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Full-Text Articles in Psychology

Cholesterol: A Possible Mediator Of Apoe Risk For Alzheimer's Disease, Michelle Marie Dunk Dec 2019

Cholesterol: A Possible Mediator Of Apoe Risk For Alzheimer's Disease, Michelle Marie Dunk

Theses and Dissertations

Despite the well-established link between the ε4 allele of the apolipoprotein E (APOE) gene and AD, the underlying mechanisms that mediate the risk of developing AD remain elusive. Literature on the role of APOE in cholesterol metabolism suggests that blood cholesterol may be a key factor in the development of AD pathology. Current study aims to investigate whether total cholesterol differs by APOE status and whether this relationship is predictive of AD diagnosis and its biomarkers. Baseline total cholesterol, APOE status, AD diagnosis, global cognitive function, brain Aβ, plasma Aβ40 and Aβ42, and cerebrospinal fluid (CSF) Aβ, tau, and phosphorylated …


Reexamining Object-Based Visual Attention: Understanding The Nature Of Direction-Dependent Attention Shifts, Adam Joseph Barnas Dec 2019

Reexamining Object-Based Visual Attention: Understanding The Nature Of Direction-Dependent Attention Shifts, Adam Joseph Barnas

Theses and Dissertations

Attentional selection is a process by which relevant sensory stimuli are afforded enhanced priority for processing over and above irrelevant sensory stimuli. Object-based attention is a form of selection that leads to preferential processing of visual information contained in/on an attended object versus an unattended object. Observers typically exhibit enhanced performance to a target at an invalidly cued same object location compared to a different-object location, which results in a same object advantage as measured by the response time (RT) difference between these two target locations. A growing body of research has shown that object-based effects are small, inconsistent, and …


Investigating The Contribution Of Instance-Reliant Learning In Visuomotor Adaptation And Its Generalization, Shancheng Bao Dec 2019

Investigating The Contribution Of Instance-Reliant Learning In Visuomotor Adaptation And Its Generalization, Shancheng Bao

Theses and Dissertations

Motor adaptation has been of great interest in the past two decades as it reflects how movement skills are acquired and consolidated by the nervous system. In our recent studies, instance-reliant learning is considered as an essential component of visuomotor adaptation, since it plays a unique role in fast and automatized control of movement output. The goal of this dissertation is to investigate the nature of instance-reliant learning on two aspects: to determine the differential contributions of algorithmic learning and instance-reliant learning to visuomotor adaptation; and to determine the nature of movement instance involved in visuomotor adaptation and its generalization …


Evaluation Of Cognitive Control Using Non-Gaussian Reaction Time Distributions In Fractionated Executive Function Tasks, Dmitriy Kazakov Aug 2019

Evaluation Of Cognitive Control Using Non-Gaussian Reaction Time Distributions In Fractionated Executive Function Tasks, Dmitriy Kazakov

Theses and Dissertations

The present study seeks to further investigate and refine the three-factor model of executive function (EF; Inhibition, Shifting, and Monitoring/Updating) known as the unity/diversity framework (Miyake et al., 2000). Past work in this area utilized “power” tasks that prioritize accuracy and difficulty, but real-world problem-solving incentivizes quick and efficient solutions. Ten computerized reaction time (RT) tasks: four elementary cognitive tasks (ECTs; Jensen, 1987; Santos, 2016) with progressively increasing task demands and six EF tasks. The ratio scale of RT necessitated the use of non-Gaussian statistics to better describe distribution shape, while diffusion modeling (DM; Ratcliff, 1978) was used to interpret …


Cannabis-Using Youth Demonstrated Blunted Rostral Anterior Cingulate Cortex Activation, But Normal Functional Connectivity, During An Emotional Go/No-Go Task, Kristin Elizabeth Maple Aug 2019

Cannabis-Using Youth Demonstrated Blunted Rostral Anterior Cingulate Cortex Activation, But Normal Functional Connectivity, During An Emotional Go/No-Go Task, Kristin Elizabeth Maple

Theses and Dissertations

Cannabis use has been associated with deficits in self-regulation, including inhibitory control. Cannabis users have previously exhibited both structural and functional deficits in the rostral anterior cingulate cortex (rACC), a region involved in self-regulation of emotional response and inhibitory control. The present study aimed to examine whether abstinent cannabis users demonstrated abnormal functional activation and connectivity of the bilateral rACC during an emotional inhibitory processing task, and whether gender moderated these relationships. The study also aimed to examine whether bilateral rACC activation and connectivity in cannabis users was related to perceived stress. It was hypothesized that cannabis users would exhibit …


White Matter Integrity In Individuals At-Risk For Ptsd Development: A Longitudinal Investigation, Carissa Weis May 2019

