University of Lethbridge Theses
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- ItemPrefrontal regulation of exploratory behavior: complementary functions of medial prefrontal and orbitofrontal cortices in a competitive choice task(Lethbridge, Alta. : University of Lethbridge, Dept. of Neuroscience, 2025) Livingstone, Benjamin A. S.; University of Lethbridge. Faculty of Arts and Science; Gruber, Aaron J.; McDonald, Robert J.Adaptive decision-making requires balancing exploration of uncertain options with exploitation of known rewards. This thesis investigates how the rat medial prefrontal cortex (mPFC) and orbitofrontal cortex (OFC) contribute to this trade-off during a competitive binary choice task (BCT), where stereotyped responses are punished and stochastic responding is rewarded. Male Long-Evans rats received excitotoxic lesions to the mPFC, OFC, or sham surgery, then performed the BCT across stable and volatile conditions. Behavior was analyzed using generalized linear mixed models to assess trial-level changes in extraneous feeder sampling (EFS), a non-rewarded exploratory action. Lesions did not impair overall task engagement. However, OFC lesions caused a persistent elevation in EFS during the first post-operative session, consistent with impaired suppression of valueless behavior. In contrast, mPFC lesions led to an accelerated within-session decline in EFS, suggesting a deficit in sustaining exploratory strategies over time. Under environmental uncertainty, when the physical configuration of the task changed mid-session, both lesion groups showed a blunted increase in EFS and failed to reduce exploration across days. These findings reveal a dissociation in stable environments: the OFC is critical for value-based suppression of exploration, while the mPFC supports its flexible maintenance. Under uncertainty, both regions are necessary for adaptive exploration, suggesting that they converge within a broader prefrontal network recruited during volatile conditions. This work clarifies the distinct and overlapping roles of the mPFC and OFC in regulating exploration and offers insight into prefrontal contributions to flexible decision-making.
- ItemFactors predicting internet gaming disorder: the role of congruent communication(Lethbridge, Alta. : University of Lethbridge, Faculty of Health Sciences, 2025) Chen, Yulin; University of Lethbridge. Faculty of Health Sciences; Lee, Bonnie K.Previous research has highlighted separate associations between adverse childhood experiences (ACEs), family satisfaction, emotion regulation, psychological distress in relation to Internet Gaming Disorder (IGD). However, the role of communication was under-examined. Further, the specific pathways and interactions among relevant variables remain under-explored. This study aims to introduce congruent communication as a new variable and its role in internet gaming disorder and determine its relationship with other salient variables found in earlier studies correlated with IGD. This cross-sectional study recruited 179 Canadian emerging adults (ages 18–29) identified as at risk for IGD who were examined for ACEs, family satisfaction, psychological distress, emotion dysregulation, and congruent communication. Pearson correlation analyses revealed that higher ACE scores were significantly associated with greater emotion dysregulation, psychological distress, congruent communication, and lower family satisfaction. IGD severity (GAS-7) was positively correlated with emotion dysregulation and negatively associated with congruent communication and psychological well-being. Multiple regression analysis showed that the combined model of psychosocial predictors significantly accounted for variance in IGD severity, R² = .094, F (5, 173) = 3.575, p = .004. However, only congruent communication was a significant predictor of IGD severity, suggesting an interactive effect of variables and the importance of congruent communication in predicting IGD. These findings suggest that while ACEs and emotion dysregulation factors are significantly associated with IGD, their predictive power may operate in complex, overlapping ways with family dissatisfaction, psychological distress, and congruent communication. The result of this study indicates that congruent communication is a potentially significant variable for IGD in addiction counselling.
- ItemSulfur diimides and their tin(IV) complexes, and contributions to improved models for X-ray crystal structures(Lethbridge, Alta. : University of Lethbridge, Dept. of Chemistry and Biochemistry, 2025) Hill, Nathan D. D.; University of Lethbridge. Faculty of Arts and Science; Boeré, René T.; Dibble, Peter W.Modernization of X-ray crystallographic structure model refinement using NoSpherA2 and an extensive investigation of the chemical and electrochemical properties of sulfur diimides (SDIs) and their tin(IV) chloride complexes are described. NoSpherA2, an X-ray model refinement tool recently integrated into the free-to-use Olex2 program, is shown by thorough comparative analysis to significantly outperform conventional Independent Atom Model (IAM) methods. Consistent improvements in hydrogen atom placement and non-H bond precisions demonstrate the benefits of incorporating NoSpherA2 into routine processing of crystallographic data. The synthesis of a systematic series of SDIs is presented alongside a comprehensive study of their fundamental properties, both on their own and as ligands in tin(IV) complexes. Their voltammetric behaviour is meticulously documented and suggests the SDIs are acting as redox-active ligands. This foundational work positions SDIs as promising candidates in this very active field of research, and provides warrant and clear direction for future endeavours therein.
