Matching Items (40)

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The effects of urbanization and human disturbance on problem solving in juvenile house finches (Haemorhous mexicanus)

Description

Urbanization exposes wildlife to many unfamiliar environmental conditions, including the presence of novel structures and food sources. Adapting to or thriving within such anthropogenic modifications may involve cognitive skills, whereby

Urbanization exposes wildlife to many unfamiliar environmental conditions, including the presence of novel structures and food sources. Adapting to or thriving within such anthropogenic modifications may involve cognitive skills, whereby animals come to solve novel problems while navigating, foraging, etc. The increased presence of humans in urban areas is an additional environmental challenge that may potentially impact cognitive performance in wildlife. To date, there has been little experimental investigation into how human disturbance affects problem solving in animals from urban and rural areas. Urban animals may show superior cognitive performance in the face of human disturbance, due to familiarity with benign human presence, or rural animals may show greater cognitive performance in response to the heightened stress of unfamiliar human presence. Here, I studied the relationship between human disturbance, urbanization, and the ability to solve a novel foraging problem in wild-caught juvenile house finches (Haemorhous mexicanus). This songbird is a successful urban dweller and native to the deserts of the southwestern United States. In captivity, finches captured from both urban and rural populations were presented with a novel foraging task (sliding a lid covering their typical food dish) and then exposed to regular periods of high or low human disturbance over several weeks before they were again presented with the task. I found that rural birds exposed to frequent human disturbance showed reduced task performance compared to human-disturbed urban finches. This result is consistent with the hypothesis that acclimation to human presence protects urban birds from reduced cognition, unlike rural birds. Some behaviors related to solving the problem (e.g. pecking at and eying the dish) also differed between urban and rural finches, possibly indicating that urban birds were less neophobic and more exploratory than rural ones. However, these results were unclear. Overall, these findings suggest that urbanization and acclimation to human presence can strongly predict avian response to novelty and cognitive challenges.

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Date Created
  • 2015-05

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Effects of Decreased Opportunity to Sleep on Cognitive Performance and Mood by Sex in Older Adults

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Objectives: The goal of this study was to compare older adults (ages 60 to 80) with a fixed sleep schedule compared to a restricted sleep schedule. The purpose was to

Objectives: The goal of this study was to compare older adults (ages 60 to 80) with a fixed sleep schedule compared to a restricted sleep schedule. The purpose was to determine if reducing one's sleep by an hour each night for 12 weeks, led to worse cognition and mood over time. Study Design: The study contained two groups: older adults with their sleep restricted and older adults with their sleep un-restricted. Participants were recruited by researchers at Arizona State University and The University of Arizona by advertising in newspapers, on flyers in senior centers, and on radio stations. After rigorous screening for health conditions, current sleep patterns and depression, individuals entered the study. Participants completed the Geriatric Depression Scale after two weeks of baseline, and again after treatment week 14 of the study. Likewise, males and females performed three cognitive tests after two weeks of baseline, and again after treatment week 14 of the study. These cognitive tests included Stroop Color and Word Test, Trail making and PVT. Results: The depression scale and three cognitive tests showed that there was no significant difference with cognition and mood over 14 weeks between individuals with a fixed sleep schedule compared to a restricted sleep schedule. Conclusions: Reducing older adult's sleep duration by an hour each night for 14 weeks does not produce negative effects, and does not provoke signs of depression or weakened cognition.

