Life Sciences Commons^™

Cognitive Differences In Parkinson’S Disease With Amyloid Positivity And Negativity, Kenya Luna

Electronic Theses, Projects, and Dissertations

In Parkinson’s Disease (PD), research has shifted to investigate how biomarkers commonly seen in Alzheimer’s Disease (AD), such as amyloid beta (AB), may be associated with cognitive functioning in PD. AB is considered a reliable biomarker for AD pathology, however in PD there is a lacking biomarker that can accurately reflect severity of cognitive impairment. AD research has shown an association between low AB and cognitive decline, but the data in PD has mixed results. Most studies that analyze cognitive decline and biomarkers do not use a cutoff level and the few that do have a threshold vary greatly in …

Harnessing Implicit Learning To Support The Discovery Of Second Language Phoneme Patterns In Adult Learners, Émilie R. Hoeppner

Electronic Thesis and Dissertation Repository

Statistical learning studies have focused primarily on artificial languages, despite having an overall goal of providing insight into how we learn natural languages. Here, we investigate the impact of statistical learning on processing phonemic regularities within a second language in adult learners. Participants passively listened to Italian (L2 exposure group) or English (control group) podcasts for three weeks and completed a word rating task with ERP recorded before and after this listening period. Behaviourally, the L2 exposure group showed a nonsignificant trend towards increased sensitivity to phonotactic probability over the three weeks. At the ERP level, only the L2 group …

A Postexercise Executive Function Benefit From Passive And Active Exercise Does Not Extend To Mental Fatigue Mitigation, Gianna Jeyarajan

Electronic Thesis and Dissertation Repository

A single bout of aerobic exercise improves executive function (EF) and is a benefit, in part, attributed to an increase in cerebral blood flow (CBF). It is, however, unknown whether a postexercise EF benefit mitigates mental fatigue (MF). My thesis assessed EF prior to and following separate 20-min conditions of active and passive cycle ergometry and a non- exercise control. Subsequently, a 20-min psychomotor vigilance task (PVT) was employed to determine whether the exercise intervention(s) decreased susceptibility to MF. Transcranial Doppler ultrasound was used throughout the protocol to estimate exercise- and PVT-based changes in CBF. Both exercise conditions increased CBF …

High Fat Diet & Social Isolation: Interactive Effects On Pain, Cognition, & Neuroinflammation, Ian M. Campuzano

Research Psychology Theses

Prior research has established a role for both social isolation and exposure to high fat Western diets in altering a range of behaviors from reduced memory performance to increased depression-like behaviors. The present study scrutinizes the interplay among these variables during the peri-adolescent developmental phase, utilizing Long-Evans rats as the experimental model. Our overarching hypothesis is that rats exposed to either social isolation, a high-fat diet, or both will result in heightened pain sensitivity, diminished cognitive flexibility, and increased neuroinflammatory responses within brain regions implicated in sociability, cognition, memory, and pain processing. Behavioral flexibility will be assessed using a maze-based …

Modulation Of The Alpha Oscillation Associated With Semantic And Somatic Self-Referential Processing With Non-Invasive Brain Stimulation, Zhongjie Bao

Electronic Thesis and Dissertation Repository

Who am I? What am I? While philosophers have pondered existential questions such as these for centuries, neuroscientists are beginning to reveal neural correlates that may partly underlie our semantic (verbal, psychological) and somatic (non-verbal, physical) senses of ourselves. Non-invasive brain stimulation (NIBS) can then introduce exogenous electric fields over brain regions to modulate a person’s self-referential processing (SRP). Effective NIBS protocols can help establish causal connections between brain and self-experience, helping develop clinical interventions for mental health problems.

