations have been found, no study has determined the impact of OCD on one's self-perception, to better understand how to resolve patients' dysmorphic construction and fear of oneself. College students (N = 410; M = 20.60, SD = 4.27) completed an anonymous online survey for course credit. The survey consisted of a demographic questionnaire, the Obsessive-Compulsive Inventory-Revised (Foa et al., 2002), theEgo-Dystonicity Questionnaire (Purdon et al., 2007), and the Self-concept Identity Measure (Kaufman et al., 2019). To determine if scores on the Obsessive-Compulsive Inventory would predict scores on the Identity Measure and if the Ego-Dystonicity scale would account for a greater percentage of the variation in Identity subscale scores than Obsessing scores alone, multiple regression analyses were utilized. Results suggest that although, symptoms of OCD were useful in predicting variance all of the identity subscales, ego-dystonicity appeared to be particularly useful for establishing incremental validity in the prediction of the lack of identity subscale. Implications for intervention and prevention efforts in regard to the effects of OCD on identity will be discussed.
55

A Representational-Hierarchical Account: A New Theory of False Memories

Wilson, D. Merika 11 July 2017 (has links) (PDF)
Past research has supported a representational-hierarchical theory of memory and perception that extends the ventral visual stream into the medial temporal lobe. In this account, representations are organized in a hierarchical manner, such that structures located further anterior in the brain contain complex representations of whole objects and areas further posterior in the visual cortex contain representations of simple features. When conjunctive representations are compromised, an individual must rely on simple-feature representations to complete mnemonic and perceptual tasks. However, these simple-feature representations are susceptible to feature-level interference, which can cause false recognition of novel objects. The goal of the present study was to explore the account’s third assumption: the effect of interference. Experiment 1 examined the effect of interference on neural representations during fMRI. Experiment 2 investigated the effect of different types of interference on a behavioral memory task with older adults thought to have impaired conjunctive representations. Although the results of the first experiment were inconclusive, the second experiment revealed that older adults’ recognition memory performance was shielded from semantic, but not perceptual, interference. The implications of this finding are discussed.
56

Explicit Memory and Brain-Electrical Activity in 10-month-old Infants

Morasch, Katherine Colona 03 May 2007 (has links)
One of the most intriguing and enduring issues in contemporary developmental cognitive neuroscience centers on the development of the ability to remember past experiences and the neural systems which support this capacity. Over the past 25 years, through methodological advancements and direct challenges to established assumptions, the focus of this developmental question has shifted to highlight the second half of the first year of life as the time when true explicit memory functionally emerges and begins to rapidly develop. The purpose of the following study was to test specific hypotheses regarding the biobehavioral development of explicit memory during infancy and present a new approach to studying the behavioral and physiological expression of this system. This study, which was guided by hypothesized neural substrates of this memory system, is the first direct investigation of continuous brain electrical activity during both the encoding and retrieval phases of explicit memory processing in infants. Memory-related differences in behavior and task-related brain activity in individual cortical areas were of particular interest. The results of this study provided some support for the hypothesis that baseline-to-task changes in EEG power can distinguish between successful and unsuccessful ordered-recall memory. Specifically, decreases in brain-electrical activity relative to a baseline period were found at both frontal and temporal locations during stimulus encoding and retrieval for infants who failed the recall tests. However, either no change, or increases in EEG power at frontal and temporal sites was related to successful performance on this task. In addition, different patterns of brain-electrical activity were present for correct and incorrect responses from the same child. This study contributes to our understanding of the biobehavioral expression of infant explicit memory in three main ways. First, changes in both frontal and temporal lobe activity are directly involved in explicit memory processing both during event encoding as well as retrieval. Second, this work provides evidence of a developmentally appropriate and valid pattern of electrophysiology specific to explicit memory processing. Finally, this study bridges the gap between a classic behavioral task of infant memory (which has been conceptually linked to neuropsychological data) and current developmental cognitive neuroscience. / Ph. D.
57

Functional roles of L1-Cam/Neuroglian in the nervous system of Drosophila Melanogaster

Unknown Date (has links)
Neuronal cell adhesion molecules of L1 family play a critical role in proper nervous system development. Various mutations on human L1-CAM that lead to severe neurodevelopmental disorders like retardation, spasticity etc. termed under L1 syndrome. The vertebrr their roles in axon pathfinding, neurite extension and cell migration, howeverate L1CAM and its homolog in Drosophila, neuroglian (nrg) have been well studied fo, much less is known about the mechanisms by which they fine tune synaptic connectivity to control the development and maintenance of synaptic connections within neuronal circuits. Here we characterized the essential role of nrg in regulating synaptic structure and function in vivo in a well characterized Drosophila central synapse model neuron, the Giant Fiber (GF) system. Previous studies from our lab revealed that the phosphorylation status of the tyrosine in the Ankyrin binding FIGQY motif in the intracellular domain of Nrg iscrucial for synapse formation of the GF to Tergo-Trochanteral Motor neuron (TTMn) synapse in the GF circuit. The present work provided us with novel insights into the role of Nrg-Ank interaction in regulating Nrg function during synapse formation and maintenance. By utilizing a sophisticated Pacman based genomic rescue strategy we have shown that dynamic regulation of the Neuroglian–Ankyrin interaction is required to coordinate transsynaptic development in the GF–TTMn synapse. In contrast, the strength of Ankyrin binding directly controls the balance between synapse formation and maintenance at the NMJ. Human L1 pathological mutations affect different biological processes distinctively and thus their proper characterization in vivo is essential to understand L1CAM function. By utilizing nrg14;P[nrg180ΔFIGQY] mutants that have exclusive synaptic defects and the previously characterized nrg849 allele that affected both GF guidance and synaptic function, we were able to analyze pathological L1CAM missense mutations with respect to their effects on guidance and synapse formation in vivo. We found that the human pathological H210Q, R184Q and Y1070C, but not the E309K and L120V L1CAM mutations affect outside-in signaling via the FIGQY Ankyrin binding domain which is required for synapse formation and not for axon guidance while L1CAM homophilic binding and signaling via the ERM motif is essential for axon guidance in Drosophila. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
58

