Neuroscience and Neurobiology Commons^™

Dopamine D1 Receptor Activity In The Basolateral Amygdala Is Important For Mediating Fear, Reward And Safety Discrimination Learning, Ka Ho Ng

Open Access Theses

Post traumatic stress disorder (PTSD) patients frequently show impairment in safety learning (Jovanovic, Kazama, Bachevalier, & Davis, 2012). Since the amygdala is known to be critical for emotional processing(Wassum & Izquierdo, 2015) and dopamine signaling in the amygdala is important for mediating both fear and reward learning, current experiments examined the role of dopamine signaling in the BLA in mediating both safety learning and reward seeking. We manipulated dopamine D1 receptor activity with a D1 receptor agonist (SKF 38393) or D1 receptor antagonist (SCH23390) either systemically or infused directly into the BLA 20 minutes prior to training rats in a …

Apoaequorin Differentially Modulates Fear Conditioning In Adult And Aged Rats, Vanessa Ehlers

Theses and Dissertations

Normal aging is associated with a number of changes in behavioral and cellular function, and is often linked to increased susceptibility to cognitive impairment. The hippocampus has been widely implicated in learning and memory, and many forms of learning that are hippocampus-dependent (e.g. trace fear conditioning) are impaired in aged animals. A proposed contributor to aging-related cognitive impairment is aging-related calcium (Ca2+) dysregulation. This dysregulation is thought to result from changes in specific Ca2+-regulatory mechanisms, including abnormal Ca2+ ion channel activity or expression, as well as reduced Ca2+-binding protein (CaBP) expression, which is associated with cognitive and synaptic impairment. Previous …

The Effects Of Exercise Pattern And Intensity On The Expression Of Flk-1 And Flt-1 Receptors In The Hippocampus And Cerebellum, Morgan E. Stevenson

Theses and Dissertations

Aerobic exercise benefits the body and brain. In the brain, these benefits include neuroprotection and improved cognition. These exercise-induced changes are attributed in part to angiogenesis: the growth of new capillaries from preexisting vessels. One critical factor involved in the regulation of angiogenesis is VEGF and its receptors Flk-1 and Flt-1. Although exercise is generally found to be beneficial, there are wide variations in the exercise regimens used across experiments. This study standardized some of these variations. In this study, rats were either assigned to a voluntary wheel running or a forced wheel running exercise condition. Within each condition, animals …

Examining Relationships Between Basic Emotion Perception And Musical Training In The Prosodic, Facial, And Lexical Channels Of Communication And In Music, Jamie Twaite

Dissertations, Theses, and Capstone Projects

Research has suggested that intensive musical training may result in transfer effects from musical to non-musical domains. There is considerable research on perceptual and cognitive transfer effects associated with music, but, comparatively, fewer studies examined relationships between musical training and emotion processing. Preliminary findings, though equivocal, suggested that musical training is associated with enhanced perception of emotional prosody, consistent with a growing body of research demonstrating relationships between music and speech. In addition, few studies directly examined the relationship between musical training and the perception of emotions expressed in music, and no studies directly evaluated this relationship in the facial …

Perceiving Oldness In Parietal Cortex: Fmri Characterization Of A Parietal Memory Network, Adrian Gilmore

Arts & Sciences Electronic Theses and Dissertations

The manner in which the human brain recognizes certain stimuli as novel or familiar is a matter of ongoing investigation. The overarching goal of this dissertation is to improve our understanding of how this may be accomplished. More specifically, work contained herein focuses on a recently described "parietal memory network" (PMN; Gilmore et al., 2015) that shows opposite patterns of activity when perceiving novel or familiar stimuli: deactivating in response to novelty, and activating in response to familiarity. Critically, our understanding of this network is based on explicit memory tasks, in which subjects are deliberately instructed to learn or remember …

Neural Circuitry Underlying The Intrusion Of Task-Irrelevant Threat Into Working Memory In Anxiety, Daniel Stout

Theses and Dissertations

Dispositional anxiety is an important risk factor for the development of anxiety and other psychological disorders. Symptoms commonly expressed by highly anxious individuals include intrusive memories, uncertainty, and worry — all occurring in the absence of immediate threat. This raises the possibility that anxious individuals have difficulty governing threat’s access to working memory, the mental workspace where goal-related information is actively retained for guiding on-going behavior. Using functional magnetic resonance imaging (fMRI) while 81 subjects completed a well-validated working memory task, I show that threat-related and neutral distracters unnecessarily gain access to working memory, as evidenced by increased neural activity …

