UMD Theses and Dissertations
Permanent URI for this collectionhttp://hdl.handle.net/1903/3
New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a given thesis/dissertation in DRUM.
More information is available at Theses and Dissertations at University of Maryland Libraries.
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Item Understanding the Relevance of Extended Amygdala Reactivity to Dispositional Negativity(2021) Grogans, Shannon Elizabeth; Shackman, Alexander J; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Elevated dispositional negativity (DN; i.e., neuroticism/negative emotionality) is associated with a range of deleterious outcomes, including mental illness. Yet, DN’s neurobiology remains incompletely understood. Prior work suggests that DN reflects heightened threat-elicited reactivity in the extended amygdala (EAc), a circuit encompassing the central nucleus (Ce) and the bed nucleus of the stria terminalis (BST), and that this association may be intensified for uncertain threat. We utilized a multi-trait, multi-occasion DN composite and neuroimaging assays of threat anticipation and perception to demonstrate that individuals with elevated DN show heightened BST activation during threat anticipation. Analyses revealed that DN is uniquely predicted by BST reactivity to uncertain threat. DN was unrelated to Ce activation during threat anticipation or EAc activation during ‘threatening’-face presentation. Follow-up analyses revealed that the threat paradigms are not interchangeable probes of EAc function. These observations lay the foundation for future studies necessary to determine causation and improve interventions.Item The benefits of testing: Individual differences based on student factors(2017) Robey, Alison Marie; Dougherty, Michael R; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The testing effect, the notion that retrieval practice compared to restudying information leads to greater and longer retention, is one of the most robust findings in cognitive science. However, not all learners experience a benefit from retrieval practice. Many manipulations that influence the benefits of the testing effect have been explored, however, there is still much to learn about potential individual differences in the benefits of retrieval practice over restudy. As the testing effect grows in popularity and increasing numbers of classrooms begin implementing retrieval practice, it is essential to understanding how students’ individual differences and cognitive abilities contribute to the effect. For my dissertation, I explore how students’ cognitive abilities, specifically, episodic memory, general fluid intelligence, and strategy use, relate to the benefit of retrieval practice. In Study 1, I developed a new measure to simultaneously capture two aspects of strategy use: variation in what strategies learners use and variation in how learners use strategies. In Study 2, I examine how these two types of strategy use, along with episodic memory and general fluid intelligence can be used to predict the magnitude of the testing effect. Converging evidence from multiple analyses suggests variation in how learners use strategies was the only individual difference to influence the benefit learners receive from retrieval practice. More specifically, learners who are less adaptive and flexible in their strategy use show a greater benefit than more skilled strategy users. These findings have implications both for improving existing theories of the mechanisms of the testing effect and for determining how to best incorporate retrieval practice into classroom settings.Item MODELING MULTIPLE SOURCE USE: USING LEARNER CHARACTERISTICS AND SOURCE USE BEHAVIORS TO PREDICT RESPONSE QUALITY(2014) List, Alexandra; Alexander, Patricia A; Human Development; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Multiple source use (MSU) has been identified as both a critical competency and a key challenge for today's students, living in the digital age (Goldman & Scardamalia, 2013b). Theoretical models of multiple source use provide insights into how the MSU process unfolds and identify points at which students may encounter challenges (i.e., in source selection, processing, and evaluation, Rouet & Britt). However, understandings of MSU have been limited by two gaps in the literature. First, while points of challenge in students' MSU process have been examined independently, comprehensive models considering the joint role of source selection, processing, and evaluation in task performance have not been fully investigated. Further, while research on MSU has focused on students' behaviors when engaging with texts, individual difference factors have been considered only to a limited extent, despite their theorized importance (Rouet, 2006). The purpose of the present study was to examine the extent to which multiple source use behaviors (i.e., source selection, processing, and evaluation) and learner characteristics (i.e., prior knowledge, domain general source evaluation behaviors, stances on the target issue) predicted open-ended task performance, both independently and in conjunction with one another. Participants were 197 undergraduate students, asked to complete measures assessing their prior knowledge, stances on the Arab Spring in Egypt, the topic of the task, and domain general source evaluation behaviors. Then, participants were tasked with using a library of six sources to respond to a controversial prompt about a contemporary event (i.e., Arab Spring in Egypt). While students engaged with sources, log data of source use were collected (e.g., number of sources accessed, time on texts) and participants were asked to rate sources accessed in terms of trustworthiness, usefulness, and interestingness. Four indices were used to assess open-ended response quality: (a) word count, (b) the number of arguments included in students' responses, (c) scores on the SOLO taxonomy (Biggs & Collis, 1982), reflecting the extent to which students' responses integrated and evaluated information presented across texts, and (d) the number of citations in students' answers. Key findings included the role of students' ratings of source interestingness and time on texts as predictive of open-ended task performance. Further, students' accessing of document information about sources (e.g., author credentials that may aid in source evaluation, Britt & Aglinskas, 2002) and trustworthiness evaluations were found to be associated with SOLO scores. Overall, as compared to multiple source use behaviors, learner characteristics were found to have a more limited effect on task performance. Findings are discussed and implications for theoretical conceptions of multiple source use and instructional practice are presented.Item WORKING MEMORY ASSESSMENT AND TRAINING(2011) Atkins, Sharona M.; Dougherty, Michael R; Neuroscience and Cognitive Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Working memory, the ability to maintain and manipulate information, is a core cognitive function important for everyday life. The capacity of working-memory differs across individuals, with working-memory capacity a reliable predictor of general fluid intelligence, verbal and mathematical abilities, and classroom achievement. However, research has been inconclusive on whether working-memory is a unitary domain-general construct, or multi-component domain-specific construct. Most theories had until recently thought that working-memory was a fixed ability; however, recent research suggests that working-memory is malleable and can be improved through cognitive training. These training-induced improvements have also been shown on untrained cognitive tasks, such as general fluid intelligence, attention, reading, and math. My research examines the structure of working-memory, validates newly designed web-administered working-memory assessments, and investigates the malleability of domain specific working-memory training.