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 …

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 …

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 …

Functions Of Fibroblast Growth Factor Homologous Factor 2 In Excitable Tissues, Christopher Marra

Dissertations, Theses, and Capstone Projects

Purpose: Fibroblast Growth Factor Homologous Factors (FHFs) are a group of proteins known to associate with and modulate voltage-gated sodium channels (Na_v) in excitable cells. The four FHF genes are differentially expressed in specific cell-types, with FHF2 expressed prominently in the hippocampus, cerebral cortex, heart and dorsal root ganglia. Due to previous unavailability of an Fhf2 knockout mouse, this gene’s functions have been understudied in comparison to other those encoding other FHFs. The purpose of this research has been to better understand the normal physiological functions of FHF2 at the cellular and system levels in the heart, sensory …

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 …

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 …

Employing High Probability Gene Choice Elements To Understand Singular Odorant Receptor Expression, Raena Mina

Dissertations, Theses, and Capstone Projects

The ability to detect odorous chemicals in the environment is the oldest of the senses necessary for survival, from escaping danger, finding mates, to locating food. It is said that humans can identify and discriminate up to a trillion different odor mixtures. For chemoreception to have such a high discriminatory power, would require a diverse population of cells dedicated for odor detection. These detector cells are the olfactory sensory neurons (OSNs), which express odorant receptors (ORs) that bind to chemical odors in the environment. In order to increase specificity and sensitivity, an essential property in olfaction is for each OSN …

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 …

Gene Regulation And Cell Fate Choice In The Developing Vertebrate Retina, Sruti Patoori

Dissertations, Theses, and Capstone Projects

The diverse neuronal cell types in the vertebrate retina all originate from multipotent retinal progenitor cells (RPCs). These undergo a series of molecular changes driven by developmental gene regulatory networks (GRNs) as they divide to generate RPCs which are more restricted in their potential fates. It is crucial to understand these GRNs and changes to gene expression in order to understand how cell identity is established during retinal development. In particular, the GRN that promotes the development of cone photoreceptors and horizontal cells is not well-defined. This work focuses on two approaches to further elucidate the components of this regulatory …

The Cortico-Motoneuronal System In The Plexina1 Knock-Out Mouse: Sculpting The Motor Response And Activity-Dependent Plasticity, John Kalambogias

Dissertations, Theses, and Capstone Projects

Higher primates, apes, and humans have cortico-motoneuronal (CM) connections between the motor cortical areas and spinal motoneurons. The CM system is thought to confer individuated finger movements and other aspects of skilled movement control; in part, by the selective CM cell they recruit, leading to fractionated patterns of muscle activity. Although CM connections have been examined using several approaches in monkeys, the presence and properties of the CM connection was elucidated in all the species using the technique of stimulus-triggered averaging (StTA). The electrophysiological signature for the CM response is short-latency EMG facilitation (post-stimulus facilitation; PStF) in individual muscles, followed …

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 …

Tamalin/Gras-1 Connects Glutamate Receptor Activity To The Insulin/Igf Signaling Cascade To Regulate Neuroprotection In A Nematode Model Of Excitotoxicity, Ayesha Chowdhury

Dissertations, Theses, and Capstone Projects

Brain ischemia is a major cause of debilitation and death in the United States. Excitotoxicity, a condition that arises from the accumulation of glutamate (Glu) in the synapse that leads to overactivation of Glu receptors (GluRs), is the major mechanism of neuronal damage in brain ischemia / stroke. Although it is commonly acknowledged that over activation of GluRs leads to neurodegeneration, it has been recently shown that even during excitotoxicity Glu has a concurrent important role in regulating neuroprotection. GluR-activated transcription factors seem to mediate this neuroprotection, but it remains unclear which signaling cascades and transcription factors are regulated by …

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. …

Activation Of The Sonic Hedgehog Effector Smoothened Counteracts L-Dopa Induced Dyskinesia By Restoring Cholinergic Interneuron Function, Lauren Malave

Dissertations, Theses, and Capstone Projects

Many types of neurons act as multimodal signaling centers. Yet, we have only limited insight into the regulation and functional consequences of neuronal co-transmission. For example, dopamine (DA) neurons, whose degeneration causes motor deficits characteristic of Parkinson’s Diseases (PD), communicate with all their targets by DA but only a selective subset of their targets using GABA, Glutamate, and the secreted cell signaling protein Sonic Hedgehog (Shh). It is unknown whether Levo-dopamine (L-Dopa) induced dyskinesia (LIDs), a severely debilitating side effect of DA supplementation in PD, might appear because DA neuron targets are exposed to high DA- but low Shh- signaling …

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 …