Psychology - Theses, Dissertations, and other Required Graduate Degree Essays

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Circadian food anticipation in dopamine-1 receptor knockout mice

Date created: 
2015-08-06
Abstract: 

Restricted daily feeding schedules induce circadian rhythms of food anticipatory activity (FAA) in mice and other species. The entrainment pathway(s) and location(s) of circadian oscillators driving these rhythms have not been definitively established. An important role for dopamine signaling and the dorsal striatum is suggested by a confluence of observations, including shifting of FAA rhythms by dopamine receptor agonists, and attenuation by antagonists and D1 receptor knockout (D1R KO). The dopamine reward system exhibits sexual dimorphisms in structure and function; if FAA rhythms are regulated by this system, then FAA may also be sexually dimorphic. To assess this prediction, disc running and general activity were recorded continuously in male and female C57BL/6J mice with food available ad libitum and then restricted to a 4 h daily meal in the middle of the light period. Compared to male mice, FAA in female mice was significantly reduced in duration, total counts, peak level and ratio relative to nocturnal activity. To determine if these differences were mediated by D1 receptors, male and female homozygous D1R KO mice were examined. Compared to wildtype and heterozygous mice, female and male D1R KO mice exhibited a marked attenuation of FAA parameters. The magnitude of the attenuation was greater in females. These results confirm an important role for dopamine D1 receptors in the circadian mechanism by which mice anticipate a daily meal, and reveal a previously unreported sexual dimorphism in the expression of food anticipatory rhythms that appears amplified by D1R KO.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Ralph Mistlberger
Department: 
Arts & Social Sciences: Department of Psychology
Thesis type: 
(Thesis) M.A.

Predicting risky sexual behaviour in adolescence and early adulthood: the unique and interactive roles of childhood conduct disorder symptoms and callous-unemotional traits

Date created: 
2015-08-11
Abstract: 

The relationship between conduct problems and risky sexual behaviour has been explored previously; however, how callous-unemotional (CU) traits and the interaction between conduct disorder (CD) symptoms and CU traits contribute to risky sexual behaviour has been explored infrequently. This study aimed to investigate the role that CD symptoms, CU traits, and their interaction play in predicting several risky sexual behaviour outcomes in adolescence and early adulthood. Results showed that CD symptoms and CU traits uniquely and interactively predicted a number of risky sexual behaviours during adolescence and early adulthood. This study provides meaningful information regarding the importance of both CD symptoms and CU traits in understanding health-risk behaviours. These findings may provide a foundation for developing and implementing interventions to address these behaviours among this population.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Dr. Robert McMahon
Department: 
Arts & Social Sciences: Department of Psychology
Thesis type: 
(Thesis) M.A.

The Psychometric Confound: A Perennial Gremlin of the Psychopathology Literature

Date created: 
2015-07-24
Abstract: 

Chapman and Chapman (1973) identified an issue in psychopathology research that has since come to be known as the Psychometric Confound (MacDonald, 2008). They claimed, essentially, that various traditional inferential methods for drawing conclusions regarding ability deficits in a population with some particular pathology were flawed. The work of the Chapmans has since been cited frequently in the psychopathology field, with most citing authors echoing their concerns, and some applying their proposed solutions. However, the precise nature of the phenomenon remains in question. The goal of the current work is to elucidate, in mathematics, the issues raised by Chapman and Chapman, and their commentators, to a level which allows for an adjudication of the core claims of these authors. We begin by providing a clear and concise description of Chapman and Chapman’s account of the Psychometric Confound, including a description of the research context; an articulation of the general inferential problem; an itemization of claims, including claims regarding methodological solutions; and a description of problems inherent in Chapman and Chapman’s account. We then consider the influence of the Chapmans’ discussion regarding the Psychometric Confound on the psychopathology literature as a whole, including a summary of the alternative accounts of the problem that have emerged in response to the work of Chapman and Chapman. A full mathematization, and consequent adjudication, of the claims of Chapman and Chapman, is then provided. Fundamentally, this involves an elucidation and formalization of the test theory, both classical and modern, nascent in all work regarding the Psychometric Confound from Chapman and Chapman on. A mathematization and adjudication of the claims of the alternative accounts follows. Finally, we determine if valid methodological solutions for the quantities of interest are possible, given the technical, test-theory based framework established. We show that a structural equation model consistent with the proto-framework implied by Chapman and Chapman provides a basis for valid inference regarding the quantity of interest.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Michael Maraun
Department: 
Arts & Social Sciences:
Thesis type: 
(Dissertation) Ph.D.

