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Full-Text Articles in Neuroscience and Neurobiology

Behavioral And Neural Correlates Of Episodic Memory Regulation, Mrinmayi Kulkarni Aug 2021

Behavioral And Neural Correlates Of Episodic Memory Regulation, Mrinmayi Kulkarni

Theses and Dissertations

Episodic memory retrieval, while critical for daily living, needs to be regulated to maintain goal-directed behavior. Past work has shown that episodic memory regulation engages brain regions involved in cognitive control, such as the dorsolateral and ventrolateral prefrontal cortex. These regions interact with the medial temporal lobe structures to control retrieval processes. In the current study, I paired eye-tracking, a sensitive index of memory, with fMRI in a novel paradigm to address several open questions in the field of episodic memory regulation. Participants initially encoded three celebrity faces and three tools with multiple indoor and outdoor scenes. In a subsequent …


Neural Correlates Underlying The Interactions Between Anxiety And Cannabis Use In Predicting Motor Response Inhibition, Richard Ward May 2021

Neural Correlates Underlying The Interactions Between Anxiety And Cannabis Use In Predicting Motor Response Inhibition, Richard Ward

Theses and Dissertations

The ability to effectively withhold an inappropriate response is a critical feature of cognitive control. Prior research indicates alterations in neural processes required for motor response inhibition in anxious individuals, including those with posttraumatic stress disorder (PTSD), and those who engage in regular cannabis use. However, thus far most research has examined how anxiety-related symptoms and cannabis use influence response inhibition in isolation of one another. The current study examined the interactions between anxious symptomology and recent cannabis use in a sample that recently experienced a traumatic event using functional magnetic resonance imaging (fMRI) during the completion of a Stop-Signal …


Restorative Potential And Working Memory Capacity Of Exposure To Vegetation In Indoor Built Environments, Jee Heon Rhee Dec 2020

Restorative Potential And Working Memory Capacity Of Exposure To Vegetation In Indoor Built Environments, Jee Heon Rhee

Theses and Dissertations

This research seeks to understand how natural elements – specifically, vegetation in the indoor environment - influence people’s ability to restore attention and working memory capacity. Previous research demonstrates the benefits of nature on human beings in various ways. For instance, numerous studies show the positive effects of nature on stress reduction (Hartig, Mang, & Evans, 1991; Ulrich et al., 1991) and attention restoration (Staats, Kieviet, & Hartig, 2003). However, most of these studies focus on the effect of nature in outdoor settings. Relatively few studies focus on the presence of natural elements indoors. This is an important gap in …


Data-Driven Approach To Dynamic Resting State Functional Connectivity In Post-Traumatic Stress Disorder, Carissa Weis Dec 2020

Data-Driven Approach To Dynamic Resting State Functional Connectivity In Post-Traumatic Stress Disorder, Carissa Weis

Theses and Dissertations

Posttraumatic stress disorder (PTSD) is a heterogenous psychological disorder that may result from exposure to a traumatic event. Using functional magnetic resonance imaging (fMRI), symptoms of PTSD have been associated with aberrations in brain networks that emerge in the absence of a given cognitive demand or task, called resting state networks. Most previous research in resting state networks and PTSD has focused on aberrations in the static functional connectivity among specific regions of interest (ROI) in the brain and within canonical networks constrained by a priori hypotheses. However, dynamic fMRI, an approach that examines changes in brain network characteristics over …


The Impact Of Task Load On Neural Entrainment To Attended Speech: A Dual-Task Magnetoencephalography (Meg) Paradigm, Michelle Tamar Kassel Aug 2020

The Impact Of Task Load On Neural Entrainment To Attended Speech: A Dual-Task Magnetoencephalography (Meg) Paradigm, Michelle Tamar Kassel

