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.
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Description
Methods to test hypotheses of mediated effects in the pretest-posttest control group design are understudied in the behavioral sciences (MacKinnon, 2008). Because many studies aim to answer questions about mediating processes in the pretest-posttest control group design, there is a need to determine which model is most appropriate to test hypotheses about mediating processes and what happens to estimates of the mediated effect when model assumptions are violated in this design. The goal of this project was to outline estimator characteristics of four longitudinal mediation models and the cross-sectional mediation model. Models were compared on type 1 error rates, statistical power, accuracy of confidence interval coverage, and bias of parameter estimates. Four traditional longitudinal models and the cross-sectional model were assessed. The four longitudinal models were analysis of covariance (ANCOVA) using pretest scores as a covariate, path analysis, difference scores, and residualized change scores. A Monte Carlo simulation study was conducted to evaluate the different models across a wide range of sample sizes and effect sizes. All models performed well in terms of type 1 error rates and the ANCOVA and path analysis models performed best in terms of bias and empirical power. The difference score, residualized change score, and cross-sectional models all performed well given certain conditions held about the pretest measures. These conditions and future directions are discussed.
ContributorsValente, Matthew John (Author) / MacKinnon, David (Thesis advisor) / West, Stephen (Committee member) / Aiken, Leona (Committee member) / Enders, Craig (Committee member) / Arizona State University (Publisher)
Created2015
Description
Missing data are common in psychology research and can lead to bias and reduced power if not properly handled. Multiple imputation is a state-of-the-art missing data method recommended by methodologists. Multiple imputation methods can generally be divided into two broad categories: joint model (JM) imputation and fully conditional specification (FCS) imputation. JM draws missing values simultaneously for all incomplete variables using a multivariate distribution (e.g., multivariate normal). FCS, on the other hand, imputes variables one at a time, drawing missing values from a series of univariate distributions. In the single-level context, these two approaches have been shown to be equivalent with multivariate normal data. However, less is known about the similarities and differences of these two approaches with multilevel data, and the methodological literature provides no insight into the situations under which the approaches would produce identical results. This document examined five multilevel multiple imputation approaches (three JM methods and two FCS methods) that have been proposed in the literature. An analytic section shows that only two of the methods (one JM method and one FCS method) used imputation models equivalent to a two-level joint population model that contained random intercepts and different associations across levels. The other three methods employed imputation models that differed from the population model primarily in their ability to preserve distinct level-1 and level-2 covariances. I verified the analytic work with computer simulations, and the simulation results also showed that imputation models that failed to preserve level-specific covariances produced biased estimates. The studies also highlighted conditions that exacerbated the amount of bias produced (e.g., bias was greater for conditions with small cluster sizes). The analytic work and simulations lead to a number of practical recommendations for researchers.
ContributorsMistler, Stephen (Author) / Enders, Craig K. (Thesis advisor) / Aiken, Leona (Committee member) / Levy, Roy (Committee member) / West, Stephen G. (Committee member) / Arizona State University (Publisher)
Created2015
Description
Fibromyalgia (FM) is a chronic musculoskeletal disorder characterized by widespread pain, fatigue, and a variety of other comorbid physiological and psychological characteristics, including a deficit of positive affect. Recently, the focus of research on the pathophysiology of FM has considered the role of a number of genomic variants. In the current manuscript, case-control analyses did not support the hypothesis that FM patients would differ from other chronic pain groups in catechol-O-methyltransferase (COMT) and mu-opioid receptor (OPRM1) genotype. However, evidence is provided in support of the hypothesis that functional single nucleotide polymorphisms on the COMT and OPRM1 genes would be associated with risk and resilience, respectively, in a dual processing model of pain-related positive affective regulation in FM. Forty-six female patients with a physician-confirmed diagnosis of FM completed an electronic diary that included once-daily assessments of positive affect and soft tissue pain. Multilevel modeling yielded a significant gene X environment interaction, such that individuals with met/met genotype on COMT experienced a greater decline in positive affect as daily pain increased than did either val/met or val/val individuals. A gene X environment interaction for OPRM1 also emerged, indicating that individuals with at least one asp allele were more resilient to elevations in daily pain than those homozygous for the asn allele. In sum, the findings offer researchers ample reason to further investigate the contribution of the catecholamine and opioid systems, and their associated genomic variants, to the still poorly understood experience of FM.
