Browsing by Subject "cognition"
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Item Alpha synuclein functions as a sex-specific modulator of cognition and gene expression(2022-12) Brown, JenniferNeurodegenerative diseases such as Alzheimer’s and Parkinson’s impact large portions of the population. Though such diseases have distinguishing features, they also often share pathology and symptomology. Alpha synuclein (αSyn; gene SNCA) is a protein commonly found in a range of neurodegenerative conditions. αSyn can interact with tau and amyloid-beta to modulate disease phenotypes, but its normal functions remain incompletely characterized. To explore the contribution of αSyn to Alzheimer’s disease, I first asked whether reducing αSyn in a mouse model of Alzheimer’s would improve cognition. Using a translationally relevant strategy, the reduction of αSyn reveled a sex-specific effect whereby male, but not female, mice showed improved spatial memory. Follow-up studies with constitutive SNCA knockout mice revealed a previously unreported female-specific deficit in spatial learning and memory. Next, we utilized electrophysiology, immunofluorescence imaging and transcriptomics to elucidate potential mechanisms underlying this effect. Results revealed a novel impairment in long-term potentiation, as well as differential expression of genes related to learning and immune function in female mice in response to SNCA ablation. These results not only describe a novel sex-specific function of αSyn, but provide translationally-relevant information regarding the potential effects of using αSyn reduction as a therapeutic strategy for neurodegenerative conditions.Item Ataxin-1 in cognition and mood(2017-11) Asher, MelissaAtaxin-1 (ATXN1), the gene mutated in spinocerebellar ataxia type 1 (SCA1), may affect cognition and mood, but much remains unknown, including which brain areas are responsible, whether ATXN1 affects mood in mice, and the mechanisms of these effects. To answer these questions, we characterized cognition and mood in several ATXN1 mutant mouse lines: Atxn1+/- and Atxn1-/- mice to compare 50% and 100% loss of ATXN1; Atxn1154Q/2Q and Atxn178Q/2Q mice to compare SCA1-like polyglutamine expansions of different lengths; and Purkinje cell specific Pcp2-ATXN1[82Q] mice to determine the cerebellar contribution. Atxn1-/- and Atxn1154Q/2Q mice showed cognitive deficits. Reduced hippocampal neurogenesis in Atxn1-/- mice may explain this. Cognition was not affected in Atxn1+/-, Atxn178Q/2Q, or Pcp2-ATXN1[82Q] mice. We also observed mood abnormalities not consistent with depression or anxiety. These results provide a foundation for further research into the function of ataxin-1 and the potential side effects of reducing ataxin-1 levels to treat SCA1.Item ESL Teachers’ Knowledge of and Experience with Written Corrective Feedback(2017-04) Cao, PeihongABSTRACT Written Corrective Feedback (WCF) in writing classes is fundamental to interactions between teachers and students about students’ writing and to help students further improve their writing. As one of the main feedback sources, teachers’ cognition (e.g., teachers’ thoughts, knowledge, and beliefs) needs to be probed to properly understand teachers and their teaching (Borg, 2006). Currently, there is little research regarding teachers’ cognition and their practice of offering WCF in mainland China. The purpose of this study was to explore ESL teachers’ knowledge of, experience with and practice of WCF, and to investigate the connection among these aspects. The participants were teachers of English from a major normal university. The phenomenological methodology was used to explore teachers’ cognition and practice of WCF when teaching writing to undergraduate and graduate students. The study employed a triangulated approach that included a questionnaire administered to 55 teachers, interviews with two teachers and a study of the two teachers’ feedback responses to 68 students’ papers/journal entries, which were collected to further explore the interviewees’ practice of WCF. Questionnaire data was statistically aggregated and tabulated. The interview data was analyzed using Hycner’s 15 steps. The teachers’ responses on students’ papers were analyzed according to WCF types (direct CF, indirect CF, metalinguistic, focus of feedback, electronic CF, and reformulation) and error types (organizational errors, stylistic errors, and linguistic errors) and the results were tabulated. Findings indicated that ESL teachers possessed different levels of knowledge concerning WCF and used a varying number of WCF types to target error types. Most teachers were not well trained or provided with opportunities to be equipped with the necessary skills, to further improve their cognition and practice of providing feedback. Differences existed between teachers’ perceptions of the employment of WCF and their actual practice of it. The findings are an indication that administrators should consider employing multiple strategies to better equip teachers of writing to teach and provide feedback more effectively and efficiently. The future of providing WCF on writing in mainland China is dependent upon a workforce that excels in feedback cognition and practice.Item For the Love of Technology: How Aesthetics Define Emotions in a Digital Education Setting(2021) Brower, AutumnEducators often admit that they are aware that emotion plays a significant role in students’ educational success, yet most of the scientific literature measures cognition in education to the exclusion of emotion. This study is intended to be a proof of concept design for future research. Its goal is to assess how an individual’s aesthetic value of a product might be a