Theses and Dissertations
This collection includes both ASU Theses and Dissertations, submitted by graduate students, and the Barrett, Honors College theses submitted by undergraduate students.
Displaying 1 - 10 of 103
Description
Perceptual learning by means of coherent motion training paradigms has been shown to produce plasticity in lower and higher-level visual systems within the human occipital lobe both supra- and subliminally. However, efficiency of training methods that produce consolidation in the visual system via coherent motion has yet to be experimentally determined. Furthermore, the effects of coherent motion training on reading comprehension, in clinical and normal populations, are still nascent. In the present study, 20 participants were randomly assigned to one of four experimental conditions. Two conditions had a participation requirement of four days while two conditions required eight days of participation. These conditions were further divided into 500 or 1000 trials per day (4 x 500, 4 x 1000, 8 x 500, 8 x 1000). Additional pre-test and post-test days were used to attain timed pre- and post-tests on the Wide Range Achievement Test IV (WRAT IV) reading comprehension battery. Furthermore, a critical flicker fusion threshold (CFFT) score was taken on a macular pigment densitometer on the pre-test and post-test day. Participants showed significant improvement in CFFT levels, WRAT IV reading comprehension, and speed of completion between pre-test and post-test; however, degree of improvement did not vary as a function of training condition. An interaction between training condition and degree of improvement was evident in coherent dot motion contrast scores, with significant training plasticity occurring in the 4 x 1000 and 8 x 500 conditions.
ContributorsGroth, Anthony (Author) / Náñez, José E. (Thesis advisor) / Hall, Deborah (Committee member) / Risko, Evan F. (Committee member) / Arizona State University (Publisher)
Created2013
Description
The processing power and storage capacity of portable devices have improved considerably over the past decade. This has motivated the implementation of sophisticated audio and other signal processing algorithms on such mobile devices. Of particular interest in this thesis is audio/speech processing based on perceptual criteria. Specifically, estimation of parameters from human auditory models, such as auditory patterns and loudness, involves computationally intensive operations which can strain device resources. Hence, strategies for implementing computationally efficient human auditory models for loudness estimation have been studied in this thesis. Existing algorithms for reducing computations in auditory pattern and loudness estimation have been examined and improved algorithms have been proposed to overcome limitations of these methods. In addition, real-time applications such as perceptual loudness estimation and loudness equalization using auditory models have also been implemented. A software implementation of loudness estimation on iOS devices is also reported in this thesis. In addition to the loudness estimation algorithms and software, in this thesis project we also created new illustrations of speech and audio processing concepts for research and education. As a result, a new suite of speech/audio DSP functions was developed and integrated as part of the award-winning educational iOS App 'iJDSP." These functions are described in detail in this thesis. Several enhancements in the architecture of the application have also been introduced for providing the supporting framework for speech/audio processing. Frame-by-frame processing and visualization functionalities have been developed to facilitate speech/audio processing. In addition, facilities for easy sound recording, processing and audio rendering have also been developed to provide students, practitioners and researchers with an enriched DSP simulation tool. Simulations and assessments have been also developed for use in classes and training of practitioners and students.
ContributorsKalyanasundaram, Girish (Author) / Spanias, Andreas S (Thesis advisor) / Tepedelenlioğlu, Cihan (Committee member) / Berisha, Visar (Committee member) / Arizona State University (Publisher)
Created2013
Description
Recent research has identified affirmation of transcendence and exposure to violent Bible verses as being related to greater prejudice toward value-violating out-groups (Blogowska & Saroglou, 2012; Shen et al., 2013). Effects of exposure to specific Bible verses on attitudes toward out-groups have not been measured in combination with the Post-Critical Belief Scale developed by Hutsebaut (1996). The relationships between exposure to scriptural endorsements of prejudice, affirmation vs. disaffirmation of transcendence, literal vs. symbolic processing of religious content, and prejudice toward value-violating out-groups were examined using an online survey administered to a sample of U.S. adults (N=283). Greater affirmation of transcendence scores were linked to greater prejudice toward atheists and homosexuals and more favorable ratings of Christians and highly religious people. Lower affirmation of transcendence scores were linked to less favorable ratings of Christians and highly religious people and more favorable ratings of atheists. Exposure to scriptural endorsements of prejudice did not have a significant effect on levels of prejudice in this study.
