Matching Items (16)

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Navigating to new frontiers in behavioral neuroscience: traditional neuropsychological tests predict human performance on a rodent-inspired radial-arm maze

Description

We constructed an 11-arm, walk-through, human radial-arm maze (HRAM) as a translational instrument to compare existing methodology in the areas of rodent and human learning and memory research. The HRAM,

We constructed an 11-arm, walk-through, human radial-arm maze (HRAM) as a translational instrument to compare existing methodology in the areas of rodent and human learning and memory research. The HRAM, utilized here, serves as an intermediary test between the classic rat radial-arm maze (RAM) and standard human neuropsychological and cognitive tests. We show that the HRAM is a useful instrument to examine working memory ability, explore the relationships between rodent and human memory and cognition models, and evaluate factors that contribute to human navigational ability. One-hundred-and-fifty-seven participants were tested on the HRAM, and scores were compared to performance on a standard cognitive battery focused on episodic memory, working memory capacity, and visuospatial ability. We found that errors on the HRAM increased as working memory demand became elevated, similar to the pattern typically seen in rodents, and that for this task, performance appears similar to Miller's classic description of a processing-inclusive human working memory capacity of 7 ± 2 items. Regression analysis revealed that measures of working memory capacity and visuospatial ability accounted for a large proportion of variance in HRAM scores, while measures of episodic memory and general intelligence did not serve as significant predictors of HRAM performance. We present the HRAM as a novel instrument for measuring navigational behavior in humans, as is traditionally done in basic science studies evaluating rodent learning and memory, thus providing a useful tool to help connect and translate between human and rodent models of cognitive functioning.

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Date Created
  • 2014-09-09

Facial Expressions and Deception in the Court Room

Description

Evidence thus far has not lent credence to facilitate lie detection by the average person. According to studies, there are five major signs of lying: lip pursing, narrowed eyebrows, shoulder

Evidence thus far has not lent credence to facilitate lie detection by the average person. According to studies, there are five major signs of lying: lip pursing, narrowed eyebrows, shoulder shrugs, looking to the left, and smirking. The present study aims to determine whether training people in detecting the five signs of lying will facilitate lie detection in the average person. We analyzed the accuracy of lie detection by examining the verdicts of 155 undergraduate students during simulated police interrogations. Comparisons between the trained and untrained subjects support the hypothesis that the average person is no better than chance at detecting lies through non-verbal cues.

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Created

Date Created
  • 2014-12

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Predicting and Promoting Healthy Diet in College-Aged Women Using the Health Action Process Approach Model

Description

One of the nation's most pressing health related issues is that of healthy diet and proper nutrition. Because much research has shown that many Americans are in poor health or

One of the nation's most pressing health related issues is that of healthy diet and proper nutrition. Because much research has shown that many Americans are in poor health or are at risk to become so due to poor diet and nutrition, understanding the psychological factors of a healthy diet or lack thereof is of the utmost importance. In order to understand the adoption and maintenance of health related behaviors, the link between intentions and behaviors must be evaluated. Of current health behavior models, the model utilized in this study was the Health Action Process Approach model (HAPA), which addressed this "intention-behavior gap." The HAPA model proposes that planning is the key mediator of the link between intentions and behavior. The current research was performed in two stages. The first stage evaluated the psychosocial constructs of the HAPA model, and their predictive utility for current diet and the second stage evaluated a planning-based intervention that aimed to increase proper nutrition in college-aged women. All HAPA constructs were found to be significantly correlated with one another, and planning was found to significantly and fully mediate the link between intention and healthy diet. The intervention did not lead to an increase in healthy diet relative to a standard-of-care control, although all participants across conditions reported increased intention, self-efficacy, and healthy diet from pre-test to follow-up.

