Behavior and Behavior Mechanisms Commons^™

Investigating Individual And Group Level Mediators Of Fear Acquisition, Rachel S. Lese

Dissertations, Theses, and Capstone Projects

The ability to discriminate between cues predictive of threat vs. safety (fear acquisition) and subsequently update fear responding when contingencies change (fear extinction) is crucial to survival for all organisms. While these processes have been the subject of intense experimental scrutiny for several decades, most human fear learning studies have focused primarily on extinction learning and fear recovery processes, with less focus on fear acquisition itself. Indeed, researchers typically aim to minimize variability during fear acquisition in order to rule out differences in extinction being driven by variability during the initial learning phase. Thus, experimental protocols are often optimized to …

Mechanisms Of Sleep Regulation In Drosophila Melanogaster, Anfal A. Abuhilal

Dissertations, Theses, and Capstone Projects

Sleep is a fundamental biological need, and sufficient sleep is required for physical and mental well-being. Sleep is regulated by two biological mechanisms: sleep-wake homeostasis and circadian rhythm. Circadian rhythms are near 24-h rhythms in behavior and physiology that are generated by endogenous mechanisms. In mammals, the suprachiasmatic nucleus (SCN) is the central circadian pacemaker, which is known to receive a significant amount of serotonergic input that likely modulates sleep rhythms. In addition to circadian modulation, sleep is subject to homeostatic regulation. Several neuromodulators have been proposed as mediators of sleep homeostasis. Serotonin has been implicated in sleep drive and …

Medication Adherence Among Partnered, Sexual Minority Men Living With Hiv: What’S Love, Interdependence And Comorbidities Got To Do With It?, Kendell M. Doyle

Dissertations, Theses, and Capstone Projects

Sexual minority men (SMM) report higher incidence and prevalence rates of HIV infection relative to their heterosexual counterparts. The burden of HIV infection has garnered research attention focused on HIV risk reduction and HIV disease management (such as medication adherence). More recently, attention has been paid to the association of comorbid chronic health conditions and ART adherence among people living with HIV (PLWH) more broadly. Yet, limited attention has been paid to the association of comorbidities among SMM living with HIV specifically, despite the high rates of HIV among this population and various other risk factors that put SMM at …

The Role Of The Infralimbic-Basal Forebrain Pathway In Fear Extinction, Carolina Maria Fernandes Henriques

Dissertations, Theses, and Capstone Projects

The medial prefrontal cortex (mPFC) is a key region for emotion regulation, and its failure to regulate extinction of aversive memories is associated with Post Traumatic Stress Disorder. Study of how the Infralimbic cortex (IL), a subregion of the mPFC, directly communicates with the Basolateral Amygdala (IL-BLA), has thus far failed to uncover the circuit mechanisms that lead to mPFC-mediated amygdala suppression of firing and diminished fear responses during extinction retrieval. One problem of this model is that it doesn’t incorporate indirect IL communication with the BLA. A key region to help understand how IL modulates extinction is the basal …

Attenuated Typicality Effect In Category-Based Inferences: Implications For Autism Spectrum Disorder, Janani Rajagopalan

Dissertations, Theses, and Capstone Projects

Individuals diagnosed with Autism Spectrum Disorder (ASD) often encounter challenges in assimilating atypical exemplars into their categorical prototypes, a cognitive hurdle that can impact their interpretative and integrative capacities. Addressing this problem, the present research sought to develop a robust methodological approach to reduce the effect of this disparity. We examined the elements embedded within the category's internal structure, with the intention of experimentally attenuating the pronounced typicality effect, which is often exaggerated in ASD.

Across four experiments, the thesis investigated the cognitive and neural underpinnings that shape the access to the typicality gradient intrinsic to a category's structure. The …

Visualizing Dopamine Activity In Deletion Of D2 Receptors In Medium Spiny Neurons, Kunhee Lee

Dissertations, Theses, and Capstone Projects

Dopamine has been implicated in motivated behaviors and reinforcement learning. In this study, we are looking at the role of dopamine in allocating efforts when obtaining reward. Using Cre recombinase genetic tool, D2 receptors in striatal indirect pathway neurons were selectively deleted, and dopamine signal was recorded in ventral striatum using fiber photometry. Behaviorally, D2 receptor deletion resulted in less effort in a Progressive Ratio (PR) paradigm shown by decreased breakpoint, number of presses, and reward pellets earned. Due to the previous evidence that dopamine positively modulates effort, we hypothesized that there would be less dopamine release in D2 deleted …

A Survey Study Of Speech-Language Therapists’ Experiences With Teletherapy At The Onset Of The Covid-19 Crisis, Jason A. Rosas

Dissertations, Theses, and Capstone Projects

The present study aimed to understand how delivering pediatric treatment services via ‘teletherapy’ affected speech-language therapists (SLTs) during the initial outbreak of the COVID-19 pandemic crisis in 2020. SLTs reported on their experiences with the change from in-person to remote service delivery via two national surveys distributed at the start of the pandemic between April 2020 and July 2020. To explain SLTs’ survey responses, this dissertation introduced the Professional Adaptation Model (PA Model). The PA Model facilitated evaluation of the SLTs’ professional environment and the psychological constructs of their professional identity believed to influence the transition to speech-language teletherapy. Specifically, …

Effects Of Chronic Stress On Safety Processing And Physiology In The Medial Prefrontal-Amygdala-Basal Forebrain Circuit, Itamar S. Grunfeld