Neural Plasticity Of Extinction: Relations With Anxiety And Extinction Retention, Emily Louise Belleau

Theses and Dissertations

ABSTRACT

NEURAL PLASTICITY OF EXTINCTION LEARNING: RELATIONS WITH ANXIETY AND EXTINCTION RETENTION

by

Emily L. Belleau

The University of Wisconsin-Milwaukee, 2016

Under the Supervision of Associate Professor Christine Larson

Anxiety is a significant public health problem characterized by substantial psychological, physical, and economic burden. A key feature of anxiety is the inability to regulate fear. Aberrant extinction of conditioned fear is one prominent model of the etiology of anxiety disorders. Previous studies have shown that the neural circuitry underlying anxiety pathology overlaps with that mediating fear extinction learning. Recently, more precise pathways supporting the expression (CMA-aMCC) and inhibition (BLA-vmPFC) of …

The Mechanisms Underlying Cocaine-Induced Overexpression Of Basic Fibroblast Growth Factor (Bfgf, Fgf2), An Effect Reversed By Extinction, Madalyn Hafenbreidel

Theses and Dissertations

Drug addiction is characterized by compulsive drug use and chronic relapse despite negative consequences. Drug-induced structural and functional changes in the brain are thought to underlie these characteristics. One mechanism that may mediate these characteristics are growth factors, such as basic fibroblast growth factor (bFGF or FGF2), as they are necessary for cellular growth, survival, differentiation, and have roles in memory, mood, and anxiety disorders. bFGF mRNA and protein expression is increased following stimulant administration and is necessary for stimulant-induced changes in dendrites and behavioral sensitization. Moreover, addiction is maintained by cues associated with the drug, as they can can …

Recognition Training For Faces Across Age Gaps, William Blake Erickson

Graduate Theses and Dissertations

Face recognition is a problem that has theoretical and applied value. However, the fact of facial aging is rarely addressed in research and unmentioned in the major theories of face recognition. Facial aging also has ramifications for missing persons and fugitive cases, confounding attempts by law enforcement to recover these people whose last known images are years or decades out of date. This dissertation reports three studies aimed at measuring baseline age-gap recognition ability and testing various training regimens designed to increase accuracy rates for this unique kind of recognition task.

An Investigation Of Short-Term Plasticity In Human Motor Cortex, Matthew Alan Gannon

Graduate Theses and Dissertations

Transcranial magnetic stimulation (TMS) produces a transient magnetic field that activates underlying cortical tissue by eliciting an electrical discharge of the neurons in the targeted area. Repetitive TMS (rTMS) uses patterns of repetitive TMS pulses and has been reliably shown to produce changes in the state of cortical excitability outlasting the time of stimulation. One such protocol that has demonstrated states of increased excitability is intermittent theta burst stimulation (iTBS). This method applies high-frequency bursts (50Hz) of pulses every 200 ms in trains of ten bursts. The effects of and differences between rTMS protocols have been investigated since gaining popularity …

Computational Modeling Of Facial Response For Detecting Differential Traits In Autism Spectrum Disorders, Manar D. Samad

Electrical & Computer Engineering Theses & Dissertations

This dissertation proposes novel computational modeling and computer vision methods for the analysis and discovery of differential traits in subjects with Autism Spectrum Disorders (ASD) using video and three-dimensional (3D) images of face and facial expressions. ASD is a neurodevelopmental disorder that impairs an individual’s nonverbal communication skills. This work studies ASD from the pathophysiology of facial expressions which may manifest atypical responses in the face. State-of-the-art psychophysical studies mostly employ na¨ıve human raters to visually score atypical facial responses of individuals with ASD, which may be subjective, tedious, and error prone. A few quantitative studies use intrusive sensors on …

On The Screen, In The Mind: An Erp Investigation Into The Interaction Between Visuo-Spatial Information And Spatial Language During On-Line Processing, Emily Zane

Dissertations, Theses, and Capstone Projects

This project used Event-Related Potentials (ERPs) to explore neurophysiological brain responses to prepositional phrases involving concrete and abstract reference nouns (e.g., "plate" and "moment", respectively) after the presentation of objects with varying spatial features. Prepositional phrases were headed by in or on and were either matching (e.g., "in the plate/moment") or mismatching (e.g., "on the plate/moment"). Conjunction phrase matches and fillers were also presented. Before half of the concrete-phrase items, a photographic depiction of the reference noun was presented. In these photographs, objects were displayed in a way that was either more appropriate for in or for on. Similarly, before …

