Doctor of Philosophy

dissertationMemory assessment can often alert practitioners and educators to learning problems children may be experiencing. Results of a memory assessment may indicate that a child has a specific memory deficit in verbal memory, visual memory, or both. Deficits in visual or verbal modes of memory could potentially have adverse effects on academic achievement. Past research in the area of memory and academics have shown mixed results, with some studies showing correlations between visual or verbal memory deficits and patterns of academic achievement and other studies showing evidence there is not a predictable pattern. The purpose of the present study was to examine the effects of visual memory deficits upon children's academic achievement in reading, spelling, and arithmetic. Archival data of children's comprehensive neuropsychological evaluations conducted at a private neuropsychology clinic were reviewed and analyzed to determine if children who showed evidence of deficits in visual memory differed significantly on academic achievement measures from a comparison group of children who did not have visual or verbal memory deficits. Overall, the results of this study found that individuals with visual memory deficits showed significantly weaker performance in arithmetic achievement compared to children without memory deficits. Children with visual memory deficits did not differ significantly from children without memory deficits on reading or spelling achievement

Aggression: Relationships with Sex, Gender Role Identity, and Gender Role Stress.

Sex, gender-role identity, and gender-role stress were assessed in terms of their relationship to observed gender differences in self-reported aggression. Physical and verbal aggression were explored, as well as the affective component of anger and cognitive component of hostility. The role of emotional intelligence in these relationships was also evaluated, as a possible correlate to the gender-related variables. The results indicated that both gender-role stress and gender-role identification were significantly associated with all components of aggression; however, only physical aggression was related to sex. Emotional intelligence was linked to sex and gender-role identity but not with gender-role stress. The results also suggested that emotional intelligence predicts physical aggression, anger, and hostility in addition to the variance explained by gender variables, presenting negative relationships with each of these variables

Social Referent Influences on Hormonal Contraceptive Decisions

Despite evidence that social referents could be influencing hormonal contraceptive decisions in adult women, the current research has done little to investigate this area. The purpose of the current work was to begin to identify whether women’s hormonal contraceptive decisions may be influenced by their social referents’ support for hormonal contraceptive use and social referents’ contraceptive behaviors. Sexually active women (n=194), aged 18-34, completed an online survey examining their sources of contraceptive information, feelings towards pregnancy, contraceptive use/preferences, contraceptive knowledge, and medical mistrust. In addition to this, as part of the survey they identified three important women in their lives and provided information on their perception of each social referent’s contraceptive use and support for contraceptives. Participants also listened to one of four audio vignettes where a doctor character and a friend character each provided either positive or negative support for a fictitious hormonal contraceptive. Participants rated their attitudes towards the fictitious contraceptive after listening to the vignette. It was hypothesized that participants’ perception of the social referents’ support of their personal hormonal contraceptive use and participants’ perceptions of referents’ hormonal contraceptive behaviors would impact the odds that participants used hormonal contraceptives at last intercourse, but that this relationship would be moderated by contraceptive knowledge. It was also hypothesized that individuals who received conflicting information about a fictitious hormonal contraceptive from the physician and friend characters in the audio vignettes (with one for the contraceptive use, the other against) would hold different contraceptive attitudes when compared to those who heard both characters agree about the contraceptive. It was expected that the relationship between vignette condition and attitudes towards the fictitious contraceptive would be moderated by medical mistrust. A number of participants identified social referents as sources of contraceptive information with 35.1% listing mothers and/or female guardians as a source, 23.2% listing their best friend, 22.7% listing friends, and 12.9% listing their sisters. In a logistic regression, social referents’ perceived support of hormonal contraceptive use was found to increase the odds that the women reported using hormonal contraceptives at last sexual intercourse. Social referents’ perceived contraceptive behaviors and participants’ contraceptive knowledge scores were not found to be related to participants’ contraceptive use at last sexual intercourse. Hierarchical regressions investigating the outcomes of the audio vignettes suggested that the friend and physician characters’ contraceptive support is statistically related to attitudes towards the fictitious contraceptive; however, the relationship between the vignette conditions and contraceptive attitudes was moderated by participants’ levels of medical mistrust. These findings point towards social referents as a potential influence on hormonal contraceptive decision-making in adult women. Future research is warranted to better determine and understand the role of social referents in hormonal contraceptive decision-making

Investigation of over-fitting and optimism in prognostic models

This work seeks to develop a high quality prognostic model for the CARE-HF data; see (Richardson et al. 2007). The CARE-HF trial was a major study into the effects of cardiac resynchronization. Cardiac resynchronization has been shown to reduce mortality in patients suffering heart failure due to electrical problems in the heart. The prognostic model presented in this work was motivated by the question as to which patient characteristics may modify the effect of cardiac resynchronization. This is a question of great importance to clinicians. Efforts are made to produce a high quality prognostic model in part through the application of methods to reduce the risk of over-fitting. One method discussed in this work is the strategy proposed by Frank Harrell Jr. The various aspects of Harrell’s approach are discussed. An attempt is made to extend Harrell’s strategy to frailty models. Key issues such as missing data and imputation, specification of the functional form of the model, and validation are examined in relation to the prognostic model for the CARE-HF data. Material is presented covering survival analysis, maximum likelihood methods, model selection criteria (AIC, BIC), specification of functional form (cubic splines and fractional polynomials) and validation methods (cross-validation, bootstrap methods). The concepts of over-fitting and optimism are examined. The author concludes that whilst Harrell’s strategy is valuable it is still quite possible to produce models that are over-fitted. MDL (Minimum Description Length) is suggested as potentially useful methods by which statistical models can be obtained that have an in built resistance to over-fitting. The author also recommends that concepts such as over-fitting, optimism and model validation are introduced earlier in more elementary courses on statistical modelling