Theses and Dissertations

Speech comprehension in a noisy environment requires active cognitive control mechanisms to select the relevant speech signal while filtering out irrelevant distractions. When processing speech in a multitask scenario, neural resources underlying cognitive control are considerably burdened and interfering information becomes more difficult to ignore. The present study utilized magnetoencephalography (MEG) to investigate the impact of multitasking on selective attention to speech. Twenty healthy adults performed a multitask paradigm with varying levels of both competing auditory distraction and concurrent visual working memory load. While increased visual working memory load was associated with reduced selective attention to speech in both the …


The Association Of Aerobic Fitness With Resting State Functional Connectivity And Verbal Learning And Memory In Healthy Young Adults, Kyle Joseph Jennette Aug 2020

The Association Of Aerobic Fitness With Resting State Functional Connectivity And Verbal Learning And Memory In Healthy Young Adults, Kyle Joseph Jennette

Theses and Dissertations

The beneficial effects of exercise and cardiopulmonary fitness on general health, quality of life, and reduction of mortality are well known in older adults. There is evidence to support the positive effects of exercise and aerobic fitness on psychiatric and neurocognitive function in children, adults, and older adults. Indeed, many studies have explored the positive effects of aerobic fitness on slowing cognitive decline associated with normal and pathological aging. However, comparatively fewer empirical studies in the literature exist to support and understand the effects of aerobic fitness on the developing brain, particularly during adolescence and young adulthood, especially as it …


Shaped By The Environment: The Influence Of Childhood Trauma Exposure, Individual Socioeconomic Position, And Neighborhood Disadvantage On Brain Morphology, Elisabeth Kathleen Webb Aug 2020

Shaped By The Environment: The Influence Of Childhood Trauma Exposure, Individual Socioeconomic Position, And Neighborhood Disadvantage On Brain Morphology, Elisabeth Kathleen Webb

Theses and Dissertations

The relationship between an individual’s socioeconomic position (SEP) and their overall physical and mental health has been well demonstrated. Far less is known about how area-level factors, such as neighborhood disadvantage, “get under the skin”. Previous research indicates lower SEP and childhood trauma negatively effects brain structure and function. The hippocampus, amygdala, and ventromedial prefrontal cortex (vmPFC) are particularly vulnerable to adversity. The current study investigated how individual SEP, childhood trauma, and neighborhood disadvantage impact these structures. Two-hundred and fifteen individuals were recruited from an Emergency Department in southeastern Wisconsin. Two-weeks post-traumatic injury, participants completed a structural magnetic resonance imaging …


Attention Capture By Episodic Long-Term Memories: Evidence From Eye Movement Data, Allison Eleanor Nickel May 2020

Attention Capture By Episodic Long-Term Memories: Evidence From Eye Movement Data, Allison Eleanor Nickel

Theses and Dissertations

Successfully navigating the world on a moment-to-moment basis requires the interaction of multiple cognitive processes. Therefore, studies that examine when and how these fundamental processes interact can provide important insights into how we behave. Many studies indicate that long-term memory can facilitate search for a target object (e.g., contextual cueing), however, the ways in which long-term memory might capture attention and disrupt goal-directed behavior have not been well studied. In five experiments, questions about whether encoded objects might capture attention, even when they are task-irrelevant, were addressed. Each experiment began with an encoding phase, where participants were instructed to commit …


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 …


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, …


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, …


Neural Circuitry Underlying The Intrusion Of Task-Irrelevant Threat Into Working Memory In Anxiety, Daniel Stout Aug 2016

Neural Circuitry Underlying The Intrusion Of Task-Irrelevant Threat Into Working Memory In Anxiety, Daniel Stout

Theses and Dissertations

Dispositional anxiety is an important risk factor for the development of anxiety and other psychological disorders. Symptoms commonly expressed by highly anxious individuals include intrusive memories, uncertainty, and worry — all occurring in the absence of immediate threat. This raises the possibility that anxious individuals have difficulty governing threat’s access to working memory, the mental workspace where goal-related information is actively retained for guiding on-going behavior. Using functional magnetic resonance imaging (fMRI) while 81 subjects completed a well-validated working memory task, I show that threat-related and neutral distracters unnecessarily gain access to working memory, as evidenced by increased neural activity …