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 31 - 40 of 97
Description
Depression, anxiety, and suicidal thoughts or actions are on the rise in adolescents (National Institute of Mental Health, 2015; Bridge, Asti, & Horowitz, 2015). Parents, school administrators, and therapists are searching for resiliency factors with in at-risk groups to aid students in need. In previous work, Luthar and Zigler (1992) reported that intelligent youth are more resilient than less intelligent youth under low stress conditions but they lose their advantage under high stress conditions. This study examined whether intelligence (reflected in grade point average; GPA) and maladaptive (internalizing and externalizing symptoms) behaviors are negatively related in adolescents, and tested whether level of stress, reflected in emotion regulation and friendship quality, moderated that association. It also probed whether the relationships differ by gender. Sixth-graders (N=506) were recruited with active parental consent from three middle schools. Adolescents completed self-report questionnaires Regarding demo graphics, maladaptive behaviors, emotion regulation, and friendship quality, and GPA data were collected from the school. Regression analyses found that GPA was negatively related to externalizing symptoms. Girls with poor friendship communication report significantly higher maladaptive behaviors. This relation was more pronounced for girls with high GPAs, as predicted. Results support the theory that intelligent female adolescents are more reactive under adverse circumstances. Future efforts should follow students through middle school into high school to evaluate whether friendships remain important to adjustment, hold for boys as well as girls, and have implications for relationship interventions.
ContributorsGonzales, Ashlyn Carol (Author) / Luthar, Suniya (Thesis director) / Davis, Mary (Committee member) / Infurna, Frank (Committee member) / Department of Psychology (Contributor) / Sanford School of Social and Family Dynamics (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
Emotions have been defined as coordinated and functional changes in subjective experience, motivation, physiological activation, instrumental behavior, expressive behavior, and cognition that are evoked by important threats or opportunities in the environment. The proposed study looks at cognitive changes associated with the experience of several positive emotions, with a specific focus on awe. Prior research shows that positive emotions tend to increase people's use of cognitive heuristics (i.e. mental shortcuts used to simplify information we intake from the environment) and changes how they apply rules of thumb from stored knowledge to make decisions. Stereotypes, or assumptions about the characteristics held by individual members of a group, are one such heuristic. Awe, in contrast to other positive emotions, has been found to reduce people's tendency to rely on heuristics, rather than increasing its use. Thus, awe should tend to reduce stereotyping specifically. Participants made judgments on three characteristics and two types of theoretically valuable true/false statements. However, for both our measures, awe had no significant effect on stereotyping. Participants in the enthusiasm condition were significantly more likely than those in the awe condition to correctly identify stereotype-inconsistent statements present in the biography, which is the opposite of the predicted direction. Patterns for all four emotion conditions trended similarly to our predictions for stereotype-consistent statements correctly marked as being absent in the biography. There were no significant differences in ratings of three traits. Implications for enthusiasm and awe are discussed in the context of stereotypes of social objects and schemas of nonsocial objects.
ContributorsMurwin, Paige Elizabeth (Co-author) / O'Neil, Makenzie (Co-author) / Shiota, Michelle (Thesis director) / Davis, Mary (Committee member) / Sanford School of Social and Family Dynamics (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
The frontostriatal reward circuit serves an underlying role in reward processing, cognitive planning, and motor control in the context of achieving a goal. Furthermore, research suggests a relationship between the reward circuits and behavior expressed in Attention Deficit Hyperactivity Disorder (ADHD); however, the specific structural differences of the reward circuits in those with ADHD remain ambiguous. Diffusion tensor imaging (DTI) techniques were used to analyze diffusion weighted magnetic resonance imaging (DWI) data in order to examine the structural connectivity of frontostriatal reward pathways in ADHD adolescents compared to typically developing (TD) adolescents. It was hypothesized that measures of impulsivity would be predicted by white matter tract integrity measures in frontostriatal tracts related to affective processing (ventromedial prefrontal cortex to ventral striatum, vmPFC) in adolescents with ADHD, and that there would be reduced tract integrity in tracts related to executive control (dorsolateral prefrontal and anterior cingulate cortex—dlPFC and ACC, respectively). Frontostriatal tracts as well as the hippocampus and amygdala were examined in relation to age and impulsivity using both correlation and regression models. Results indicated that impulsivity declined with age in the TD group while no significant trend was identified for the ADHD group. The hypotheses were not supported and results for both predictions on the affective and executive circuits showed opposite trends from what was expected.