ContributorsFinan, Patrick Hamilton (Author) / Zautra, Alex (Thesis advisor) / Davis, Mary (Committee member) / Lemery-Chalfant, Kathryn (Committee member) / Presson, Clark (Committee member) / Arizona State University (Publisher)
Created2011
Description
In rehabilitation settings, activity limitation can be a significant barrier to recovery. This study sought to examine the effects of state and trait level benefit finding, positive affect, and catastrophizing on activity limitation among individuals with a physician-confirmed diagnosis of either Osteoarthritis (OA), Fibromyalgia (FM), or a dual diagnosis of OA/FM. Participants (106 OA, 53 FM, and 101 OA/FM) who had no diagnosed autoimmune disorder, a pain rating above 20 on a 0-100 scale, and no involvement in litigation regarding their condition were recruited in the Phoenix metropolitan area for inclusion in the current study. After initial questionnaires were completed, participants were trained to complete daily diaries on a laptop computer and instructed to do so a half an hour before bed each night for 30 days. In each diary, participants rated their average daily pain, benefit finding, positive affect, catastrophizing, and activity limitation. A single item, "I thought about some of the good things that have come from living with my pain" was used to examine the broader construct of benefit finding. It was hypothesized that state and trait level benefit finding would have a direct relation with activity limitation and a partially mediated relationship, through positive affect. Multilevel modeling with SAS PROC MIXED revealed that benefit finding was not directly related to activity limitation. Increases in benefit finding were associated, however, with decreases in activity limitation through a significant mediated relationship with positive affect. Individuals who benefit find had a higher level of positive affect which was associated with decreased activity limitation. A suppression effect involving pain and benefit finding at the trait level was also found. Pain appeared to increase the predictive validity of the relation of benefit finding to activity limitation. These findings have important implications for rehabilitation psychologists and should embolden clinicians to encourage patients to increase positive affect by employing active approach-oriented coping strategies like benefit finding to reduce activity limitation.
ContributorsKinderdietz, Jeffrey Scott (Author) / Zautra, Alex (Thesis advisor) / Davis, Mary (Committee member) / Barrera, Manuel (Committee member) / Okun, Morris (Committee member) / Arizona State University (Publisher)
Created2012
Description
Evidence thus far has not lent credence to facilitate lie detection by the average person. According to studies, there are five major signs of lying: lip pursing, narrowed eyebrows, shoulder shrugs, looking to the left, and smirking. The present study aims to determine whether training people in detecting the five signs of lying will facilitate lie detection in the average person. We analyzed the accuracy of lie detection by examining the verdicts of 155 undergraduate students during simulated police interrogations. Comparisons between the trained and untrained subjects support the hypothesis that the average person is no better than chance at detecting lies through non-verbal cues.
ContributorsRivera, Aylin Melissa (Author) / Lanyon, Richard (Thesis director) / Aiken, Leona (Committee member) / Barrett, The Honors College (Contributor) / School of Criminology and Criminal Justice (Contributor) / Department of Psychology (Contributor)
Created2014-12
Description
The rates of anxiety, depression, and attempted suicide for transgender individuals are extremely elevated relative to the general population. Yet, little research has been conducted about the transgender population regarding social transition (an individual presenting as their authentic/true gender, one different than the gender they were assigned at birth, in the context of everyday life) and parental acceptance. Both of which have been shown to impact the mental health of transgender individuals. The purposes of this study were: (1) To characterize a sample of transgender adults on their age of awareness of their authentic gender identity and their age of social transition. (2) Examine whether age of social transition, (3) parental acceptance, and (4) the gap in time between age of awareness and age of social transition (awareness-transition gap) were related to mental health. (5) Examine whether parental acceptance was related to age of social transition or to awareness-transition gap. (6) Examine whether age of social transition or awareness-transition gap interact with parental acceptance as correlates of mental health. The sample consisted of 115 transgender adults, ages 18 to 64. Measures were separated into 7 subheadings: demographics, transgender
on-cisgender identity, age of awareness, age of social transition, primary caregiver acceptance, secondary caregiver acceptance, and mental health. Hypotheses were partially supported for age of social transition with mental health, parental acceptance with mental health, and awareness-transition gap with parental acceptance. This study investigated under studied concepts of social transition and parental acceptance that appear to have an effect on the mental health of transgender adults.