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Date Created
  • 2017-05

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On Memory and Physiological Signals of Experts and Novices-Case Study: Chess

Description

Abstract Chess has been a common research topic for expert-novice studies and thus for learning science as a whole because of its limited framework and longevity as a game. One

Abstract Chess has been a common research topic for expert-novice studies and thus for learning science as a whole because of its limited framework and longevity as a game. One factor is that chess studies are good at measuring how expert chess players use their memory and skills to approach a new chessboard con�guration. Studies have shown that chess skill is based on memory, speci�cally, "chunks" of chess piece positions that have been previously encountered by players. However, debate exists concerning how these chunks are constructed in players' memory. These chunks could be constructed by proximity of pieces on the chessboard as well as their precise location or constructed through attack-defense relations. The primary objective of this study is to support which one is more in line with chess players' actual chess abilities based off their memory, proximity or attack/defense. This study replicates and extends an experiment conducted by McGregor and Howe (2002), which explored the argument that pieces are primed more by attack and defense relations than by proximity. Like their study, the present study examined novice and expert chess players' response times for correct and error responses by showing slides of game configurations. In addition to these metrics, the present study also incorporated an eye-tracker to measure visual attention and EEG to measure affective and cognitive states. They were added to allow the comparison of subtle and unconscious behaviors of both novices and expert chess players. Overall, most McGregor and Howe's (2002) results were replicated supporting their theory on chess expertise. This included statistically significance for skill in the error rates with the mean error rates on the piece recognition tests were 70.1% for novices and 87.9% for experts, as well as significance for the two-way interaction for relatedness and proximity with error rates of 22.4% for unrelated/far, 18.8% for related/far, 15.8% for unrelated
ear, and 29.3% for related
ear. Unfortunately, there were no statistically significance for any of the response time effects, which McGregor and Howe found for the interaction between skill and proximity. Despite eye-tracking and EEG data not either support nor confirm McGregor and Howe's theory on how chess players memorize chessboard configurations, these metrics did help build a secondary theory on how novices typically rely on proximity to approach chess and new visual problems in general. This was exemplified by the statistically significant results for short-term excitement for the two-way interaction of skill and proximity, where the largest short-term excitement score was between novices on near proximity slides. This may indicate that novices, because they may lean toward using proximity to try to recall these pieces, experience a short burst of excitement when the pieces are close to each other because they are more likely to recall these configurations.

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Date Created
  • 2017-05

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The first in its class? The cognitive effects of the contraceptive hormone drospirenone when given with and without an estrogen

Description

Drospirenone (DRSP) is a novel, pharmacologically unique synthetic progestin with properties more similar to the endogenous progestogen, progesterone, than any other progestin currently on the market. While a significant amount

Drospirenone (DRSP) is a novel, pharmacologically unique synthetic progestin with properties more similar to the endogenous progestogen, progesterone, than any other progestin currently on the market. While a significant amount of research has been conducted on the risks associated with DRSP, the impact of DRSP on cognition, especially in reference to learning and memory, is not well understood. However, it is imperative to fully understand the cognitive effects of DRSP, both alone and in combination with EE (as taken in a combined oral contraceptive [COC]), so that women and their physicians can make a fully-informed decision when deciding to take a DRSP-containing COC. Study 1 examined the effects of three doses of DRSP in order to determine the optimal dose for combining with EE, and found that the medium dose of DRSP (30 µg/day) enhanced spatial working memory performance. In Study 2, the medium dose of DRSP from Study 1 was combined with low (0.125 µg/day) and high (0.3 µg/day) doses of EE to examine the effects of DRSP as taken with EE in a COC. The results from Study 2 indicated that when DRSP was combined with a low, but not high, dose of EE, spatial working memory impairments were seen at the highest working memory load. Anxiety-like behavior was evaluated using the OFT, and DRSP was shown to decrease measures of anxiety-like behavior. Additionally, while treatment with a high dose of EE decreased several measures of anxiety-like behavior, a low dose of EE did not, suggestive of a dose response. Taken together, the findings presented from both studies suggest that some of the cognitive effects of the combination of DRSP with EE are different than those of either hormone administered on its own. Further exploration in a preclinical, ovary-intact animal model is a next step to fully understand these effects in the translational context of a contraceptive, given that women taking an EE-DRSP combination are typically ovary-intact.