ContributorsHarrison, Sydney Rae (Author) / McClure, Samuel (Thesis director) / Brewer, Gene (Committee member) / Davis, Mary (Committee member) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
Posttraumatic Stress Disorder (PTSD) affects nearly 10% of adult women in general population samples. In populations of impoverished ethnic minority women, those lifetime prevalence rates may possibly exceed national averages due to lack of mental health resources. Mothers with PTSD are more likely to exhibit negative parenting styles and experience higher levels of perceived parenting stress, both of which are associated with poor child outcomes. However, there is a lack of evidence on how maternal PTSD may affect parenting for ethnic minority mothers. This study evaluated the prevalence of lifetime PTSD and its effects on parenting stress and infant problem behaviors in a sample of 322 low-income Mexican-American mothers (mean age = 27.8; 86% born in Mexico). Lifetime PTSD diagnoses were assessed at a prenatal home visit (24-36 weeks gestation) using the WHO Composite International Diagnostic Interview (CIDI). Mothers reported parenting hassles at 24-weeks postpartum (PDLH; Crnic & Greenberg, 1990), and child problem behaviors at infant age one-year (BITSEA; Briggs-Gowan et al., 2004). I hypothesized that 1) women with PTSD would report more parenting stress than women without PTSD, 2) women with PTSD would report more infant problem behavior symptoms than women without PTSD, and 3) parenting stress mediates the relationship between PTSD and infant problem behavior. Results found that 16.5% of women met criteria for past or present PTSD. Compared to women without PTSD, women with PTSD reported more parenting stress but a similar level of infant problem behaviors. Parenting stress significantly mediated the relationship between maternal PTSD and infant problem behaviors. Study findings suggest a need for mental health screenings during prenatal care in order to promote the healthy development of high-risk children.
ContributorsPreves, Ashley Maria (Author) / Luecken, Linda (Thesis director) / Davis, Mary (Committee member) / Mauricio, Anne (Committee member) / Department of Psychology (Contributor) / School of Social Transformation (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
This paper explores the idea of xenophilia and the circumstances under which it may occur. Xenophilia is the preference for an outgroup member over an ingroup member. This preference does not have to be amicable, and in fact can be exploitative under certain circumstances. Previous research indicates that xenophobia is much more common, but a few researchers have found support for the existence of xenophilia. To experimentally test the circumstances under which xenophilia might occur, I conducted a survey-based experiment on Amazon’s Mechanical Turk. This consisted of directed visualizations that manipulated participant goal (self-protection vs. mate acquisition) and the resources offered by both a fictitious outgroup and the hometown ingroup, followed by measures of ingroup/outgroup preference. I hypothesized that when the resource offered by the group addressed the participants’ goal, they would prefer the group with the “matched” resource—even if it was the outgroup providing that resource. My hypothesis was not supported, as the univariate analysis of variance for preference for the outgroup was not significant, F (2, 423) = .723, p = .486. This may have occurred because the goal manipulations were not strong enough to counteract the strong natural preference for ingroup members.
ContributorsDrury, Margaret E. (Author) / Neuberg, Steven (Thesis director) / Davis, Mary (Committee member) / Kenrick, Douglas (Committee member) / Department of Psychology (Contributor) / School of Life Sciences (Contributor) / School of Social and Behavioral Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Swarms of low-cost, autonomous robots can potentially be used to collectively perform tasks over large domains and long time scales. The design of decentralized, scalable swarm control strategies will enable the development of robotic systems that can execute such tasks with a high degree of parallelism and redundancy, enabling effective operation even in the presence of unknown environmental factors and individual robot failures. Social insect colonies provide a rich source of inspiration for these types of control approaches, since they can perform complex collective tasks under a range of conditions. To validate swarm robotic control strategies, experimental testbeds with large numbers of robots are required; however, existing low-cost robots are specialized and can lack the necessary sensing, navigation, control, and manipulation capabilities.
