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

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The role of lane position in right-of-way violation collisions involving motorcycles

Author: 
Date created: 
2016-12-02
Abstract: 

Low motorcycle conspicuity is believed by many researchers, drivers, and motorcyclists to be causally involved in motorcycle collisions that involve another driver. Substantial improvements in motorcycle conspicuity have been made over the last four decades, but in spite of this, motorcycle collisions involving other vehicles are on the rise, specifically the type of collision where another driver violates the motorcyclist’s right-of-way because they “did not see them”. Because the hypothesis that motorcycles lack conspicuity in traffic is so intuitively appealing and so pervasive, it has never been tested. This work provides an argument against the notion that right-of-way-violation collisions are due to poor motorcycle detection resulting from their low conspicuity and proposes an alternate hypothesis: These collisions seem related to failures in motion-perception which are partially caused by the motorcycle’s approach path in a left-of-lane position which, ironically, is partly intended to increase the motorcycle’s conspicuity.

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

The Structured Assessment of Protective Factors for Violence Risk – Youth Version (SAPROF-YV): The Association Between Protective Factors and Aggression in Adolescents

Author: 
Date created: 
2016-12-07
Abstract: 

The Structured Assessment of Protective Factors for Violence Risk – Youth Version (SAPROF-YV; de Vries Robbé et al., 2015) is a new measure of protective factors that is used with a risk-focused tool, such as the Structured Assessment of Violence Risk in Youth (SAVRY; Borum et al., 2006), to provide a more balanced assessment of risk. The present study investigated the relationship between the SAPROF-YV and aggression in a sample of 69 adolescents. Using a retrospective study design, files were reviewed at an inpatient treatment facility and a probation office. Results indicated that the SAPROF-YV demonstrated good convergent and discriminant validity with the SAVRY. The SAPROF-YV was predictive of the absence of verbal and physical aggression; however, it did not add incrementally to SAVRY Risk factors. Finally, some evidence suggested the SAPROF-YV was more predictive for higher risk adolescents than lower risk adolescents. Implications for research and clinical applications are discussed.

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

The Role of Chronic Illness in Theory of Mind Performance in Older Adults

Date created: 
2016-12-13
Abstract: 

Theory of Mind (ToM) reflects the ability to reason about mental states in order to understand and predict behavior. Research has identified links between increased pulse pressure, a measure of vascular health, and reduced ToM in older adults. Furthermore, previous findings suggest that cognitive ToM is particularly vulnerable to increased pulse pressure. However, to date, the relationships between other chronic vascular and nonvascular conditions and reduced ToM are unknown. We aimed to investigate the effects of vascular and nonvascular illness burden on cognitive and affective ToM in N = 86 older adults (59 females; 27 males, M = 72 years). While vascular illness burden emerged as a significant predictor of older adults’ ToM, nonvascular illness burden was not significantly associated with ToM. Further, executive functioning and semantic memory mediated the relationship between vascular illness burden and cognitive ToM. Our findings highlight the specific importance of considering vascular health as a risk factor for declines in ToM in later life, beyond pulse pressure. Further elucidation of the associations between health, neurocognition and ToM will be valuable in developing effective interventions for older adults given the high prevalence of vascular illness in later life.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Wendy Loken Thornton
Department: 
Arts & Social Sciences: Department of Psychology
Thesis type: 
(Thesis) M.A.

The Electrophysiology of Cognitive Dissonance-elicited Attitude Change

Date created: 
2016-12-08
Abstract: 

Despite the influence that cognitive dissonance theory has had in psychology over the last sixty years, its neural correlates have only recently been investigated. The current study used electroencephalography (EEG) to explore cognitive dissonance-elicited attitude change in a free-choice paradigm. Event-related potentials (ERPs) time-locked to stimulus onset found greater voltage negativity over centro-parietal scalp during re-evaluation of dissonant choice items relative to consonant choice items, and greater negativity over left lateral anterior scalp during trials containing dissonance-reducing attitude change relative to trials without. Left lateral anterior scalp voltage amplitude was found to be negatively correlated with the magnitude of resulting attitude change. A time-frequency analysis revealed effects for high and low alpha and theta frequencies. These finding are consistent with a model of cognitive dissonance in which cortical projections of ventral striatal activity reflect reward signal changes, and where left prefrontal cortex is recruited for cognitive control and emotional down-regulation.