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Created

Date Created
  • 2013-12

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Estimating causal direct and indirect effects in the presence of post-treatment confounders: a simulation study

Description

In investigating mediating processes, researchers usually use randomized experiments and linear regression or structural equation modeling to determine if the treatment affects the hypothesized mediator and if the mediator affects

In investigating mediating processes, researchers usually use randomized experiments and linear regression or structural equation modeling to determine if the treatment affects the hypothesized mediator and if the mediator affects the targeted outcome. However, randomizing the treatment will not yield accurate causal path estimates unless certain assumptions are satisfied. Since randomization of the mediator may not be plausible for most studies (i.e., the mediator status is not randomly assigned, but self-selected by participants), both the direct and indirect effects may be biased by confounding variables. The purpose of this dissertation is (1) to investigate the extent to which traditional mediation methods are affected by confounding variables and (2) to assess the statistical performance of several modern methods to address confounding variable effects in mediation analysis. This dissertation first reviewed the theoretical foundations of causal inference in statistical mediation analysis, modern statistical analysis for causal inference, and then described different methods to estimate causal direct and indirect effects in the presence of two post-treatment confounders. A large simulation study was designed to evaluate the extent to which ordinary regression and modern causal inference methods are able to obtain correct estimates of the direct and indirect effects when confounding variables that are present in the population are not included in the analysis. Five methods were compared in terms of bias, relative bias, mean square error, statistical power, Type I error rates, and confidence interval coverage to test how robust the methods are to the violation of the no unmeasured confounders assumption and confounder effect sizes. The methods explored were linear regression with adjustment, inverse propensity weighting, inverse propensity weighting with truncated weights, sequential g-estimation, and a doubly robust sequential g-estimation. Results showed that in estimating the direct and indirect effects, in general, sequential g-estimation performed the best in terms of bias, Type I error rates, power, and coverage across different confounder effect, direct effect, and sample sizes when all confounders were included in the estimation. When one of the two confounders were omitted from the estimation process, in general, none of the methods had acceptable relative bias in the simulation study. Omitting one of the confounders from estimation corresponded to the common case in mediation studies where no measure of a confounder is available but a confounder may affect the analysis. Failing to measure potential post-treatment confounder variables in a mediation model leads to biased estimates regardless of the analysis method used and emphasizes the importance of sensitivity analysis for causal mediation analysis.

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Created

Date Created
  • 2013

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Collateral effects of a family-focused behavioral intervention on physical activity

Description

There are significant and wide-ranging health benefits of physical activity, yet the majority of adolescents in the United States do not engage in the recommended amount. This poses a significant

There are significant and wide-ranging health benefits of physical activity, yet the majority of adolescents in the United States do not engage in the recommended amount. This poses a significant public health challenge. Parents have a substantial influence on adolescents' levels of activity, indicating that parenting may be an especially salient target of interventions designed to promote physical activity. The current study tested the hypothesis that a family intervention to promote effective parenting would have a positive collateral effect on adolescent physical activity. This study also tested whether the increase in activity was mediated by changes in parental monitoring and family relationship quality. Furthermore, the current study assessed whether adolescent gender moderated the relationship between parental monitoring and physical activity, such that increased parental monitoring predicted increases in physical activity for girls, but not for boys. Participants were 232 adolescents at risk for behavior problems drawn from a larger randomized controlled trial of the Family Check-Up. Adolescents completed questionnaires and participated in a family assessment with their caregivers in the 6th through 9th grades. Youth randomized to the intervention reported significantly more physical activity at follow-up relative to controls. Results failed to confirm the role of family factors as mediators of the effect of the intervention on physical activity. When gender was considered as a moderator, it appeared that parental monitoring was strongly and positively correlated with physical activity for girls, but not for boys. While the mechanism by which the Family Check-Up leads to increased physical activity remains unclear, its robust effects suggest that family intervention can be used to promote physical activity and might therefore have further-reaching health benefits.

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Agent

Created

Date Created
  • 2015

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Testing the limits of latent class analysis

Description

The purpose of this study was to examine under which conditions "good" data characteristics can compensate for "poor" characteristics in Latent Class Analysis (LCA), as well as to set forth

The purpose of this study was to examine under which conditions "good" data characteristics can compensate for "poor" characteristics in Latent Class Analysis (LCA), as well as to set forth guidelines regarding the minimum sample size and ideal number and quality of indicators. In particular, we studied to which extent including a larger number of high quality indicators can compensate for a small sample size in LCA. The results suggest that in general, larger sample size, more indicators, higher quality of indicators, and a larger covariate effect correspond to more converged and proper replications, as well as fewer boundary estimates and less parameter bias. Based on the results, it is not recommended to use LCA with sample sizes lower than N = 100, and to use many high quality indicators and at least one strong covariate when using sample sizes less than N = 500.