To address these challenges, this thesis presents a formal approach to designing biologically-inspired swarm control strategies for spatially-confined coverage and payload transport tasks, as well as a novel low-cost, customizable robotic platform for testing swarm control approaches. Stochastic control strategies are developed that provably allocate a swarm of robots around the boundaries of multiple regions of interest or payloads to be transported. These strategies account for spatially-dependent effects on the robots' physical distribution and are largely robust to environmental variations. In addition, a control approach based on reinforcement learning is presented for collective payload towing that accommodates robots with heterogeneous maximum speeds. For both types of collective transport tasks, rigorous approaches are developed to identify and translate observed group retrieval behaviors in Novomessor cockerelli ants to swarm robotic control strategies. These strategies can replicate features of ant transport and inherit its properties of robustness to different environments and to varying team compositions. The approaches incorporate dynamical models of the swarm that are amenable to analysis and control techniques, and therefore provide theoretical guarantees on the system's performance. Implementation of these strategies on robotic swarms offers a way for biologists to test hypotheses about the individual-level mechanisms that drive collective behaviors. Finally, this thesis describes Pheeno, a new swarm robotic platform with a three degree-of-freedom manipulator arm, and describes its use in validating a variety of swarm control strategies.
To address these challenges, this thesis presents a formal approach to designing biologically-inspired swarm control strategies for spatially-confined coverage and payload transport tasks, as well as a novel low-cost, customizable robotic platform for testing swarm control approaches. Stochastic control strategies are developed that provably allocate a swarm of robots around the boundaries of multiple regions of interest or payloads to be transported. These strategies account for spatially-dependent effects on the robots' physical distribution and are largely robust to environmental variations. In addition, a control approach based on reinforcement learning is presented for collective payload towing that accommodates robots with heterogeneous maximum speeds. For both types of collective transport tasks, rigorous approaches are developed to identify and translate observed group retrieval behaviors in Novomessor cockerelli ants to swarm robotic control strategies. These strategies can replicate features of ant transport and inherit its properties of robustness to different environments and to varying team compositions. The approaches incorporate dynamical models of the swarm that are amenable to analysis and control techniques, and therefore provide theoretical guarantees on the system's performance. Implementation of these strategies on robotic swarms offers a way for biologists to test hypotheses about the individual-level mechanisms that drive collective behaviors. Finally, this thesis describes Pheeno, a new swarm robotic platform with a three degree-of-freedom manipulator arm, and describes its use in validating a variety of swarm control strategies.
ContributorsWilson, Sean Thomas (Author) / Berman, Spring M (Thesis advisor) / Artemiadis, Panagiotis (Committee member) / Sugar, Thomas (Committee member) / Rodriguez, Armando A (Committee member) / Taylor, Jesse (Committee member) / Arizona State University (Publisher)
Created2017
Description
The advancements in the technology of MEMS fabrication has been phenomenal in recent years. In no mean measure this has been the result of continued demand from the consumer electronics market to make devices smaller and better. MEMS inertial measuring units (IMUs) have found revolutionary applications in a wide array of fields like medical instrumentation, navigation, attitude stabilization and virtual reality. It has to be noted though that for advanced applications of motion tracking, navigation and guidance the cost of the IMUs is still pretty high. This is mainly because the process of calibration and signal processing used to get highly stable results from MEMS IMU is an expensive and time-consuming process. Also to be noted is the inevitability of using external sensors like GPS or camera for aiding the IMU data due to the error propagation in IMU measurements adds to the complexity of the system.
First an efficient technique is proposed to acquire clean and stable data from unaided IMU measurements and then proceed to use that system for tracking human motion. First part of this report details the design and development of the low-cost inertial measuring system ‘yIMU’. This thesis intends to bring together seemingly independent techniques that were highly application specific into one monolithic algorithm that is computationally efficient for generating reliable orientation estimates. Second part, systematically deals with development of a tracking routine for human limb movements. The validity of the system has then been verified.
The central idea is that in most cases the use of expensive MEMS IMUs is not warranted if robust smart algorithms can be deployed to gather data at a fraction of the cost. A low-cost prototype has been developed comparable to tactical grade performance for under $15 hardware. In order to further the practicability of this device we have applied it to human motion tracking with excellent results. The commerciality of device has hence been thoroughly established.
First an efficient technique is proposed to acquire clean and stable data from unaided IMU measurements and then proceed to use that system for tracking human motion. First part of this report details the design and development of the low-cost inertial measuring system ‘yIMU’. This thesis intends to bring together seemingly independent techniques that were highly application specific into one monolithic algorithm that is computationally efficient for generating reliable orientation estimates. Second part, systematically deals with development of a tracking routine for human limb movements. The validity of the system has then been verified.