Dissertations, Theses, and Capstone Projects

Chronic stress increases generalization of fear to non-threatening cues, a key symptom in numerous psychiatric mood disorders. However, the mechanisms through which stress impacts safety learning remain poorly understood. To probe the relationship between stress and safety learning, this dissertation employed multiple behaviors, in conjunction with in-vivo multisite physiology during explicit safety and fear discrimination learning. In Chapter 1, I outline the role of chronic stress in driving neurological adaptations that result in generalized fear and highlight how this occurs because of impaired safety cue encoding. In Chapter 2, I show that chronic stress in the form of social defeat …

Reducing Fear Overgeneralization With Safety Learning: Attention Bias As A Moderator, Boyang Fan

Dissertations, Theses, and Capstone Projects

Anxiety disorders are the most prevalent mental health condition and affect one out of nine individuals around the world. Fear generalization is a neurocognitive mechanism thought to maintain and exacerbate anxiety, and thus is an important target of therapeutic interventions. Yet, intervention research and practice place relatively little emphasis on its importance. Given that a significant proportion of individuals do not respond to extant treatments of anxiety disorders, a strengthened focus on fear generalization may inform the development and personalization of new treatment approaches. Recent notions have linked fear generalization to failures in distinguishing between signals that predict the occurrence …

A Randomized Controlled Trial Of Psychological Outcomes Of Mobile Guided Resonant Frequency Breathing In Young Adults With Elevated Stress During The Covid-19 Pandemic, Al Amira Safa Shehab

Dissertations, Theses, and Capstone Projects

Deep breathing practices have shown promise in reducing stress, anxiety, and depression in different populations, including young adults. Specifically, resonant frequency breathing can exert an impact on stress response systems through the vagus nerve and the hypothalamo-pituitary-adrenal (HPA) axis. This may induce reductions in stress and improvement in emotion regulation. Young adults, including college students, tend to be at a higher risk for psychological distress, as they face several psychosocial challenges. The COVID-19 pandemic has imposed new and unique stressors that resulted in higher levels of stress and emotional symptoms and it has been shown that this may have placed …

Overcoming Challenges In The Assessment And Treatment Of Problem Behavior In Adults With Autism, Julia A. Iannaccone

Dissertations, Theses, and Capstone Projects

Problematic behaviors, such as self-injurious behavior or aggression, demonstrated by adults with autism spectrum disorder (ASD), create many significant life complications, some life-threatening. Applied Behavior Analysis (ABA) is established as an evidence-based approach to treat problem behavior for children with ASD and shows promise as an effective treatment for adults, yet little research has been conducted within the adult population. Assessment and treatment of problem behavior with adults is often challenging due to funding limitations, increased severity and complexity of problem behavior, and underqualified staff. The purpose of the present study was to overcome these challenges by (1) identifying a …

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 …

Emotion Processing Deficits In Psychopathy: Does Cueing To Relevant Facial Features Increase Cognitive And Emotional Empathy?, Shawn E. Fagan

Dissertations, Theses, and Capstone Projects

Psychopathy is a multifaceted disorder characterized by a lack of cognitive and emotional empathy. The traditional model of psychopathy divides the disorder into two factors: Factor 1 consists of the interpersonal and affective traits of psychopathy while Factor 2 measures antisocial behaviors and lifestyle choices. The attention-to-the-eyes hypothesis argues that psychopathic individuals have impaired emotion recognition (specifically for fear) due to deficits in orienting attention to salient facial features like the eyes. Psychopathic individuals also display blunted autonomic responding to emotional stimuli, though whether this is due to attention-orienting deficits remains to be clarified. The present project investigated whether empathy-related …

Observational Assessment Of Empathy In Parent-Child Verbal Exchanges And Their Influence On Child Behavior, Patty Carambot

Dissertations, Theses, and Capstone Projects

Empathy, the ability to both experientially share in and understand others’ thoughts, behaviors, and feelings, is vital for human adaptation. Deficits in empathy development have implications across the lifespan for the development of prosocial behavior, social functioning, mental health disorders, and risk for antisocial behavior (e.g., Guajardo, Snyder, & Petersen, 2009; Moreno, Klute & Robinson, 2008). In light of these societal and individual burdens, it is imperative to foster and strengthen the development of this ability early in life to prevent or ameliorate such negative outcomes. This type of prevention can take a variety of forms, but parent and child …

The Neurophysiology Of Intersensory Selective Attention And Task Switching, Jeremy W. Murphy

Dissertations, Theses, and Capstone Projects

Our ability to selectively attend to certain aspects of the world and ignore others is fundamental to our day-to-day lives. The need for selective attention stems from capacity limitations inherent in our perceptual and cognitive processing architecture. Because not every elemental piece of our environment can be fully processed in parallel, the nervous system must prioritize processing. This prioritization is generally referred to as selective attention. Meanwhile, we are faced with a world that is constantly in flux, such that we have to frequently shift our attention from one piece of the environment to another and from one task to …

Using Otoacoustic Emissions To Evaluate Efferent Auditory Function In Humans, Simon Henin

Dissertations, Theses, and Capstone Projects

The auditory system continually adapts to changes in the acoustic environment over short periods of time. This fine-tuning of its dynamics is mediated in part by the medial olivocochlear (MOC) bundle, a neural feedback loop which aids in the regulation of cochlear micro-mechanics. The ability to measure the response of the MOC system in humans may provide significant insight into unique cochlear functions, such as its sharp frequency selectivity and wide dynamic range. In humans the efferent system can be investigated non-invasively using otoacoustic emissions (OAEs). However, how OAEs can best be used to evaluate efferent function, the pitfalls associated …