The Neural And Cognitive Basis Of Cumulative Lifetime Familiarity Assessment, Devin Duke

Electronic Thesis and Dissertation Repository

Perirhinal cortex (PrC) has been implicated as a brain region in the medial temporal lobes (MTL) that critically contributes to familiarity-based recognition memory, a process that allows for recognition to occur independently of contextual recollection. Informed by neurophysiological research in non-human primates, fMRI, as well as behavioural work in humans, the current thesis research tests the novel hypothesis that PrC cortex functioning also underlies the ability to assess cumulative lifetime familiarity with object concepts that are characterized by a lifetime of experiences. In Chapter 2, a patient (NB) with a left anterior temporal lobe (ATL) lesion that included PrC as …

The Effects Of Lipopolysaccharide-Induced Neuroinflammation On Learning And Forgetting In Juvenile Rats, Michele Barry

Seton Hall University Dissertations and Theses (ETDs)

The inability to remember events experienced very early in life is referred to as Infantile Amnesia (IA) and has been observed in both humans and animals. Over the years interest in the phenomenon waned, but has recently increased with the discovery of new neurobiological methods to study brain function (e.g., Callaghan, Li & Richardson, 2014). The neurobiological mechanism behind IA has yet to be determined, but several innovative theories have been developed with these new research methods. The neurogenesis hypothesis theorizes that increased neurogenesis during early development disrupts previously established memories. The hippocampus, an area that mediates both the memory …

Working Memory Impairments In Chromosome 22q11.2 Deletion Syndrome: The Roles Of Anxiety And Stress Physiology, Ashley F. P. Sanders

University of New Orleans Theses and Dissertations

Stress and anxiety negatively impact the working memory system by competing for executive resources. Broad memory deficits have been reported in individuals with chromosome 22q11.2 deletion syndrome (22q11.2DS). We investigated anxiety and physiological stress reactivity in relation to visuospatial working memory impairments in 20 children with 22q11.2DS and 32 typically developing children (M = 11.10 years, SD = 2.95). Results indicate reduced post-stress RSA recovery and overall increased levels of cortisol in children with 22q11.2DS. Additionally, anxiety mediated the relationship between 22q11.2DS and visuospatial working memory impairment. However, there was no indication that stress response physiology mediated this association. …

The Effects Of Chronic Partial Sleep Deprivation And Chronic Voluntary Alcohol Consumption On Δfos B Accumulation, Kristian Ponder

Masters Theses, 2010-2019

The present study explores the relation between sleep restriction and alcohol use and the neural substrates that result from chronic behaviors. Accumulation of the transcription factors ΔFosB is suggested as a possible outcome of chronic behaviors, such as addiction. Sleep is discussed as possible mediating factor in the relationship between ΔFosB and chronic alcohol consumption. There were four experimental groups in this study: Control (C), Sleep Deprivation only (SD), Alcohol Exposure only (AO), and both sleep deprivation and alcohol exposure (B). Levels of ΔFosB accumulation in the Nucleus Accumbens (NAc) revealed a significant main effect of sleep deprivation, but no …

Eye Movement Effects In Simulated Object Recognition Memory Impairment, Dmitriy Kazakov

Theses and Dissertations

Malingering is the purposeful fabrication of symptoms for secondary gain. Memory problems are the most reported symptom, and object recognition tests are often used in clinical settings to evaluate these claims. Past research has shown that eye movements can indirectly index memory, in that greater viewing is directed at studied stimuli 500-750 ms after display onset. The present study evaluated eye movements as a potential method of detecting feigned memory impairment. Forty-eight participants, half simulators, studied standardized images and took a memory test. Several levels of analysis were used to detect broad trends and brief effects. Simulators performed significantly worse …

Cannabis Use And Affective Processing: A Brain Structure Analysis, Kristin E. Maple

Theses and Dissertations

Cannabis is the most commonly used illicit drug amongst adolescents and young adults in the United States. Previously, cannabis and its components have been associated with differences in affective processing and neural functioning. Participants (ages 16-25) were cannabis users and non-users excluded for psychiatric disorders, major medical conditions, and excessive other drug use. A series of multiple regressions examined whether past year cannabis use and cannabis x gender predicted measures of emotional face processing (using the PennCNP affective battery) as well as volumes in bilateral prefrontal, temporal, limbic, and cerebellar regions, as well as frontolimbic white matter tracts. Subsequently, Pearson …