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

Heroin Use, Traumatic Brain Injury, and Schizophrenia Predict Everyday and Social Functioning in Marginally Housed Persons: Direct Effects and Mediation by Neurocognition

Author: 
Date created: 
2016-11-14
Abstract: 

Multimorbid illness, including substance use, psychiatric illness, viral infection, and traumatic brain injury (TBI), is prevalent in marginally housed persons, but it is unclear how these problems influence everyday and social functioning. We conducted mediation analyses in 210 participants in order to evaluate the effects of substance use, psychiatric illness, viral infection, and traumatic brain injury on predicting 6-month follow-up ratings of functioning, and to examine whether neurocognitive performance significantly mediated the relationship between these health characteristics and ratings of functioning. Neurocognition, alongside positive and negative symptoms, explained 47% of the effect of schizophrenia on functioning and 11% of the effect of TBI on functioning. Additionally, greater heroin use frequency was significantly associated with lower ratings of functioning, but this effect was not mediated by neurocognition. Our findings highlight the role of neurocognition in mediating the relationship between illness and functioning in the marginally housed, and inform treatment targeting toward specific morbidities in populations with complex health issues.

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

Mechanisms of attentional processing during visual search: how distraction is handled by the brain

Author: 
Date created: 
2016-11-23
Abstract: 

In order to effectively search the visual environment, an observer must continually locate objects of interest amid an abundance of irrelevant and distracting stimuli. These visual distractors can sometimes inadvertently attract attention to their locations, even when an observer is attempting to search for an entirely different object. To deal with visual distractors, it has been well established that the visual system can implement a suppression mechanism to filter out irrelevant stimuli. Within the past decade, event-related potential (ERP) recordings have isolated an attentional component that is thought to reflect this suppressive processing. This ERP component—termed the distractor positivity (PD)—has been used to demonstrate that the sensory processing of irrelevant information can be strongly modulated in line with the visual search goals of an observer. Here, four electrophysiological studies of attention are presented which focus on yielding insight into how the visual system deals with irrelevant information during visual search and seeks to further our understanding of the PD component. Chapter 2 tests the stimulus conditions necessary to elicit the distractor suppression indexed by the PD by examining how differences in the salience of an irrelevant stimuli affect visual search. Chapter 3 explores how individual differences in target and distractor processing are associated with variations in visual working memory (vWM) capacity. Chapter 4 asks how distractor processing is altered during a disruption of attentional control by examining how visual search is affected during the attentional blink (AB). Chapter 5 explores how high levels of trait anxiety alter inhibitory control and the ability to ignore distracting information. In the final chapter, future directions are discussed and a model for attentional processing is proposed.

Document type: 
Thesis
File(s): 
Supervisor(s): 
John McDonald
Department: 
Arts & Social Sciences: Department of Psychology
Thesis type: 
(Dissertation) Ph.D.

Revisiting itemmetrics: Do psychologists need to watch their language?

Date created: 
2016-12-13
Abstract: 

Despite a long tradition of studying psychometric properties of self-report questionnaires in psychology, the literature identifying specific linguistic features of questionnaire items is sparse. Moreover, it is unclear whether linguistic features affect all individuals similarly, or interact with individual characteristics. The present study offers a novel methodological contribution whereby a variety of linguistic features, based on the domains typically studied by linguists (i.e., morphology, syntax, semantics), are proposed. To demonstrate how these itemmetrics can be used empirically, we analyzed data from the Center for Epidemiological Studies-Depression (CES-D) scale. Additionally, we probed interactions between sex and English fluency and each of the features to examine whether there were differential effects depending on the individual. Our results suggest that certain features may impact responding and interact with individual characteristics. We argue that our findings necessitate a stronger focus on this area of research.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Rachel T. Fouladi
Department: 
Arts & Social Sciences: Department of Psychology
Thesis type: 
(Thesis) M.A.

An Examination of the Interrater Reliability and Concurrent Validity of the Spousal Assault Risk Assessment Guide – Version 3 (SARA-V3)

Author: 
Date created: 
2016-12-08
Abstract: 

The Spousal Assault Risk Assessment Guide-Version 2 (SARA-V2; Kropp, Hart, Webster, & Eaves, 1995, 1999, 2008) is one of the most widely used Intimate Partner Violence (IPV) risk assessment tools in the world. After over 20 years, the SARA has been updated to reflect advances in research related to IPV and risk assessment more generally. The purpose of this thesis is to examine the interrater reliability and concurrent validity of the most recent version of the Spousal Assault Risk Assessment-Version 3 (SARA-V3). A total of N = 97 closed IPV cases were used to rate SARA-V3. To examine interrater reliability, a second rater coded n = 30 of the same files using SARA-V3. Interrater reliability for individual risk factors, SARA-V3 numerical total scores, and summary risk ratings fell primarily in the moderate range and consistent with prior research. Other raters had previously coded the same files with SARA-V2 and a number of other IPV risk assessment tools, and these tools served as the basis for evaluating the concurrent validity of the SARA-V3. ICCs were mostly in the fair to good range indicating adequate interrater reliability. Correlations between SARA-V3 and other IPV risk assessments were medium to large indicating good concurrent validity. Overall, the interrater reliability and concurrent validity findings were in line with previous research on SARA-V2 and the other assessments of IPV risk. Limitations of this study and implications for future research and practice are discussed.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Stephen D. Hart
Department: 
Arts & Social Sciences: Department of Psychology
Thesis type: 
(Thesis) M.A.