White Matter Integrity In Individuals At-Risk For Ptsd Development: A Longitudinal Investigation, Carissa Weis

Theses and Dissertations

Trauma exposure is prevalent and while most are resilient, some go on to develop post-traumatic stress disorder (PTSD)—an anxiety-related disorder that results from traumatic experience. The brain changes that result from traumatic experience and PTSD are not well understood. Further, little is known about what distinguishes those who are resilient after trauma from those at risk for developing PTSD. Previous work indicates white matter integrity may be a useful biomarker in predicting PTSD and researchers have found changes in the integrity of three white matter tracts—the cingulum bundle, corpus callosum (CC), and uncinate fasciculus (UF)—in the aftermath of trauma. However, …


Memory-Based Viewing: A Potential Marker Of Pathological Aging, Jenna Blujus May 2019

Memory-Based Viewing: A Potential Marker Of Pathological Aging, Jenna Blujus

Theses and Dissertations

Markers of cognitive impairment are needed to distinguish normal from pathological aging prior to the onset of clinical symptomology to improve Alzheimer’s disease (AD) treatment or prevention efforts. AD pathology is believed to develop years or even decades prior to diagnosis in medial temporal lobe subregions that provide input to the hippocampus (Braak & Braak, 1991), disrupting the ability of the hippocampus to bind individual elements of an experience to form cohesive memory representations. Eye movement behavior is a sensitive index of learning and effects of memory on eye movements have been shown to emerge rapidly (within 500-750ms of stimuli …


Memory-Based Viewing: A Potential Marker Of Pathological Aging, Jenna Blujus May 2019

Memory-Based Viewing: A Potential Marker Of Pathological Aging, Jenna Blujus

Theses and Dissertations

Markers of cognitive impairment are needed to distinguish normal from pathological aging prior to the onset of clinical symptomology to improve Alzheimer’s disease (AD) treatment or prevention efforts. AD pathology is believed to develop years or even decades prior to diagnosis in medial temporal lobe subregions that provide input to the hippocampus (Braak & Braak, 1991), disrupting the ability of the hippocampus to bind individual elements of an experience to form cohesive memory representations. Eye movement behavior is a sensitive index of learning and effects of memory on eye movements have been shown to emerge rapidly (within 500-750ms of stimuli …


White Matter Integrity In Individuals At-Risk For Ptsd Development: A Longitudinal Investigation, Carissa Weis May 2019

White Matter Integrity In Individuals At-Risk For Ptsd Development: A Longitudinal Investigation, Carissa Weis

Theses and Dissertations

Trauma exposure is prevalent and while most are resilient, some go on to develop post-traumatic stress disorder (PTSD)—an anxiety-related disorder that results from traumatic experience. The brain changes that result from traumatic experience and PTSD are not well understood. Further, little is known about what distinguishes those who are resilient after trauma from those at risk for developing PTSD. Previous work indicates white matter integrity may be a useful biomarker in predicting PTSD and researchers have found changes in the integrity of three white matter tracts—the cingulum bundle, corpus callosum (CC), and uncinate fasciculus (UF)—in the aftermath of trauma. However, …


Contextually Modulated Avoidance Behavior In Rats Post-Pavlovian Extinction, Lauren Branigan Feb 2019

Contextually Modulated Avoidance Behavior In Rats Post-Pavlovian Extinction, Lauren Branigan

Theses and Dissertations

The following study sought to examine the psychological substrates of renewal (e.g.., context dependent extinction processes) for conditioned avoidance behaviors in rats. Using signaled active avoidance conditioning, rats acquired two-way shuttle responding, to two different auditory stimuli. These behaviors were then extinguished through exposure to the auditory stimuli where shuttling behavior was now without consequence. Subjects were then tested for renewal of avoidance in three distinct renewal sequences (e.g., ABA vs ABB, AAB vs AAA, and ABC vs ABB) in three separate groups of rats. It was found that subjects showed more responding to a stimulus presented outside of its …


The Role Of Mindfulness In Self-View Investment: Neural And Subjective Indicators, Hadley Rahrig Jan 2019

The Role Of Mindfulness In Self-View Investment: Neural And Subjective Indicators, Hadley Rahrig

Theses and Dissertations

Self-concept is strongly influenced by beliefs about one’s personal psychological attributes, and these beliefs are held with varying degrees of confidence and consequence. Hence, it is investment in self-views of those attributes that helps to regulate and maintain stable self-concept. Self-view investment is relevant to numerous self-related functions, but high self-view investment can also contribute to maladaptive self-views. Theory suggests that mindfulness cultivates a less personal, more objective perception of one’s thoughts, emotions and behaviors, and training in mindfulness has been shown to alter self-referential processing. The current pilot study (N=21) investigates the possible role of dispositional mindfulness in two …