The central idea is that in most cases the use of expensive MEMS IMUs is not warranted if robust smart algorithms can be deployed to gather data at a fraction of the cost. A low-cost prototype has been developed comparable to tactical grade performance for under $15 hardware. In order to further the practicability of this device we have applied it to human motion tracking with excellent results. The commerciality of device has hence been thoroughly established.
ContributorsShetty, Yatiraj K (Author) / Redkar, Sangram (Thesis advisor) / Sugar, Thomas (Committee member) / Berman, Spring (Committee member) / Lee, Hyunglae (Committee member) / Arizona State University (Publisher)
Created2016
Description
The present study utilized longitudinal data from a high-risk community sample (n= 377; 166 trauma-exposed; 54% males; 52% children of alcoholics; 73% non-Hispanic/Latino Caucasian; 22% Hispanic/Latino; 5% other ethnicity) to test a series of hypotheses that may help explain the risk pathways that link traumatic stress, posttraumatic stress disorder (PTSD) symptomatology, and problematic alcohol and drug use. Specifically, this study examined whether pre-trauma substance use problems increase risk for trauma exposure (the high-risk hypothesis) or PTSD symptoms (the susceptibility hypothesis), whether PTSD symptoms increase risk for later alcohol/drug problems (the self-medication hypothesis), and whether the association between PTSD symptoms and alcohol/drug problems is due to shared risk factors (the shared vulnerability hypothesis). This study also examined the roles of gender and ethnicity in these pathways. A series of logistic and negative binomial regressions were performed in a path analysis framework. A composite pre-trauma family adversity variable was formed from measures of family conflict, family life stress, parental alcoholism, and other parent psychopathology. Results provided the strongest support for the self-medication hypothesis, such that PTSD symptoms predicted higher levels of later alcohol and drug problems among non-Hispanic/Latino Caucasian participants, over and above the influences of pre-trauma family adversity, pre-trauma substance use problems, trauma exposure, and demographic variables. Results partially supported the high-risk hypothesis, such that adolescent substance use problems had a marginally significant unique effect on risk for assaultive violence exposure but not on overall risk for trauma exposure. There was no support for the susceptibility hypothesis, as pre-trauma adolescent substance use problems did not significantly influence risk for PTSD diagnosis/symptoms over and above the influence of pre-trauma family adversity. Finally, there was little support for the shared vulnerability hypothesis. Neither trauma exposure nor preexisting family adversity accounted for the link between PTSD symptoms and later substance use problems. These results add to a growing body of literature in support of the self-medication hypothesis. Findings extend previous research by showing that PTSD symptoms may influence the development of alcohol and drug problems over and above the influence of trauma exposure itself, preexisting family risk factors, and baseline levels of substance use.
ContributorsHaller, Moira (Author) / Chassin, Laurie (Thesis advisor) / Davis, Mary (Committee member) / Pina, Armando (Committee member) / Tein, Jenn-Yun (Committee member) / Arizona State University (Publisher)
Created2014
Description
The effects of meditation on attention control have been widely studied in recent years. However, the methodological flaws of many of these studies raise serious concerns on the validity of meditation training as a cognitive enhancer. This study investigated the near and far transfer effects of mindfulness meditation training on attention control when a stringent experimental design was implemented. Participants in the experimental group practiced meditation for three twenty-minute sessions, and participants in the active control group listened to an audio book about meditation for similar times. No significant effect of meditation on change in performance on cognitive tasks was found. This study suggests that short-term mindfulness meditation training does not result in increased attention control.
ContributorsPatel, Sachi Rajul (Author) / Brewer, Gene (Thesis director) / Presson, Clark (Committee member) / Davis, Mary (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / Department of Psychology (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor)
Created2013-05
Description
Cardiovascular disease is the leading cause of death in the United States, and classic risk factors only predict half of the variance of cases. In this study, parental overprotection and temperamental negative affectivity both significantly correlated with blood pressure and heart rate, which suggests the importance of examining early life factors when determining one's risk for CVD.
ContributorsCarter, Steven Cross (Author) / Luecken, Linda (Thesis director) / Presson, Clark (Committee member) / Davis, Mary (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor) / School of Life Sciences (Contributor)
Created2013-05