Effort of Odyssey of the Mind Creative Problem Solving Teams: Effects on Creativity, Creative Self-Concept, Locus of Control and General Self-Concept in Gifted Children

Applied Behavioral Studie

Casper-1, Part 6: Uncertainty Quantification, Factor Effects, and Outlier Analysis for an On-Board Airplane Trajectory Prediction Function

This report presents data analysis results for a simulation-based approach named CASPEr (Characterization of Airplane State Prediction Error) to characterize the performance of onboard energy state and automation mode prediction functions for terminal area arrival and approach phases of flight over a wide range of conditions. In particular, the results include quantification of energy state (i.e., altitude and airspeed) prediction performance, models for prediction performance as a function of initial energy state (i.e., initial altitude, airspeed, and weight) and weather factors, and analysis of outlier prediction performance. Wind speed, wind direction, and wind gradient were found to be major factors in energy state prediction performance. Initial energy and gust intensity were also significant factors in airspeed prediction performance. Furthermore, the results suggest that errors in automation mode prediction may be a major contributor to outlier prediction performance

Toward an understanding of the cognitive etiology of depressive reactions to life stressors: An evaluation of the hopelessness theory of depression

Abramson, Metalsky, and Alloy\u27s (1989) theory of hopelessness depression is the most recent model of depression to emerge from the learned helplessness tradition (Seligman, 1975). Hopelessness theory describes an etiological pathway by which a unique subtype of depression--hopelessness depression--is believed to emerge. The most proximal cause of hopelessness depression is the formation of a hopelessness expectancy. Experiencing a significant life stressor and either making stable and global causal attributions, anticipating adverse consequences, or inferring derogatory self-attributes is thought to contribute to hopelessness. In turn, generalized tendencies to make stable and global causal attributions, expect negative consequences, or perceive personal deficiencies in response to life stress purportedly increase the likelihood of making hopelessness-inducing inferences, and thus increase the risk of hopelessness and depressive symptoms. The present research sought to (a) provide a comprehensive assessment of the proposed etiological pathway and (b) evaluate the competing predictions made by the hopelessness model and its most immediate theoretical precursor, the reformulated theory of learned helplessness depression (Abramson, Seligman, & Teasdale, 1978). In a two-wave panel design, college undergraduates $(N=247)$ completed measures assessing the constructs of both models. Higher levels of dysfunctional cognitive styles and event-based inferences predicted increases in depressive symptoms only among subjects who experienced an upsetting interpersonal stressor that was also perceived as uncontrollable. Little support was obtained for the hypothesis that hopelessness mediates associations between depressive symptoms and either maladaptive cognitive styles or event-inferences. Consistent with the postulates of hopelessness theory, dysfunctional cognition appeared to render individuals vulnerable to depressive symptomatology in the face of life stress. However, the present findings call into question hopelessness theory\u27s elimination of control perceptions in its etiological pathway. Continued study of the control construct is encouraged as are future tests of hopelessness theory that use more sophisticated assessments of life stress and fine-grained measures of hopelessness expectancies

Effects of Gender, Cognitive Style, and Modeling on Levels of Sensation Seeking

Applied Behavioral Studie

Group Separation and Classification of Non-Suicidal Self-Injury in a University Student Population

Non-suicidal self-injury (NSSI) has gained an increasing amount of attention in the research literature since being included as topic for future research in the DSM-5 (APA, 2013). Currently, two models of NSSI exist, and both place a primacy on the role of the behaviour in regulating negative affect (Chapman et al., 2006; Nock, 2009). Past research has shown that there is considerable heterogeneity in the contextual, functional, and psychiatric profiles of people engaging in this behaviour (Klonsky & Olino, 2008). This underlying heterogeneity likely indicates that distinct sub-populations of people engaging in NSSI exist based on these factors. In the current study, university students were placed into three groups based on the last episode of NSSI (e.g., no history, proximal episode or past year, and distal episode or not within past year) and these groups were separated based on responses to variables covering personality, emotionality, emotion regulation, impulsivity, psychopathology, resiliency, mindfulness, and self-compassion. Results revealed that the NSSI-Proximal year group was best separated from the other two groups by a linear discriminant function conceptualized as compassionate self-care. Higher scores on the function were more indicative of participants in both NSSI groupings. However, results from a MANOVA revealed no significant difference between No NSSI and the NSSI-Distal group on the variables. The results from the study provide additional support for the importance of identifying NSSI sub-groups in order to improvement the prevention and treatment of non-suicidal self-injury