way to gauge emotion in educational settings. Three faculty members at the University of Minnesota were interviewed about their viewpoints pertaining to the product design of a static Canvas page and asked to evaluate its design based on its visceral, behavioral, and reflective beauty. Page orientation and font were used to represent product design. Results of the interviews showed that readability was the most frequently mentioned reason people are drawn to certain aesthetic features of a product’s design in digital education, followed by alignment, accessibility, mobile devices, tradition, and font personalities. Additionally, this paper evaluates the participants’ valence response; their responses to the design’s functionality; and their thoughts on meaningfulness as they relate to Norman’s (2007) three aesthetic levels of product design. At the end of the paper, suggestions for how we might use this data to increase productivity in our classes and enhance educational technology are addressed. Future directions for how these results might apply to cognition, emotion, and computation are also discussed.Item The Information Economics of Social Interactions(2019-02) Heinen, VirginiaWhen animals should attend to information is a diverse and fascinating topic, with answers ranging from neurological mechanisms to evolutionary forces. The broad theme of this thesis is examining learning and information use and social interactions from a game theoretical perspective, but I use this framework to address two distinct topics. The first half of my thesis is a fairly traditional investigation hypotheses about animals’ use of social information in uncertain environments, and how social information use fits within the broader interaction of environmental certainty and information reliability. The second half introduces the more novel topic of behavioral conventions, or coordination problems with multiple equilibria, and how topics in behavioral ecology can benefit from a conventions perspective. Through investigating conventions in general, and conventional communication specifically, I develop a novel laboratory system for investigating learned conventional communication.Item Iron Deficiency, Depression, and Other Affective Disorders in Female State Fair Attendees(2018-05) Price, KathleenIron deficiency persists as the most prevalent nutrient deficiency on the planet, and women of menstruating age are at high risk due to menstrual blood loss. Recent data suggests that iron deficiency in the absence of anemia impacts quality of life, and currently the prevalence of menstruating females with inadequate ferritin values in the US is high. Although the literature on iron status and depression is conflicting, a relationship is suggested with a proposed mechanism of altered neurotransmitter functioning. This cross-sectional study gathered survey data and blood samples from 182 female subjects at the Minnesota State Fair in August of 2015. Whole blood hemoglobin, hematocrit, serum ferritin and serum TIBC were determined and correlated to survey data detailing reported iron deficiency symptoms and their severity, including the PHQ9, a validated depression screen. 15% of subjects were anemic as defined by a hematocrit value under 38% or a hemoglobin value below 12 g/dL. Additionally, 74% had low ferritin status as defined by a value less than 20 g/L. Overall, 10% of subjects reported moderate to severe depression as defined by the PHQ9. Although independent relationships between anemia, low ferritin values, or elevated TIBC values and depression were not seen, inclusion of symptomatic iron deficiency, a variable combining iron deficiency symptoms of dizziness and shortness of breath to assess whether deficiency was exerting a physiological effect, improved the correlation between the biochemical measures of iron status and depression (p < 0.0001), as well as self-reported incidence of other affective and executive functioning disorders, including stress or moodiness, ease of anger, emotional unresponsiveness, and alertness or concentration. This data suggests that iron deficiency must be symptomatic for the association with depression and other affective or executive functioning disorders to be apparent.Item Linking topiramate exposure to changes in electrophysiological activity and behavioral deficits through quantitative pharmacological modeling(2019-05) Callisto, SamuelTopiramate is a broad-spectrum anti-epileptic drug used to treat a variety of conditions, including epilepsy, migraine, substance abuse, mood, and eating disorders. We investigated the effects of topiramate on the working memory system using population pharmacokinetic-pharmacodynamic modeling and unsupervised machine learning approaches. Working memory is the capacity-limited neurocognitive system responsible for simultaneous maintenance and manipulation of information in order to achieve a goal. Behavioral and electrophysiological indices of working memory function were measured using data collected during a double-blind, placebo-controlled crossover study in healthy volunteers. Subjects completed a Sternberg working memory task, during which accuracy and reaction time were measured, while subjects’ EEG was recorded. A pharmacokinetic-pharmacodynamic model was constructed which demonstrated that accuracy decreased linearly as a function of plasma concentration, and that the magnitude of individual deficits was predicted by working memory capacity. A separate pharmacokinetic-pharmacodynamic model was developed which showed that spectral power in the theta frequency band (4-8 Hz) recorded during the retention phase of the Sternberg task increased as a function of plasma concentration. Furthermore, a