In this dissertation, I present a series of studies investigating the neuro-electrophysiology partially mediating SRP by combining electroencephalography (EEG) with NIBS. …

The Effect Of A Single Bout Of Sub-Symptom Threshold Aerobic Exercise On Executive Function During Early Sport-Related Concussion Recovery, Alma Rahimidarabad

Electronic Thesis and Dissertation Repository

Background: Impaired executive function (EF) is a primary sequela of sport-related concussion (SRC). Aerobic exercise below symptom exacerbation may improve post-SRC EF via increased cerebral blood flow (CBF). Objectives: To examine the impact of a single bout of sub-symptom threshold aerobic exercise on CBF and EF during SRC recovery. Methods: SRC participants (n = 16) and age- and sex-matched healthy controls (HC) completed 20-min of aerobic exercise at 80% of their heart rate threshold (HRt). Pre- and postexercise EF was assessed via antisaccades. Transcranial Doppler ultrasound (TCD) estimated exercise-mediated CBF changes. Results: SRC and HC participants showed an exercise-mediated increase …

Investigating Synergistic Effects Of Mild Traumatic Brain Injury And Reduced Cholinergic Tone On Attentional Deficits And Alzheimer's-Like Pathology In Haβ And Htau Mice, Elizabeth M. Teasell

Electronic Thesis and Dissertation Repository

Mild traumatic brain injury (mTBI) increases the risk of Alzheimer’s disease. The early cholinergic decline in Alzheimer’s disease and cholinergic damage observed after TBI suggest a distinct role of this neural system in vulnerability to Alzheimer’s disease following TBI. This thesis evaluated the role of repetitive mTBI and cholinergic dysfunction in the development of cognitive deficits, specifically attentional deficits, and Alzheimer’s-related pathology in mice expressing humanized amyloid-beta and tau and a vesicular acetylcholine transporter knockdown to induce a mild cholinergic deficit. Using the rodent continuous performance test, it was shown that repetitive mTBI in the presence of an already vulnerable …

The Blessed Assembly: Irreplaceable Physical Co-Presence In Worship And Healthy Hybridity Reimagined After The Pandemic In The Digital Age, Yvette, Ying Wai Lau

Doctor of Pastoral Music Projects and Theses

Because of the unprecedented and unexpected force of the pandemic since 2020, most churches around the world have experienced some online worship during the lockdown of their cities or the mandated closure of the church buildings. For many people, online worship seems to be an equivalent, if not better, alternative for gathering together—a physical co-presence in worship—even after the pandemic has ended. As necessary and vital as online worship experiences have been for Christians during the pandemic, the witness of the church from Pentecost throughout Christian history indicates that gathered worship in physical spaces is irreplaceable for faith formation and …

Cognitive Changes In Early Untreated Parkinson's Disease, Kunj Patel

Electronic Thesis and Dissertation Repository

Cognitive impairment is the most common non-motor symptom in Parkinson’s disease (PD), affecting up to one-third of early-stage patients. However, the cognitive profile in early PD remains unclear due to the use of heterogenous samples of disease severity, small sample sizes, and the inclusion of medication effects. This study aims to characterize cognitive deficits in early PD using a large, drug-naive sample. This study examined performance on the Montreal Cognitive Assessment and the Hopkins Verbal Learning Test from the Parkinson’s Progression Markers Initiative dataset (n= 643 patients with PD; n= 240 healthy controls). Patients were restricted to …

Quantifying Resting-State Functional Connectivity In Critically Brain-Injured Patients: A Graph-Theoretical Approach With Fnirs, Ira Gupta

Electronic Thesis and Dissertation Repository

Assessment of consciousness in behaviourally unresponsive patients with critical brain injuries continues to be a challenge. There remains a need for robust tools that can accurately characterize preserved cortical function and predict patient outcomes. In the present study, functional near-infrared spectroscopy is employed in conjunction with graph theory and machine learning to quantify resting-state functional connectivity in 16 acutely brain-injured patients and 23 healthy controls. Results revealed significant channel-level differences between the groups for three graph metrics, including degree, clustering coefficient, and local efficiency. Further investigation using machine learning algorithms revealed that these metrics can be used to distinguish between …

The Impact Of Emotional Sounds On Arousal And Task Performance, Brian Wu

Electronic Thesis and Dissertation Repository

In times of emotional arousal, it is hypothesized that neural processes are triggered to “heighten” our senses to better respond to threatening stimuli. Some studies have tested this by exposing participants to emotional sounds to determine their impacts on visual acuity but have found mixed results. Previous studies have not investigated interactions between arousal induced by emotional sounds and visual acuity. Participants (N = 42) performed an orientation detection task while presented in silence or with sounds that varied in valence. Results displayed comparable accuracy across conditions but significantly faster response times during the presentation of negative sounds on the …