ContributorsGrove, Richard (Author) / Robles, Elías (Thesis advisor) / Hall, Deborah (Committee member) / Schweitzer, Nicholas (Committee member) / Arizona State University (Publisher)
Created2013
Description
While acceptance towards same-sex marriage is gradually increasing, same-sex marriage is banned in many states within the United States. Laws that prohibit same-sex couples from marrying have been shown to increase feelings of depression, exclusion, and stigma for same-sex attracted individuals. The intention of this study was to explore the effect both pro- and anti-same-sex marriage advertisements have on heterosexual individuals' implicit attitudes towards same-sex couples. It was predicted that exposure to anti-same-sex advertisements would lead to viewing same-sex couples as more unpleasant and heterosexual couples as being more pleasant. However, heterosexual participants who viewed anti-same-sex marriage ads were more likely to rate heterosexual couples as being unpleasant and same-sex couples as pleasant. It is theorized that viewing anti-same-sex marriage advertisements led heterosexual individuals to report heterosexual stimuli as being more unpleasant compared to same-sex stimuli as a form of defensive processing.
ContributorsWalsh, Theodora Michelle (Author) / Newman, Matt (Thesis advisor) / Hall, Deborah (Committee member) / Salerno, Jessica (Committee member) / Arizona State University (Publisher)
Created2013
Description
The recent spotlight on concussion has illuminated deficits in the current standard of care with regard to addressing acute and persistent cognitive signs and symptoms of mild brain injury. This stems, in part, from the diffuse nature of the injury, which tends not to produce focal cognitive or behavioral deficits that are easily identified or tracked. Indeed it has been shown that patients with enduring symptoms have difficulty describing their problems; therefore, there is an urgent need for a sensitive measure of brain activity that corresponds with higher order cognitive processing. The development of a neurophysiological metric that maps to clinical resolution would inform decisions about diagnosis and prognosis, including the need for clinical intervention to address cognitive deficits. The literature suggests the need for assessment of concussion under cognitively demanding tasks. Here, a joint behavioral- high-density electroencephalography (EEG) paradigm was employed. This allows for the examination of cortical activity patterns during speech comprehension at various levels of degradation in a sentence verification task, imposing the need for higher-order cognitive processes. Eight participants with concussion listened to true-false sentences produced with either moderately to highly intelligible noise-vocoders. Behavioral data were simultaneously collected. The analysis of cortical activation patterns included 1) the examination of event-related potentials, including latency and source localization, and 2) measures of frequency spectra and associated power. Individual performance patterns were assessed during acute injury and a return visit several months following injury. Results demonstrate a combination of task-related electrophysiology measures correspond to changes in task performance during the course of recovery. Further, a discriminant function analysis suggests EEG measures are more sensitive than behavioral measures in distinguishing between individuals with concussion and healthy controls at both injury and recovery, suggesting the robustness of neurophysiological measures during a cognitively demanding task to both injury and persisting pathophysiology.
ContributorsUtianski, Rene (Author) / Liss, Julie M (Thesis advisor) / Berisha, Visar (Committee member) / Caviness, John N (Committee member) / Dorman, Michael (Committee member) / Arizona State University (Publisher)
Created2014
Description
This study investigates the presence of a dual identity defendant, and how sharing an in-group can create a judgment bias. A sample of 256 participants was used to test whether there was a relationship between judgment punitiveness, perceptions of shared identity, hypocrisy and the social identities (religion and sexual orientation) of the participants and a defendant charges with a sexual offence. Results suggest that Christian participants selected more punitive outcomes for the defendant compared to non-Christian participants. Further, participants were more punitive when the defendant was gay compared to when the defendant was heterosexual. Also, when the defendant was straight there was a stronger feeling of similarity between the participants and defendant compared to when the defendant was gay, and non-Christian participants had a stronger feeling of closeness to the defendant compared to Christian participants. There was a significant interaction found, suggesting that when the defendant was Christian and gay he was seen as more hypocritical compared to when he was Christian and straight; there was no interaction when the defendant was not Christian. These findings should aid in future research and a better understanding of how dual identity defendants are perceived in the courtroom.