- ItemThe factors associated with suicidality among Canadian youth: a cross-sectional secondary analysis(Lethbridge, Alta. : University of Lethbridge, Faculty of Health Sciences, 2025) Doctor, Jenessa; University of Lethbridge. Faculty of Health Sciences; Sanders, JamesThe focus of this thesis was to examine the association between vulnerable youth and suicidality. This was done by conducting a secondary analysis on youth aged 15 to 29. A secondary data analysis took place utilizing the Statistics Canada 2022 Mental Health and Access to Care Survey for two separate papers. In the first paper exposure to childhood maltreatment was examined as an exposure variable for the outcome suicidality among the age group 18 to 29. Results indicated that those exposed to childhood maltreatment were more likely to experience suicidality than those not exposed. Additionally, the odds of suicidality increased with the number of maltreatment types experienced, suggesting a potential dose-response relationship. This association showed evidence for being partially mediated by mental health conditions, specifically meeting diagnostic criteria for depression or anxiety. In the second paper, minority status was created as an exposure variable for the outcome suicidality by combining racialized minorities (including Indigenous groups), and sexual identity minorities for the age group 15 to 24. These results showed minorities were more likely to experience suicidality compared to non-minority youth. This association appeared to be partially mediated by childhood maltreatment, which consisted of experiencing any form of maltreatment in the past. Findings from both studies suggest that vulnerable youth are more likely to experience suicidality, placing them at an increased risk for negative health outcomes. This emphasizes the importance of reducing systemic inequalities and developing context specific interventions to support these groups of youth. Policy makers, governments, and the community should aim to use proactive measures for prevention rather than implementing more crisis interventions in the future.
- ItemUnderstanding Indigenous data governance when collaborating with post-secondary institutions(Lethbridge, Alta. : University of Lethbridge, Faculty of Health Sciences, 2025) Shouting, Melissa A.; University of Lethbridge. Faculty of Health Sciences; Vogelsang, Laura; Rice, JackieBackground: The Blood Tribe Department of Health (BTDH), with support from the Blood Tribe’s Chief and Council, are moving toward self-determination by establishing a collaborative partnership with a local post-secondary institution to create sustainable models of governance. This thesis is a small but essential piece of the work being conducted to determine best practices for developing data collection tools to assess and evaluate the community needs of Kainai Nation while understanding the resources needed for BTDH to enact the Ownership, Control, Access, and Possession (OCAP) Principles of data storage and management. Objective: This scoping review aimed to explore and describe what exists in the current literature on Indigenous Data Governance principles, and how the information is understood and utilized in collaborative health research initiatives. A goal and purpose for this review are to explore and understand the role that Indigenous populations or communities assume in collaborative research with academics and scholars. Methodology: The search was conducted using nine databases from inception until May 2024. Two reviewers independently screened for inclusion and exclusion using the Arksey & O’Malley (2005) scoping review framework. The principal investigator conducted the final review for full-text articles, based on content and findings, with additional criteria added. Results: Fifteen reports were included. Our included reports consisted of qualitative research (n=7), mixed methods approach (n=6), and quantitative studies (n=2). Findings are presented within a framework that discusses IDG in six areas: 1) study characteristics and demographics; 2) study objectives, designs and theoretical frameworks; 3) Indigenous data governance: an overview of community engagement; 4) ethical practices in research and data governance; 5) enacting community collaboration to guide and support Indigenous data governance; 6) limitations. Conclusion: Themes identified related to Indigenous Data Governance (IDG), as well as challenges and barriers to implementing IDG in collaborative health research projects that are situated within universities. A collaborative approach involving stakeholders, culturally competent training and capacity building are approaches to move forward, but the establishment of Indigenous-led research institutes, a source of stable funding, and further collaborative research opportunities focusing on building and supporting IDG through building nation-specific data ecosystems are needed.