Matching Items (22)
Description
Type 1 Diabetes Mellitus (T1DM) is a chronic disease that requires maintaining tight metabolic control through complex behavioral and pharmaceutical regimens. Subtle cognitive impairments and stress response dysregulation may partially account for problems negotiating life changes and maintaining treatment adherence among emerging adults. The current study examined whether young adults with T1DM physiologically respond to psychological stress in a dysregulated manner compared to non-diabetic peers, and if such individuals also demonstrated greater cognitive declines following psychological stress. Participants included 23 young adults with T1DM and 52 non-diabetic controls yoked to T1DM participants based on age, gender, ethnicity, participant education, and maternal education. Participants completed a laboratory-based social stressor, pre- and post-stressor neurocognitive testing, provided fingerstick blood spots (for glucose levels) and salivary samples (for cortisol levels) at five points across the protocol, and completed psychosocial questionnaires. Related measures ANOVAs were conducted to assess differences between T1DM participants and the average of yoked controls on cortisol and cognitive outcomes. Results demonstrated that differences in cortisol reactivity were dependent on T1DM participants' use of insulin pump therapy (IPT). T1DM participants not using IPT demonstrated elevated cortisol reactivity compared to matched controls. There was no difference in cortisol reactivity between the T1DM participants on IPT and matched controls. On the Stroop task, performance patterns did not differ between participants with T1DM not on IPT and matched controls. The performance of participants with T1DM on IPT slightly improved following the stressor and matched controls slightly worsened. On the Trail Making Test, the performance of participants with T1DM was not different following the stressor whereas participants without T1DM demonstrated a decline following the stressor. Participants with and without T1DM did not differ in patterns of performance on the Rey Verbal Learning Task, Sustained Attention Allocation Task, Controlled Oral Word Association Task, or overall cortisol output across participation. The results of this study are suggestive of an exaggerated cortisol response to psychological stress in T1DM and indicate potential direct and indirect protective influences of IPT.
ContributorsMarreiro, Catherine (Author) / Luecken, Linda (Thesis advisor) / Doane, Leah (Thesis advisor) / Barrera, Manuel (Committee member) / Aiken, Leona (Committee member) / Arizona State University (Publisher)
Created2013
Description
Methods to test hypotheses of mediated effects in the pretest-posttest control group design are understudied in the behavioral sciences (MacKinnon, 2008). Because many studies aim to answer questions about mediating processes in the pretest-posttest control group design, there is a need to determine which model is most appropriate to test hypotheses about mediating processes and what happens to estimates of the mediated effect when model assumptions are violated in this design. The goal of this project was to outline estimator characteristics of four longitudinal mediation models and the cross-sectional mediation model. Models were compared on type 1 error rates, statistical power, accuracy of confidence interval coverage, and bias of parameter estimates. Four traditional longitudinal models and the cross-sectional model were assessed. The four longitudinal models were analysis of covariance (ANCOVA) using pretest scores as a covariate, path analysis, difference scores, and residualized change scores. A Monte Carlo simulation study was conducted to evaluate the different models across a wide range of sample sizes and effect sizes. All models performed well in terms of type 1 error rates and the ANCOVA and path analysis models performed best in terms of bias and empirical power. The difference score, residualized change score, and cross-sectional models all performed well given certain conditions held about the pretest measures. These conditions and future directions are discussed.
ContributorsValente, Matthew John (Author) / MacKinnon, David (Thesis advisor) / West, Stephen (Committee member) / Aiken, Leona (Committee member) / Enders, Craig (Committee member) / Arizona State University (Publisher)
Created2015
Description
Missing data are common in psychology research and can lead to bias and reduced power if not properly handled. Multiple imputation is a state-of-the-art missing data method recommended by methodologists. Multiple imputation methods can generally be divided into two broad categories: joint model (JM) imputation and fully conditional specification (FCS) imputation. JM draws missing values simultaneously for all incomplete variables using a multivariate distribution (e.g., multivariate normal). FCS, on the other hand, imputes variables one at a time, drawing missing values from a series of univariate distributions. In the single-level context, these two approaches have been shown to be equivalent with multivariate normal data. However, less is known about the similarities and differences of these two approaches with multilevel data, and the methodological literature provides no insight into the situations under which the approaches would produce identical results. This document examined five multilevel multiple imputation approaches (three JM methods and two FCS methods) that have been proposed in the literature. An analytic section shows that only two of the methods (one JM method and one FCS method) used imputation models equivalent to a two-level joint population model that contained random intercepts and different associations across levels. The other three methods employed imputation models that differed from the population model primarily in their ability to preserve distinct level-1 and level-2 covariances. I verified the analytic work with computer simulations, and the simulation results also showed that imputation models that failed to preserve level-specific covariances produced biased estimates. The studies also highlighted conditions that exacerbated the amount of bias produced (e.g., bias was greater for conditions with small cluster sizes). The analytic work and simulations lead to a number of practical recommendations for researchers.