The Psychophysiology of Social Anxiety: An Integrative Perspective

Miskovic, Vladimir 10 1900 (has links)
<p>Social fears gain in prominence among higher primates, including humans, where threats associated with other conspecifics become more common. Social fearfulness is expressed on a continuum, ranging from shyness to a diagnosable psychiatric disorder. Despite the wide prevalence and considerable distress associated with social anxiety, our understanding of its neural and cognitive correlates remains in its infancy and remains an imperative for future translational research. The current dissertation examined social anxiety by utilizing multiple experimental approaches and employing a broad range of measures involving neural, cognitive, behavioural and clinical assessments.</p> <p>Chapters 2 to 4 relied on nonclinical samples of adults selected for social anxiety from a large adult population. Chapters 2 and 3 employed event-related brain potentials to index distinct aspects of perceptual and cognitive processing in tasks that manipulated novelty under socio-emotional and affectively neutral contexts. The aim was to provide a fine-grained characterization of the information processing stages that are biased by social anxiety. Chapter 4 measured reaction times in a selective attention task that independently varied the temporal and energetic aspects of affective stimulus delivery to provide convergent evidence into how affective processing is perturbed by social anxiety. Chapter 5 employed a novel method of quantifying continuous EEG to examine large-scale brain activity during rest and symptom provocation in patients diagnosed with social anxiety disorder. The aim was to examine, for the first time, whether there are treatment-related changes in a measure that putatively indexes communication across different (cortical and subcortical) neuronal systems.</p> <p>Findings suggest that social anxiety is associated with a sensitization of (bottom-up) systems reacting to social threat and that these biases appear during the early, relatively automatic stages of information processing. Some of these systems may be susceptible to evidence-based psychological treatments that are correlated with changes in brain activity detectable in EEG patterns. <br /><br /></p> / Doctor of Philosophy (PhD)
59

The role of motor information in learning and behavior in the presence and absence of challenge, physical or cognitive.

Fenney, Alison L. 10 1900 (has links)
<p>This thesis was specifically designed to explore the role of motor information in behavior and learning in the presence and absence of physical and cognitive challenges. The first experiment examined the role of motor information in the maintenance of standing balance. This study found that light touch (motor information) was most useful when visual condition was challenging, eyes closed. Increased benefit of touch in the presence of challenge suggests that motor information may provide similar information as other senses, and act in a compensatory fashion when those senses are challenged. The second study examined the role of motor information, in the form of enactment, in learning a motor communication task. Results from this study support a role for motor information in enriching the learning environment by strengthening memory to reduce rate of forgetting. The third study examined the role of motor information in disease, using motor-centric instruction and guided movements to teach persons with Alzheimer Dementia to bowl using the Nintendo Wii <sup>TM</sup>. The spared motor learning observed in these participants confirms claims in the literature of spared motor function in persons with dementia and strengthens the claim the motor system can provide compensatory information to support challenged cognitive systems. Taken together, these findings add to the current literature supporting motor pathways with information separable form other sensory pathways and spared motor capacity to learn in dementia.</p> / Doctor of Philosophy (PhD)
60

The Effects of Aging on Motion Perception in Healthy Older Adults

Tsotsos, Lia E. 10 1900 (has links)
<p>Motion perception is required for nearly all aspects of daily living. Previous work has shown that the ability to perceive a variety of different types of motion is significantly affected by increasing age. The research described in this thesis further probes the complex effects of aging on motion perception using a number of different stimulus configurations and performance measures. In order to relate psychophysical performance to neurophysiological recordings, we used two different notched-noise masking techniques to estimate the directional selectivity of masking in younger and older adults. We found evidence to suggest that the directionally-selective mechanisms of older adults are more broadly tuned than their younger counterparts, which is consistent with the animal literature that links decreased neural inhibition with broader directional tuning. Behaviourally however, task-specific contrast sensitivity may play a role in explaining that result. We also uncovered a previously unobserved difference between horizontal and vertical motion perception which bears further study. We also tested peripheral motion perception both under focused and divided attentional conditions. Older adults were impaired compared to younger adults when asked to make judgments about motion patterns in the peripheral vision field, but they were not differentially impaired under divided attention conditions. The findings presented in this thesis paint a more complex picture of how increasing age impairs motion perception than previously described. Specifically, our observations show that age effects interact with stimulus contrast, attention, and motion direction, and these interactions each present an interesting avenue for further exploration.</p> / Doctor of Philosophy (PhD)

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