Neurosciences Commons^™

Neurophysiological Activity Related To Speech Production: An Erp Investigation, Adithya Chandregowda

USF Tampa Graduate Theses and Dissertations

The event related potential (ERP) technique is enjoying widespread application in neurophysiological research due to its fine temporal resolution. Of relevance to this study are ERPs related to voluntary movements. The precision with which movement related processes could be recorded using the ERP technique was demonstrated by Gilden, Vaughan and Costa (1966) and Kutas and Donchin (1974, 1977, and 1980) who found that the readiness potential (RP) immediately preceding hand movement was larger over the hemisphere contralateral to the responding hand. Given that left hemisphere controls right hand movements and vice versa, their findings confirmed that the lateralized readiness potential …

An Animal Model Of Flashbulb Memory: Insights Into The Time-Dependent Mechanisms Of Memory Enhancement, Laura Ashley Bullard

USF Tampa Graduate Theses and Dissertations

The vivid memory of an emotional event, as well as memory for incidental details associated with the arousing event, has been referred to collectively as a “flashbulb memory”. An important aspect of flashbulb memory in people is that an emotional event enhances memory of contextual details, such as the weather, or clothes one was wearing at the time of the event. Therefore, an emotional event not only produces a detailed memory of the event, itself, but also enhances memory for contextual details that would otherwise not be remembered. The first goal of this work is to describe the development of …

A Neurobiological Pathway That Mediates Stress-Induced Drug Use, Oliver Vranjkovic

Dissertations (1934 -)

Cocaine addiction represents a tremendous health and financial burden on our society and the high rate of relapse to cocaine use in abstinent addicts represents a major barrier to effective therapy. Thus, understanding the factors that contribute to relapse and the underlying neurobiological processes is important for guiding the development of treatment for addiction. Stressful life events often trigger drug use in recovering addicts. The contribution of stress to drug use is problematic due to the unpredictable and often uncontrollable nature of stress. A growing literature indicates that norepinephrine and corticotropin releasing factor (CRF) in the brain play key roles …

Relationships Between Age And White Matter Integrity In Children With Phenylketonuria, Erika M. Wesonga

Arts & Sciences Electronic Theses and Dissertations

Objective: Phenylketonuria (PKU) is a hereditary metabolic disorder associated with cognitive compromise. Diffusion tensor imaging (DTI) has allowed detection of poorer microstructural white matter integrity in children with PKU, with decreased mean diffusivity (MD) in comparison with healthy children. However, very little research has been conducted to examine the trajectory of white matter development in this population. The present study investigated potential differences in the developmental trajectory of MD between children with early- and continuously-treated PKU and healthy children across a range of brain regions.

Methods: Children with PKU (n = 31, mean age = 12.2 years) were …

The Effect Of Sleep On Perceptual Learning And Memory Consolidation, Vanessa Claire Irsik

UNLV Theses, Dissertations, Professional Papers, and Capstones

An ability to segregate speech accurately is essential given that most auditory environments contain other overlapping conversations or environmental noise. While perceiving speech among background noise can be difficult in and of itself, those with hearing impairments can experience considerable difficulty. While training has been shown to benefit perceptual segregation of trained sounds, it is unclear how such training transfers to sounds not included in a training regimen. The current study aimed to address this question by training listeners on a portion of sounds during a vowel segregation task, and subsequently testing on both the trained sounds and untrained sounds. …

Neural Plasticity In Response To Intervention In Adolescents With Autism Spectrum Disorders, Sheryl Jayne Stevens

Dissertations (1934 -)

Current theories of Autism Spectrum Disorders (ASD) suggest that they may develop from the transactional interaction between biological risk factors and environmental processes (Dawson et al., 2009). Due to the brain’s experience-expectant nature, one’s degree of social exposure may have a significant impact on their brain development and behavioral presentation. In addition to the primary critical neurodevelopmental period identified in early childhood, recent research has demonstrated a second period of substantial neurodevelopment during the adolescent period (Sisk & Foster, 2004). This study investigated the neural and behavioral impact of participation in an empirically validated behavioral intervention (The Program for the …

Functional Capacity In Schizophrenia: Relationship Among Effort, Reinforcement Learning And Self-Beliefs, Sally J. Vogel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Individuals with schizophrenia exhibit a wide range of complex neurocognitive, psychiatric and behavioral impairments. Recent research suggests that this complex array of symptoms can be at least partially accounted for by dysfunction in more basic mechanisms, such as the ability to learn from positive and negative reinforcement, or the ability to exert adequate effort when completing simple tasks. Evidence also suggests that deficits in these basic mechanisms may contribute to more complex symptoms, such as functional impairment. Also, the relationship between neurocognitive deficits and functional impairment has been found to be mediated by defeatist performance beliefs. However, studies have not …

A Comparison Of The Effects Of Different Doses Of Gabab Receptor Ligands On Spatial Learning And Memory And Memory Flexibility, Chelcie Heaney