Cross-Linguistic Differences In Neural Encoding And Processing Of Stop Consonants: The Impact Of Language Experience On Attention Allocation, Aline Dos Santos Oliveira

Dissertations, Theses, and Capstone Projects

This study aims to examine the intricate relationship between language experience and the neural processing of stop consonant speech sounds. Previous research has shown minimal differences in amplitudes and latencies of cortical Auditory Evoked Potentials (AEPs) to speech sounds across listeners from various language backgrounds. It is only towards the later latencies (around the P2 peak at 200 ms), that there have been suggestions of cross-linguistic differences. In addition, a recent study, observed an AEP difference between monolinguals and bilinguals when processing speech, specifically an "Nd effect”. The Nd effect, which is an increased negativity of the AEP is proposed …

Flanker Task Performance In Young And Older Adults: A Behavioral And Erp Study, Fatima Medrano

Dissertations, Theses, and Capstone Projects

Research suggests that as we get older, executive function abilities decline (Hasher & Zacks, 1988; Salthouse, 1996). One affected ability is that of inhibitory control, which aids in monitoring our responses to non-target stimuli or information. Current research on inhibition reveals inconsistencies across studies. Monitoring brain responses during the Flanker (used to measure inhibitory control) task may add valuable insight into the processes underlying group differences behaviorally, by studying the N200 and P300 event-related potentials which have been associated with inhibitory control processes. This study investigated whether there are differences between older and younger adults in inhibitory control and whether …

How Sensory Exploration Using Expressive Arts Provides A Cohesive Experience For Children With Multiple Diagnoses, Chanelle Goguen

Expressive Therapies Capstone Theses

This thesis looks at the potential benefits and cohesive experience of sensory exploration for children with multiple diagnoses through a trauma informed lens. The researcher was inspired by Prendiville’s (2021) idea of how interactive sensory exploration and art making can help foster and develop reciprocal communication and socio-affective relationships influenced the researcher to design a method that would be used to collect data about potential similar findings. In the method, the interaction of the sensory-specific art mediums were reflected through the expressive therapies continuum (ETC) framework. The research of this thesis acknowledges and explores how trauma and adverse childhood experiences …

Estrogen Replacement Therapy To Reduce Neurodegeneration And Socio-Cognitive Deficits In A Female Sprague Dawley Rat Model Of Early-Onset Alzheimer’S Disease, Miriam Kirylo

Senior Theses and Projects

No abstract provided.

Individual Differences In Age And Testosterone Are Uniquely Associated With Neural Oscillatory Activity Serving Verbal Working Memory In Children And Adolescents, Abraham D. Killanin

Theses & Dissertations

During the sensitive period of adolescence, the human brain undergoes dynamic changes in structure and function resulting in vast executive function gains. Verbal working memory (VWM) is one executive function that serves as a foundation to language acquisition, reading, and learning. Many have examined the development of VWM in youth, but few have probed age-related changes in the underlying neural oscillatory dynamics, and none have examined testosterone-related changes. We recorded magnetoencephalography during a modified Sternberg VWM task in 82 youth participants aged 6 – 14 years old and collected salivary testosterone samples. Significant oscillatory responses were identified and imaged using …

Exploring Available Information On The Gut-Brain Axis And Alzheimer’S Disease For Clinicians Making Dietary Recommendations: A Scoping Review, Megan Gibson

Electronic Theses and Dissertations

Abstract: Alzheimer’s Disease (AD) is a complex neurodegenerative disease that requires interprofessional collaboration. Pharmacological options are currently ineffective, increasing the need for preventative strategies to combat the rise of AD. Considerations of gut-targeted interventions have increased as a key component in the prevention of AD, based on the understanding that the state of the gut microbiome can impact cognitive function through the pathway known as the gut-brain axis.

Methods: This scoping review explored information on the gut-brain axis in persons with AD. A comprehensive search was conducted in November 2023. Forty reviews and 13 human studies were analyzed.