Building Object Representations: Mechanisms Of Perceptual Learning In Human Visual Cortex, Stephanie M. Long

Psychological Science Undergraduate Honors Theses

Extensive literature in the cognitive neurosciences has been dedicated to understanding the neural processes involved in object category learning. However, much remains to be learned regarding the mechanisms by which high-level visual patterns are extracted from a crowded visual scene, segregated into discrete object categories, and represented in the cortical visual hierarchy. Here, we used event-related potentials (ERPs) to investigate the neural underpinnings of visual object category extraction in a cluttered visual environment. Electroencephalography (EEG) was continuously recorded while subjects were given a hybrid of an object category learning and visual search task. In this hybrid task, a peripheral array …

Gap Junction Communication In Memory Retrieval And Extinction Of Cocaine Seeking, Michael Fitzgerald

Theses and Dissertations

Blocking drug-associated memory retrieval or enhancing extinction of drug-seeking behavior are two strategies that could limit relapse in drug addicts. The loci of retrieval and extinction memory processes include the prelimbic medial prefrontal cortex and the infralimbic medial prefrontal cortex, respectively. The neurochemical and synaptic mechanisms underlying drug-related behavior have received considerable attention, but extrasynaptic mechanisms are relatively unexplored. One form of cellular communication, gap junction communication, may play a role in drug-related learning and memory. Gap junction communication between neurons and astrocytes provide a cytoplasmic continuity between connected cells and both neuronal and astrocytic gap junction communication have been …

Assessing Clinical Significance Of The Immediate Post-Concussion Assessment And Cognitive Testing Battery When Comparing Adjusted And Unadjusted Rci Methods For Different Ranges Of Baseline Scores, Ashley N. Figaro

UNLV Theses, Dissertations, Professional Papers, and Capstones

The growing concern revolving around the dangers of sports-related concussions have led to the most recent implementation of neurocognitive (NC) test batteries as a means to objectively determine the presence of a cognitive defect. Whereas any other sports-related injury can be diagnosed with tools such as an x-ray or MRI, a concussion represents a metabolic disturbance that cannot be identified by these diagnostic tools. Many neurocognitive test batteries employ statistical techniques to derive cut off scores in order to represent significant or insignificant changes as compared to individual baseline scores, or pre-established normative values. If an individuals’ post-injury score exceeds …

The Effects Of Cognitive Rehabilitation For Improving Prospective Memory In Acquired Brain Injury, Emily M. Aiken

Masters Theses

Acquired Brain Injury (ABI) includes any damage to the brain resulting from traumatic (e.g. motor vehicle accident) or non-traumatic (e.g. stroke) incidence, that occurs after birth and is not resulting from genetic or congenital factors. Individuals with ABI report that prospective memory (PM) deficits are the most detrimental cognitive impairment following injury, persistently and negatively impacting their ability to function properly in everyday life. PM refers to the ability to remember to carry out intended tasks in the future, including the recall of both time and event regulated intentions. Using neuropsychological assessments to produce patient deficit profiles, this study examines …

The Impact Of Affect On Neural Mechanisms Underlying Orientation Perception, Michelle L. Fowler

Dissertations, Theses, and Capstone Projects

The underlying mechanisms used to process 2D visual information to form a unified 3D percept of the world remain largely unknown. Previous work in our lab has shown that accurate 3D perception of textured surfaces depends on the presence of specific patterns of orientation flows in the retinal image. Recent research has shown that affective state may influence the visual perception of oriented patterns. Relative to neutral face stimuli, fearful face stimuli have been shown to increase sensitivity to orientation of low spatial frequency patterns and decrease sensitivity to orientation of high spatial frequency patterns. How affective state influences the …

Status Signaling And The Characterization Of A Chirp-Like Signal In The Weakly Electric Fish Steatogenys Elegans, Caitlin E. Field

Dissertations, Theses, and Capstone Projects

Sensory systems are critical to both exploratory and communicatory processes, the study of which is critical to our understanding of how animals perceive and respond to their environments. In weakly electric fishes the electrosensory system is utilized for both of these purposes. One type of communication, status signaling, is widespread across taxa and frequently hormonally modulated. This hormonal modulation keeps the signal honest, wherein the status of the sender and the production of the status signal itself are both hormone dependent. We investigated exploratory and communicatory strategies of the electromotor system in pulse-type gymnotiforms, with a focus on status communication …