Investigating the role of boldness in the conceptualization of psychopathy

Date created: 
2015-07-02
Abstract: 

The Triarchic model of psychopathy (Patrick, Fowles, & Krueger, 2009) posits that psychopathic personality comprises three domains: boldness, meanness, and disinhibition. The present Master’s thesis aimed to clarify the role of boldness (i.e., social dominance, venturesomeness, emotional resiliency) in the definition of psychopathy—a topic of recent debate. Undergraduate students (N = 439) compared the lexical similarity of boldness, meanness, and disinhibition with two contemporary models of psychopathy: the Comprehensive Assessment of Psychopathic Personality (Cooke, Hart, Logan, & Michie, 2012) and the Five Factor Model of psychopathy (Widiger & Lynam, 1998). Participants also completed the Triarchic Psychopathy Measure (Patrick, 2010) and a variety of antisocial and prosocial outcomes. Boldness was generally rated as lexically unrelated to contemporary models of psychopathy. Boldness did not add incrementally to or interact with meanness and disinhibition in their associations with external criteria. These findings bear implications for our definition and assessment of psychopathy.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Kevin Douglas
Department: 
Arts & Social Sciences:
Thesis type: 
(Thesis) M.A.

Mindfulness Skills Training for Elite Adolescent Athletes

Author: 
Date created: 
2015-06-24
Abstract: 

The present study explores psychological skills training (PST) and performance in a population of elite adolescent athletes. Clinical sport psychology research has recently begun to assess mindfulness as a psychological skill; mindfulness focuses on present moment non-judgmental awareness and acceptance of one’s internal state and affect. The present study was a novel mindfulness intervention focusing on teaching 38 elite adolescent soccer players mindfulness skills in six-one hour training sessions. It was expected that participation in the mindfulness training would yield increases in self-reported performance, self-efficacy and emotion regulation. Participants completed the dependent measures pre-intervention, post-intervention and three-months after the start of the intervention. Significant improvements in performance and self-efficacy were observed; however, no significant changes in emotion regulation were observed. The results were significant at the three-month measurement. This six-session developmentally modified mindfulness intervention is a promising advance in the field of sport psychology and performance enhancement with young athletes. The importance of adapting and targeting mindfulness interventions for working with adolescent athletes and specific methodological considerations are discussed.

Document type: 
Thesis
File(s): 
Supervisor(s): 
David Cox
Department: 
Arts & Social Sciences: Psychology
Thesis type: 
(Thesis) Ph.D.

The rags-to-riches story of income mobility and its impact on emotional well-being

Date created: 
2015-06-16
Abstract: 

Recent research has demonstrated that people believe they are more likely to climb the income ladder than they actually are. However, no one has explored the downstream psychological consequences of these unrealistically optimistic perceptions, particularly their impact on emotional well-being. Across four studies I explored the correlational and causal relationship between perceptions of one’s own income mobility and emotional well-being. In Studies 1 and 2, I measure and assess the relationship between perceptions of income mobility and emotional well-being. I found that most participants see themselves as having high income mobility, and these perceptions of upward mobility are related to higher levels of happiness. In Study 3, I randomly assigned participants to read an article depicting income mobility as high, moderate, or low. Participants led to believe income mobility is high reported higher happiness relative to those led to believe income mobility is low. Lastly, in Study 4, utilizing a more diverse and generalizable sample from a National Panel Survey, I replicated the findings of Study 3. In sum, the present research demonstrates that people tend to be optimistic about their own chances of climbing the income ladder, and this sustained optimism translates into positive downstream emotional consequences.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Lara B. Aknin
Department: 
Arts & Social Sciences:
Thesis type: 
(Thesis) M.A.

Age Differences in Theory of Mind: An Investigation of Neurocognitive, Health, and Demographic Predictors

Date created: 
2015-06-22
Abstract: 

Theory of mind (ToM) is the ability to understand and reason about a variety of meta-cognitive and emotional mental states. Compared to young adults, older adults are more susceptible to reduced ToM, though the fundamental supporting processes are unclear. Earlier work demonstrates that neurocognitive performance, health status, and biological sex differences each contribute to ToM variability, yet no research has examined these predictors concurrently. In this dissertation we examined how these key predictors related to age differences in the cognitive and affective components of ToM. We tested 86 young (mean age = 19.8) and 85 older adults (mean age = 71.4) on standardized measures assessing neurocognitive performance and ToM. Predictor variables were derived from demographic information (sex), in-office blood pressure readings (pulse pressure or PP), and measures of three neurocognitive domains closely linked to ToM: executive functions, verbal comprehension, and episodic memory. We used path analysis to identify concurrent predictors of cognitive and affective ToM between age groups and partial invariance analyses to assess age differences in the strength of identified predictors. Our findings make several important contributions to this literature. We provide the first evidence that poor vascular health (high PP) directly predicts lower cognitive ToM across age groups, beyond other explanatory variables. Furthermore, in agreement with child development and cognitive neuroscience theory, we present the first neuropsychological evidence suggesting that cognitive ToM is a key predictor of affective ToM performance. Finally, while certain neurocognitive predictors of ToM are more salient in later life, we demonstrated that most predictors are shared between age groups and are equivalent in magnitude. Taken together, our study represents the most comprehensive investigation of predictors of ToM in aging to date, and suggests the value of continued investigation of ToM within a multidimensional framework.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Wendy Loken Thornton
Department: 
Arts & Social Sciences: Psychology
Thesis type: 
(Dissertation) Ph.D.