Results: There …

Exploring Resilience With Neuroimaging: Moderators Of The Impacts Of Childhood Traumatic Stress On Fear Processing., Karisa June Hunt

Electronic Theses and Dissertations

Childhood trauma is an alarming public health crisis, and the field of trauma research is relatively underdeveloped given population rates of childhood trauma and post-trauma pathology. Even less studied than the impacts of trauma are the impacts of resilience, and the protective factors that foster it. It is widely acknowledged that an investigation of trauma is incomplete without an investigation of its impacts on fear processing. Understanding the neural underpinnings of resilience to childhood trauma during fear conditioning is vital to the development of therapeutic interventions able to moderate its devastating impacts. The present study investigated the complex neurobiological interplay …

P300 Event-Related Potential Responses To Self-Relevant Stimuli, Jordan Razzak

Electronic Theses and Dissertations

Previous literature has suggested an apparent P300 sensitivity to self-relevant stimuli. To further explore this relationship, we asked participants to submit 10 photos, each of a particular category (e.g. footwear, plants), to be used as either targets or distractors in a given condition of an oddball task. Furthermore, we attempted to see whether the effect of self-relevance on the P300 could be induced in a participant by allowing them to study a set of unique photos which would then be used as targets. Our analysis suggested that P300 amplitude elicited in response to self-relevant stimuli used as targets was statistically …

Biophysical Model Of Retraction Motor Neurons And Their Modification By Operant Conditioning, Maria Rasheed

Dissertations & Theses (Open Access)

Operant conditioning (OC) is a form of associative learning in which an animal modifies its behavior based on the consequences that follow that behavior. Despite its ubiquity, the underlying mechanisms of OC are poorly understood. Insights into the mechanisms of OC can be obtained by studying Aplysia feeding behavior as it can be modified by OC. This behavior is mediated by a central pattern generator (CPG) network in the buccal ganglia that contains a relatively small number of neurons. This CPG generates rhythmic motor patterns (BMPs) that move food into the gut by closing a tongue-like structure (i.e., radula) during …

Competition And Criticality In Cortical Neural Circuits Underlie Behavior And Optimize Working Memory, Jacob Harrison Barfield

Graduate Theses and Dissertations

One of the primary goals of neuroscience is to explain how brain function emerges from dynamic interactions among large populations of neurons. A long-standing hypothesis at the interface of physics and neuroscience posits that neural circuits may operate close to the critical point of a phase transition. In this dissertation, we will investigate a new form of criticality and the implications that it has in working memory and the generation of voluntary body movements. We will utilize this new form of criticality to investigate the functional benefits that can be harnessed by operating near the critical point when performing working …

Towards Understanding And Improving Speech Processing, Sonia Yasmin

Electronic Thesis and Dissertation Repository

This dissertation explores mechanisms for understanding and improving speech processing. First, I used EEG to investigate the acoustic and semantic processing of continuous naturalistic speech masked by multi-talker babble. I found that different features of the same speech signal are reflected in different aspects of the neural tracking response, which are themselves differentially affected by noise. These findings point to a complex relationship between speech intelligibility and neural speech encoding.

Next, I systematically reviewed the current advancements in speech enhancement technologies. I find that speech enhancement algorithms are limited in their generalizability to speech-noise (i.e., babble). I demonstrate that, for …

Cultivating Excellence: A Literature Review On Harnessing The Power Of The Gut Microbiome For Athletic Performance, Maya Katharine Dean

Honors Projects

The interplay between our gut microbiome and health is immense. This literature review analyzes the current research assessing the interplay between gut microbiome and athletic performance. Knowing how to improve gut microbial diversity via nutrition and supplementation can take athletic performance to the next level; namely improvements in immune, mental, and physical health.

The Anatomical Embodiment Of Morning Routines In The Reduction Of Anxiety: An Intervention, Natalie Wright

Expressive Therapies Capstone Theses

The topic under investigation is whether physically embodying a morning routine that was designed through the lens of Laban Bartenieff Movement Analysis (LBMA) will reduce daily symptoms of individuals diagnosed with Generalized Anxiety Disorder.