From Rainman To Rainmaker: A Presentation Of Jim’S Journey And Rapidly Advancing Technologies: Integrating Proven Behavioral Therapies With Emergent Measurement And Testing Advances Will Result In Transformational Progress In Autistic Individuals, Richard Zajac

CMC Senior Theses

The autism treatment status quo was reviewed and accompanied by a narrative contextualizing past and present progress with my younger brother Jim’s journey with the condition, sharing proposed next steps for bettering the current state of affairs in the space. The impetus for this piece was to share in the lessons of Jim’s life thus far and the revelations of those who have supported him, as well as to determine ways to create more impactful, lasting change in the limited window of early intervention therapy whilst empowering individuals on the spectrum to optimize for their skills and talents rather than …

Acute And Chronic Effects Of Inhalants In Intracranial Self-Stimulation, Matthew Tracy

Theses and Dissertations

Inhalants are a loosely defined diverse group of volatile substances which people abuse. Despite widespread misuse of inhalants, there are limited preclinical methods available to study the reinforcement-like properties of inhalants. One procedure which has demonstrated substantial promise as a tool to investigate inhalant pharmacology is the intracranial self-stimulation (ICSS) procedure. ICSS utilizes pulses of electrical stimulation to the mesolimbic reward pathway to serve as a temporally defined and controlled operant reinforcer with a highly adjustable efficacy. The first aim of the project was to characterize the effects of commonly abused inhalants: including toluene, trichloroethane, nitrous oxide, isoflurane and R134a …

Reduced Conscious Recollection And Its Detection In Three Performance Validity Tests : A Dual Task Interference Investigation, Graham Michael Silk-Eglit

Legacy Theses & Dissertations (2009 - 2024)

Performance validity is an essential component of neuropsychological assessment. Research suggests that examinees with specific neurological conditions cannot successfully complete certain performance validity tests (PVTs). However, very little basic research has explored the information processing underlying performance on PVTs that might explain why these examinees fail certain PVTs. The current study used a dual task interference paradigm to isolate the impact of reducing conscious recollection on the performance of three PVTs, the Test of Memory Malingering (TOMM), Victoria Symptom Validity Test (VSVT), and Word Memory Test (WMT). One-hundred-and-twenty-six non-clinical undergraduate research participants were administered these three PVTs as part of …

Effect Of Prior Trauma Exposure On Alpha Amplitude, Heart Rate, And Self-Reported Negative Affect, Gina L. Denoble

All Master's Theses

This study was conducted to investigate whether the number of traumatic events an individual has previously experienced influences that individual’s physiological and psychological reactions when exposed to a negative affective stimulus followed by a mindfulness-based stress reduction (MBSR) intervention. Twenty-eight participants were placed into intact quasi-experimental groups based on their scores on the Traumatic Life Events Questionnaire (TLEQ). The negative affective stimulus consisted of a series of photos bearing negative affective valence. The photos were selected from the International Affective Picture System (IAPS), and paralleled the areas of trauma exposure evaluated by the TLEQ. All participants were exposed to the …

Does The Pain Of Rejection Promote The Pleasure Of Revenge? A Neural Investigation Of Cingulo-Striatal Contributions To Violence, David Chester

Theses and Dissertations--Psychology

Aggression is a dynamic and costly feature of human behavior. One reliable cause of aggression is social rejection, though the underlying mechanisms of this effect remain to be fully understood. Previous research has identified two psychological processes that are independently linked to aggressive retaliation: pain and pleasure. Given recent findings that pain magnifies the experience of pleasure, I predicted that the pain of rejection would promote the pleasure of aggression and thus, aggression itself. I also expected that this indirect effect of aggressive pleasure would only be observed among individuals with weaker self-regulatory abilities that are necessary to cope with …

Evaluating Competition Between Verbal And Implicit Systems With Functional Near-Infrared Spectroscopy, Troy A. Schiebel

Honors Undergraduate Theses

In category learning, explicit processes function through the prefrontal cortex (PFC) and implicit processes function through the basal ganglia. Research suggested that these two systems compete with each other. The goal of this study was to shed light on this theory. 15 undergraduate subjects took part in an event-related experiment that required them to categorize computer-generated line-stimuli, which varied in length and/or angle depending on condition. Subjects participated in an explicit "rule-based" (RB) condition and an implicit "information-integration" (II) condition while connected to a functional near-infrared spectroscopy (fNIRS) apparatus, which measured the hemodynamic response (HR) in their PFC. Each condition …