Social and Behavioral Sciences Commons^™

The Cognitive Thalamus: Source Analysis Of Scene Working Memory Delay Activity, Bernard A. Gomes

Dissertations, Theses, and Capstone Projects

Working Memory represents a limited-capacity store for maintaining information and manipulating the store's contents over a short period for the guidance of goal-directed behavior. Working Memory is an essential component of executive functions that are intricately associated with the prefrontal cortex (PFC). The PFC has been implicated in maintaining task-related information online for brief periods in the absence of relevant information. This active maintenance phase is called the delay period that occurs between encoding and retrieval of the stimulus. Previous studies have attempted to understand the relationship between working memory and the PFC, especially during the delay or maintenance phase …

Structural And Functional Brain Markers Of Trauma-Related Symptoms, Glenn Blessington

Dissertations, Theses, and Capstone Projects

The neurocircuitry model of posttraumatic stress disorder suggests an association between trauma-related symptoms and abnormalities in the structure and function of limbic and prefrontal brain regions. Evidence also suggests that these structural and functional abnormalities are related. We tested the relation between whole brain white matter integrity, resting-state functional connectivity of a fronto-limbic network, and trauma-related symptoms in 22 trauma-exposed women. We hypothesized that components of whole brain white matter would correlate with components of resting connectivity within a fronto-limbic network. We used parallel independent component analysis (pICA) to test the associations between whole brain fractional anisotropy (FA) maps and …

Analysis Of Newspaper Coverage Of Psilocybin From January 1, 1989 To December 31, 2019, Dax Oliver

Dissertations, Theses, and Capstone Projects

Psilocybin is a chemical compound that has received a lot of attention from medical researchers in recent years. However, this research is not merely a medical issue but a social and political one as well. In the 1960s, psilocybin and other psychedelic compounds were widely ingested outside of clinical settings. This alarmed some of the American public, resulting in severe legal restrictions on psilocybin use and research.

Today, many psilocybin advocates hope that it will avoid the negative public sentiment of the 1960s. To help gauge public sentiment about other psychoactive compounds, some studies have examined newspaper coverage, but there …

The Temporal Dynamics Of Ensemble Perception, Michael L. Epstein

Dissertations, Theses, and Capstone Projects

The striking disparity between the subjective richness of experience and the considerable limitations of perceptual processing has emerged as an essential, enduring question in both vision science and philosophy of mind. A potential solution to this issue is ensemble perception: the ability for the visual system to compute the statistical summaries of object groups, effectively compressing an otherwise overwhelming amount of information. Previous work has supported that ensemble statistics can be perceived quickly and accurately for a wide range of object features. This has motivated models of ensemble perception as an early process in vision, providing an initial sense of …

Rehabilitative Movement Approaches And Dance Interventions In Parkinson’S Disease, Cecilia Fontanesi

Dissertations, Theses, and Capstone Projects

The scope of this work is to address the functional deficits and symptoms experienced by those living with Parkinson’s Disease through movement interventions.

Chapter 1 offers a brief overview of current pharmacotherapy and rehabilitation approaches in Parkinson’s, focusing on dance in particular as a movement intervention that may be particularly suited to this population.

Chapter 2 focuses on brain plasticity and motor learning in PD, reporting the effects of rTMS applied after the acquisition of a motor skill. In this study, adaptation tested in patients with PD was comparable in the sham and TMS sessions, while retention indices tested on …

Neurodevelopmental Mechanisms Of Adverse Trauma Outcomes In Emerging Adulthood, Olena Kleshchova

Dissertations, Theses, and Capstone Projects

Background: Exposure to traumatic stress and adversity during the formative years of development can have adverse effects on mental health, neuroendocrine stress system function, and the brain, that persist into adulthood. One candidate mechanism that might confer vulnerability to enduring adverse outcomes of early life trauma is disruption of normal brain maturation. As the brain matures, functional interactions among brain regions change until the functional brain architecture (i.e., the functional connectome) reaches a mature state in adulthood. Given that different neural circuits have distinct developmental trajectories and sensitive periods, traumatic stress at a given point in development might have …

Sex/Gender Differences In Serial Position Profiles In Patients With Mild Cognitive Impairment And Healthy Controls, Emnet Z. Gammada

Dissertations, Theses, and Capstone Projects

Introduction: Alzheimer’s disease disproportionately affects more women, but paradoxically, men have a higher incidence of Mild Cognitive Impairment (MCI). Researchers have suggested that women’s verbal memory advantage across the lifespan reflects better premorbid skills, which then require more neurodegeneration to manifest early clinical impairment. To date, measurement of sex differences in verbal memory have used total list scores. We proposed that a granular examination of serial position effects (SPE) in list-learning can refine the source of sex/gender differences.