on-cisgender identity, age of awareness, age of social transition, primary caregiver acceptance, secondary caregiver acceptance, and mental health. Hypotheses were partially supported for age of social transition with mental health, parental acceptance with mental health, and awareness-transition gap with parental acceptance. This study investigated under studied concepts of social transition and parental acceptance that appear to have an effect on the mental health of transgender adults.
ContributorsRosenberg, Beth Ann (Author) / Gonzales, Nancy (Thesis director) / Saenz, Delia (Committee member) / Davis, Mary (Committee member) / Department of Psychology (Contributor) / Sanford School of Social and Family Dynamics (Contributor) / College of Public Service and Community Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The goal of my study is to test the overarching hypothesis that art therapy is effective because it targets emotional dysregulation that often accompanies significant health stressors. By reducing the salience of illness-related stressors, art therapy may improve overall mood and recovery, particularly in patients with cancer. After consulting the primary literature and review papers to develop psychological and neural mechanisms at work in art therapy, I created a hypothetical experimental procedure to test these hypotheses to explain why art therapy is helpful to patients with chronic illness. Studies found that art therapy stimulates activity of multiple brain regions involved in memory retrieval and the arousal of emotions. I hypothesize that patients with chronic illness have a reduced capacity for emotion regulation, or difficulty recognizing, expressing or altering illness-related emotions (Gross & Barrett, 2011). Further I hypothesize that art therapy improves mood and therapeutic outcomes by acting on the emotion-processing regions of the limbic system, and thereby facilitating the healthy expression of emotion, emotional processing, and reappraisal. More mechanistically, I propose art therapy reduces the perception or salience of stressors by reducing amygdala activity leading to decreased activation of the hypothalamic-pituitary-adrenal (HPA) axis. The art therapy literature and my hypothesis about its mechanisms of action became the basis of my proposed study. To assess the effectiveness of art therapy in alleviating symptoms of chronic disease, I am specifically targeting patients with cancer who exhibit a lack of emotional regulation. Saliva is collected 3 times a week on the day of intervention: morning after waking, afternoon, and evening. Stress levels are tested using one-hour art therapy sessions over the course of 3 months. The Perceived Stress Scale (PSS) assesses an individual's perceived stress and feelings in past and present situations, for the control and intervention group. To measure improvement in overall mood, 10 one-hour art sessions are performed on patients over 10 weeks. A one-hour discussion analyzing the participants' artwork follows each art session. The Spielberger State-Trait Anxiety Inventory (STAI) assesses overall mood for the intervention and control groups. I created rationale and predictions based on the intended results of each experiment.