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Date Created
  • 2017-05

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An Evaluation of the Cognitive Effects of Clinically Used Combination Hormone Therapy

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Estradiol (E2) and Levonorgestrel (Levo) are two hormones commonly used in hormone therapy (HT) to decrease symptoms associated with menopause. Both of these hormones have been shown to have beneficial

Estradiol (E2) and Levonorgestrel (Levo) are two hormones commonly used in hormone therapy (HT) to decrease symptoms associated with menopause. Both of these hormones have been shown to have beneficial effects on cognition when given alone in a rodent model of menopause. However, it is unknown whether these hormones, when taken in combination, are beneficial or harmful to cognition. This is a critically important question given that these hormones are most often given in combination versus separately. This thesis is composed of two studies examining the cognitive effects of E2 and Levo using a rat model of surgical menopause. Study 1 assessed how the dose of E2 treatment in rats impacted cognitive performance, and found that low dose E2 enhanced working memory performance. Next, based on the results from Study 1, Study 2 used low dose E2 in combination with different doses of Levo to examine the cognitive effects of several E2 to Levo ratio combinations. The results from Study 2 demonstrated that the combination of low dose E2 with a high dose of Levo at a 1:2 ratio impaired cognition, and that the ratio currently used in HT, 3:1, may also negatively impact cognition. Indeed, there was a dose response effect indicating that working and reference memory performance was incrementally impaired as Levo dose increased. The findings in this thesis suggest that the E2 plus Levo combination is likely not neutral for cognitive function, and prompts further evaluation in menopausal women, as well as drug discovery research to optimize HT using highly controlled preclinical models.

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Date Created
  • 2016-12

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Effects of Ketones from Intermittent Fasting

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Ketone bodies are produced in the liver from the acetyl CoA derived from fatty acids that cannot enter the Krebs cycle. This is a sub-analysis of a larger study which

Ketone bodies are produced in the liver from the acetyl CoA derived from fatty acids that cannot enter the Krebs cycle. This is a sub-analysis of a larger study which had numerous outcome markers. This analysis focuses on the relationship between ketone blood levels and cognition. The study looked at the relationship between Time Restricted Feeding (TRF), a method of intermittent fasting. TRF is something that can be easily adapted into an individual’s lifestyle and has been shown to have multiple advantages. This 8-week study began with 23 enrolled participants, but due to COVID-19 only 11 participants could be tested for cognition and blood ketone levels after week 4. All participants had similar ranges of weight, height, age, BMI, hip, and waist measurements at baseline. Moreover, these demographic variables were not related to ketone levels or cognition. The data indicate that ketone bodies increased in participants practicing TRF and that the increase in ketone bodies in the blood, specifically β-hydroxybutyrate was strongly correlated to increased cognitive function. This is consistent with theories that elevated ketone levels allowed for early hunter-gather communities and other mammals to survive prolonged periods of nutrient deprivation while keeping high cognitive function.

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Date Created
  • 2020-05

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Highly Gifted Students in the Sciences: Predicting Academic Proficiency Based on Personality, Conative, and Cognitive Traits

Description

This study sought to identify traits that act as possible predictors of academic science proficiency of highly gifted adolescent students. A combination of cognitive, personality, and conative traits were selected

This study sought to identify traits that act as possible predictors of academic science proficiency of highly gifted adolescent students. A combination of cognitive, personality, and conative traits were selected for evaluation as predictors of scientific proficiency using student General Ability Index (GAI), Revised NEO Personality Index (NEO-PI R), and Kolbe Index scores to evaluate each, respectively. Statistical correlational analyses revealed that high expressions of the conative trait Fact Finder and the personality traits Ideas and Straight-forwardness predicted higher degrees of academic science proficiency. In contrast, lower expressions of the personality traits Excitement Seeking and Order predicted higher degrees of scientific proficiency. Further, stepwise regression confirmed that the NEO-PI R facets of Excitement Seeking and Ideas traits were significant predictors of science proficiency and suggested that the personality trait Vulnerability may also be a predictor. The repeated appearance of the Excitement Seeking and Ideas facets and the dependence of the other identified traits suggests that these traits were the most promising possible predictors of scientific proficiency in highly gifted students and should be the target of future research.