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Agent

Created

Date Created
  • 2012

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Dynamic assessment of narratives among Navajo Head Start children

Description

Purpose: Over-identification of Navajo Head Start children into special education on the Navajo Reservation has come to the attention of Tribal leaders, Educational leaders, and parents due to the use

Purpose: Over-identification of Navajo Head Start children into special education on the Navajo Reservation has come to the attention of Tribal leaders, Educational leaders, and parents due to the use of invalid assessment measures. Dynamic assessment (DA) of narratives may be a tool for distinguishing language differences from language disorders. The purpose of this study is to determine whether the Predictive Early Assessment of Reading and Language (PEARL), a dynamic assessment of narratives, accurately classifies Navajo Head Start students with typically developing (TD) language or with language impairment (LI), and to examine which measures best predict children’s overall performances on the PEARL.

Method: Ninety, 4- and 5-year-old Navajo preschoolers with LI and with TD language were selected. Children completed the PEARL, which measured both language comprehension and production using pretest and posttest scores, and a modifiability scale. In addition, children completed the Clinical Evaluation of Language Fundamental, Preschool, Second Edition (CELF – Preschool 2) and language samples. A Navajo Speech Language Pathologist confirmed the diagnosis of the participants. Research assistants pretested, briefly taught the principles of narrative structure (story grammar, language complexity and episode) and evaluated response to learning using an index of modifiability.

Results: Results of discriminant analysis indicated that PEARL pretest differentiated both ability groups with 89% accuracy. In addition, posttest scores discriminated with 89% accuracy and modifiability scores with 100% accuracy. Further, the subtest story grammar was the best predictor at pretest and posttest, although modifiability scores were better predictors of both ability groups.

Conclusion: Findings indicate that the PEARL is a promising assessment for accurately differentiating Navajo preschool children with LI from Navajo preschool children with TD language. The PEARL’s recommended pretest cut score over-identified Navajo children with TD language; therefore, a new recommended cut score was determined.

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Agent

Created

Date Created
  • 2017

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Peer reputation among affluent middle school youth: ramifications for maladjustment versus competence by age 18

Description

Given the major investment young people make in earning and maintaining a peer reputation, our goal in this study was to explore the association between dimensions of negative and positive

Given the major investment young people make in earning and maintaining a peer reputation, our goal in this study was to explore the association between dimensions of negative and positive peer reputation in middle school and adjustment several years later, by the end of high school, among upper middle class youth. Prior research has shown negative reputations such as aggressive-disruptive and sensitive-isolated to be associated with maladjustment later in life, whereas reputations like popular and prosocial-leader have been related to positive future outcomes. However, there are contrary findings that reveal a more complex relationship between peer reputation and adjustment, showing certain “negative” reputations to be tied with better outcomes in some domains and the converse in others. Using a sample of middle school students, a confirmatory factor analysis (CFA) was performed to test a four-factor model of the Revised Class Play, a peer report measure on peer reputations. CFA findings supported the four-factor model with the following reputations: popular, prosocial, aggressive, and isolated. Structural equation models were used to predict 12th grade adjustment outcomes (academic achievement, psychopathology, substance use) from middle school peer reputation. Prosocial reputation in middle school was connected to higher academic achievement and fewer externalizing symptoms in 12th grade. Both prosocial and isolated peer reputation were negatively associated with alcohol, cigarette, and marijuana use, whereas a popular reputation was related to higher levels of alcohol use. Middle school reputation did not predict internalizing symptoms in 12th grade. Findings are discussed in terms of adaptive and maladaptive adjustment outcomes associated with each peer reputation and implications for future research.