ContributorsAluri, Bineetha C. (Author) / Orchinik, Miles (Thesis director) / Davis, Mary (Committee member) / Essary, Alison (Committee member) / School of Life Sciences (Contributor) / School for the Science of Health Care Delivery (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Sibling interactions are natural contexts for learning about the appropriate expression of emotions. The emotionally charged nature of sibling interactions creates a convenient context to explore emotional reactivity and regulation. The purpose of this study was to examine the relations among parent-reported sibling relationship quality, observed sibling prosocial and antisocial behaviors displayed when playing a competitive marble game, and children's emotions coded from videotape. The sample consisted of 58 twin children who are currently participating in the longitudinal Arizona Twin Project. Parents completed the Sibling Relationship Questionnaire online at 5 and 8 years. Additionally, a competitive marble game interaction between the siblings took place in the home at 8 years and was videotaped for objective coding of prosocial, antisocial, and control behavior. Facial expressions were also coded from videotape using Emotient FACET software across the marble game interaction. Three mean composites of emotion were created, including positive and negative emotional facial expressions. Results showed that parent reported warmth did not predict the occurrence of positive emotions during the sibling interaction. However, siblings with high conflict showed less fear during the interaction. Parent reports of warmth predicted the extent to which siblings differed on emotion expression, however conflict did not. Parent ratings of conflict and warmth did not predict the extent to which the sibling dyad was emotionally intense. Findings regarding genetic and environmental effects were in line with previous reports of genetic influence on prosocial behavior and negative emotion, and expressions of joy being influenced by the environment. This study investigated noteworthy aspects of the sibling relationship that appear to promote children's adaptive development.
ContributorsGanase, Anaelle Shelina (Co-author) / Oro, Veronica (Co-author) / Roth, Winter (Co-author) / Doane, Leah (Co-author) / Lemery-Chalfant, Kathryn (Co-author, Thesis director) / Miadich, Samantha (Committee member) / Davis, Mary (Committee member) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
It is a well-established finding in memory research that spacing or distributing information, as opposed to blocking all the information together, results in an enhanced memory of the learned material. Recently, researchers have decided to investigate if this spacing effect is also beneficial in category learning. In a set of experiments, Carvalho & Goldstone (2013), demonstrated that a blocked presentation showed an advantage during learning, but that ultimately, the distributed presentation yielded better performance during a post-learning transfer test. However, we have identified a major methodological issue in this study that we believe contaminates the results in a way that leads to an inflation and misrepresentation of learning levels. The present study aimed to correct this issue and re-examine whether a blocked or distributed presentation enhances the learning and subsequent generalization of categories. We also introduced two shaping variables, category size and distortion level at transfer, in addition to the mode of presentation (blocked versus distributed). Results showed no significant differences of mode of presentation at either the learning or transfer phases, thus supporting our concern about the previous study. Additional findings showed benefits in learning categories with a greater category size, as well as higher classification accuracy of novel stimuli at lower-distortion levels.
ContributorsJacoby, Victoria Leigh (Author) / Homa, Donald (Thesis director) / Brewer, Gene (Committee member) / Davis, Mary (Committee member) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
Prior research has identified that clinicians in the treatment of eating disorders often do not adhere closely to empirically-supported treatments (EST), and are particularly likely to modify Cognitive-Behavioral therapy (CBT). Several reasons for this phenomenon, dubbed "clinician drift", have been identified, including level of clinician training, education, and type of patient care. In addition to the phenomenon of clinician drift, there has been a growing controversy within the field of clinical psychology about the compatibility of ESTs and multiculturalism. Some argue that the standardization inherent to EST resists the concept of cultural adaptability; while others have countered that cultural adaptability is essential in order for empirically supported treatments to remain relevant, ethical, and effective. In order to shed more light on this issue, this study examined how clinicians tend to drift from CBT in the treatment of Latinos suffering from eating disorders, in order to accommodate Latino culture and elements of eating behavior specific to Latino populations. We both attempted to replicate prior findings regarding predictors of clinician drift, as well as build upon the little existing research into the "culturally-motivated clinician drift." It was discovered that no therapist characteristics or client characteristics were predictive of drift. However, the majority of the sample still adapted or abandoned at least part of the CBT treatment. Their responses regarding the weaknesses of CBT for their Spanish-speaking clients can provide insight into how the treatment can be modified for more diverse clients.
ContributorsJosephs, Jamie Elise (Author) / Perez, Marisol (Thesis director) / Luecken, Linda (Committee member) / Davis, Mary (Committee member) / Department of English (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12