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 - 2 of 2
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- All Subjects: Neuroimaging
- All Subjects: Temperament
Description
Adults with autism spectrum disorder (ASD) face heightened risk of co-occurring psychiatric conditions, especially depression and anxiety disorders, which contribute to seven-fold higher suicide rates than the general population. Mindfulness-based stress reduction (MBSR) is an 8-week meditation intervention centered around training continuous redirection of attention toward present moment experience, and has been shown to improve mental health in autistic adults. However, the underlying therapeutic neural mechanisms and whether behavioral and brain changes are mindfulness-specific have yet to be elucidated. In this randomized clinical trial, I utilized functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) to characterize fMRI functional activity (Study 1) and connectivity (Study 2) and EEG neurophysiological (Study 3) changes between MBSR and a social support/relaxation education (SE) active control group. Study 1 revealed an MBSR-specific increase in the midcingulate cortex fMRI blood oxygen level dependent signal which was associated with reduced depression. Study 2 identified nonspecific intervention improvements in depression, anxiety, and autistic, and MBSR-specific improvements in the mindfulness trait ‘nonjudgment toward experience’ and in the executive functioning domain of working memory. MBSR-specific decreases in insula-thalamus and frontal pole-posterior cingulate functional connectivity was associated with improvements in anxiety, mindfulness traits, and working memory abilities. Both MBSR and SE groups showed decreased amygdala-sensorimotor and frontal pole-insula connectivity which correlated with reduced depression. Study 3 consisted of an EEG spectral power analysis at high-frequency brainwaves associated with default mode network (DMN) activity. Results showed MBSR-specific and nonspecific decreases in beta- and gamma-band power, with effects being generally more robust in the MBSR group; additionally, MBSR-specific decreases in posterior gamma correlated with anxiolytic effects. Collectively, these studies suggest: 1) social support is sufficient for improvements in depression, anxiety, and autistic traits; 2) MBSR provides additional benefits related to mindfulness traits and working memory; and 3) distinct and shared neural mechanisms of mindfulness training in adults with ASD, implicating the salience and default mode networks and high-frequency neurophysiology. Findings bear relevance to the development of personalized medicine approaches for psychiatric co-morbidity in ASD, provide putative targets for neurostimulation research, and warrant replication and extension using advanced multimodal imaging approaches.
ContributorsPagni, Broc (Author) / Braden, B. Blair (Thesis advisor) / Newbern, Jason (Thesis advisor) / Davis, Mary (Committee member) / Brewer, Gene (Committee member) / Arizona State University (Publisher)
Created2022
Description
Approximately 20% of youth experience mental health problems (Vasileva et al., 2021), and dimensions of early childhood temperament, specifically negative affectivity and effortful control, predict later mental health (Rothbart, 2007). Examining temperament using person-centered methods, particularly in stressful contexts, may improve our understanding of vulnerability to adolescent emotional problems. The current study examined whether specific patterns, or types, of infant temperament longitudinally predicted adolescent anxiety and depression symptoms and whether family relationship stress moderated this association. We hypothesized that infants with a Negative Dysregulated temperament would experience higher anxiety and depression symptoms in later childhood compared to those with a Typical Expressive temperament, and that family relationship stress would exacerbate this link. In an ongoing-longitudinal study of families with twins (N=563, 51% female, 29.8% Hispanic/Latinx, 58.4% White; Lemery-Chalfant et al., 2019), primary caregivers (PCs) reported on infant temperament at 12 months (IBQ; Gartstein & Rothbart, 2003, α=.74-.90). In a prior study (Murillo et al., 2023), latent profile analysis yielded three infant temperament types: Negative Dysregulated, Positive Well-Regulated, and Typical Expressive. PCs reported on partner strain (PSS; Schuster, Kessler, & Asseltine, 1990, α=.87) and family conflict (FCS; Porter & O’Leary, 1980, α=.80) at age 8 and a composite of these two measures represented Family Relationship Stress (r = .689). Confirmatory factor analysis was used to form Depression and Anxiety outcome composites based on PC (4 reports), secondary caregiver (2 reports), teacher (2 reports), and self-report (3 reports) measures of depression and anxiety symptoms collected from ages 8-11 (HBQ, Armstrong & Goldstein, 2003; BPI, Measelle et al., 1998, all α’s > .80). We randomly selected one twin from each pair and conducted regression analyses, and then used the second twin for an internal replication. Family relationship stress had a significant main effect on both anxiety and depressive symptoms. The Negative Dysregulated temperament type did not predict anxiety and depression at ages 8-11, however, it interacted with family relationship stress to predict anxiety and depression in 1 of 2 samples. When family relationship stress was low, the Negative Dysregulated type was significantly associated with higher anxiety and depression outcomes compared to the Typical Expressive type, and high family relationship stress was significantly associated with lower depression outcomes. Elucidating these longitudinal relations is important for informing early intervention and reducing the burden of adolescent psychopathology.
ContributorsSingh, Ajuni (Author) / Lemery-Chalfant, Kathryn (Thesis director) / Corbin, William (Committee member) / Davis, Mary (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor) / Sanford School of Social and Family Dynamics (Contributor)
Created2023-12