UNLV Theses, Dissertations, Professional Papers, and Capstones

The principal inhibitory neurotransmitter in the brain, gamma amino-butyric acid (GABA), mediates several types of learning and memory. Of the two main receptor subtypes for GABA, the in vivo role of GABAB receptor in learning and memory is less well characterized and the current data often conflict. Based on the current literature, it is unclear, for instance, whether enhancing GABAergic activity via the GABAB receptor could be beneficial for or detrimental to learning and memory. Hippocampally-dependent learning and memory tasks are of particular interest due to their clinical relevance to patients with schizophrenia or Alzheimer’s disease, who exhibit impaired performance …

Neural Correlates Of Episodic Memory Formation In Children And Adults, Lingfei Tang

Wayne State University Theses

The medial temporal lobe (MTL) and prefrontal cortex (PFC) are two key brain regions that support episodic memory formation in both children and adults, but the functional developmental of these regions remains unclear. In this study, we investigated the development of neural correlates of episodic memory formation using functional MRI with a subsequent memory paradigm, administered to a cross-sectional sample of 83 children and adults. We found that MTL subregions showed an age-related increase in activation supporting memory formation of complex scenes. In addition, a functionally defined scene-sensitive region in the posterior MTL also showed similar increase and predicted better …

Age Related Decline In Memory: Examining The Mediation Effect Of Processing, Executive Functioning And Intelligence In Normal Adults, Jada J. Stewart

Theses and Dissertations

Multiple mediation analyses that collectively examine the prominent theories of cognitive aging (i.e., Common Cause, Processing, and Executive Decline Hypotheses) along with other cognitive domains that are sensitive to aging are rare. Moreover, having identified that cognition begins to decline as early as 30 years old, few studies have examined the mechanisms that underlie memory change among younger aging individuals. As a result, it is unclear whether relevant mediating variables have been excluded from early research on age-related memory decline, or to what extent rehabilitative strategies are applicable as early interventions for maintaining cognitive functioning into late life.

The present …

Glycogen Synthase Kinase-3Β: An Investigation Of The Novel Serine 389 Phosphorylation Site, Brendan Deegan Hare

Graduate College Dissertations and Theses

Stress associated psychiatric disorders such as depression, anxiety, and post-traumatic stress disorder affect a large proportion of the population. Reductions in the complexity of neuronal morphology and reduced neurogenesis are commonly observed outcomes following stress exposure in rodent models and may represent a mechanism for the reduced brain volume in stress sensitive regions such as the hippocampus observed in individuals diagnosed with stress associated disorders. Multiple lines of evidence suggest that glycogen synthase kinase (GSK)-B may play a role in the neurodegenerative phenotype observed following stress exposure. GSK3B is atypical in that it is inhibited by phosphorylation. This inhibitory phosphorylation …

Effects Of Nicotine Withdrawal On Motivation, Reward Sensitivity And Reward-Learning, Jason A. Oliver

USF Tampa Graduate Theses and Dissertations

Research on addictive behavior has traditionally emphasized the role that primary reinforcing effects of drugs of abuse plays in the development and maintenance of dependence. However, contemporary behavioral economic theory and animal models of nicotine dependence suggest the need for greater attention to the impact that response to alternative rewards may have on smoking behavior. The present study sought to investigate the impact of nicotine withdrawal on self-report, behavioral and neural indices of motivation, immediate response to rewards and the capacity to learn and modify behavior in response to positive and negative feedback. Heavy smokers (n = 48) completed two …

Influence Of Planning Resources On Gait Control In Parkinson’S Disease, Frederico P. Faria

Theses and Dissertations (Comprehensive)

Movement disturbances in individuals with Parkinson’s disease (PD) have been associated with difficulties to plan complex actions. Performance of simple and complex actions overloads resources for individuals with Parkinson’s disease (PD). However, it is unclear if central resources required to plan gait adjustments while walking exacerbate gait disturbances of patients with PD. More specifically, it is unclear how gait impairments, sensory processing, and the dopaminergic system influence the load on processing resources (e.g. cognitive load) during the planning of step modifications. In order to investigate the relative influence of these factors on cognitive load and its impact on gait control, …

Development Of An Avian Model For Identifying Individual Differences In Drug Vulnerability, Beth A. Rice

Theses and Dissertations--Psychology

The attribution of incentive salience to cues that become associated with drugs of abuse is a critical characteristic of individuals who may be vulnerable to drug addiction. Rodents with the propensity to sign track are thought to be vulnerable to drug abuse. The goal of the current work was to investigate whether sign trackers (STs) would acquire cocaine conditioned place preference (CPP) to a discrete cue using an avian species. In Experiment 1, sign and goal trackers (GTs) were first identified using a one third rank order split. Following identification, cocaine-CPP was conducted with a discrete cue in each end …