ContributorsMistler, Stephen (Author) / Enders, Craig K. (Thesis advisor) / Aiken, Leona (Committee member) / Levy, Roy (Committee member) / West, Stephen G. (Committee member) / Arizona State University (Publisher)
Created2015
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 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.
ContributorsWurpts, Ingrid Carlson (Author) / Geiser, Christian (Thesis advisor) / Aiken, Leona (Thesis advisor) / West, Stephen (Committee member) / Arizona State University (Publisher)
Created2012
Description
Family plays an important yet understudied role in the development of psychopathology during childhood, particularly for children at developmental risk. Indeed, much of the research on families has actually concentrated more on risk processes in individual family members or within-family subsystems. In general, important and complex associations have been found among family-related constructs such as marital conflict, parent-child relationships, parental depression, and parenting stress, which have in turn been found to contribute to the emergence of children's behavioral problems. Research has begun to emerge that certain family system constructs, such as cohesion, organization, and control may influence children's development, but this research has been limited by a focus on parent-reports of family functioning, rather than utilizing observational methods. With notable exceptions, there is almost no observational research examining families of children at developmental risk. This study examined the longitudinal relations among family risk and family system constructs, as well as how family systems constructs mediated the relations between family risk and child outcome. Further, the study examined how developmental risk moderated these relations. The sample followed 242 families of children with and without developmental risk across the transition-to-school period. Family risk factors were assessed at 5 years, using parental reports of symptomatology, parenting stress, and marital adjustment, and observational assessments of the parent-child relationship. Family system constructs (cohesion, warmth, conflict, organization, control) were measured at age 6 using structured observations of the entire family playing a board game. Child behavior problems and social competence were assessed at age 7. Results indicated that families of children with developmental delays did not differ from families of typically developing children on the majority of family system attributes. Cohesion and organization mediated the relations between specific family risk factors and social competence for all families. For families of typically developing children only, higher levels of control were associated with more behavior problems and less social competence. These findings underscore the importance of family-level assessment in understanding the development of psychopathology. Important family effects on children's social competence were found, although the pathways among family risk and family systems attributes are complex.
ContributorsGerstein, Emily Davis (Author) / Crnic, Keith A (Thesis advisor) / Aiken, Leona (Committee member) / Bradley, Robert (Committee member) / Gonzales, Nancy (Committee member) / Arizona State University (Publisher)
Created2012
Description
Monoamine neurotransmitters (e.g., serotonin, norepinephrine, and dopamine) are powerful modulators of mood and cognitive function in health and disease. We have been investigating the modulation of monoamine clearance in select brain regions via organic cation transporters (OCTs), a family of nonselective monoamine transporters. OCTs are thought to complement the actions of selective monoamine transporters in the brain by helping to clear monoamines from the extracellular space; thus, assisting to terminate the monoamine signal. Of particular interest, stress hormones (corticosterone; CORT) inhibit OCT3-mediated transport of monoamine, to putatively lead to prolonged monoamine signaling. It has been demonstrated that stress levels of CORT block OCT3 transport in the rat hypothalamus, an effect that likely underlies the rapid, stress-induced increase in local monoamines. We examined the effect of chronic variable stress (CVS) on the development of mood disorders and OCT3 expression in limbic and hypothalamic regions of the rat brain. Animals subjected to CVS (14-days with random stressor exposure two times/day) showed reduced body weight gain, indicating that CVS was perceived as stressful. However, behavioral tests of anxiety and depressive-like behaviors in rats showed no group differences. Although there were no behavioral effects of stress, molecular analysis revealed that there were stress-related changes in OCT3 protein expression. In situ hybridization data confirmed that OCT3 mRNA is expressed in the hippocampus, amygdala, and hypothalamus. Analysis of Western blot data by two-way ANOVA revealed a significant treatment effect on OCT3 protein levels, with a significant decrease in OCT3 protein in the amygdala and hippocampus in CVS rats, compared to controls. These data suggest an important role for CORT sensitive OCT3 in the reduction of monoamine clearance during stress.
ContributorsBoyll, Piper Savannah (Author) / Orchinik, Miles (Thesis director) / Conrad, Cheryl (Committee member) / Talboom, Joshua (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
The purpose of the present study was to investigate seasonal changes in cell proliferation in the brains of adult American bullfrog. Our main question was whether there are seasonal differences in the proliferation and/or differentiation of newborn brain cells into arginine vasotocin- (AVT) or gonadotropin releasing hormone- (GnRH) producing neurons that might regulate bullfrog reproduction. . Bullfrogs in four distinct seasonal groups received injections of bromodeoxyuridine (BrdU), a thymidine analog that is taken up by dividing cells, and then euthanized six weeks later. Using doubleimmunofluorescence procedures to visualize BrdU and AVT or GnRH, we found no evidence for newborn AVT- or GnRH-ergic cells, but observed newborn cells in close proximity to AVT and GnRH cells. My project was a follow-up study to explore seasonal changes in adult cytogenesis related to AVT and GnRH terminal fields. GnRH fiber density fluctuated seasonally in the rostral pre-optic area (RPOA) and lateral septum (LS), and newborn cell numbers changed seasonally in the amygdala (AM) and RPOA. Seasonal differences in plasma testosterone concentrations were negatively related to GnRH fiber density in the LS. These results reinforce the seasonality of reproductive signaling and adult cytogenesis and support a role for seasonal steroid-peptide hormone interactions in modulating GnRH levels. Our results suggest a relationship between seasonal adult cytogenesis and reproduction, and set the stage for further research into the nature of this relationship.