Risk Assessment with the HCR-20v3 across Genders, Subsamples, and Time-Frames

Author: 
Date created: 
2016-11-24
Abstract: 

One of the most well-established violence risk assessment schemes, the HCR-20: Assessing Risk for Violence Manual, Version 2 (HCR-20v2; Historical/Clinical/Risk Management-20), has recently been revised. The present study evaluated the performance of the new HCR-20v3 in a sample of 119 participants on probation or recently discharged into the community (i.e., from incarceration or short-term psychiatric hospitalization). The HCR-20v3 demonstrated concurrent validity with the HCR-20v2 and was predictive, prospectively, of whether, and how rapidly, participants engaged in violence. The SRRs added incrementally to the presence and relevance scores. Generally, no moderation effects of subsample type were noted, with the exception of the impact of subsample on the ability of the C subscale to predict the likelihood of verbal violence, as well as its impact on the SRRs, which might more strongly predict violence for the participants who were receiving short-term psychiatric inpatient care. As pertains to gender, some moderation effects were observed at 6 weeks for violence and physical violence, but this was no longer the case at 8 months. However, the H relevance rating may be more strongly predictive of time to physical violence in women, than it is in men.Moreover, the HCR-20v3 components generally demonstrated a relationship to violent victimization, whereas they did not do so for suicide. Some ratings might exhibit a relationship to self-harm. There was no moderation effect of subsample type on the ability of HCR-20v3 to forecast violent victimization. The HCR-20v3 components were not predictive of violent victimization, suicide, or self-harm in men at 6 weeks, but some demonstrated a relationship with violent victimization at 8 months. For women, some of HCR-20v3 components were predictive of violent victimization and self-harm for both time-frames. The H presence score was more predictive of violent victimization in women. Generally, the higher the scores on all HCR-20v3 presence ratings, the sooner participants were violently victimized and there was no moderation effect of subsample type. However, there was a moderation effect of gender on the ability of the C subscale to forecast the imminence of this outcome, and this may also the case for the total presence score.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Kevin S. Douglas
Department: 
Arts & Social Sciences: Department of Psychology
Thesis type: 
(Dissertation) Ph.D.

Predictors of Medication Adherence in Renal Transplant Recipients: Self-Efficacy, Depressive Symptomatology, and Neurocognitive Abilities.

Date created: 
2016-12-12
Abstract: 

Background: Estimates indicate 20-70% of renal transplant recipients (RTR) are medication non-adherent, significantly increasing the risk of organ rejection. Medication adherence decreases in relation to everyday problem solving (EPS), and associations between depressive symptoms, self-efficacy (SE), and adherence are reported in RTR. Nonetheless, to date, these individual associations have not been examined concurrently and comprehensively. To increase our understanding of adherence in RTR, we computed an omnibus model examining relationships among neurocognitive abilities, depressive symptoms, SE, and medication adherence. Methods: RTR (N= 211) underwent transplant at least 6-months prior to participation. Adherence was measured via self-report, medication possession ratio, and immunosuppressant blood-level. Traditionally-measured neurocognitive and everyday problem-solving abilities were assessed. Depressed and positive affect, somatic, and interpersonal symptoms of depression were measured via self-report, as were general and medication adherence related SE. Structural equation modeling was used to assess the fit of the model to available data. Results: For our final model, the fit indices examined indicated a good fit between the model and the data (CFI =.97; SRMR =.072; RMSEA =.031). EPS and SE had direct positive effects on adherence. Depressive symptoms were negatively associated with SE. Traditionally-measured neurocognitive abilities were positively associated with SE, and negatively associated with depressive symptoms. Conclusions: This study presents a comprehensive investigation of relationships between neurocognitive and psychosocial factors and adherence in RTR. Findings confirm the importance of EPS and SE in predicting adherence within a causal model, and suggest that influences of depressive symptoms and neurocognitive abilities are indirect. Findings have important implications for future development of interventions to improve medication adherence in RTR.

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