Explaining Individual Differences in the Cognitive Processes Underlying Hindsight Bias

Date created: 
2015-04-13
Abstract: 

Outcome knowledge influences recall of earlier predictions of an event. Compared to younger adults, older adults are more susceptible to the two underlying bias processes that contribute to this hindsight bias (HB) phenomenon, recollection bias and reconstruction bias. However, the role of cognitive abilities in these processes remains unclear. In Experiment 1, we extended the multinomial processing tree model for HB by incorporating individual variation in cognitive abilities into parameter estimation in a sample of 60 older (M = 72.50, range = 65 to 87) and 62 younger (M = 20.10, range = 18 to 25) adults. In older adults, our findings revealed that (1) higher episodic memory was associated with higher recollection ability in the absence of outcome knowledge, (2) higher episodic memory, inhibitory control, and working memory capacity were associated with higher recollection ability in the presence of outcome knowledge, and (3) higher inhibitory control was associated with less reconstruction bias. Although the pattern of effects was similar in younger adults, the cognitive covariates did not significantly predict the underlying processes in this age group. In Experiment 2, we collected memory judgment HB data on an additional 80 older adults (M = 71.40, range = 65 to 87) to assess whether a) experimentally increasing inhibition demands via outcome rehearsal during the HB task impacts the underlying HB processes, and b) the effects of this cognitive load manipulation on the underlying HB processes vary with an individuals’ inherent cognitive abilities. Our findings revealed that cognitive load increased recollection bias independently of individuals’ cognitive abilities. Conversely, cognitive load only increased reconstruction bias in individuals with high inhibitory control, resulting in these individuals performing similarly to individuals with low inhibitory control. Our findings support the role of inhibitory control in older adults’ recollection and reconstruction biases, and suggest that even high functioning individuals are susceptible to HB when available processing resources are limited.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Wendy Thornton
Department: 
Arts & Social Sciences:
Thesis type: 
(Dissertation) Ph.D.

Make me why don't you: understanding barriers to treatment engagement in coercive contexts

Date created: 
2015-04-14
Abstract: 

The high cost of mandated or coercive treatment in terms of time, money, and emotional distress highlights the importance of determining whether and how this kind of treatment can lead to positive outcomes. Findings suggest that even treatment resistant patients can benefit given the right circumstances. A recent Task Force concluded that there was evidence for the influence of three factors in treatment outcomes including relationship principles, non-diagnostic patient characteristics and the technical details of the treatment. The authors called for future research to further their stated aim, “to identify empirically based principles of change in psychotherapy …that provide guidelines about how to most effectively deal with clients that aren’t tied to particular approaches or theories” (Castongauy & Beutler, 2006, p. 632).The aim of the present study was to examine factors thought to influence relationship principles (patient perceptions of the hospital admission process and subsequent treatment) and patient characteristics associated with negative treatment outcomes (antisocial personality traits and negative emotionality) in an attempt to identify which variables are at play during the experience of treatment that prevent active participation (therapeutic alliance, treatment motivation and treatment compliance). The participants were 139 civil psychiatric patients recently discharged. Data was collected via semi-structured interview and record review at baseline and 5 prospective follow-ups to examine relationships between variables over time. Results indicated that patient perceptions are related to treatment indices at baseline and these relationships are stable over time. Further, antisocial personality traits were related to treatment compliance and dispositional anger. Findings hold implications for the impact of interventions designed to target treatment interfering perceptions and emotions at initial contact, on treatment engagement over time.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Kevin Douglas, LLB, PhD
Department: 
Arts & Social Sciences:
Thesis type: 
(Dissertation) Ph.D.

The Role of Supportive Contact in Increasing Collective Action Engagement Among Disadvantaged Group Members

Date created: 
2015-03-26
Abstract: 

Recent research and theorizing suggests that friendly cross-group contact, while effective at improving intergroup attitudes, can undermine disadvantaged group members’ collective action engagement. In a series of 3 experimental studies, the present research investigated “supportive contact” - friendly cross-group contact in which an advantaged group member demonstrates their interest and engagement in opposing group-based inequality. I hypothesized that supportive contact would not undermine collective action, and would instead empower disadvantaged group members, because of its potential to strengthen disadvantaged group members’ perceptions of injustice and ingroup identification. Study 1 focused on immigrants to Canada, and provided an opportunity for cross-group contact with a Canadian-born individual. Study 2 focused on international students at an Australian university, and investigated the effects of recalling past contact with a domestic student. These two studies revealed that compared to a number of other forms of friendly cross-group contact, supportive contact led to greater collective action engagement. Across both studies, increased perceptions of injustice emerged as the key mediator of the relationship between supportive contact and increased collective action engagement. Study 3 focused on cross-group contact between men and women, and revealed a complex pattern of results. Overall, supportive contact led to lower collective action engagement among women, compared to low supportiveness contact. However, analysis of the indirect effects revealed a pattern of results consistent with a suppressor effect: supportive contact also increased collective action engagement among women, due to the supportive group-based emotions shared by the male friend, and the positive impact of these emotions on ingroup identification. The paper discusses the promise of supportive contact, suggests applied applications, and makes recommendations for future research.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Stephen Wright
Department: 
Arts & Social Sciences: Psychology
Thesis type: 
(Thesis) Ph.D.