ContributorsFehr, Tristan (Author) / Orchinik, Miles (Thesis director) / Deviche, Pierre (Committee member) / Talboom, Joshua (Committee member) / Barrett, The Honors College (Contributor)
Created2013-05
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 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.
ContributorsRivera, Aylin Melissa (Author) / Lanyon, Richard (Thesis director) / Aiken, Leona (Committee member) / Barrett, The Honors College (Contributor) / School of Criminology and Criminal Justice (Contributor) / Department of Psychology (Contributor)
Created2014-12
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 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.
ContributorsWells, Jordan Rebecca (Author) / Aiken, Leona (Thesis director) / Glenberg, Arthur (Committee member) / Hansen, Whitney (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor)
Created2013-12
Description
The organic cation transporter 3 (OCT3) is a polyspecific monoamine transporter
found in the human and rat brain. In Rats, OCT3 is the only known monoamine transporter inhibited by physiological concentrations of corticosteroids. We hypothesized that CORT- mediated inhibition of OCT3 blocks the clearance of serotonin (5-HT) leading to an increase 5-HT receptor-mediated signaling. In experiment 1, due to conflicting reports on the location of OCT3 mRNA in the rat brain, in situ hybridization was performed on brain tissue sections. RNA was extracted from rat brain tissue, reverse transcribed into cDNA, and then polymerase chain reaction (PCR) was performed to generate riboprobe templates. The riboprobe templates were then used for in vitro transcription of digoxigenin (DIG)-labeled riboprobes complementary to OCT3. In experiment 2, 12 rats from an identical cohort were exposed to a chronic restraint stress paradigm (two hours/day for seven days, STRESS group), while the other 12 remained in their home cages (CTRL group). Twenty-four hours after the last stressor, all animals were euthanized and their brains immediately removed and frozen. Bilateral tissue punches were collected from 300μm coronal sections from the CA1 region of the dorsal hippocampus, basolateral amygdala (BLA), and dorsomedial hypothalamus (DMH). The relative OCT2, OCT3, and 5HT2a mRNA levels from each tissue punch were determined via quantitative real-time polymerase chain reaction (qPCR). The results of experiment 1 confirmed the presence of OCT3 mRNA in the CA1, amygdala, and the DMH. The results of experiment 2 show that chronic restraint stress did not alter gene expression for 5-HT2A, OCT2, and OCT3. These data may help reveal new information involving OCT3’s role in the hippocampus, amygdala and DMH in regards to localization and mRNA expression levels after exposure to a stressor.
found in the human and rat brain. In Rats, OCT3 is the only known monoamine transporter inhibited by physiological concentrations of corticosteroids. We hypothesized that CORT- mediated inhibition of OCT3 blocks the clearance of serotonin (5-HT) leading to an increase 5-HT receptor-mediated signaling. In experiment 1, due to conflicting reports on the location of OCT3 mRNA in the rat brain, in situ hybridization was performed on brain tissue sections. RNA was extracted from rat brain tissue, reverse transcribed into cDNA, and then polymerase chain reaction (PCR) was performed to generate riboprobe templates. The riboprobe templates were then used for in vitro transcription of digoxigenin (DIG)-labeled riboprobes complementary to OCT3. In experiment 2, 12 rats from an identical cohort were exposed to a chronic restraint stress paradigm (two hours/day for seven days, STRESS group), while the other 12 remained in their home cages (CTRL group). Twenty-four hours after the last stressor, all animals were euthanized and their brains immediately removed and frozen. Bilateral tissue punches were collected from 300μm coronal sections from the CA1 region of the dorsal hippocampus, basolateral amygdala (BLA), and dorsomedial hypothalamus (DMH). The relative OCT2, OCT3, and 5HT2a mRNA levels from each tissue punch were determined via quantitative real-time polymerase chain reaction (qPCR). The results of experiment 1 confirmed the presence of OCT3 mRNA in the CA1, amygdala, and the DMH. The results of experiment 2 show that chronic restraint stress did not alter gene expression for 5-HT2A, OCT2, and OCT3. These data may help reveal new information involving OCT3’s role in the hippocampus, amygdala and DMH in regards to localization and mRNA expression levels after exposure to a stressor.
ContributorsTompkins, Heather Camila (Author) / Orchinik, Miles (Thesis director) / Neisewander, Janet (Committee member) / Talboom, Joshua (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2013-05