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Agent

Created

Date Created
  • 2016

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On the cognitive impact of endogenous and exogenous hormone exposures across the lifespan

Description

Women are exposed to numerous endogenous and exogenous hormones across the lifespan. In the last several decades, the prescription of novel hormonal contraceptives and hormone therapies (HTs) have resulted in

Women are exposed to numerous endogenous and exogenous hormones across the lifespan. In the last several decades, the prescription of novel hormonal contraceptives and hormone therapies (HTs) have resulted in aging women that have a unique hormone exposure history; little is known about the impact of these hormone exposures on short- and long- term brain health. The goal of my dissertation was to understand how lifetime hormone exposures shape the female cognitive phenotype using several innovative approaches, including a new human spatial working memory task, the human radial arm maze (HRAM), and several rodent menopause models with variants of clinically used hormone treatments. Using the HRAM (chapter 2) and established human neuropsychological tests, I determined males outperformed females with high endogenous or exogenous estrogen levels on visuospatial tasks and the spatial working memory HRAM (chapter 3). Evaluating the synthetic estrogen in contraceptives, ethinyl estradiol (EE), I found a high EE dose impaired spatial working memory in ovariectomized (Ovx) rats, medium and high EE doses reduced choline-acetyltransferace-immunoreactive neuron population estimates in the basal forebrain following Ovx (chapter 4), and low EE impaired spatial cognition in ovary-intact rats (chapter 5). Assessing the impact of several clinically-used HTs, I identified a window of opportunity around ovarian follicular depletion outside of which the HT conjugated equine estrogens (CEE) was detrimental to spatial memory (chapter 6), as well as therapeutic potentials for synthetic contraceptive hormones (chapter 9) and bioidentical estradiol (chapter 7) during and after the transition to menopause. Chapter 6 and 7 findings, that estradiol and Ovx benefitted cognition after the menopause transition, but CEE did not, are perhaps due to the negative impact of ovarian-produced, androstenedione-derived estrone; indeed, blocking androstenedione’s conversion to estrone prevented its cognitive impairments (chapter 8). Finally, I determined that EE combined with the popular progestin levonorgestrel benefited spatial memory during the transition to menopause, a profile not seen with estradiol, levonorgestrel, or EE alone (chapter 9). This work identifies several cognitively safe, and enhancing, hormonal treatment options at different time points throughout female aging, revealing promising avenues toward optimizing female health.

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Created

Date Created
  • 2015

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The roles of sensation seeking and level of response to negative, sedative alcohol effects in the intergenerational transmission of risk for developing alcohol use disorders

Description

The present study tested the respective mediating effects of sensation seeking and initial level of response (LR) to negative, sedative alcohol effects on the relation between the density of familial

The present study tested the respective mediating effects of sensation seeking and initial level of response (LR) to negative, sedative alcohol effects on the relation between the density of familial history of alcoholism and adolescent alcohol use. Additionally, the present study tested the direct effect of LR to negative, sedative alcohol effects on adolescent drinking over and above the effects of sensation seeking; and also tested the moderating effect of sensation seeking on the relation between level of response negative, sedative alcohol effects and adolescent drinking. Specifically, OLS regression models first estimated the effects of sensation seeking, LR to negative, sedative alcohol effects, and their interaction on alcohol outcomes, over and above the influence of covariates. Indirect effects were then tested using the PRODCLIN method through RMediation. Analyses failed to support sensation seeking as a mediator in the relation between familial history of alcoholism and adolescent drinking, and as a moderator of the relation between LR and adolescent drinking. However, analyses did support a robust direct effect of LR to negative, sedative alcohol effects on adolescent alcohol involvement. A significant mediating effect of initial LR to negative, sedative alcohol effects on the relation between familial alcoholism and adolescent drinking was found, however failed to maintain significance in post-hoc analyses attenuating the downward bias of the measure of initial LR. Initial LR to negative, sedative alcohol effects continued to predict adolescent drinking after attenuating measure bias. These findings strengthen research on initial LR to negative, sedative alcohol effects as a risk for greater alcohol involvement in adolescence, and underscore the complexity of studying the familial transmission of alcoholism in adolescent populations

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Agent

Created

Date Created
  • 2015