Since morning routines play a significant part in one’s preparation for the day, I created an individualized LBMA morning routine for a specific client to embody. In addition to the routine, the client documented the process of their anxiety levels on a weekly basis. This client was a white, female, 19-year-old, lesbian college student who was previously diagnosed with Generalized Anxiety Disorder (GAD). The movement analysis …

The Role Of Spreading Depolarizations In Mild Traumatic Brain Injuries, Natalie J. Pinkowski

Biomedical Sciences ETDs

Mild traumatic brain injuries (mTBIs) often lead to acute symptoms like disorientation and discoordination, but the underlying mechanisms are unknown. Although most patients recover quickly from a single mTBI, repeated injuries can be debilitating. After an mTBI, a neurometabolic cascade produces metabolic burden and vulnerability. Spreading depolarizations (SDs) have been observed after mTBIs. Here we investigated SDs’ role in short-term motor behavioral deficits post-mTBI. We hypothesized that SDs contribute to the deficits, and exacerbated symptoms after repeated mTBIs. To test this, we used acute motor behavioral tests and long-term behavioral and cognitive tests after initiating SDs by mTBI, chemical, or …

Frontoparietal Circuitry Underlying Saccade Control In The Common Marmoset, Janahan Selvanayagam

Electronic Thesis and Dissertation Repository

Our visual world is full of far more stimuli than can be processed simultaneously. Yet we are able to efficiently extract behaviourally relevant information from a scene, primarily by performing rapid saccadic eye movements. These processes are under the control the frontoparietal network, two critical nodes of which are: the lateral intraparietal area (LIP) and the frontal eye fields (FEF). Extensive research in the macaque has causally implicated these areas in visual attention and oculomotor control. However, the organization of the activity of single neurons in these areas across cortical layers remains poorly understood as these regions are deep within …

Neurochemical Signaling Of Reward-Based Learning In Ventral Tegmental Area Dopamine Neurons, Kyla F. Wholley

Dissertations, Theses, and Capstone Projects

Ventral tegmental area (VTA) dopamine neurons signal and participate in reward-related learning. Specifically, dopamine is postulated to encode reward-related environmental stimuli to compute reward prediction errors (RPEs). It is through the computation and maintenance of RPEs that learning occurs. However, little is known about the neural mechanisms that underlie how dopamine neurons compute RPEs and facilitate reward-related learning. The present study utilized fiber photometry in conjunction with a Pavlovian reward-based task to identify how GABA inputs to VTA dopamine neurons contribute to the computation of RPEs and reward-based behavior. Activity of GABA inputs to VTA dopamine neurons increased for reward-predicting …

The Relationship Between Cognitive Impairment In Psychiatric Patients And Readmission Rate To An Inpatient Facility, Cherilyn Isis Schuff

Theses and Dissertations

The primary intention of this study was to further understand the impact of assessing cognitive impairment in psychiatric patients, as a mediating factor on readmission rates. Mild cognitive dysfunction impacts a patient’s functional outcomes (Bowie & Harvey, 2006; Davis et al., 2012; Marcantonio, et al., 2001). Little information exists to guide best practices in the treatment of adults with cognitive impairment who are hospitalized for acute conditions (Davis et al., 2012). A cognitive impairment may impact patient prognosis and ability to function outside of a setting focused on stabilization. Neuropsychological testing is a valuable tool in predicting a patient’s cognitive …

The Divided Self: Internal Conflict In Literature, Philosophy, Psychology, And Neuroscience, Yulia Greyman

Dissertations, Theses, and Capstone Projects

This thematic project examines the notion of self-division, particularly in terms of the conflict between cognition and metacognition, across the fields of philosophy, psychology, and, most recently, the cognitive and neurosciences. The project offers a historic overview of models of self-division, as well as analyses of the various problems presented in theoretical models to date. This work explores how self-division has been depicted in the literary works of Edgar Allan Poe, Don DeLillo, and Mary Shelley. It examines the ways in which artistic renderings alternately assimilate, resist, and/or critique dominant philosophical, psychological, and scientific discourses about the self and its …

Changes In Flanker Task Performance Following High-Intensity Exercise In Endurance Athletes, Felix E. Cottet-Puinel

Dissertations, Master's Theses and Master's Reports

Executive function performance following acute aerobic exercise can be influenced by multiple variables. However, little is known about the lasting effects of these exercise-induced changes. This study aimed to determine the extent to which exercise intensity impacts executive function. 14 young endurance-trained adults (5 female, 9 male) performed an Eriksen flanker task before and immediately after running high-intensity until failure and isochronal moderate-intensity (~12 min). Pre- to post-exercise-induced changes in reaction time (ms), accuracy (%), and self-reported mental effort (1-9 rating) were analyzed by overall tasks and through tasks subsections. Results showed improvement in reaction time following high- and moderate-intensity …