Methods: A cross-sectional analysis of participants with Mild Cognitive Impairment (MCI) and Healthy Controls (HC) was examined from the Alzheimer’s Disease Neuroimaging …

A Glance At The Mirror: Ensemble Perception Of Symmetry, Gene Jerskey

Dissertations, Theses, and Capstone Projects

A growing body of research has demonstrated the ability of subjects to extract representative statistics from visual ensembles, images of similar but distinct groups of objects, without conscious effort or attention focused on individual members of the ensemble. When presented with ensembles, subjects have been able to accurately report the mean, range, and even distribution of various features in the ensemble. Research into ensemble perception, as it has become known, has divided mainly into studies of either low-level features, such as orientation, motion, and color, which are processed in early visual areas, at least for individual objects, or high-level features, …

The Effects Of Self-Esteem And Motivation On Cognitive Control, Andrea Benavides

Dissertations, Theses, and Capstone Projects

Cognitive control describes a set of mechanisms that guide behavior towards a goal (Cohen, 2017). The successful execution of cognitive control is essential for effective learning, information processing, problem solving, and academic achievement (Visu-Petra et al., 2011). The Expected Value of Control framework (EVC; Shenhav et al., 2013) suggests that control carries an inherent cost, which is weighed against the potential benefits of expending it. This cost-benefit analysis determines the direction and intensity that a goal is pursued. Importantly, motivation plays a role in this cost-benefit analysis and may function as the factor that offsets the cost of control expenditure …

Experience-Dependent Changes In Nucleus Accumbens Activity Predict Cued Approach Learning: Contribution Of Nmda Receptors, Mercedes Vega Villar

Dissertations, Theses, and Capstone Projects

Animals learn associations between environmental cues and the natural rewards they predict (e.g., food, water, sex). As a result, reward-predictive cues come to trigger vigorous reward-seeking responses. Many neurons in the nucleus accumbens (NAc) become excited upon presentation of an already-learned reward-predictive cue. These NAc responses encode the motivational value of the cue and are necessary for the expression of the subsequent approach behavior. However, the precise temporal relationship between the emergence of cue-evoked excitations in the NAc and the acquisition of cued approach behavior remains unknown. In Experiment 1, NAc activity was recorded as rats learned to approach a …

A Neural Mechanism For Capnotaxis In The Naked Mole-Rat, Michael Zions

Dissertations, Theses, and Capstone Projects

A Neural Mechanism for Capnotaxis in the Naked Mole-Rat

The Naked Mole-Rat (NM-R) is a small hairless rodent that has thrived underground in the Horn of Africa for the past 40 million years. It was first discovered in 1847, but has only been maintained in captivity and studied as a laboratory animal over the past 40 years. To date, more than 400 scientific papers have been published on this species. This is relatively few compared to established lab animals like rats and mice, but those papers contain a trove of information that has changed our understanding of the constraints of …

Mapping The Spatial And Temporal Dynamics Of Visual Percepts Elicited By A Non-Invasive Brain Stimulation Technique, Kelly Webster

Dissertations, Theses, and Capstone Projects

While many of us rely on vision to interact with and experience the world, for people with damage or disease to the eye or visual cortex, experience through this modality is extremely limited. Brain and retinal stimulation devices show exciting promise for restoring vision, but little is understood about where and when vision percepts can be induced through stimulation. Using a non-invasive brain stimulation technique called transcranial magnetic stimulation (TMS), we characterized the spatial and temporal dynamics of perception induced through brain stimulation. In the first set of experiments, we explore the importance of higher visual and non-visual areas vs. …

Mechanisms Of Value-Biased Prioritization In Fast Sensorimotor Decision Making, Kivilcim Afacan-Seref

Dissertations and Theses

In dynamic environments, split-second sensorimotor decisions must be prioritized according to potential payoffs to maximize overall rewards. The impact of relative value on deliberative perceptual judgments has been examined extensively, but relatively little is known about value-biasing mechanisms in the common situation where physical evidence is strong but the time to act is severely limited. This research examines the behavioral and electrophysiological indices of how value biases split-second perceptual decisions and the possible mechanisms underlying the process. In prominent decision models, a noisy but statistically stationary representation of sensory evidence is integrated over time to an action-triggering bound, and value-biases …