mixture model identified two subpopulations with differential sensitivity in topiramate-induced theta reactivity. In the subpopulation defined by lower reactivity, reaction times were 20% slower than in the high theta reactivity subpopulation. Principal component regression was used to quantify the relationship between changes in multiple measures of electrophysiological activity and behavioral deficits. Theta power during retention was found to be the best predictor of topiramate-related behavioral deficits. Performance on another working memory task, Digit Span Forward, was also predicted by theta power during retention, as well as alpha (8-12 Hz) power during encoding and retrieval stages. In conclusion, two treatment-independent factors that predict differences in behavioral and electrophysiological responses to topiramate administration were identified: working memory capacity and theta reactivity. Future research will be needed to determine the utility of these demographic factors in predicting risk of cognitive side effects in patients eligible for treatment with topiramate.Item Relationships Among Physical Activity, Motor Skill Competence, Cardiovascular Fitness, Perceived Competence, and Cognition In Preschool Children(2018-06) Zeng, NanEarly childhood is marked as one of the most critical and intensive periods of development in the human lifespan. Physical activity is a crucial contributor to health and cognition in early childhood, and therefore is considered to be a vital part of development. In this cross-sectional study, my purpose was to examine relationships among physical activity, motor skill competence, perceived physical competence, cardiovascular fitness, and cognition in preschool children, including possible gender differences in all variables. I recruited 65 preschool children (4-6 years old) from two local elementary schools in Minneapolis, Minnesota. Children’s 3 days physical activity during school time was assessed via Actigraph Link; motor skill competences was measured via Test of Gross Motor Development–Second Edition; perceived physical competence was assessed via Pictorial Scale of Perceived Competence and Social Acceptance; cardiovascular fitness was assessed via a modified YMCA 3-Minute Step Test; and cognition was assessed via the computer-administered NIH Toolbox. Using IBM-SPSS 25.0 (IBM, Inc., Armonk, NY), I computed Pearson Product-Moment Correlation Coefficients to determine the relationships among all outcomes. I used independent samples t-test to detect gender differences in all measures. I found that preschool children’s moderate-to-vigorous physical activity (MVPA) during school time was not significantly related to their motor skills competence (r = 0.182, p > 0.05), perceived competence (r = 0.121, p > 0.05), cardiovascular fitness (r = -0.141, p > 0.05), cognition (r = -0.095, p > 0.05), but their step counts were significantly positively related to motor skills competence (r = 0.282, p < 0.05), with preschool children’s motor skill competence was a significant predictor of step counts [F (4, 63) = 4.65, β = 0.12, p < 0.05, R2 = 0.24] after age, gender, and BMI were controlled. In addition, I found that perceived competence was significantly positively correlated with motor skills competence (r = 0.366, p < 0.01), and was a significant predictor of motor skills competence [F (4, 63) = 2.66, β = 0.26, p = 0.04, R2 = 0.15] in preschool children. Meanwhile, I observed that children’s cognition was significantly positively correlated with motor skills competence (r = 0.266, p < 0.01) and cardiovascular (r = 0.372, p < 0.01), respectively, but only cardiovascular fitness seemed to be a significant predictor of cognition [F (2, 62) = 4.52, β = 0.35, t = 2.73, p = 0.01, R2 = 0.14]. I observed significant mean differences in preschool children’s MVPA, with boys spending more time in MVPA as compared to girls (Mean: 41.72 mins vs. 36.87 mins, t = -2.04, p < 0.05, Cohen’s d = 0.51). I also found that boys took more steps per minute than girls (Mean: 22.26 vs. 19.11, t = -3.96, p < 0.01, Cohen’s d = 0.98). Last, I found that boys demonstrated higher motor skill competence than girls (Mean: 33.16 vs. 29.88, t = -2.13, p < 0.05, Cohen’s d = 0.53). The current study supports the need for effective strategies that simultaneously promote motor skill competence, cardiovascular fitness, cognition, and physical activity behaviors in early childhood. Future research with larger and more diverse samples is necessary to further explore the relationships of preschool children’s physical activity patterns (inside and outside of school) with other health-related fitness.Item The Roles of Convergent, Divergent Thinking, and Contextual Focus during Scientific Reasoning: Birth of the “Z” Model(2019-09) Quillien, Jean-BaptisteThe aim of this paper is to bridge the process of scientific reasoning with the field of cognitive science, and more specifically, the cognitive mechanisms involved during reasoning. This intent of bridging scientific reasoning with cognitive mechanisms gave birth to a new model: the “Z” model of scientific reasoning. This model integrates the traditional scientific reasoning steps while depicting the cognitive mechanisms and mental flexibilities at use during reasoning. The goal of this experiment was to test the “Z” model and thus investigate the role of divergent and convergent thinking during scientific reasoning. In addition, the “Z” model highlights the importance of Contextual Focus during scientific reasoning. Contextual Focus is defined as the cognitive shift between modes of thoughts. Contextual Focus was tested to investigate its predictive power on our specific measure of scientific reasoning (Bouncing Ball Reasoning Task; BBRT) and a broader measure of scientific reasoning (Lawson Test of Scientific Reasoning; LTSR). In addition, the predictive power over scientific reasoning performances of Intellect and Openness, the personality traits of interest, was also tested. First, we hypothesized that participants experimentally primed to think divergently should perform better during the exploration of the problem space during a scientific reasoning task (Phase 1 of BBRT). As predicted, participants in the divergent thinking group generated on average more hypotheses than the participants in the convergent thinking and the control groups. Secondly, we hypothesized that participants experimentally primed to think convergently should perform better during the exploitation of the evaluative space during a scientific reasoning task (Phase 2 of BBRT). As predicted, participants in the convergent thinking group displayed on average fewer categorical errors than the participants in the divergent thinking or the control groups. In addition, Contextual Focus was found to be a significant predictor of the overall performance in exploring the problem space of our specific scientific reasoning problem. Intellect score over broader scientific reasoning (LTSR) performance, Contextual Focus and Intellect were found to be significant predictors of broader scientific reasoning (LTSR) performance. Those findings can also be interpreted with broader cognitive science lenses. Given that complex mental tasks such as problem solving and critical thinking also require divergent and convergent thinking, future research should test whether the priming used during our experimental protocol also leads to an advantage on more general reasoning tasks.Item The Royal Road to Semantic Cognition: Untangling Semantic Components in Temporal Lobe(2015-06) Hoversten, ShaneFunctional magnetic resonance imaging (fMRI) research into semantic cognition has returned highly variable results, especially in anterior temporal regions. One likely reason for this variability is that tasks used to investigate this topic are believed to engage only shallow semantic processing. Another reason is that certain classes of stimuli (particularly abstract words) are often confounded by un-modeled social or emotional content; many researchers believe that it is this social and emotional information, rather than general semantic information per se, that elicits response in ATL. Our experiments use a task designed to elicit deep semantic processing (the triads task) along with explicit investigation into the social and emotional content of semantic stimuli to try to pry these factors apart and characterize the temporal lobes in general, and the ATLs in particular, with regard to their involvement in semantic cognition. We find that, contrary to some reports, the ATL is highly involved in semantic processing even in its most anterior aspects; that counter to prominent theories this involvement is not (or is not always) due to the inclusion of social or emotional content in the stimuli; and that a semantic task that engages deep semantic processing has an activation signature that closely resembles the signature of full-sentence processing, despite the seeming un-structured nature of the processing required by the triads task. We propose a general role for ATL as semantic integrator to characterize these disparate findings.Item The Social Pattern and Causes of Dementia Prevalence Decline in the United States(2022-07) Lee, MarkAge-adjusted dementia prevalence has significantly declined in the United States over the last 25 years, despite little advancement in the biomedical treatment of Alzheimer’s Disease or improvement in proximal dementia risk factors. In this dissertation, I analyze data from the Health and Retirement Study (HRS) to improve current understanding of the descriptive trends and causal mechanisms underlying dementia prevalence decline. In my first study, I rebut the argument that dementia decline in the HRS is an artefact of unmeasured panel conditioning. I show that practice effects do not bias the estimated secular trend in dementia prevalence after accounting for selective panel attrition. In my second study, I argue that cohort trends in early life risk factors offer a more plausible explanation of the observed dementia improvement than period trends, which have been emphasized in previous research. In my third study, I empirically test the contribution of early life risk factors to cohort trends in dementia prevalence. I find that age- and sex-adjusted dementia prevalence declined 2.3 percentage points per 10-year increase in birth year for cohorts born 1892-1952. The majority (72%) of this trend was explained by increases in educational attainment for more recent cohorts. Proximal risk factors had little influence net of education and other early life factors. The trend in dementia decline was steeper for Black than White Americans, and the causal mechanisms also differed by race. In my fourth study, I document cohort trends in midlife cognitive aging. I find that, compared with those born 1942-1947, those born 1954-1959 entered midlife with lower cognitive function, but exhibited greater maintenance of cognition over time. This suggests that dementia prevalence may continue to improve as this latter-born cohort ages. Overall, this research reinforces the importance of social improvement (especially educational expansion) across the 20th century for cognitive health improvements in the 21st century. This work indicates that interventions to reduce or delay dementia and ameliorate racial disparities should be expanded to include social determinants of health across the life course.