Neuroscience and Neurobiology 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 …

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 …

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, …

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 …

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 …

Investigating The Neural Mechanisms Of Unconscious And Illusory Touch Perception, Lua Koenig

Dissertations, Theses, and Capstone Projects

Despite our everyday reliance on touch, from manipulating tools to dressing ourselves, relatively little is known about the neural correlates of tactile perception. As with other modalities, our conscious, reportable experiences of touch can dissociate from the physical tactile stimulation processed by the skin. In unconscious touch perception, tactile stimuli can be processed and guide our behavior without an accompanying conscious percept. For example, we may swat away a mosquito without having consciously registered its presence on our skin. In tactile illusions, conscious tactile experiences occur without a corresponding tactile stimulus. Multisensory tactile illusions arise when stimulation of a different …

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 …

The Impact Of A Single Session Of Mindfulness Meditation On The Attentional Blink In Non-Meditators, Arielle L. Klopsis

Dissertations, Theses, and Capstone Projects

Attentional resources are limited therefore a stimulus can go undetected if it closely follows another target by 200-500ms. This phenomenon is known as the attentional blink. Mindfulness meditation has been shown to be beneficial in target detection and in decreasing the attentional blink. Since there is no standard for the type of meditation or duration of practice that leads to attention benefits, this study compares the two most popular types of meditation in a group of non-meditators: focused attention and open monitoring meditation. This study utilized an attentional blink paradigm to measure if a single session of mindfulness meditation can …

Proactive And Reactive Aggression, Respiratory Sinus Arrhythmia, And Sleep In Adolescents, Allison L. Brasch

Dissertations, Theses, and Capstone Projects

Current research evaluating the relationship between proactive and reactive aggression, sleep, and autonomic dysfunction has shown inconsistencies. The unique etiologies, manifestations, and presentation of these two aggressive subtypes have garnered much speculation, and research has shown mixed, and oftentimes conflicting, results. Generally speaking, insufficient sleep has been linked to increased agitation, cognitive impairment, emotional dysregulation, and poorer physical health. Many studies have provided support for an inverse relationship existing between sleep problems and sympathovagal health, implicating hypo- or hyper-autonomic function with proactive and reactive aggression, respectively. Concurrently and conflictingly, additional research has shown support for the exact opposite relationships between …

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. …

Blocking Visual Awareness With Continuous Flash Suppression Prevents Cognitive Control, Jonathan Lovoi

Dissertations, Theses, and Capstone Projects

Cognitive control refers to a set of functions that allow for the execution of goal-directed behavior while remaining flexible to changes in task demands. Findings addressing whether or not awareness is necessary to elicit cognitive control are inconsistent, possibly stemming from the short stimulus presentation times employed in most masking paradigms, which could prevent sufficient processing time in some cases or provide a gist of the masked stimulus in other cases. The present study examined the necessity of awareness in cognitive control using Continuous Flash Suppression (CFS) to suppress stimulus awareness for periods of time longer than possible with other …