ContributorsAltholz, Rachel Leah (Author) / Salerno, Jessica (Thesis advisor) / Hall, Deborah (Committee member) / Schweitzer, Nick (Committee member) / Arizona State University (Publisher)
Created2014
Description
Interest in health and wellness has significantly increased in today's society. Living a healthy and active lifestyle is suggested to promote overall physical and psychological well-being. This study explored the effects of wearing a Fitbit Zip activity monitor and the impact of expressing mindfulness on levels of physical activity. It was predicted that expressing mindfulness, as measured by the use of present-tense language during the daily emotional writing task, would moderate the relationship between wearing a Fitbit Zip activity monitor and change in physical activity. Specifically, it was hypothesized daily monitoring would only lead to increased activity among those higher in mindful language. Over the course of five days, participants were asked to wear a Fitbit Zip and to complete a daily questionnaire and writing task at the end of each evening. On the last day of the study, participants completed a follow-up assessment, which suggested that the combination of wearing a Fitbit Zip activity monitor and expressing more mindfulness throughout the week increased levels of physical activity. An important issue for future research is to conduct this study for a longer period of time in order to get more variability in the data. However, despite the limitations of the design, these findings suggest that activity monitoring may be a promising way to promote healthy lifestyle change.
ContributorsTarachiu, Viorela (Author) / Newman, Matt L. (Thesis advisor) / Hall, Deborah (Committee member) / Salerno, Jessica (Committee member) / Arizona State University (Publisher)
Created2014
Description
A sample of 193 participants viewed one of six variations of an eyewitness giving mock testimony. Each participant viewed testimony, which varied by level of emotion (none, moderate, or high) and frame (waist-up or head only). Participants then rated the witness using the Brodsky Witness Credibility Scale and the Reyson Likability Scale. A set of ANOVA's was performed revealing an effect of emotion level on both credibility and likability. Emotion level was found to influence participant judgments of poise, however, to a lesser degree than judgments of credibility and likability. These results suggest that attorneys may want to avoid the use of videoconferencing with certain types of witnesses where testimony may be highly emotional.
ContributorsHavener, Shannon (Author) / Schweitzer, Nicholas (Thesis advisor) / Salerno, Jessica (Committee member) / Hall, Deborah (Committee member) / Arizona State University (Publisher)
Created2014
Description
Past research suggested that lutein (L) and zeaxanthin (Z) play a role in many aspects of cognitive functions including motor speed, working memory, executive function, psychomotor speed and verbal fluency among elderly people. Moreover, L and Z are the only carotenoids found in the eye, and they are correlated with improved contrast sensitivity, improved temporal vision, reduced glare disability, and reduced risk of age related-macular degeneration (AMD). Animal and postmortem research suggests that MPOD may be a biomarker for predicting cognitive decline with age. The purpose of this study is to evaluate the potential relationship between MPOD and cognition in young healthy adults. There were fifty participants in the current study, 25 had low MPOD. The remaining participants exhibited high MPOD, which was measured using a macular pigment densitometer. People with low MPOD did not perform any worse than people with high MPOD. Although low MPOD in young adults may be a biomarker for future cognitive decline, the effects may lay dormant until later in life. Future research should explore this possibility by replicating this study with an older population.
ContributorsZimmerman, Daniel (Author) / Nanez, Jose E (Thesis advisor) / Shipstead, Zachary (Committee member) / Hall, Deborah (Committee member) / Arizona State University (Publisher)
Created2014
Description
This study was designed to investigate whether workplace positivity of full-time workers was related to health ratings. Positivity was conceptualized by a high rating of perceived work-performance, and work-engagement as defined by the Utrecht Work-Engagement Scale, including vigor, dedication, and absorption (Schaufeli, & Bakker, 2004). Health was measured utilizing the RAND SF-36 health survey including the eight subscales: overall, general health, physical and social functioning, emotional well-being, role limitations due to physical health or emotional problems, energy or fatigue, and bodily pain. All measures were collected simultaneously. It was predicted that perceived work-performance and all measures of work-engagement are positively associated with the aforementioned health ratings. Multiple regression analyses revealed that higher (positive) perception of work-performance and vigor were positively related to health ratings. Absorption was negatively related to health ratings. Dedication was only negatively related to physical functioning. These findings suggest that not all measures of positivity in the workplace are related to better health. Implications and future directions are discussed.
ContributorsFlores, Melissa Ann (Author) / Vargas, Perla A (Thesis advisor) / Burleson, Mary H (Committee member) / Hall, Deborah (Committee member) / Arizona State University (Publisher)
Created2014