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Date Created
  • 2014-05

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The Importance of Studying Interactions With Ovarian Hormones: Implications for Depressive Symptoms in Premenopausal and Menopausal Women

Description

The relevance of depression in the clinical realm is well known, as it is one of the most common mental disorders in the United States. Clinical depression is the leading

The relevance of depression in the clinical realm is well known, as it is one of the most common mental disorders in the United States. Clinical depression is the leading cause of disease for women worldwide. The sex difference in depression and anxiety has guided the research of not just recent studies but older studies as well, supporting the theory that gonadal hormones are associated with the mechanisms of emotional cognition. The scientific literature points towards a clear correlative relationship between gonadal hormones, especially estrogens, and emotion regulation. This thesis investigates the neural pathways that have been indicated to regulate mood and anxiety. Currently, the research points to the hypothalamic-pituitary-adrenal axis, which regulates the stress response through its ultimate secretion of cortisol through the adrenal cortex, and its modulated response when exposed to higher levels of estrogen. Another mechanism that has been investigated is the interaction of estrogen and the serotonergic system, which is noteworthy because the serotonergic system is known for its importance in mood regulation. However, it is important to note that the research seeking to determine the neurobiological underpinnings of estrogen and the serotonergic system is not expansive. Future research should focus on determining the direct relationship between cortisol hypersecretion and estrogens, the specific neurobiological effects of serotonergic receptor subtypes on the antidepressant actions of estrogens, and the simultaneous effects of the stress and serotonergic systems on depressive symptoms.

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Date Created
  • 2021-05

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Relationships Between the Inflammatory Responses of the Immune System and Periods of Critical Hormonal Shifts in Females Across the Lifespan: A Pregnancy Review

Description

In females, critical hormonal shifts occur during puberty, menstruation, pregnancy, and <br/>menopause. The fluctuating ovarian hormone levels across a woman’s lifespan likely contribute <br/>to inflammatory responses driven by the immune

In females, critical hormonal shifts occur during puberty, menstruation, pregnancy, and <br/>menopause. The fluctuating ovarian hormone levels across a woman’s lifespan likely contribute <br/>to inflammatory responses driven by the immune system, which is regulated by a variety of <br/>physiological pathways and microbiological cues. Pregnancy in particular results in drastic <br/>changes in circulating hormone profiles, and involves a variety of physiological changes, <br/>including inflammatory responses of the immune system. There is evidence that these effects are <br/>mediated, in part, by the significant hormone fluctuations that characterize pregnancy and <br/>postpartum periods. This thesis highlights and synthesizes important physiological changes <br/>associated with pregnancy, and their potential implications on cognitive and brain aging in <br/>women. A tertiary model of cognition is presented depicting interactions between hormonal <br/>history, reproductive history, and immune functions. This research is important to create a better <br/>understanding of women’s health and enhance medical care for women throughout pregnancy <br/>and across reproductive hormone shifts across the lifespan.

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Date Created
  • 2021-05

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Sit-to-stand task with physical and cognitive perturbations: A comparison of linear and nonlinear methods of analyzing postural data

Description

Variability is inherent in human movement, and poses a challenge to researchers attempting to measure balance. Human movement variability was analyzed using two methods: standard deviation and largest Lyapunov exponent.

Variability is inherent in human movement, and poses a challenge to researchers attempting to measure balance. Human movement variability was analyzed using two methods: standard deviation and largest Lyapunov exponent. The experiment was a sit-to-stand task with physical and cognitive perturbations. The physical perturbation consisted of stable and unstable platform conditions, while the cognitive perturbation consisted of a counting task. The data were collected from 24 healthy young adults. The purpose of this study was to compare the standard deviation and largest Lyapunov exponent as measures of stability, and to determine the Lyapunov exponent's sensitivity to cognitive perturbation. Evidence suggests that the Lyapunov exponent serves as a more accurate indicator of stability than standard deviation, and that it lacks sensitivity to the counting task.

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Date Created
  • 2016-12